Sunday, June 23, 2019

New Stuff!! Treatment options and current trials for melanoma patients! The first installment of this year's ASCO review.


As I expected, there was not a great deal of NEW news for melanoma patients coming out of ASCO this year.  However, there were a few new things in the works as well as supporting and dismissive data - (this last often being under reported, but certainly important!!!) - for some existing ideas/treatment strategies.  Over the next few days I will be posting some of the hits and misses (from my perspective) with my take (in red).  Here we go....

#1:  I first reported on NKTR in 2013.  Click here for that report as well as abstracts and analysis from 2018.  After examining the Phase 1 and Phase 2 reports of the PIVOT trial I wrote:

"...back to NKTR-214 combined with nivo.  Like many drugs/trials in cancer/melanoma world, the Phase 1 trials were super promising.  Phase II results were a little less so.  Responses as noted in the article were "(ORR) of 50% in treatment-naïve patients with melanoma, including an ORR of 42% in PD-L1–negative patients".  We have already determined that treatment naive patients tend to have the best responses.  But even so, 50% beats 40%.  Additionally, we also know that PD-L1 status has not been particularly definitive in attaining responses to anti-PD-1 drugs, but it is still good to note a 42% ORR in PD-L1 negative patients and that side effects were really no worse in this combo than when anti-PD-1 is taken alone.  So....

I still hold out hope ~ for vaccines, for IDO-inhibitors, and the current responses to NKTR-214 combined with nivo to hold.  BUT!  Unlike Melanoma Big Dogs in their ivory towers....we canaries in the coalmines...the ratties...you and me...can't afford to pontificate on the hypothetical.  We have to deal with the real live results that are happening for real.  Today.  To us."

That's how I look at melanoma research!!!!   ALWAYS! Now....this:

CA045-001: A phase III, randomized, open label study of bempegaldesleukin (NKTR-214) plus nivolumab (NIVO) versus NIVO monotherapy in patients (pts) with previously untreated, unresectable or metastatic melanoma (MEL).  2019 ASCO.  Nikhil, Khushalani, Diab, .... Sznol, Long.  J Clin Oncol 37, 2019 (suppl; abstr TPS9601)

Background: Standard of care for pts with previously untreated, unresectable or metastatic MEL includes checkpoint inhibitors. Bempegaldesleukin is a CD122-preferential IL-2 pathway agonist designed to provide sustained signaling through the IL-2 βγ receptor to activate and proliferate effector CD8+ T and NK cells over T-regulatory cells in the tumor (Hurwitz ME et al. ASCO GU 2017). In the dose-expansion phase of the phase 1/2 PIVOT-02 trial, bempegaldesleukin + NIVO was well tolerated at the recommended phase 2 dose (RP2D; bempegaldesleukin 0.006 mg/kg IV Q3W + NIVO 360 mg IV Q3W), and previously untreated pts with MEL receiving the RP2D achieved an objective response rate (ORR) of 20/38 (53%) and a complete response of 9/38 (24%) by independent radiology review (Diab A et al. SITC 2018). Presented is the design of the first phase 3 trial in the bempegaldesleukin + NIVO development program in pts with previously untreated, unresectable or metastatic MEL. Methods: This phase 3, randomized, open-label study aims to evaluate the effectiveness, safety, and tolerability of bempegaldesleukin + NIVO (NCT03635983). Eligible pts are greater that/= to 2 y with histologically confirmed stage III (unresectable) or stage IV MEL and ECOG PS less that/= to 1 or Lansky PS greater than/= to 80% (minors 12-17 y). Pts are ineligible if they have active brain or leptomeningeal metastases, uveal MEL, or a recurrence within 6 mo of completing adjuvant treatment with any approved agent. Pts will be stratified by PD-L1 status (measured using PD-L1 IHC 28-8 pharmDx), BRAF mutation status, and lactate dehydrogenase level, and will be randomized to receive bempegaldesleukin 0.006 mg/kg IV Q3W + NIVO 360 mg IV Q3W or NIVO 360 mg IV Q3W up to 24 mo, or until progression or unacceptable toxicity (N ~ 764). Primary endpoints are ORR and progression-free survival (PFS) by blinded independent central review (BICR) and overall survival (OS). Secondary endpoints include ORR and PFS by investigator, ORR and PFS by BICR in biomarker population, OS in biomarker population, and safety. Additional endpoints include pharmacokinetics and quality-of-life assessment. Clinical trial information: NCT03635983

