New trials for NRAS and Mucosal Melanoma patients - ASCO 2021

Melanoma sucks great big green hairy stinky wizard balls for everyone!  Still, it remains even more challenging for NRAS positive and mucosal melanoma patients.  Here are prior posts on Mucosal Melanoma. Now, there's this neoadjuvant trial:

A phase 2 clinical trial of neoadjuvant anti-PD-1 ab (toripalimab) plus axitinib in resectable mucosal melanoma.  Cui, Wang, Lian, et al.  ASCO 2021.

Background:  The outcome of patients (pts) with resectable mucosal melanoma (MM) is still poor. Toripalimab combined with axitinib has shown impressive results in metastatic MM with an ORR of 48.3% and a median PFS of 7.5 months in a phase 1b trial. It was hypothesized that this combination therapy might cause pathologic response in neoadjuvant setting for resectable MM, so we conducted this single arm phase 2 trial.

Methods:  Eligible pts were adults (aged 18 to 75) with histologically confirmed resectable (localized or regional lymph node metastasis) MM disease. Exclusion criteria included ocular or unknown primary melanoma, distant metastatic disease or previous use of anti PD-1 ab. Pts received toripalimab 3 mg/kg Q2W plus axitinib 5 mg BID for 8 weeks as neoadjuvant therapy, then surgery and the adjuvant toripalimab 3 mg/kg Q2W starting 2±1week after surgery for totally 52 weeks. The primary end point is pathologic response rate according to the International Neoadjuvant Melanoma Consortium (pCR+pPR, pCR is defined as the complete absence of residual viable tumor and pPR less than/= to 50% of viable tumor cells). The secondary end point is RFS in the ITT population.

Results:  From Aug 2019 to Dec 2020, 21 pts have been eligible and enrolled. Basic characteristics: median age 62 years; M: F 28.6% : 71.4%; primary sites 8 female genital(1urethra, 7vagina), 5 esophagus, 4 ano-rectal, 4 head and neck(3 nasal,1 oral), in which 47.6% localized disease (T3/4 60%), 52.4% regional lymphatic disease; Gene mutation: 4 cKit (1 amplification), 2 Nras,1 Braf (N581), 1mTOR. This therapy was tolerable with grade 3-4 treatment related AEs of 23.8% (liver dysfunction 14.3%, hyperglycemia 9.5% and hypertension 4.8%). 13 pts had received surgeries (local excision 30.8%, wide excision ± CLND72.7%)and 5 pts still in neoadjuvant treatment. One patient was inoperable for bone metastasis, and 2 pts withdrew for covid 19 epidemic. At a median follow up time of 59 weeks, the pathologic response rate was 28.6% (4/14, 2 pCR, 2pPR). Of the post-surgical specimens, 61.5% (8/13) showed significant TIL infiltration, with 38.5% Brisk and 23.1% Nonbrisk according to the definition of AJCC 8th edition. Plenty of plasma cells, histiocyte and pigment with hyaline fibrosis were also found in responders. No recurrence or metastasis was observed in responders until now, with a RFS reaching more than 58weeks. 5 pts with pNR (greater than 50% viable tumor cells) got disease progression, with 1 local recurrence, 1 regional lymphatic metastasis, and 3 distant metastases. The median RFS has not been reached.

Conclusions:  Neoadjuvant toripalimab plus axitinib in resectable MM has shown promising pathologic responses with good tolerance, which supports further investigation of neoadjuvant therapies in MM. Survival is still in follow-up. Clinical trial information: NCT04180995.

And this report on patients with unresectable disease:

Atezolizumab in combination with bevacizumab in patients with unresectable locally advanced or metastatic mucosal melanoma: Interim analysis of an open-label phase II trial.  Si, Fang, Chen, et al.  ASCO 2021.

Background:  Mucosal melanoma is a rare malignant melanoma in Caucasians but ranks the second most common subtype in the Asian population. It is more often diagnosed at an advanced stage and responds poorly to current PD-1/PD-L1 inhibitors. Here we report the interim analysis results of ML41186, an open-label, multicenter, single-arm phase II study, aiming to evaluate the efficacy and safety of atezolizumab in combination with bevacizumab in patients (pts) with advanced mucosal melanoma.

Methods:  Eligible pts aged 18 to 75 years with histologically confirmed unresectable locally advanced or metastatic mucosal melanoma had at least one measurable lesion per RECIST version 1.1 at baseline, with an ECOG PS 0 or 1 and adequate hematologic and organ function. ML41186 is a Simon two-stage design study, if 22 pts completed ORR evaluation and more than 3 pts respond in stage I, the study then continue to Stage II. Atezolizumab and bevacizumab were administered at a fixed dose of 1200 mg and 7.5 mg/kg Q3W respectively (on day 1 of each 21-day cycle) until unacceptable toxicity or loss of clinical benefit. The primary endpoint is the objective response rate (ORR). The secondary endpoints include progression-free survival (PFS), duration of objective response (DoR), disease control rate (DCR), and safety.

Results:  By the cut-off date of 9th September 2020, 35 pts has been enrolled, among whom 22 pts in the stage I analysis set has completed two efficacy evaluation, while 28 pts (full analysis set) has completed at least one efficacy evaluation. In ITT populations (n=35), mean age was 58.9 years with 10 (28%) pts had ECOG PS of 1. LDH level elevated in 9 (25.7%) pts. More than half pts (19, 54.3%) had metastatic mucosal melanoma, of whom 3 (15.8%) pts had more than 3 metastasis sites and 4 (21.1%) pts had liver metastasis. In stage I analysis set (n=22), the best confirmed ORR was 36.4% (17.0%-59.3%). Median progression-free survival was 5.32 months (1.58-not reached), and the best confirmed DCR was 59.1% (36.4%-79.3%). The median confirmed DoR was not reached ( 2.76-NR). In the full analysis set (n=28), the unconfirmed ORR was 42.9% (24.5%-62.8%). In ITT populations (n=35), 28 pts (80%) experienced at least one adverse event (AE) and 5 pts (14.3%) experienced at least one grade 3-4 AEs. Only one patient experienced AE leading to treatment discontinuation. One patient died of autoimmune lung disease.

Conclusions:  The combination of atezolizumab plus bevacizumab showed promising benefit and was tolerable in pts with advanced mucosal melanoma. At the time of this interim analysis, the primary endpoint did not cross the futility boundary, thus the study will run into Stage II. Clinical trial information: NCT04091217.

The NRAS mutation has it's own challenges.  Here are prior NRAS Reports.  Now, there are these:

A phase Ib trial of belvarafenib in combination with cobimetinib in patients with advanced solid tumors: Interim results of dose-escalation and patients with NRAS-mutant melanoma of dose-expansion. Shin, Lee, Kim, et al.  ASCO 2021.

Background:  Belvarafenib, a potent, selective RAF dimer (type II) inhibitor, exhibits clinical activity in BRAFV600E- and NRAS-mutant (NRASm) melanoma patients. The combination of belvarafenib and cobimetinib more potently and durably suppressed MAPK pathway output and tumor growth than currently approved BRAF/MEK inhibitors in RAS- or RAF-mutant tumor xenograft models. This interim results of phase 1b trial evaluated the safety, tolerability, pharmacokinetics, and anti-tumor activity of belvarafenib in combination with cobimetinib in dose-escalation and NRASm melanoma patients among the 9 indication-specific expansion cohorts.

Methods: Patients with locally advanced or metastatic solid tumors harboring RAS or RAF mutation were enrolled in the dose-escalation stage, and the recommended doses were explored in the indication-specific expansion stage. Patients in the dose-escalation stage were given belvarafenib (100–300mg BID) in combination with cobimetinib (20–40mg QD) and the dose of subsequent cohorts was decided by a traditional 3+3 design and safety profile. Primary objectives were to evaluate the safety and tolerability, to estimate the maximum tolerable dose, and to identify the RP2D of the combination.

Results:  A total of 32 patients enrolled were evaluated for safety analysis; 19 were enrolled in 4 cohorts in the dose-escalation stage and 13 NRASm melanoma patients were enrolled in the indication-specific expansion stage (cut-off date: 2020-7-24). There were 3 DLTs (G3 colitis, G3 diarrhoea, G3 nausea) in 2 patients at the starting dose of belvarafenib 200mg BID continuously and cobimetinib 40mg QD 21/7 schedule. Belvarafenib dose was escalated to 300mg BID with cobimetinib 20mg QD, which did not result in DLTs. The most common treatment-emergent adverse events that occurred in ≥30% of 32 patients were dermatitis acneiform, diarrhoea, constipation, and increase in blood creatine phosphokinase. Two combination doses were explored in the indication-specific expansion stage. Out of the 9 indication-specific expansion cohorts, NRASm melanoma patients exhibited promising efficacy signal; 5 patients reached partial responses (PRs) out of 13, giving a response rate of 38.5%. Among them, 11 had been previously treated with checkpoint inhibitors (CPIs), including 5 (45.5%) who achieved PR. The median PFS was 7.3 months and 5 patients remained on the treatment at the cut-off date.

Conclusions: Belvarafenib in combination with cobimetinib showed acceptable tolerability and encouraging efficacy in NRASm melanoma, and in those with prior CPI treatment. Further research is ongoing in other cohorts (Clinicaltrial.gov, NCT03284502) and in NRASm melanoma (reference GO42273 by clinicaltrials.gov ID number). Clinical trial information: NCT03284502.

Fingers crossed that there will soon be viable treatments for all melanoma ratties.  For what it's worth - c

ASCO 2021 - Outcomes of treatments on advanced disease - Reasons for HOPE!!!!!

 As disheartening as it can be to experience treatment that does not do all that we need it to or have dear ones who do not respond to current melanoma treatments - therapies for melanoma have come a long way, baby!!!!  Not only are more folks than ever before responding to therapy - these responses are proving durable!  Here are some outcome studies ~

Five-year overall survival from the anti-PD1 brain collaboration (ABC Study): Randomized phase 2 study of nivolumab (nivo) or nivo+ipilimumab (ipi) in patients (pts) with melanoma brain metastases (mets).  Georgina V. Long, Victoria Atkinson, Serigne Lo, et al.  ASCO 2021.

Background:  Preliminary data from the ABC (76 pts) and CheckMate 204 (94 pts) trials showed that nivo and nivo+ipi have activity in active melanoma brain metastases, with durable responses in a subset of pts. Here, we report updated 5-yr data from all pts enrolled on the ABC trial (NCT02374242).

Methods:  This open-label ph2 trial enrolled 3 cohorts of pts with active melanoma brain mets naïve to anti-PD1/PDL1/PDL2/CTLA4 from Nov 2014-Apr 2017. Pts with asymptomatic brain mets with no prior local brain therapy were randomised to cohort A (nivo 1mg/kg + ipi 3mg/kg, Q3Wx4, then nivo 3mg/kg Q2W) or cohort B (nivo 3mg/kg Q2W). Cohort C (nivo 3mg/kg Q2W) had brain mets i) that failed local therapy, ii) with neuro symptoms and/or iii) with leptomeningeal disease. Prior BRAF inhibitor (BRAFi) was allowed. The primary endpoint was best intracranial response (ICR) ≥wk12. Key secondary endpoints were IC PFS, overall PFS, OS, & safety.

Results: A total of 76 pts (med f/u 54 mo) were enrolled; median age 59y, 78% male. For cohorts A, B and C: elevated LDH 51%, 58% and 19%; V600BRAF 54%, 56% and 81%; prior BRAFi 23%, 24%, 75%. Efficacy and toxicity are shown in the table. There were no treatment-related deaths. 1/17 deaths in cohort A & 4/16 in cohort B were due to IC progression only.

Conclusions:  Nivo monotherapy and ipi+nivo are active in melanoma brain mets, with durable responses in the majority of patients who received ipi+nivo upfront. A study of upfront ipi+nivo+/-SRS is underway (NCT03340129).Clinical trial information: NCT02374242.

My takeaway - Immunotherapy works for brain mets!  BUT - most folks need the combo!!!!

As was mentioned briefly in yesterday's post - the ipi/nivo combo can be a rough road in regard to side effects and a good 40% of patients cannot tolerate all of the approved doses.  However, as far back ASCO 2016 we knew that folks who had to stop therapy early due to side effects, responded about as well as those who completed all doses:  ASCO 2016 - Nivo plus ipi, CheckMate 069 trial....18 month OS similar even if you stop meds due to side effects!!!  This study wanted to see if those responses were durable ~

Survival outcomes associated with fewer combination ipilimumab/nivolumab doses in advanced-stage melanoma.  Ma, Sun, Sitto, et al.  ASCO 2021.

Background:  Standard combination ipilimumab/nivolumab (I/N) is given as 4 induction doses for advanced stage melanoma. While many patients receive less than 4 doses due to treatment-related toxicities, it is unclear if fewer doses of I/N may still provide long term clinical benefit. Our aim is to determine if response assessment after 1 or 2 doses of I/N can predict long-term survival and if fewer doses of I/N can achieve similar survival outcomes.

Methods:  We performed a single-center, retrospective analysis on a cohort of patients with metastatic or unresectable melanoma from 2012 to 2020 who were treated with standard I/N. Cox regression of progression free survival (PFS) and overall survival (OS) models were performed to assess the relationship between response assessment after 1 or 2 doses of I/N and risk of progression and/or death. Clinical benefit response (CBR) was assessed, defined as SD (stable disease) + PR (partial response) + CR (complete response) by imaging or physical examination. Among patients who achieved a CBR after 1 or 2 doses of I/N, a multivariable Cox regression of survival was used to compare 3 or 4 vs 1 or 2 doses of I/N adjusted by age, gender, pre-treatment LDH level, BRAF mutation status, primary melanoma site, time to initial assessment, brain metastasis, and liver metastasis.

Results:  199 patients were identified and considered evaluable in our study. Median follow up was 28.8 months. Patients with CBR after 1 dose of I/N had improved PFS and OS compared to progressive disease (PD). Patients with CBR (vs PD) after 2 doses of I/N also had improved PFS and OS. The survival risk comparing 3 or 4 vs 1 or 2 doses of I/N were HR 0.82 for PFS and HR 0.56 for OS.

Conclusions:  Clinical benefit response (CBR) after 1 or 2 doses of I/N may be predictive of long-term survival in advanced stage melanoma. Patients who have CBR after 1 or 2 doses of I/N may achieve a similar survival benefit with fewer doses of I/N. Longer follow up and prospective studies are warranted to validate our findings.

Per this report, it looks as though those who showed benefit to therapy early, did indeed have similar survival, even when they took fewer that the 4 recommended combo doses!

This study looked at the characteristics of peeps who lived 5 years past immunotherapy for melanoma ~

Characteristics and probability of survival for patients with advanced melanoma who live five or more years after initial treatment with immune checkpoint blockade (ICB).  Loo, Goldman, Panageas, …Chapman…Wolchok…Postow, et al.  ASCO 2021.

Methods:  We retrospectively reviewed all patients treated at Memorial Sloan Kettering for unresectable stage III/IV melanoma who survived at least five years following their first dose of ICB (N = 151). Demographics, disease characteristics, and nature of progression were examined. Overall survival (OS) was calculated from 5 years post-ICB. Time to Treatment failure (TTF) was calculated conditionally from 5 years out until next therapy, progression, or death.

Results:  Of the 151 long-term survivors, median age at first ICB treatment was 62 years (range 22-83), with 101 (66.9%) male and 50 (33.1%) female patients. Stage at first ICB treatment was unresectable stage III (26, 17.2%), M1a (21,13.9%), M1b (39, 25.8%), M1c (52, 34.4%), M1d (13, 8.6%). Melanoma subtype was cutaneous (122, 80.8%), unknown primary (24, 15.9%), mucosal (3, 2%), and acral (2, 1.3%). First ICB was ipi (108, 71.5%), PD-1 (nivo or pembro) (5, 3.3%), and nivo+ipi (37, 24.5%). The best overall response to first ICB was CR (76, 50.3%), PR (27, 17.9%), SD (16, 10.6%) and PD (32, 21.2%). Of the patients who progressed after initial ICB, 38 received subsequent systemic treatment as follows: PD-(L)1 in 20 (53%), BRAF ± MEK in 9 (23.7%), ipi in 7 (18.4%), and chemotherapy in 2 (5.3%). Median duration of follow-up among survivors (N = 138) was 93 months (range 60-192). From 5 years post-ICB, 85% (95% CI: 73-92%) survived an additional 5 years. In those who made it to 5 years without treatment failure (N = 72), the probability of remaining failure-free was 92% (95% CI: 86-99%) at 7 years. Of the 151 patients, only 4 patients (2.6%) experienced disease progression after 5 years. Three patients had radiographic or pathologic disease progression in the lymph nodes and one in the subcutaneous tissue. No patients progressed in the lungs, visceral organs, or CNS after 5 years. At time of analysis, 13 (8.6%) patients died after 5 years post ICB, none died of progressive melanoma. 6 patients died of unknown causes, 2 died of other causes, and 5 died of other non-melanoma cancer-related causes.

Conclusions:  Patients who survive five years after their initial immunotherapy have excellent overall survival and treatment failure-free survival. Given the anxiety surrounding survivorship and late progression, long-term survivors should be reassured of their excellent prognosis. These data suggest that aggressive follow-up schedules and imaging of melanoma patients after 5 years of survival may not be required.

WHOOP!  WHOOP!!!  The C-word (NO!  Not cancer!  CURE!!) was not used, but this data on peeps 5 years out who may no longer need scans to follow up and can carry on with their lives is AWESOME!  On a personal note, Weber let me off the hook for continued follow-up for melanoma at 8 years post my Stage IV diagnosis. I am currently 11 years out.

This study looked at peeps treated with nivo alone vs the ipi/nivo combo.  Now we are blessed to look at 6.5 year outcomes. These reports would not exist without the lives and dedication of all the ratties; and sometimes a special mouse!!!  Thanks, Edster!!!!

CheckMate 067: 6.5-year outcomes in patients (pts) with advanced melanoma. Wolchok, Chiarion-Sileni, Gonzalez, et al.  ASCO 2021.

Background: In the phase 3 CheckMate 067 trial, a durable and sustained clinical benefit was achieved with nivolumab (NIVO) + ipilimumab (IPI) and NIVO alone vs IPI at 5-y of follow-up (overall survival [OS] and progression-free survival [PFS] rates: 52%, 44%, 26% and 36%, 29%, 8%, respectively). Here we report 6.5-y efficacy and safety outcomes.

Methods:  Eligible pts with previously untreated unresectable stage III or IV melanoma were randomly assigned in a 1:1:1 ratio and stratified by PD-L1 status, BRAF mutation status, and metastasis stage. Pts received NIVO 1 mg/kg + IPI 3 mg/kg for 4 doses Q3W followed by NIVO 3 mg/kg Q2W (n = 314), NIVO 3 mg/kg Q2W + placebo (n = 316), or IPI 3 mg/kg Q3W for 4 doses + placebo (n = 315) until progression or unacceptable toxicity. Co-primary endpoints were PFS and OS with NIVO + IPI or NIVO vs IPI. Secondary endpoints included objective response rate (ORR), descriptive efficacy assessments of NIVO + IPI vs NIVO alone, and safety.

Results:  With a minimum follow-up of 6.5 y, median OS was 72.1 mo with NIVO + IPI, 36.9 mo with NIVO, and 19.9 mo with IPI (table). Median time from randomization to subsequent systemic therapy was not reached with NIVO + IPI, 25.2 mo with NIVO, and 8.0 mo with IPI; 36%, 49%, and 66% of pts, respectively, received any subsequent systemic therapy. Median treatment-free interval (which excluded pts who discontinued follow-up prior to initiation of subsequent systemic therapy) was 27.6 mo (range, 0–83.0), 2.3 mo (range, 0.2–81.6), and 1.9 mo (range, 0.1–81.9) with NIVO + IPI, NIVO, and IPI, respectively. Of the pts alive and in follow-up, 112/138 (81%; NIVO + IPI), 84/114 (74%; NIVO), and 27/63 (43%; IPI) were off treatment and never received subsequent systemic therapy; 7, 8, and 0 pts, respectively, were still on treatment. Grade 3/4 treatment-related adverse events were reported in 59% of NIVO + IPI-treated pts, 24% of NIVO-treated pts, and 28% of IPI-treated pts. Since the 5-y analysis, no new safety signals were observed and no additional treatment-related deaths occurred.

Conclusions:  This 6.5-y analysis represents the longest follow-up from a phase 3 melanoma trial in the modern checkpoint inhibitor combination therapy and targeted therapy era. The results show durable improved outcomes with NIVO + IPI and NIVO vs IPI in pts with advanced melanoma. We observed improvement in OS, PFS, and ORR with NIVO + IPI over NIVO alone. Clinical trial information: NCT01844505.