So, this is an open and recruiting trial.  It is randomized.  Some folks will be getting the NKTR-214 drug with nivo, some will get nivo only.  Prior ORR of 53% is better than the usual of about 40% to anti-PD-1 products given alone, but about equal to the ipi/nivo combo.  If the side effects of this combo is less than those caused by ipi/nivo, that could be a good thing.  Lots of the usual melanoma peeps are excluded.  But, there you go.

#2: In 2017, I posted:  IMO-2125, a TLR agonist combined with Yervoy (ipi) for folks with melanoma refractory to anti-PD-1 - writing:

"Hmmm.....  Well, it is certainly a fact that we have folks who fail to gain effective control of their melanoma with anti-PD-1 and its 40% response rate, leaving them in desperate need of an effective therapy!  It is also true that I encourage and fully support looking at any and all possible treatments to help them.  Yet, I remain a little puzzled here.  This statement sounds strong, but is substantially lacking in, hmmm....what's the word??????  "...data from multiple parameters of immune markers from tumor biopsies have been very informative in establishing proof-of-mechanism and supporting the dose selection for the Phase 2 portion of the trial.”  Oh!  I know what it is....DATA!!!!!!!!!!!!!!!  This report tells us NOTHING about how the folks in the phase 1 trial are doing!!!

An interesting aside:  The name TLR, toll-like receptor, came from the appearance the fruit fly larvae developed when used as subjects by researchers to isolate the molecule's function.  The larvae in whom the receptor was changed, looked very peculiar, or "droll", according to the German researchers who won a Nobel prize in medicine for this work.  And the German word for "droll" (i.e. funny) is "toll"!  The more you know....

While I hope IMO-2125 will absolutely be the cure for ever so many cancers, including melanoma, we need to remember that current intratumoral/intralesional therapies that are being combined with immunotherapy daily, to good effect, are available for melanoma patients in need and come WITH data supporting their efficacy!  Here's a post reviewing a wide variety of them and the DATA required for them to sally forth:

ASCO 2017: All things intralesional/intratumoral

If TLR agonists become the next great thing....will we all be cured of our melanoma AND have a great sense of humor...or just look a little funny?????  Hang tough ratties!  The road is long with lots of tolls!  And I mean LOTS!!! - c"

Now, there's this:

ILLUMINATE 301: A randomized phase 3 study of tilsotolimod in combination with ipilimumab compared with ipilimumab alone in patients with advanced melanoma following progression on or after anti-PD-1 therapy.  2019 ASCO.  Butler, Rober, Negrier....Ascierto, et al.  J Clin Oncol 37, 2019 (suppl; abstr TPS9599)

Background: Tilsotolimod (IMO-2125) is a Toll-like receptor (TLR) 9 agonist with potent immunostimulating activity. In an ongoing Phase 1/2 clinical study in patients with advanced melanoma who progressed on or after anti-PD-1 therapy (NCT02644967), intratumoral (IT) tilsotolimod with ipilimumab was well-tolerated, demonstrating durable responses (including complete response; 21 months), dendritic cell activation, type I interferon response, CD8+ T-cell proliferation in responders, and an abscopal effect. Methods: ILLUMINATE 301 (NCT03445533) is a randomized phase 3 global, multi-center, open-label study of IT tilsotolimod (8 mg) in combination with ipilimumab (3 mg/kg) versus ipilimumab monotherapy in patients with advanced melanoma and progression on or after anti-PD-1 therapy. Eligible patients are greater than/= to 18 years with histologically confirmed unresectable Stage III or Stage IV melanoma, greater than/= to 1 measurable lesion accessible for injection (superficial or visceral, the latter with image guidance), ECOG PS 1, and adequate organ function. Exclusion criteria include prior TLR agonists, prior ipilimumab (except adjuvant ≥12 weeks before progression), and CNS disease other than stable brain metastases. Patients are randomized 1:1 and stratified by duration of prior anti-PD-1.