My takeaway - AGAIN - though nivo alone works for many (look at me!!) - BUT - data shows responses and durability were better with the ipi/nivo combo.  Way to rock it out, ratties!!  Thanks, dear Ed!

Finally, a non-ASCO report from earlier this year looking at folks who chose to stop anti-PD-1 monotherapy with nivo (Opdivo) or pembro (Keytruda) at 1 year of therapy ~

Real-world experience with elective discontinuation of PD-1 inhibitors at 1 year in patients with metastatic melanoma.  Pokorny, McPherson, Haaland, et al.  J Immunother Cancer.  Jan 2021.

Background: Randomized trials evaluating programmed cell death protein 1 (PD-1) inhibitors in metastatic melanoma either permitted treatment for 2 years (pembrolizumab) or more (nivolumab). The optimal duration of therapy is currently unknown due to limited data, and shorter therapies may be effective.

Methods: Data of patients with metastatic cutaneous melanoma treated with single-agent PD-1 inhibitors at Huntsman Cancer Institute from January 1, 2015, to December 31, 2018, was reviewed to identify a continuous series of patients who made the joint decision with their provider to electively discontinue therapy at 1 year (greater than 6 months and less than 18 months) in the setting of ongoing treatment response or disease stability. Patients were excluded if they received PD-1 inhibitors with other systemic therapy, had prior exposure to PD-1 therapy, or discontinued treatment due to disease progression or immune-related adverse event. Best objective response (BOR) per RECIST V.1.1 at treatment discontinuation, progression-free survival (PFS), and retreatment characteristics was analyzed.

Results: Of 480 patients who received PD-1 inhibitors, 52 met the inclusion criteria. The median treatment duration from first to the last dose was 11.1 months (95% CI 10.5 to 11.4). BOR was complete response in 13 (25%), partial response in 28 (53.8%), and stable disease in 11 (21.2%) patients. After a median follow-up of 20.5 months (range 3-49.2) from treatment discontinuation, 39 (75%) patients remained without disease progression, while 13 (25%) had progression (median PFS 3.9 months; range 0.7-30.9). On multivariable analysis, younger age, history of brain metastasis, and higher lactate dehydrogenase at the time of anti-PD-1 discontinuation were associated with recurrence. Patients with recurrent melanoma were managed with localized treatment, anti-PD-1 therapies, and BRAF-MEK inhibitors. All patients except one were alive at data cutoff.

Conclusion: In this large real-world, observational cohort study, the majority of patients with metastatic melanoma after 1 year of anti-PD-1 therapy remained without progression on long-term follow-up. The risk of disease progression even in patients with residual disease on imaging was low. After prospective validation, elective PD-1 discontinuation at 1 year may reduce financial and immunotherapy-related toxicity without sacrificing outcomes.

In my 2010, nivo as a single agent, phase 1 study, we took nivo for 2 1/2 years on a rather different schedule than is utilized currently (every 2 weeks for 6 months, then every 3 months for 2 years) and at dosages of 1mg/kg (my cohort), 3 mg/kg, and 10 mg/kg.  The 3mg/kg dosage is basically what is used today.  Still, even with all that, Weber often said that he felt we were treated too long and explained that while a certain amount of drug would be helpful, beyond that, benefit was nil and the risk of side effects was increased.  Today - whether we are looking at anti-PD-1 as a single agent or the ipi/nivo combo - researchers are still trying to figure out exactly what that "certain amount" is.  It is likely that the answer may vary person to person.  As this study pointed out, the ratties who elected to stop therapy at one year had experienced treatment response or stable disease.  Clearly, that is an important factor.  Additionally, in this rather small study of 52 patients, recurrence was associated with those who were younger, had a history of brain mets and elevated LDH when therapy ceased.  Interesting, in that I was 39 at diagnosis and 46 with brain mets at the start of my trial.  However, I took nivo for 2 1/2 years, never had an elevated LDH and have yet to have a melanoma recurrence.  So many variables.  So many different peeps.  It is a hard road to walk, much less to predict.

Hang tough, guys.  There is hope! - c  

New treatments - kinda. Anti-LAG-3 plus anti-PD-1 to boost response. Ipi/nivo plus tocilizumab to decrease side effects.

Unfortunately, as mentioned in yesterday's post, current melanoma treatments do not meet the needs of all melanoma patients.  Also as mentioned, a great deal of current research is building on existing immunotherapies - attempting to fortify response rates by adding a wide variety of pharmaceuticals to existing products.

Here is another study looking at combining an anti-LAG-3 product with yet another anti-PD-1 product: (Note:  Yesterday's post includes a link to previous data and info about anti-LAG-3 generally.)

Clinical activity of fianlimab (REGN3767), a human anti-LAG-3 monoclonal antibody, combined with cemiplimab (anti-PD-1) in patients (pts) with advanced melanoma.  Hamid, Wang, Kim, et al.  ASCO 2021.

Background:  Fianlimab and cemiplimab are two high-affinity, fully human, hinge-stabilized IgG4 monoclonal antibodies. In a Phase 1 dose escalation study, fianlimab combined with cemiplimab showed an acceptable safety profile and some clinical activity in pts with advanced malignancies. Here, we present safety and clinical activity data from two expansion cohorts of pts with advanced melanoma (anti–programmed cell death/ligand-1 [anti–PD-(L)1] naïve or experienced) who were treated with fianlimab + cemiplimab and had an opportunity for first on-treatment tumor assessment (cut-off date: Jan 4, 2021).

Methods:  Pts with advanced melanoma who had no prior anti–PD-(L)1 treatment (naïve) or prior anti–PD-(L)1 treatment within 3 months of screening (experienced) received fianlimab 1600 mg + cemiplimab 350 mg by IV infusion every 3 weeks. Tumor measurements were performed every 6 weeks for the first 24 weeks and subsequently every 9 weeks per RECIST v1.1.

Results:  48 pts with advanced melanoma were treated with the combination therapy: 33 were anti–PD-(L)1 naïve and 15 were anti–PD-(L)1 experienced (median age: 69 years vs 59 years; male: 66.7% vs 46.7%; Caucasian: 87.9% vs 60%). The safety profile (including immune-related adverse events [AEs]) of fianlimab + cemiplimab combination therapy was similar to that of anti–PD-1 monotherapy with one exception. The rate of adrenal insufficiency, 8.3% (4/48) of pts, is similar to the rate previously observed with anti–PD-1 + anti–cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) combination therapy but higher than that observed with anti–PD-1 monotherapy. Grade greater than/= to treatment-emergent AEs (TEAEs) occurred in 35.4% (17/48) of patients; Grade greater than/= to serious TEAEs occurred in 22.9% (11/48) of patients; 8.3% (4/48) of patients discontinued treatment due to a TEAE. The most common TEAEs were fatigue (n = 15, 31.3%) and rash (n = 11, 22.9%). By investigator assessment, objective response rate (includes unconfirmed complete [CR] and partial responses [PR]) was 63.6% (3 CRs and 18 PRs) for anti–PD-(L)1 naïve pts and 13.3% (1 CR and 1 PR) for anti–PD-(L)1 experienced pts. Median progression-free survival and median duration of response for the anti–PD-(L)1 treatment naïve cohort have not been reached. Prognostic clinical markers and tumor biomarkers such as expression of LAG-3, PD-L1, and major histocompatibility complex II are being evaluated. Recruitment is ongoing.

Conclusions:  The safety profile of fianlimab + cemiplimab is similar to that observed with cemiplimab monotherapy and other anti–PD-1s, with the exception of higher rate of adrenal insufficiency. Fianlimab + cemiplimab combination has shown clinical activity for pts with advanced melanoma that is similar to anti–PD-1 + CTLA-4 combination therapy, but with lower demonstrated rates of TEAEs. Clinical trial information: NCT03005782.

Fingers crossed!

With its 50%+ response rate and durable results, the ipi/nivo combo has thus far been the best thing going for melanoma patients.  However, side effects caused by the treatment force roughly 40% of patients to discontinue therapy. (With that in mind, you may find this report from 2017 of interest:  40% of melanoma patients stop ipi/nivo due to side effects...BUT...efficacy is about the same!!!)  Anyhow, in an effort to DECREASE those side effects, this trial is adding tocilizumab - a monoclonal antibody that blocks interleukin 6 and is often used to treat rheumatoid arthritis - to the combo.  Interesting too, to look back on the addition of leflunomide (another drug used for RA) to targeted therapy as noted in this post:  An anti-rheumatic drug that increases the effect of vemurafenib and selumetinib?)  

Ipilimumab, nivolumab and tocilizumab as first-line therapy for advanced melanoma.  Mehmi, Hamid, Hodi, et al.  ASCO 2021.

Background:  Interleukin 6 (IL-6) functions in the maintenance of hepatocytes, haemotopoietic progenitor cells, a variety of other tissues, and regulates the innate and adaptive immune system. IL-6 may play a role as a chronic inflammatory mediator in altering levels of acute phase proteins synthesized by the liver and circulating myeloid cells which have been shown to be associated with short survival with checkpoint inhibition and which are immune suppressive. The immunomodulatory properties of interleukin-6 may in part also be responsible for immune related adverse events, given the reversal of those toxicities observed with IL-6 receptor blockade in clinical practice. To assess if blockade of IL-6 binding is associated with a decrease in irAEs and/or an increase in efficacy defined as overall response rate (ORR) at week 24 in patients receiving ICB, we added tocilizumab to ipilimumab and nivolumab therapy.

Methods:  The current phase II trial is a two-stage design to assess the safety, tolerability, and grades 3-5 immune related toxicities of tocilizumab administered every 6 weeks up to week 24 in combination with ipilimumab at 1 mg/kg and nivolumab at 3 mg/kg every 3 weeks for 4 doses each during a 12 week induction period, then administered every 6 weeks with nivolumab at 240 mg flat dose every 2 weeks in maintenance for up to 24 weeks, and nivolumab alone will be given at 480 mg flat dose every 4 weeks thereafter for up to 2 years. Eligible patients include those age 18 or older with measurable and unresectable stages III/IV melanoma (cutaneous, acral, mucosal), without prior systemic treatment for metastatic disease. Adjuvant therapy (IFN-alpha, ipilimumab and/or nivolumab, or pembrolizumab) is allowed. Patients with metastatic melanoma of brain are allowed, if neurologically stable and off immunosuppressive steroids. A total of 18 patients will be treated in the first stage, and 49 additional patients in the second stage for a total of 67. The comparator data are from the N3I1 arm of Checkmate-511 trial, in which treatment-related grades 3-5 irAEs were 33.9% with a 45.6% response rate (1). Prespecified activity goal for the first stage of accrual has been met; second stage accrual began in January 2021.  Clinical trial information: NCT03999749.

For what it's worth.  - c

P.S. With great thanks to the Edster - this link, that includes an explanatory video from the Wizard Weber, gives important background on the whys and wherefores related to IL-6 in this instance and indicates that adding an IL-6 blockade may not only decrease side effects from immunotherapy but ADD effectiveness - Elevated Levels of Serum CRP and IL-6 Are Biomarkers of Poor Prognosis in Patients Receiving Immune Checkpoint Inhibitors.  Gotta love a man in a bow tie who can elucidate the difference between predictive and prognostic!!!!  - c

Strategies for treating melanoma subtypes - Acral, Mucosal, Uveal, Nodular, Lentigo

 

While melanoma, despite the huge improvements made when targeted and immunotherapies gained FDA approved in 2011 remains a very difficult cancer to treat and survive, the subtypes noted in the title make cutaneous melanoma look like a walk in the park.  This LINK takes you to reports on those subtypes that I have previously posted.  The link below takes you to a pretty thorough report addressing these particular forms of melanoma as well as a good history regarding BRAF status.  I have included much of the report below.  Words are from the authors - not me.  However, checking out the link is valuable, as it includes tables and references not reported here.

Emerging strategies to treat rare and intractable subtypes of melanoma. Gretchen and Vito. Pigment Cell Melanoma Res. Jan 2021.

Melanoma is the deadliest form of skin cancer, possessing a diverse landscape of subtypes with distinct molecular signatures and levels of aggressiveness. Although immense progress has been achieved therapeutically for patients with the most common forms of this disease, little is known of how to effectively treat patients with rarer subtypes of melanoma. These subtypes include acral lentiginous (the rarest form of cutaneous melanoma; AL), uveal, and mucosal melanomas, which display variations in distribution across (a) the world, (b) patient age-groups, and (c) anatomic sites. Unfortunately, patients with these relatively rare subtypes of melanoma typically respond worse to therapies approved for the more common, non-AL cutaneous melanoma and do not have effective alternatives, and thus consequently have worse overall survival rates. Achieving durable therapeutic responses in these high-risk melanoma subtypes represents one of the greatest challenges of the field. This review aims to collate and highlight effective preclinical and/or clinical strategies against these rare forms of melanoma.

INTRO - 

The melanoma field represents a paradigm for preclinical and clinical advancements in targeted and immune therapy modalities, with 13 new FDA-approved therapies since 2011. The catalyst for the development of targeted therapy modalities was the identification of activating NRAS mutations and BRAF mutations in 1984 and 2002... which paved the way for molecular stratification of the melanoma patient population. Approximately 45%–50% of non-acral lentiginous (AL) cutaneous melanoma patients have tumors that harbor activating BRAF mutations, with a single amino acid substitution of valine for glutamic acid at codon 600 (V600E) occurring in 90% of cases. Activating NRAS mutations at codon 12, 13, or 61 are detectable in 15%–20% of non-AL cutaneous melanoma patients and serve as an independent predictor of worse patient overall survival. Mutations of BRAF and NRAS are considered mutually exclusive; however, there are rare reports where both mutations exist in different regions of the same tumor or at different metastatic sites of the same patient. To date, it remains unclear whether the same melanoma cell can harbor both a BRAF and an NRAS mutation, or at the single-cell level, these mutations are indeed mutually exclusive.

With discoveries revealing that ~70% of non-AL cutaneous melanomas contain mutations constitutively activating the mitogen-activated protein kinase (MAPK) pathway came intense development of inhibitors capable of targeting various nodes of the mitogen-activated protein kinase (MAPK) pathway (i.e., BRAF, MEK, and ERK inhibitors) that continues to date. The first targeted therapy approved for the treatment of patients with BRAFV600E/K mutant melanoma was the small molecule inhibitor vemurafenib, an agent designed to have high specificity against the mutant V600E, V600K, V600D, and V600R forms of BRAF. Vemurafenib had response rates of ~48% in phase II and III clinical trials leading to the 2011 Food Drug and Agriculture (FDA) approval. A few years later, the combination of a BRAF inhibitor and a MEK inhibitor was observed to further increase the response rate to ~76% leading to the 2014 FDA approval of dabrafenib and trametinib. There are now three BRAF inhibitor plus MEK inhibitor combinations FDA approved for melanoma patients with BRAFV600E/K mutations (dabrafenib/trametinib, vemurafenib/cobimetinib, and encorafenib/binimetinib.

For patients with wild-type BRAF, treatment with BRAF inhibitors that specifically target V600E/K mutant BRAF may increase melanoma aggressiveness due to the paradoxical activation of wild-type BRAF and downstream MAPK pathway signaling. Preclinically, targeting downstream of BRAF with MEK inhibitors in BRAF-wild-type melanoma cells demonstrates the importance of the MAPK pathway for their survival, with significant anticancer activity. However, clinical trials testing multiple MEK inhibitors (i.e., binimetinib, trametinib) have concluded that although encouraging response rates and small increases in progression-free survival could be achieved in certain trials relative to dacarbazine, no significant increase in overall survival of patients with BRAF-wild-type melanoma was achieved with MEK inhibition. In an effort to increase MEK inhibitor efficacy, combination strategies with other agents (i.e., PI3K inhibitors, CDK4/6 inhibitors) are being clinically tested in the BRAF-wild-type (i.e., patients with or without NRAS-MT melanoma) setting after failure of immunotherapy. ERK inhibitors are also being clinically investigated to see if durable efficacy can be achieved in patients with wild-type BRAF, with reports showing the first-in-class ERK1/2 inhibitor ulixertinib has an acceptable safety profile and early evidence of clinical activity. Preclinical evidence suggests that concurrent inhibition of multiple nodes of the MAPK pathway in NRAS-mutant melanoma (i.e., MEK and ERK) may have synergistic activity on par with the BRAF inhibitor and MEK inhibitor combination in BRAF-mutant melanomas, and further studies evaluating this strategy are under way.

In parallel, large strides have been made in the development of immune checkpoint blockade strategies with the FDA approval of antibodies targeting cytotoxic T-lymphocyte antigen 4 (CTLA4, ipilimumab) in 2011 and programmed cell death 1 (PD1, pembrolizumab, nivolumab) in 2014  and the combination of ipilimumab and nivolumab in 2015. Immune checkpoint blockade describes the use of therapeutic antibodies that overcome immunosuppressive checkpoints with the goal of unchaining antitumor immune responses. CTLA4 and PD-1 are both receptors that suppress effector T-cell activity. These immunotherapy-based strategies elicit long-lasting responses in a subset of patients and represent a therapeutic strategy suitable for all genotypes of non-AL cutaneous melanoma. However, the majority of patients treated with immunotherapy progress within 5 years due to poorly understood primary resistance mechanisms, and clinicians still cannot reliably discriminate which patients will respond or not respond. Both tumor intrinsic (i.e., insufficient tumor antigenicity, tumor interferon-γ signaling, tumor stemness) and extrinsic (i.e., regulatory T cells, myeloid-derived suppressor cells) resistance mechanisms have been reported, and there are intense efforts focused on overcoming these therapeutic hurdles to further increase the efficacy of immune checkpoint blockade strategies.

The promising efficacy of these new therapeutic strategies has been demonstrated largely in non-AL cutaneous melanoma patients with either superficial spreading melanoma (SSM), nodular melanoma (NM), or lentigo maligna melanoma (LMM). SSM, NM, and LMM represent the most common forms of melanoma in Caucasians (>85% of cases). It is important to appreciate that most of the recent pivotal discoveries in melanoma were performed on SSM cell lines, short-term cultures, animal models, and tumor biopsies taken from patients with SSM largely due to their greater availability. AL melanoma represents the fourth and rarest subtype of cutaneous melanoma. In addition, mucosal melanoma and uveal melanoma are other rare subtypes of melanoma that are non-cutaneous in origin. The efficacy of immune checkpoint blockade is lower in rarer subtypes of melanoma relative to patients with non-AL cutaneous melanoma, which will be discussed later. There is also little information regarding the efficacy of combination BRAF inhibitor and MEK inhibitor therapy in these subtypes. 

Acral - 

Acral lentiginous melanoma is an uncommon yet relatively aggressive subtype of CMM that accounts for 2%–3% of all melanoma cases. AL melanoma arises on sun-protected, glabrous skin of the soles, palms, and nail beds. AL melanoma has been historically associated with worse 10-year survival rates relative to other forms of CMM (67.5% vs. 87.5%). Further, 10-year AL melanoma survival rates are highest in non-Hispanic Whites (69.4%), intermediate in Blacks (71.5%), and lowest in Hispanic Whites (57.3%) and Asian/Pacific Islanders (54.1%), as found by the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute evaluating data from 17 population-based cancer registries from 1986 to 2005. Another analysis of AL melanoma prognostic features in a cohort of German, Swiss, and Austrian patients suggests no significant difference exist relative to other subtypes of cutaneous melanoma; however, this conclusion may stem due to differential ethnicity landscapes between this patient cohort and that in the SEER study. There does not appear to be a gender bias, with a similar frequency between men and women and a comparable median age of diagnosis of 63.1 years for men and 62.2 years for women. The incidence of AL melanoma increases with age, and for reasons poorly understood, men are twice as likely to develop AL melanoma relative to women after the age of 80.

The distribution of AL melanoma varies geographically among populations throughout the world. While AL melanoma represents only ~2%–3% of all melanoma cases in Caucasian populations, AL melanoma makes up 50%–80% of all cases in non-Caucasian individuals in the United States (i.e., those of African, Latin American, and Asian descent). Furthermore, the incidence in Hispanic Whites doubles compared to non-Hispanic Whites after the aged of 70. A 2009 SEER study found the overall incidence rates of AL melanoma were similar between non-Hispanic Whites and Blacks; however, Hispanic Whites have statistically higher incidence rates relative to non-Hispanic Whites . Updated epidemiological studies should be performed to continue understanding the differential incidence trends that may exist across different ethnicities. Of note, the incidence of other subtypes of cutaneous melanoma (i.e., NM, SSM) is much lower in non-Caucasians relative to Caucasians. As this subtype of melanoma is not related to ultraviolet radiation (UV), there are different theories of the cause of AL melanoma. Some reports state that trauma and pressure in the foot (a predilected area of AL) is causal. However, the hand is also exposed to trauma but its location is less favorable. The main sites of AL melanoma metastases are the lungs, distant lymph nodes, scalp, contralateral limb, and liver.