So....another recruiting option for those who have progressed on anti-PD-1 and have an injectable lesions.  Stage III or IV melanoma ratties will be randomized to get either injections of tilsotolimod  (IMO-2125) directly into their lesion along with ipi or ipi alone.  You cannot have already taken a TLR agonist, ipi (unless it was only as adjuvant more than 12 weeks before progression) and can have no CNS disease other than stable brain mets.


A phase Ia/b study of TIM-3/PD-L1 bispecific antibody in patients with advanced solid tumors.  2019 ASCO.  Hellmann, Shimizu, Toshihiko, Hodi, et al.  J Clin Oncol 37, 2019.

Background: Programmed cell death 1 immune checkpoint inhibitors (anti-PD-1, anti-PD-L1) have demonstrated clinical benefit in a subset of patients with manageable safety across a variety of tumor types. T-cell immunoglobulin and mucin-domain-containing molecule-3 (TIM-3) can be co-expressed with PD-1 on exhausted T-cells and may be upregulated in tumors refractory to anti-PD-1 therapy (Koyama et al. 2016). Pre-clinical studies demonstrated that blockade of both PD-1 and TIM-3 improved survival of tumor-bearing mice compared to blocking anti-PD-1 only (Koyama et al. 2016). LY3415244 is a TIM-3/PD-L1 bispecific antibody that has the ability to target and inhibit both TIM-3 and PD-L1 and the potential to overcome primary and acquired anti-PD-(L)1 resistance by a novel mechanism to bridge TIM-3- and PD-L1-expressing cellsMethods: Study JZDA is a multicenter, nonrandomized, open-label, Phase 1a/1b study of LY3415244 in patients with advanced solid tumors. In Phase 1a, subjects with any tumor type who are either PD-(L)1 inhibitor-naïve or exposed are eligible. In Phase 1b, expansion cohorts are planned in subjects with PD-(L)1-experienced NSCLC, urothelial carcinoma, and melanoma. Patients with malignant mesothelioma are not required to have received prior anti-PD-(L)1 therapy. The primary objective is to assess safety and tolerability of LY3415244 and identify the recommended Phase 2 dose (RP2D) in Phase 1a (dose escalation). Safety and tolerability of the RP2D will be assessed in Phase 1b (dose expansion). The secondary objectives are to assess the pharmacokinetics of LY3415244 in Phase 1a/1b and assess early antitumor activity of LY3415244 in Phase 1b cohorts. Pre- and on-treatment biopsies will be obtained to explore potential biomarkers of response. During Phase 1a, dose escalation cohorts will proceed via a modified toxicity probability interval-2 (mTPI-2) design with a 1-cycle (28-day) dose-limiting toxicity (DLT) observation period. LY3415244 will be dosed intravenously every 2 weeks. Data from Phase 1a will determine the RP2D, which will be used for all cohorts in Phase 1b. The study is currently open to enrollment. Clinical trial information: NCT03752177.

I seems that you can already have had anti-PD-1, or not, and still qualify.  Folks with NSCLC, urothelial carcinoma or melanoma may enter.  Initially, it is a just a dose limiting study...how much can you give without making folks grow 2 heads?...but then they are also going to look at the impact on the tumors as well.  Early days for this one, but....

#4:  TNF is tumor necrosis factor is a protein that plays a role in cell life, differentiation, growth, and death and has a lot to do with inflammation in our bodies.  In cancer, it's even more complicated.  In this article, the authors note: "In regard to cancer, TNF is a double-dealer. On one hand, TNF could be an endogenous tumor promoter, because TNF stimulates cancer cells’ growth, proliferation, invasion and metastasis, and tumor angiogenesis. On the other hand, TNF could be a cancer killer. The property of TNF in inducing cancer cell death renders it a potential cancer therapeutic, although much work is needed to reduce its toxicity for systematic TNF administration. Recent studies have focused on sensitizing cancer cells to TNF-induced apoptosis through inhibiting survival signals such as NF-κB, by combined therapy."

Now, there's this:

Prophylactic TNF blockade uncouples efficacy and toxicity in dual CTLA-4 and PD-1 immunotherapy.  Perez-Ruiz, Minute, Otano, et al.  Nature. 2019 May 1. 