Acral lentiginous melanomas possess a significantly lower mutational burden relative to the more common cutaneous melanoma subtypes, likely due to the sun-protected locations they arise from. BRAF mutations in are found in 1 in every 5 Al melanoma patients, leaving ~80% ineligible to receive BRAF inhibitor and combination BRAF/MEK inhibitor strategies . Therefore, new targets specific for AL melanoma are needed. 80% of AL melanomas display genetic aberrations of cyclin-dependent kinase 4/6 (CDK4/6) pathway-related genes (i.e., amplification of CDK4 and CCND1, and/or loss of CDK2NA), representing the most frequent copy number alteration detected . Additionally, activating KIT mutations are present in ~6% of cases. AL melanoma displays similar incidence of NRAS mutations as non-AL cutaneous melanoma, detectable in 15%–28% of AL melanoma patients, and NRAS mutations are an independent prognostic factor of worse overall survival.

Considerable barriers exist to treat patients with AL melanoma: (a) a contrasting genomic and genetic landscape relative to non-AL cutaneous melanomas, (b) unclear targetable drivers, and (3) sparse experimental models available for preclinical drug development. Unfortunately, FDA-approved targeted therapy strategies for melanoma are not available for the majority of AL melanoma patients (i.e., BRAF inhibitors since AL melanoma has a low frequency of BRAF mutations), and the efficacy of immune checkpoint blockade strategies is not well known in AL melanoma, with differing overall response rates (ORR) differing by country. For example, the ORR of anti-PD-1 in AL melanoma patients was found to be similar to that in non-AL cutaneous melanoma patients within the United States. In contrast, the ORR was 66.7% for SSM patients and 28.6% of AL melanoma patients in a recent Japanese study, suggesting the efficacy of immune checkpoint blockade may vary with ethnicity. The lower mutational burden observed in AL melanoma cases is thought to drive the reduced efficacy of immune checkpoint inhibitor strategies (e.g., PD-1 blockade) in patients. Although AL melanoma patients with Kit mutations can be treated with a KIT inhibitor per National Comprehensive Cancer Network (NCCN) guidelines, resistance mechanisms that reactivate downstream MAPK and PI3K pathway signaling have been suggested to blunt long-term durability. Due to the high percentage of AL melanoma tumors with CDK4/6-pathway aberrations, CDK4/6 inhibition represents one of the most promising targeted therapy strategies for AL melanomas clinically. However, durable responses are not observed in all patients due to resistance and CDK4/6 inhibitor-based combinations will likely be needed to improve the curative rate for patients with AL melanoma. Preclinical investigation to optimize targeted therapy strategies has not been extensively performed in AL melanoma models, but the rich body of literature that exists from studies in non-AL cutaneous melanoma models strongly suggests that single-agent approaches will not be durable due to the nearly universal onset of resistance. In SSM models, treatment with a MAPK pathway inhibitor plus a CDK4/6 inhibitor has shown synergistic activity in BRAF-MT and BRAF-wild-type settings; however, residual disease persists. Resistance mechanisms to CDK4/6 inhibitors and/or MEK inhibitors must be delineated to develop combination strategies that produce durable responses in AL melanoma patients.

Mucosal Melanoma - 

Mucosal melanoma (MM) is one of the rarest types of melanoma, accounting for only 1% of all cases, and has a significantly worse prognosis relative to the other subtypes. Distinct from cutaneous melanoma, MM arises from melanocytes located in mucosal membranes inside the body (i.e., genitourinary, anorectal, nasopharyngeal). The head and neck (55), vulva (18), and anus (24) are the most common observed sites; however, MM can also occur in the gut, lungs, and urinary track. It is rarely diagnosed at early stages due to difficult visual detection, which is much more tractable for cutaneous subtypes of melanoma. The overall median age of diagnosis is 70 years, with the exception of MMs arising in the mouth that manifest more frequently in younger patients. The incidence of MM has been stable for the last few years with the exception of MM in the genital tract, which is higher in females relative to males for reasons not clearly understood.

Approximately 3%–15% of MMs harbor an activating mutation in BRAF, with ~63% located on the V600 codon and 37% located on a non-V600 codon. This is in contrast to non-AL cutaneous melanomas where <10% of BRAF mutations are outside of the V600 codon, and more closely resembles the high prevalence of non-V600 mutations found in 48% of lung adenocarcinomas. A closer analysis of the most common non-V600 mutations reveals (a) a difference between the frequency of mutations on D594, G469, and K601 between non-AL cutaneous melanomas and MMs, and (b) convergence in the non-V600 mutational landscape between MM and lung cancers where mutations are often associated with genotoxic agents.

In regard to NRAS mutations, approximately 12% of MMs harbor activating mutations, which is lower relative to cutaneous melanomas where NRAS mutations occur in 15%–20% of cases. There is also a divergence in the location of NRAS mutations between MM and cutaneous melanoma, with 54% located on codon 61 in MM versus 88% in cutaneous melanoma, and 46% located on codons 12 and 13 in MM versus 12% for cutaneous melanomas. Approximately 7%–22% of MMs have v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT) somatic mutations or amplifications. MMs located in the genital area appear to be driven by mutations in SF3B1 which encodes the subunit 1 of splicing factor 3b, a component of the spliceosome that processes pre-mRNA into mature transcripts. A recent study analyzing the mutational landscape of MM identified IGF2R mutations in 31.7% of MM samples relative to 6.3% of SSM cases. Interestingly, a lower frequency of UV-induced DNA damage, a lower number of mutations and a link to high tobacco exposure have also been identified in MM.

Unfortunately, MM is typically detected at relatively more advanced states due to difficulty in early detection. The main treatment for MM differs slightly on where the tumor is located; however, like any other subtype of melanoma, patients are initially treated with surgical excision. MMs arising in the head and neck are treated with complete surgical excision of the tumor when the patient is in stages III and IVA. However, this is associated with a high rate of recurrence. MMs that have arisen in the vulvovaginal or anorectal area also receive radiation in addition to surgical tumor excision. Therapeutic efficacy may be improved in select patients when treatment is personalized by tumor mutational status. Clinical trials targeting KIT with imatinib show no clear effect in unselected metastatic melanoma patient populations, but encouraging clinical benefit has been observed with KIT inhibition specifically in patients with melanomas harboring KIT mutations (not in patients whose melanoma harbor KIT amplification only). Nonetheless, disease progression ultimately occurs in the majority of cases. These data support the practice of determining KIT mutational status for MM patients to have a higher chance of receiving additional clinical benefi. Subsequent phase II clinical trials now require a KIT alteration for enrollment. For the relatively small number of MM patients whose tumors harbor BRAF mutations (relative to the ~50% in non-AL cutaneous melanoma patients), treatment with combination BRAF inhibitor and MEK inhibitor therapy is available. However, the efficacy of targeted therapy specifically in the MM patient population is not completely understood due to the low number available for analysis.

The efficacy of immune checkpoint inhibitor therapy also remains unclear in MM patients, with conflicting evidence of whether MM patients respond as well as non-AL cutaneous melanoma patients. In one multi-institutional analysis of clinical trials focusing on all the subtypes of metastatic melanoma, patients with MM had similar responses compared with non-AL cutaneous melanoma patients when treated with anti-PD-1 single-agent therapy, with a progression-free survival of 3.9 months . In another pooled analysis, MM patients treated with nivolumab as monotherapy or nivolumab in combination with ipilimumab experienced reduced clinical benefit relative to non-AL cutaneous melanoma patients. MM patients experienced 50% shorter progression-free survival (3.0 months) relative to patients with non-AL cutaneous melanoma (6.2 months) for monotherapy (nivolumab) and for nivolumab plus ipilimumab (5.9 vs. 11.7 months. Another recent study combining axitinib (small molecule receptor tyrosine kinase inhibitor) with toripalimab (anti-PD-1) found a median progression-free survival of 7.5 months in among 29 patients with chemotherapy-naïve mucosal melanoma. Although these data suggest that MM patients may not achieve as much benefit with immune checkpoint inhibitor therapy as non-AL cutaneous melanoma patients, it should be considered that in each of the pooled analyses, the number of MM cases was only 10% of patients compared to 75% from cutaneous melanoma. Also notable, another prospective study where 44 patients with unresectable MM were treated with immune checkpoint inhibitors concluded that the site of origin for MM (i.e., vaginal, anal) may not have a significant impact on the objective response rate, which was 8.2% for ipilimumab and 35% for pembrolizumab. The lower mutational burden in MM relative to non-AL cutaneous melanoma may explain the decreased efficacy of immune checkpoint blockade in MM.

Uveal Melanoma -

Uveal melanoma (UM) is the most common form of ocular melanoma, as well as the most prevalent form of non-cutaneous melanoma, accounting for 5% of all melanomas . It most commonly arises in non-Hispanic Whites relative to other races (i.e., African and Asian Americans), with a slight predominance for men (52.3%) relative to women (47.7%). The incidence of UM has remained stable over the last few decades and is diagnosed in 4–5 per million individuals in the United States each year. The median age of diagnosis is 62, and the incidence of UM increases with age. Early detection of UM provides a favorable 85% survival rate; however, this survival rate significantly decreases to 15% once UM cells have disseminated. Approximately 50% of UM patients develop metastases, and among patients with metastatic disease, 90% have liver involvement and ~70% have liver-only disease. This is a distinct metastatic pattern relative to cutaneous melanoma or mucosal melanoma.

Unlike non-AL cutaneous melanomas, UMs have a much lower mutational burden due to the sun-protected site they arise from within the ocular cavity. Activating mutations in BRAF or NRAS are not detected (extremely rare) in tumor cells of UM patients. In contrast, the main drivers for UM are activating mutations of guanine nucleotide-binding protein G (GNAQ/11), splicing factor 3B subunit 1 (SF3B1), eukaryotic translation initiation factor (EIF1AX), and inactivating mutations of the tumor suppressor BRCA-associated protein-1 (BAP1). The GNAQ/11 genes encode specific GTP binding proteins that mediate signal transduction from the inner cell surface to the MAPK pathway through activation of the protein kinase C (PKC) enzyme. GNAQ and GNA11 mutations are mutually exclusive, and thus in total are detected in 85%–94% of UM across all stages of disease. Due to their detection in benign uveal nevi, GNAQ/11 mutations are thought to be early mutational events.