Combined PD-1 and CTLA-4-targeted immunotherapy with nivolumab and ipilimumab is effective against melanoma, renal cell carcinoma and non-small-cell lung cancer. However, this comes at the cost of frequent, serious immune-related adverse events, necessitating a reduction in the recommended dose of ipilimumab that is given to patients. In mice, co-treatment with surrogate anti-PD-1 and anti-CTLA-4 monoclonal antibodies is effective in transplantable cancer models, but also exacerbates autoimmune colitis. Here we show that treating mice with clinically available TNF inhibitors concomitantly with combined CTLA-4 and PD-1 immunotherapy ameliorates colitis and, in addition, improves anti-tumour efficacy. Notably, TNF is upregulated in the intestine of patients suffering from colitis after dual ipilimumab and nivolumab treatment. We created a model in which Rag2-/-Il2rg-/- mice were adoptively transferred with human peripheral blood mononuclear cells, causing graft-versus-host disease that was further exacerbated by ipilimumab and nivolumab treatment. When human colon cancer cells were xenografted into these mice, prophylactic blockade of human TNF improved colitis and hepatitis in xenografted mice, and moreover, immunotherapeutic control of xenografted tumours was retained. Our results provide clinically feasible strategies to dissociate efficacy and toxicity in the use of combined immune checkpoint blockade for cancer immunotherapy.

Knowing that TNF is "upregulated in the intestines of patients suffering from colitis" due to ipi/nivo, these researchers gave mice a TNF inhibitor BEFORE treating them with ipi/nivo.  Per this report, blocking TNF improved episodes of colitis and hepatitis caused by ipi/nivo in these poor mice AND the ipi/nivo was still effective against their tumors.  Let's hope it works in real live ratties!!

#5:  TIL is complicated in lots of ways.  I posted this in 2016:  TIL - Tumor infiltrating lymphocytes  writing in part:

"What is TIL?  TIL (Tumor infiltrating lymphocytes) are used in an ACT (adoptive cell transfer) therapy like this:  A tumor is removed from the patient's body.  Lymphocytes are collected from it.  Those lymphocytes are tested in order to identify the cells that show the greatest anti-tumor activity.  Then....those particular cells are grown in a lab for several weeks.  If the TIL cells grow sufficiently, the patient is given a body pounding dosing of chemotherapy to rid the body of other lymphocytes so that the new TIL batch will be accepted more readily when they are infused with no other immune cells there to attack them.  The newly grown lymphocytes are then returned to the patient in an infusion along with a cytokine (immune stimulating agent) like IL2 (interleukin 2).  In numerous studies TIL demonstrates a 50% response rate in patients with metastatic melanoma."

"So....basically.  A tumor is harvested.  T-cells are extracted from it...with the idea that they were good soldiers who had already recognized and were in the process of attacking that tumor.  To increase their numbers...they are grown in a dish.  To further their interests...the patient (ie the battlefield) is injected with bad stuff (IL-2, IL-21, or cyclophosphomide and fludarabine, are frequently used) to kill off T-cells that might try to block their fight with the tumor...and/or support the good T-cells...which are then sent back into battle (ie injected into the patient)!" 

Further, I posted this earlier this year:  Baseline levels of IL-9 predicted response to Adoptive cell therapy (ACT) using TIL in melanoma and a complete response in TIL paired with nivo (a case study)  Where it was noted that:  "Best overall response for the entire cohort was 42%; 47% in 43 checkpoint naïve patients, 38% when patients were exposed to anti-CTLA4 alone (21 patients) and 33% if also exposed to anti-PD1 (9 patients) prior to TIL ACT. Median overall survival was 17.3 months; 24.6 months in CTLA4 naïve patients and 8.6 months in patients with prior CTLA4 blockade. "

Growing useful cells to be injected back to the patient is tricky and just one of many obstacles in TIL therapy.  As the process has advanced, it has diverged into a variety of techniques and methods that can be utilized.  Now, there's this:

Safety and efficacy of cryopreserved autologous tumor infiltrating lymphocyte therapy (LN-144, lifileucel) in advanced metastatic melanoma patients who progressed on multiple prior therapies including anti-PD-1.  2019 ASCO.  Sasnaik, Nikhill,Khushalani, et al.  J Clin Oncol 37, 2019 (suppl; abstr 2518)