BAP1 (located on the short arm of chromosome 3) loss-of-function mutations are posited to serve as a predisposing factor for diverse hereditary cancers including mesothelioma, cutaneous melanoma, renal cell carcinoma, and UM. A recent comprehensive review identified that among 174 patients harboring germline BAP1 mutations, 130 developed tumors that were either UM (31% of cases), cutaneous melanoma (13% of cases), renal cell carcinoma (10% of cases), or MM (22% of cases). In UM, loss of BAP1 returns melanoma cells to a more stem cell-like state as BAP1 is involved in melanocyte differentiation. BAP1 is frequently mutated in metastasizing uveal melanomas, which supports the growing evidence that stem-like melanoma cell states drive elements of the metastatic cascade.

There has been a recent decline in UM patients treated solely with surgery due to micrometastases that develop years before primary tumor detection. The current approach for treatment of metastatic UM is radiation; however, the survival rate is not significantly improved relative to what is possible from surgery. There have been an array of clinical studies trying to identify efficacious therapeutic strategies for patients with metastatic UM. UM patients that possess GNAQ or GNA11 mutations can be treated in clinical trials with targeted therapy approaches specific for the MAPK pathway (i.e., MEK inhibitor, ERK inhibitor) as these tumors display elevated MAPK activity. Preclinical studies have shown that treatment of UM with a combination of a MAPK pathway inhibitor and a PKC inhibitor may provide synergistic efficacy relative to what is achievable by either agent alone. Clinical trials with selumetinib, a MEK inhibitor, reported a higher progression-free survival among UM patients (15.9 vs. 7 weeks); however, no clinically meaningful increase in overall survival was observed in comparison to the chemotherapeutic temozolomide in the metastatic setting (10.8 vs. 9.4 months). Additionally, preclinical studies identified that targeting the PI3K/AKT pathway (in GNAQ and GNA11 mutant xenograft models) in combination with a MEK inhibitor may be an effective treatment strategy for patients with GNAQ or GNA11 mutations; however, clinical trials using this combination have stopped due to low response rates and high toxicity. Inhibitors against bromodomain and extraterminal (BET) proteins have had encouraging activity preclinically in UM, which could be further increased by concurrent inhibition of escape mechanisms mediated by fibroblast growth factor receptors. Similarly, targeting microenvironment-derived factors including HGF can also increase MEK inhibitor efficacy against UM cells, preclinically. For UM with BAP1 mutations, it has been shown preclinically that treatment with a histone deacetylase (HDAC) inhibitor could be beneficial. Because BAP1 mutations are associated with loss of melanocytic differentiation, treatment with HDAC inhibitors (valproic acid) are postulated to inhibit the growth of uveal melanoma in vivo by inducing morphological differentiation.

While immune checkpoint inhibitors are the standard of care for cutaneous melanoma, UM has not yet had a phase III clinical trial for immune therapy. Small studies in UM patients (10 patients) treated with pembrolizumab (anti-PD-1) after treatment with ipilimumab reported a median progression-free survival of 18 weeks; ranging from 3.14 to 49.3 weeks. Of the eight evaluable patients, four rapidly progressed, one had stable disease, two had partial responses, and one had a complete response. Although this small study resulted in comparable results seen in patients with non-AL cutaneous melanoma, other studies suggest far lower response rates to single agent anti-PD-1 and combination anti-PD-1 plus anti-CTLA-4 in UM patients. An analysis of Danish UM patients observed partial responses in 7% of patients to anti-PD-1 and 21% to concurrent anti-PD-1 plus anti-CTLA-4. Metastatic UM patients treated with ipilimumab from two additional clinical studies had a median overall survival of 9 months (in contrast to 19.9 months in non-AL cutaneous melanoma). Despite the reduced efficacy of immune checkpoint blockade in UM patients, this option may represent the most effective strategy to date.

Nodular Melanoma -

Nodular melanoma represents the second most common subtype of melanoma, responsible for 10%–15% of total melanomas in Caucasians. NM is the melanoma subtype most associated with increased thickness at clinical presentation, which is attributed to the relatively poorer prognosis of patients with NM. The median age of diagnosis for NM is 53 years, with thicker tumors more common in older patients. NM is more common in women than men for reasons poorly understood and commonly presents de novo on the head, neck, or trunk of patients.

Activating BRAF mutations are detected in patients with NM at a slightly lower frequency relative to SSM, with 43%–47% of patients possessing mutations mostly (88% of cases) in V600E. A recent study identified evidence that BRAFV600E expression may serve as a prognostic marker in primary NM associated with ulceration and reduced survival. Preclinically, it was reported that hyperactivation of the downstream MAPK effector ribosomal protein S6 kinase (RSK1) is detectable in metastatic tumor tissues derived from NM to a higher extent relative to SSM. Activating NRAS mutations are detected at a significantly elevated frequency in NM relative to SSM in 30%–33% vs. 19% of cases, respectively. Interestingly, BRAF and NRAS mutations may not be as mutually exclusive in NM relative to SSM, with the identification of both mutations in the same tumor specimens when assessed by laser capture dissection followed by direct sequencing analysis of exons 11 and 15 of the BRAF gene and exons 1 and 2 of the NRAS gene. Additional high-throughput sequencing of patient-derived samples of single nucleotide variations (SNVs) expected to impact protein coding reveals NOTCH4, RPSKA6, BCL2L12, TERT, ERBB3, ZNF560, SSPO, and SNX31 to be significantly under-mutated in NM relative to SSM.

An analysis of the most recent Surveillance, Epidemiology, and End Results (SEER) cohort and the New York University (NRU) cohort suggests that relative to patients with metastatic SSM treated with BRAF inhibitor (BRAFi) therapy, patients with metastatic NM may respond worse to BRAFi for reasons not completely understood, suggesting the potential existence of distinct clinical and biological properties between NM and SSM. The observation of activated RSK1 via constitutive phosphorylation at the Ser-380 residue may explain the poorer efficacy of BRAFi and/or BRAFi/MEKi in patients with this melanoma subtype. In contrast, no significant difference in response rates and survival was detected in NM versus SSM among a cohort of 154 patients treated with either anti-CTLA-4, anti-PD-1, or the combination of both immune checkpoint inhibitor approaches. Immune checkpoint blockade may serve an ideal first-line therapy for patients with this subtype.

Lentigo Maligna - 

Lentigo maligna (LM) is the third most common subtype of melanoma, comprising roughly 4%–15% of all melanoma cases and its incidence has dramatically increased over the past few decades across the United States, and other regions of the world. LM melanoma typically presents on chronically sun-damaged (CSD) skin of the head and neck, appearing as an irregular brown macule commonly on the head and neck in the elderly. In contrast to the mean age of diagnosis of SSM between 40 and 60 years, the mean age of diagnosis for LM melanoma is 66–72 years. Credit is given to Sir John Hutchinson for the earliest description of LM melanoma in 1890. LM melanoma was initially referred to as “Hutchinson’s melanocytic freckle” due to the prevailing thought that it was benign, non-infectious lesion owing to its slow growing nature. Critical work by Ackerman and Silvers in the late 1970s–1980s finally led to wide acceptance of LM melanoma as a malignant disease worthy of clinical attention and intervention. Chronic ultraviolet radiation is the major risk factor for the development of LM melanoma, which differs from NM and SSM that are associated with intense intermittent ultraviolet radiation exposure. LM melanomas arise most frequently on the face and other sites of chronic sun damage which also differs from NM and SSM that arise most commonly on the trunk in men and legs in women. LM melanoma is thought to occur in older patients due to the increased lifetime sun and ultraviolet radiation exposure.

Lentigo maligna melanomas have a relatively high mutational burden compared to other melanoma subtypes due to chronic ultraviolet exposure. The frequency of activating BRAF mutations in LM is unclear, with reports finding 16.7%–53.4% of LM patients harboring BRAF mutations. The large variation may, in part, be attributed to the regional differences among tested patient tissue cohorts. In a Greek cohort, 16.7% of LM melanoma cases expressed BRAF mutations and 50% of LM cases in a Japanese cohort expressed BRAF mutations. When BRAF mutations are present, the V600K substitution is frequently observed (~77%) relative to the V600E (~23%) as observed in SSM, in this small set of 13 LM patient tumor samples. This finding is consistent with V600K mutations arising on chronically sun-damaged skin. Activating NRAS mutations have been reported to occur in ~8.1%–16% of LM cases .

The treatment of choice for patients with localized LM melanoma consists of surgical excision as first line of therapy, followed by radiation therapy with fractionated superficial radiotherapy, or topical imiquimod cream as an alternative to surgery. Once LM melanoma metastasizes to visceral organs, the five-year survival is similar to SSM. Interestingly, the efficacy of immune checkpoint blockade may be significantly higher in patients with LM melanoma relative to the other subtypes discussed. A study investigating the overall response rate (ORR) of anti-PD-1/PD-L1 in different subtypes of melanoma found patients with melanoma on CSD skin (including LM melanoma, desmoplastic melanoma, and subtype not-specified cases) exhibited an overall response rate of 70%, which fits the theory that cancer cells with high mutational burdens may be more sensitive to immune checkpoint blockade due to the increased presence of immune-stimulatory neoepitopes. Additional investigations on the efficacy of targeted and immune-based therapy are needed specifically for patients with LM melanoma to ensure the optimal treatment(s) is identified for this cohort and further improved through preclinical experimentation and clinical trials.

To date, this is the most comprehensive review of the data and treatments best suited for these melanoma subtypes that I have found.  So hoping that understanding and effective treatment options increase for these patients very soon.  -  c

Advanced Melanoma - A smattering of 2020 literature for Stage IV peeps

Unfortunately, though some promising trials are underway, no major breakthroughs have occurred in melanoma research of late.  Still, there are studies and data that are meaningful.  Here is a collection of reports that may be valuable to Stage IV melanoma peeps.  (My comments in red.) -

Overall Survival Improved for Contemporary Patients with Melanoma: A 2004-2015 National Cancer Database Analysis.  Farrow, Turner, Salama, Beasley.  Oncol Ther. 2020 Dec.

Introduction: Since 2011, encouraging clinical trial results have led to approval of multiple new therapies for advanced melanoma, but the impact of these therapies outside of trial populations is largely unknown. This study examines use of novel therapies and survival in contemporary patients with melanoma.

Methods: Stage I-IV melanoma patients were identified in the 2004-2015 National Cancer Database and grouped into historic (2004-2010) and contemporary (2011-2015) cohorts. Overall survival (OS) was compared using Kaplan-Meier and Cox proportional hazard modeling adjusting for patient, tumor, and facility characteristics.

Results: Of 268,668 patients, 136,828 were classified as historic and 131,840 as contemporary. Among all stages, immunotherapy utilization was significantly higher among contemporary patients. Adjusted OS was improved in the contemporary cohort. There was no difference in OS among stage I/II patients between groups, while OS was significantly improved for contemporary stage III/IV patients. Among stage III/IV patients who received immunotherapy, OS was improved for the contemporary cohort.

Conclusions: Adjusted overall survival for contemporary melanoma patients is improved. This effect is driven by improvements for those with advanced stage disease, particularly those that received immunotherapy and BRAF/MEK targeted therapies.

Confirmation of what we already know - targeted therapy (BRAF/MEK combo's) for BRAF positive melanoma patients and immunotherapy - have made a world of difference for melanoma peeps.  

Systemic Therapy for Melanoma: ASCO Guideline.  Seth, …Kirkwood, Kudchadkar…Weber, Agarwala, Ascierto, …, Faries… Robert,…Sondak, et al.  J Clin Oncol, 2020 Nov 20.

Purpose: To provide guidance to clinicians regarding the use of systemic therapy for melanoma.

Methods: ASCO convened an Expert Panel and conducted a systematic review of the literature.

Results: A systematic review, one meta-analysis, and 34 additional randomized trials were identified. The published studies included a wide range of systemic therapies in cutaneous and noncutaneous melanoma.

Recommendations: In the adjuvant setting, nivolumab or pembrolizumab should be offered to patients with resected stage IIIA/B/C/D BRAF wild-type cutaneous melanoma, while either of those two agents or the combination of dabrafenib and trametinib should be offered in BRAF-mutant disease. No recommendation could be made for or against the use of neoadjuvant therapy in cutaneous melanoma. In the unresectable/metastatic setting, ipilimumab plus nivolumab, nivolumab alone, or pembrolizumab alone should be offered to patients with BRAF wild-type cutaneous melanoma, while those three regimens or combination BRAF/MEK inhibitor therapy with dabrafenib/trametinib, encorafenib/binimetinib, or vemurafenib/cobimetinib should be offered in BRAF-mutant disease. Patients with mucosal melanoma may be offered the same therapies recommended for cutaneous melanoma. No recommendation could be made for or against specific therapy for uveal melanoma. 

YEP!

Five-Year Outcomes With Nivolumab in Patients With Wild-Type BRAF Advanced Melanoma.  Robert, Long, Brady, et al.  J Clin oncol.  2020 Nov.

Purpose: The CheckMate 066 trial investigated nivolumab monotherapy as first-line treatment for patients with previously untreated BRAF wild-type advanced melanoma. Five-year results are presented herein.

Patients and methods: In this multicenter, double-blind, phase III study, 418 patients with previously untreated, unresectable, stage III/IV, wild-type BRAF melanoma were randomly assigned 1:1 to receive nivolumab 3 mg/kg every 2 weeks or dacarbazine 1,000 mg/m2 every 3 weeks. The primary end point was overall survival (OS), and secondary end points included progression-free survival (PFS), objective response rate (ORR), and safety.

Results: Patients were followed for a minimum of 60 months from the last patient randomly assigned (median follow-up, 32.0 months for nivolumab and 10.9 months for dacarbazine). Five-year OS rates were 39% with nivolumab and 17% with dacarbazine; PFS rates were 28% and 3%, respectively. Five-year OS was 38% in patients randomly assigned to dacarbazine who had subsequent therapy, including nivolumab (n = 37). ORR was 42% with nivolumab and 14% with dacarbazine; among patients alive at 5 years, ORR was 81% and 39%, respectively. Of 42 patients treated with nivolumab who had a complete response (20%), 88% (37 of 42) were alive as of the 5-year analysis. Among 75 nivolumab-treated patients alive and evaluable at the 5-year analysis, 83% had not received subsequent therapy; 23% were still on study treatment, and 60% were treatment free. Safety analyses were similar to the 3-year report.

Conclusion: Results from this 5-year analysis confirm the significant benefit of nivolumab over dacarbazine for all end points and add to the growing body of evidence supporting long-term survival with nivolumab mono-therapy. Survival is strongly associated with achieving a durable response, which can be maintained after treatment discontinuation, even without subsequent systemic therapies.

So over comparing any melanoma treatment with dacarbazine.  At the onset of this study, I suppose it was okay - but hopefully we are well past that now!!!  At any rate - important points are just relative to nivo only treatment and survival.  Overall response rate was 42%.  Of patients alive at five years ORR was 81%.  Of the patients on nivo with a complete response, 88% were alive at 5 years.  Of nivo treated patients alive at 5 years - 83% had needed no additional treatment, 23% were still on treatment, and 60% were treatment free.

Safety and efficacy of combination nivolumab plus ipilimumab in patients with advanced melanoma: results from a North American expanded access program (CheckMate 218).  Hodi, Chapman, Sznol, et al.  Melanoma Res.  2020 Nov.

CheckMate 218, a North American expanded access program (EAP), investigated nivolumab plus ipilimumab in patients with advanced melanoma. Safety and efficacy, including 2-year survival in clinically relevant patient subgroups, are reported. Eligible patients were aged greater than/equal to18 years with unresectable stage III/IV melanoma, an Eastern Cooperative Oncology Group performance status of 0/1, and no prior checkpoint inhibitors. Patients received nivolumab 1 mg/kg plus ipilimumab 3 mg/kg every 3 weeks for 4 cycles (induction) followed by nivolumab 3 mg/kg every 2 weeks (maintenance) until progression or unacceptable toxicity or a maximum of 48 weeks. Safety and overall survival (OS) data were collected. This EAP included 754 treated patients from the USA (n = 580) and Canada (n = 174). Median follow-up time was 17.8 months. All-grade and grade 3-4 treatment-related adverse events were reported in 96% and 53% of patients and led to treatment discontinuation in 36% and 26% of patients, respectively. OS rates at 12 and 24 months were 82%  and 70%, respectively. Twenty-four-month OS rates were 63% in patients aged ≥75 years, 56% in patients with elevated lactate dehydrogenase levels, 73% in patients with BRAF wild-type tumors, 70% in patients with BRAF mutant tumors, and 56% in patients with mucosal melanoma. In this EAP, nivolumab plus ipilimumab demonstrated high survival rates and safety outcomes consistent with those from randomized clinical trials, further supporting the use of this combination for advanced melanoma across multiple subgroups.

Again - ipi/nivo with better survival than nivo alone, though with a more significant side effect profile.

PD-1 inhibitors might limit the development of brain metastases in patients with advanced melanoma.  Marcaillous, Linder, Chaltiel, et al.  Melanoma Res. 2020 Dec.

Brain metastases are a common and severe complication potentially leading to death in patients with metastatic melanoma. Immunotherapy and targeted therapy have significantly improved progression-free survival (PFS) and overall survival (OS) in patients with advanced melanoma. Few studies focus on patients with central nervous system (CNS) metastases, and these patients are often excluded and have a poor prognosis. It has been suggested that immunotherapy could reduce the incidence of brain metastases. We tested this hypothesis in a retrospective bicentric study. We performed a retrospective, bicentric descriptive analysis on a cohort of 293 patients treated for metastatic melanoma between May 2014 and October 2017. Patients with brain metastasis at diagnosis were excluded from the analysis. Patients were separated into two groups according to the first line of treatment: immunotherapy [immune checkpoint inhibitor (ICI)] vs other and anti-PD-1 vs other. The primary endpoint was the cumulative incidence of brain metastases, and secondary endpoints were OS and PFS. At 12 months, the cumulative incidence of brain metastases was 13.78% in the ICI group and 27.26% in the other group. The cumulative incidence was 9.49% in the anti-PD-1 group vs 30.11% in the other group . In multivariable analysis, anti-PD-1 reduced the risk of brain metastases by almost 70%. The use of ICI (anti-PD-1/PD-L1) in advanced melanomas without initial brain metastasis shows a protective effect and prevents their occurrence.

Yep.  Been yelling it for over 10 years!!!  Immunotherapy works in the brain.  Folks treated with anti-PD-1 had an incidence of brain met development of 9.49% vs 30.11% in patients not treated with anti-PD-1.  Analysis found that anti-PD-1 reduced the risk of brain mets by almost 70%.

PD-L1 blockade in combination with inhibition of MAPK oncogenic signaling in patients with advanced melanoma. Ribas, Algazi, Ascierto, et al.  Nat Commun.  2020 Dec.

Combining PD-L1 blockade with inhibition of oncogenic mitogen-activated protein kinase (MAPK) signaling may result in long-lasting responses in patients with advanced melanoma. This phase 1, open-label, dose-escalation and -expansion study (NCT02027961) investigated safety, tolerability and preliminary efficacy of durvalumab (anti-PD-L1) combined with dabrafenib (BRAF inhibitor) and trametinib (MEK inhibitor) for patients with BRAF-mutated melanoma (cohort A, n = 26), or durvalumab and trametinib given concomitantly (cohort B, n = 20) or sequentially (cohort C, n = 22) for patients with BRAF-wild type melanoma. Adverse events and treatment discontinuation rates were more common than previously reported for these agents given as monotherapy. Objective responses were observed in 69.2% (cohort A), 20.0% (cohort B) and 31.8% (cohort C) of patients, with evidence of improved tumor immune infiltration and durable responses in a subset of patients with available biopsy samples. In conclusion, combined MAPK inhibition and anti-PD-L1 therapy may provide treatment options for patients with advanced melanoma.

In this trial of either Durvalumab (anti-PD-L1) combined with dabrafenib/trametinib or just with trametinib or given sequentially - patients given the combination of the three drugs had a 69.2% response rate, of the 2 a response rate of 20% and in the sequential group (not clear, but I suspect that they got the three drugs) a response rate of 31.8%.  For comparison here is a report on atezo and pembro when combined with a BRAF/MEK therapy from 2019 that includes links to other reports of results when immunotherapy was combined with targeted therapy - Treating melanoma by COMBINING targeted therapy AND immunotherapy!!  When atezo and pembro were combined with a BRAF/MEK combo - responses rates were 70+%.  Of course, this treatment option is only available to about half of us as patients need to be BRAF positive.

Chemotherapy combined with antiangiogenic drugs as salvage therapy in advanced melanoma patients progressing on PD-1 immunotherapy.  Wang, Weiran, Zhihong, et al.  Transl Oncol. 2020 Nov.