Background: Treatment options are limited for patients with advanced melanoma who have progressed on checkpoint inhibitors and targeted therapies such as BRAF/MEK inhibitors (if BRAF-V600E mutated). Adoptive cell therapy utilizing tumor-infiltrating lymphocytes (TIL) has shown antitumor efficacy with durable long-term responses in heavily pretreated melanoma patients. Safety and efficacy of lifileucel (LN-144), a centrally manufactured autologous TIL therapy are presented. Methods: C-144-01 is a global Phase 2 open-label, multicenter study of the efficacy and safety of lifileucel in patients with unresectable metastatic melanoma. We report on Cohort 2 (N = 55) patients who received cryopreserved lifileucel. Tumors resected at local institutions were processed in central GMP facilities for TIL production in a 22-day process. Final TIL infusion product was cryopreserved and shipped to sites. Patients received one week of cyclophosphamide/fludarabine preconditioning lymphodepletion, a single lifileucel infusion, followed by up to 6 doses of IL-2. Results: In 55 patients with Stage IIIC/IV unresectable melanoma, 3.1 mean prior therapies (anti-PD1 100%; anti-CTLA-4 80%; BRAF/MEK inhibitor 24%), high baseline tumor burden (110 mm mean target lesion sum of diameters), ORR was 38% (2 CR, 18 PR, 1 uPR). Of 21 responders, 4 have progressed to date with median follow up of 7.4 months. Overall disease control was 76%. Improved responses in some patients were observed with longer follow up. Most (54) patients progressed on prior anti-PD1 and those with PD-L1 negative status were among responders. Mean cells infused was 28 x109. Median IL-2 doses administered was 6.0. Adverse events resolved to baseline, 2 weeks post TIL infusion, a potentially important benefit of one-time TIL therapy. Conclusions: Lifileucel treatment results in 38% ORR in heavily pretreated metastatic melanoma patients with high baseline disease burden who received prior anti-PD1 and BRAF/MEK inhibitor if BRAF mutated. Based on these data, a new Cohort 4 in C-144-01 has been initiated to support lifileucel registration. Clinical trial information: NCT0236057

Here 55 Stage III/IV melanoma patients previously treated with anti-PD-1, ipi, and/or BRAF/MEK, with progressive disease and high tumor burden were given "cryopreserved lifileucel" derived from "tumors resected" at several institutions, then "processed" at a central facility for "TIL production in a 22-day process" then "cryopreserved and shipped to sites".  As is typical with TIL therapy, patients were given one of the nasty pre-treatment concoctions to kill off their existing lymphocytes, were then given a single infusion of lifileucel, followed by up to 6 doses of hell (I mean IL-2).  ORR = 38%.  Of 21 initial responders, 4 have progressed over the f/u of 7.4 months.  Overall disease control was 76%.  Both folks who had progressed on anti-PD-1 and those with PD-L1 negative status were among the responders.  Based on this result, a new cohort is recruiting.

#6:  The "microbiome" craze is not exactly 'new' as it has taken over the universe! BUT!!!  How much is hype?  How much is real?  How can we drill down on the details?  How can we harness what we know to impact treatments such that patients benefit?  The next 3 posts address this topic.  Now, there's this:

A phase I/II study of live biotherapeutic MRx0518 in combination with pembrolizumab in patients who have progressed on prior anti-PD-1 therapy.  2019 ASCO.  Shubham, Imke, Amishi, et al. J Clin Oncol 37, 2019 (suppl; abstr TPS2670) 

Background: The gut microbiome has emerged as a new therapeutic target to augment the efficacy of immune checkpoint blockade. MRx0518 is a novel, gut microbiome-derived, oral live biotherapeutic, designed to induce a broad immunostimulatory response to re-engage PD-1 inhibitor activity. Preclinical studies showed that MRx0518 reduced tumour growth in models of kidney, lung and breast cancer. MRx0518 increased CD4 and CD8 T cell and NK cell infiltration into the tumour and decreased Tregs. Upregulation of tumour TLR5 was observed and linked to the bacterial flagellin moiety, which was shown to strongly induce NFκB, cytokine responses and IFNγ+ CD4 and CD8 T cells. The study, one of the first oncology trials conducted with live biotherapeutics, is a single center, open label, safety and preliminary efficacy study of MRx0518 in combination with pembrolizumab in patients with solid tumors who have progressed on PD-1 inhibitors. Methods: Trial consists of 2 parts. In Part A, 12 patients receive pembrolizumab 200 mg every 3 weeks plus 1 capsule (bid) of MRx0518 with a DLT period of 1 cycle (21 days). In Part B, up to 30 patients per cohort (NSCLC, Urothelial, Renal and Melanoma) will receive pembrolizumab 200 mg every 3 weeks plus 1 capsule (bid) of MRx0518 for up to 35 cycles or until disease progression per RECIST 1.1. The primary end points are safety and tolerability of MRx0518 in combination with pembrolizumab (Parts A and B) and clinical benefit of MRx0518 in combination with pembrolizumab (Part B). Secondary end points are objective response rate, duration of response, disease control rate, and progression-free survival. Exploratory end points include biomarkers of treatment effect, effect on microbiota and overall survival. Recruitment is ongoing. Clinical trial information: NCT03637803

Here, researchers are going to give the first 12 patients with solid tumors who have progressed on anti-PD-1, Pembro every 3 weeks along with a capsule of MRx0518, a "live biotherapeutic", taken by mouth, twice a day for one 21 day cycle.  In part b, the plan is that 30 patients could be given the same for up to 35 cycles or until disease progression.  My only concern here would be the fact that we've found that folks who took probiotics from a bottle did not do so well, while those that got their cooties from foods like Kefir, kimchi, yogurt, sauerkraut, etc. - did better.  If I were to consider participation in this study, I'd be asking my doc about that.

#7:  As I noted above, these last two reports are more along the lines of ~ "What once was old is new again!" I've been talking about the Cooties in our Gut since 2015, putting it all together in this post from 2018:  Microbes again...and how they may be associated with improved response to anti-PD-1 for melanoma patients...and you might even laugh!!!  Still, there is much we don't understand about how all this works.  Now, there's this:

Gut microbiota dependent anti-tumor immunity restricts melanoma growth in Rnf5-/- mice.  Li, Tinoco, Elmen, et al.  Nat Commun. 2019 Apr 2.

Accumulating evidence points to an important role for the gut microbiome in anti-tumor immunity. Here, we show that altered intestinal microbiota contributes to anti-tumor immunity, limiting tumor expansion. Mice lacking the ubiquitin ligase RNF5 exhibit attenuated activation of the unfolded protein response (UPR) components, which coincides with increased expression of inflammasome components, recruitment and activation of dendritic cells and reduced expression of antimicrobial peptides in intestinal epithelial cells. Reduced UPR expression is also seen in murine and human melanoma tumor specimens that responded to immune checkpoint therapy. Co-housing of Rnf5-/- and WT mice abolishes the anti-tumor immunity and tumor inhibition phenotype, whereas transfer of 11 bacterial strains, including B. rodentium, enriched in Rnf5-/- mice, establishes anti-tumor immunity and restricts melanoma growth in germ-free WT mice. Altered UPR signaling, exemplified in Rnf5-/- mice, coincides with altered gut microbiota composition and anti-tumor immunity to control melanoma growth.

So, a lot of fancy words to say that mice with a certain microbiome component (less UPR expression) responded better to immunotherapy.  Further, when those mice lived with mice whose gut initially did not possess those properties, researchers found that they too developed an altered gut flora and a greater ability to restrict the growth of melanoma.  Bottom line:  Live with somebody who has the right cooties!  (If you can figure out who exactly that is!!!)

#8:  Given the fact that a certain "microbiome" aids our responses to immunotherapy while a different one does not, it makes sense that antibiotics, which kill off bacteria that are trying to do us harm as well as those who may do a body good, could be problematic when trying to foster cooties that improve our response to immunotherapy.  Here are some earlier articles and explanations:

This from 2017:  Antibiotic use MAY decrease effectiveness of immunotherapy?????