Background: This study aimed to evaluate the effect of salvage therapy with nab-paclitaxel (nab-p) or temozolomide (TMZ) combined with antiangiogenic drugs in programmed death 1 (PD-1) inhibitor-resistant patients with unresectable metastatic melanoma.

Methods: We conducted a retrospective review of 69 metastatic melanoma patients who received nab-p or TMZ combined with antiangiogenic drugs after developing PD-1 inhibitor resistance and were treated at the Beijing Cancer Hospital between 2016 and 2019. The disease control rate (c-DCR) and progression-free survival (c-PFS) of salvage CA (chemotherapy combined with antiangiogenic drugs) regimens were investigated. Univariate and multivariate analyses were performed to evaluate the clinical pathological factors affecting the outcomes. Then, a nomogram was formulated to predict the probability of 3-month and 6-month c-PFS based on the multivariate analysis results.

Results: The c-DCR was 63.8%, and the median c-PFS was 3.0 months. In the univariate analysis, factors associated with the c-DCR were included the melanoma subtype, baseline platelet-to-lymphocyte ratio (PLR) and best response status to PD-1 inhibitors. Factors influencing c-PFS included age, baseline lactic dehydrogenase, PLR, neutrophil-to-lymphocyte ratio (NLR), PFS duration of anti-PD-1 therapy (p-PFS), and the best response and progression pattern of PD-1 inhibitors. In the multivariate analysis, age <65 years, heterogeneous progression pattern and baseline PLR<200 were significantly associated with improved c-PFS. The concordance index (C-index) of the nomogram was equal to 0.65.

Conclusions: CA regimens demonstrated promising effects in PD-1 inhibitor-resistant patients. The nomogram could be a valuable predictive module for salvage therapy choice in PD-1 inhibitor-resistant patients.

So these peeps created a fancy scale to determine whether a chemo cocktail would provide 3 vs 6 months of progression free survival in unresectable Stage IV melanoma folks who had become unresponsive to anti-PD-1.  Sad thing to face.  But, if this formula works, perhaps it can provide patients with knowledge that may inform their decision to accept or decline such therapy.

So there you have it.  Final 2020 reports in review for advanced melanoma patients - my take, anyway.  Over the coming days, I will plow through some other 2020 research on other topics pertinent to melanoma.  Stay safe.  Wear a mask.  Get a COVID vaccine when you can.  - c

How to deal with recurrence on or after anti-PD-1 as adjuvant or treatment for active melanoma disease

Current melanoma treatment options are nothing short of a miracle to those of us who survived the Melanoma Dark Ages when there were literally NO effective treatments available.  Still, melanoma treatment remains far from clear or easy.  Should one who is BRAF positive choose immunotherapy or targeted therapy?  Does one opt for anti-PD-1 as a single agent or combined with anti-CTLA-4 (ipi)?  [Noting that the combo is not yet approved for Stage III patients.] And if those puzzlers are not enough, what do you do if you respond to anti-PD-1 initially, but then progress either while still on it or after having been on it?  Research has been trying to grapple with these questions ~

2018:  Melanoma patients treated beyond progression with anti-PD-1  - with the conclusion that:  "Treatment beyond progression with anti-PD-1 antibody therapy might be appropriate for selected patients with unresectable or metastatic melanoma, identified by specific criteria at the time of progression, based on the potential for late responses in the setting of the known toxicity profile."

2018:  anti-PD-1 after progression - In this report, after progression on stopping anti-PD-1 the authors conclude:  "Our data suggest that anti-PD(L)1 therapy should be resumed if progression occurs after a planned anti-PD(L)1 interruption. Further prospective studies are needed to confirm these results. "

and I note: "Small numbers here and not all are melanoma patients.  But, some responses on the re-do."

A bit of a review in 2019:  Anti-PD-1 results in melanoma patients: outcomes plus responses to retreatment where the new data presented ended up with mixed and unclear results on retreatment.

This post in 2020:  Response after discontinuation of anti-PD-1 in melanoma patients whether due to disease progression, side effects or choice - presents articles that try to address what happens to patients who stop anti-PD-1 therapy.

So, as you can see, many patients and their docs are unclear as to what path is best if a patient progresses or recurs while on or after anti-PD-1 therapy.

Now, there's this:

Management of early melanoma recurrence despite adjuvant anti-PD-1 antibody therapy.  Owen, Shoushtari, Chauhan, et al.   Ann Oncol. 2020 May 6.

BACKGROUND:

Anti-PD-1 antibodies (PD1) prolong recurrence-free survival in high-risk resected melanoma; however, approximately 25-30% of patients recur within one year. This study describes the pattern of recurrence, management and outcomes of patients who recur with adjuvant PD1 therapy.

PATIENTS AND METHODS:

Consecutive patients from 16 centres who recurred having received adjuvant PD1 therapy for resected stage III/IV melanoma were studied. Recurrence characteristics, management and outcomes were examined; patients with mucosal melanoma were analysed separately.

RESULTS:

Melanoma recurrence occurred in 147 (17%) of ∼850 patients treated with adjuvant PD1. In those with cutaneous melanoma (n=136), median time to recurrence was 4.6 months (range 0.3-35.7); 104 (76%) recurred during (ON) adjuvant PD1 after a median 3.2 months, and 32 (24%) following (OFF) treatment cessation after a median 12.5 months, including in 21 (15%) who ceased early for toxicity. Fifty-nine (43%) recurred with locoregional disease only and 77 (57%) with distant disease. Of those who recurred locally, 22/59 (37%) subsequently recurred distantly. Eighty-nine (65%) patients received systemic therapy after recurrence. Of those who recurred ON adjuvant PD1, none (0/6) responded to PD1 alone; 8/33 evaluable patients (24%) responded to ipilimumab (alone or in combination with PD1), and 18/23 (78%) responded to BRAF/MEK inhibitors. Of those who recurred OFF adjuvant PD1, 2/5 (40%) responded to PD1 monotherapy, 2/5 (40%) responded to ipilimumab-based therapy, and 9/10 (90%) responded to BRAF/MEK inhibitors.

CONCLUSIONS:

Most patients who recur early despite adjuvant PD1 develop distant metastases. In those who recur ON adjuvant PD1, there is minimal activity of further PD1 monotherapy, but ipilimumab (alone or in combination with PD1) and BRAF/MEK inhibitors have clinical utility. Retreatment with PD1 may have activity in select patients who recur OFF PD1.

These researchers looked at 850 Stage III and IV melanoma patients who had their disease removed and were treated with anti-PD-1.  17% (136 patients) recurred.  Average time to recurrence was about 5 months.  76% of those patients (104) recurred while they were still taking anti-PD-1 after about 3 months.   24% of that same subgroup (32 patients) recurred in about 12 months after coming off anti-PD-1.  89 patients were given systemic therapy.  Of those who recurred while ON anti-PD-1 ~ none responded to anti-PD-1 as a single agent, 24% responded to ipi alone or in combination with anti-PD-1, and 78% responded to targeted therapy.  Of those who recurred AFTER anti-PD-1 ~ 40% responded to retreatment with anti-PD-1, 40% responded to ipi, and 90% responded to targeted therapy.  Therefore, their conclusion is as noted above.

There is also this:

Ipilimumab (IPI) alone or in combination with anti-PD-1 ((_( + PD1) in patients with metastatic melanoma (MM) resistant to PD1.  Da Silva, Ahmed, Lo, et al.  ASCO Meeting Library, 2020.

PD1 induces long-term responses in approximately 30% of MM pts, however 2/3 are resistant (innate or acquired) and will require further treatment. A subset of these pts will benefit from IPI or IPI+PD1, but these pts are yet to be identified. We sought to determine; i) response rate (RR) and survival to IPI+/-PD1 after PD1 progression, and ii) clinical predictors of response and survival to IPI+/-PD1.

MM pts resistant to PD1 and then treated with IPI+/-PD1 were studied. 

Of 330 MM pts resistant to PD1 (median time to prog 2.9 months [0.5 – 42.3], 12% adjuvant, 88% metastatic; 70% innate, 30% acquired), 161 (49%) had subsequent IPI and 169 (51%) had IPI+PD1. Characteristics at start of IPI+/-PD1 were similar in IPI vs IPI+PD1 groups (stage M1D 27% vs 34%; elevated LDH 38% vs 40%), except IPI group had more ECOG greater than/= to 1 (60% vs 34%) and less BRAF mutation (mut) (21% vs 37%). Median follow-up from start of IPI+/-PD1 was 22.3 months (19.8 - 25.8); RR was 22%, higher in IPI+PD1 (31%) vs IPI (12%). PFS and OS at 1 year were 20% and 48%, respectively; better with IPI+PD1 (27%/57%) vs IPI (13%/38%). PD1 setting (adjuvant/metastatic) and response did not impact response to IPI+/-PD1. Most pts progressing on adjuvant PD1 had IPI+PD1 (88%) and RR was 33%. Neither the interval between PD1 and IPI+/-PD1 nor use of other drugs affected response to IPI+/-PD1. RR was similar in BRAF WT (23%) vs BRAF mut (RR 21%) pts. In BRAF WT pts, RR was higher with IPI+PD1 vs IPI (38% vs 9%), while RR was similar with IPI (24%) or IPI+PD1 (19%) in BRAF mut pts. One third of BRAF mut pts had BRAF inhibitors (BRAFi) prior to IPI+/-PD1 and lower RR (13%) vs those without BRAFi (RR = 25%). High grade (greater than/= to G3) toxicity (tox) was similar with IPI+PD1 (30%) or IPI (34%), and was not associated with response. Stage III/M1A/M1B, normal LDH and treatment with IPI+PD1 were the best predictors of response. These factors, in addition to sex (male), ECOG PS = 0, BRAF mut, progressed/recurred greater than 3 months on PD1, and absence of bone mets were the best predictors of longer OS.

In pts resistant to PD1, IPI+PD1 has higher RR, longer survival, yet similar high grade tox than IPI alone. Predictive models of response & survival will help select pts for IPI+/-PD1 after progressing on PD1.

This study looked at patients who did not attain long term durable response to initial anti-PD-1 therapy - about 70% of patients.  They followed 330 melanoma patients who had progressed on or after anti-PD-1 therapy and were then treated with either ipi alone or ipi combined with anti-PD-1. Overall, patients retreated or changed to the ipi/anti-PD-1 combo had higher response rates and longer survival.

For what it's worth. - c