And this from April of this year:  DECREASED progression free survival in melanoma patients treated with antibiotics prior to or at start of immunotherapy!!!!  In that study it was noted that, despite - "Small numbers. ..the 10 folks, from the 74 advanced melanoma peeps examined, who were given antibiotics within 30 days of their immunotherapy, had more resistance to treatment, a shorter length of progression free survival (2.4 vs 7.3 months) and overall survival was shorter at 10.7 months vs 18.3 months." 

Now, there's this:

Effect of antibiotic exposure in patients with metastatic melanoma treated with PD-1 inhibitor or CTLA-4 inhibitor or a combination of both.  2019 ASCO. Kapoor, Runnels, Boyce, et al.  J Clin Oncol 37, 2019 (suppl; abstr e14141)

Background: Pre clinical studies have demonstrated the effect of gut microbiome in the efficacy of immune check point inhibitors. The effect of antibiotic exposure to patients receiving PD-1/CTLA-4 inhibitor therapy has not been extensively studied, especially in metastatic melanoma. In this study, we demonstrate the effect of antibiotic exposure to metastatic melanoma patients receiving PD-1/CTLA-4 inhibitor therapy. Methods: We performed a retrospective analysis of 108 patients with stage 4 metastatic melanoma who received immunotherapy with PD-1 inhibitors or CTLA-4 inhibitors or combination of both between Nov 2010 and Oct 2017. Patients were divided into Abx(+) and Abx(-) groups that were defined as patients exposed or not exposed to antibiotics respectively. The time frame for antibiotic exposure was taken from 6 months prior to 1 month after initiation of immunotherapy. We compared progression free survival (PFS), overall survival (OS) and response rate (RR) between the two groups. RR was calculated based on the entire length of follow-up.  Results: Out of 108 patients, 66 were men, with a mean age 64.6 ± 15.1 years. 46 patients were exposed to antibiotics of varied classes. Median PFS in abx(+) group [88 days] was shorter as compared to abx(-) group [322 days]. Patients in abx(-) group had a 68% reduced risk of progression within 200 days of immunotherapy initiation adjusting for sex, age and number of immunotherapy cycles . Median OS in ab(+) group [294 days] was shorter as compared to abx(-) group [573 days]. Response rate defined as percentage of patients whose cancer was stable or entered remission was 12.9% in abx(-) group as compared to 8.7% ab(+) group. Patients in abx(-) group had a 52% reduced risk of death adjusting for sex, age and number of immunotherapy cycles. Conclusions: Antibiotic exposure is associated with poorer outcomes in patients with advanced metastatic melanoma being treated with PD-1/CTLA-4 inhibitors which is likely related to alteration of gut microbiome. Antibiotics should be prescribed with caution in patients undergoing treatment with immune check point inhibitors. These data should be validated in a larger patient population.

In this retrospective study of 108 melanoma patients treated with immunotherapy, it was noted that 46 were given antibiotics at some point between 6 months prior and 1 month after starting their immunotherapy treatment.  PFS was 88 days in those who took antibiotics and 322 days in the group who didn't.  OS was 294 days in the antibiotic group - 573 days in the non-antibiotic group.  Response rate was 8.7% in the group that had taken antibiotics vs 12.9% in the group that had not been exposed to antibiotics.  As I wrote in the post I put up in April:  "So...if you really NEED antibiotics, they may save your life and will certainly decrease misery. BUT, if you DON'T really NEED them...they can cause harm, in lots of ways."

WHEW!!!  Melanoma is a lot.  A lot of crap.  And an actual crap shoot for far too many!  But, just like today...


...there is still beauty, despite the storm.

More to come. c

4 comments:

  1. I'm new to your blog and new to metastatic melanoma, too. Diagnosis was June 5 and my first Keytruda infusion is tomorrow, June 25. No need to tell you what the last few weeks have been like. My mind is still a whirlwind of activity.
    I want to thank you for writing this blog and sharing so much of your life with us. You have helped me and I've only been here an hour!
    You have a new fan from San Diego, CA.

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    1. Sorry you have the need. But glad to be of help. The search bubble is your friend. I wish you my best. c

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  2. Went through TIL 6 weeks ago (my 7th clinical trial ) Wasn't that bad a little vomiting some rigors well worth it

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  3. Sorry you had to do it! But, good for you! Way to gut it out!!!

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