Colitis in melanoma patients treated with immunotherapy - biopsies to check bowel that looks normal may be important!

Colitis is unfortunately a fairly common, and sometimes persistent, side effect folks treated with immunotherapy deal with.  This may be helpful to those with symptoms who keep getting told their bowel "looks fine"!!!

Five-year review of corticosteroid duration and complications in the management of immune checkpoint inhibitor-related diarrhoea and colitis in advanced melanoma.  Favara, Au, Clark, et al.  ESMO Open.  July 2020.

Background: Immune-related diarrhoea/colitis (ir-D/C) is a common adverse event of immune checkpoint inhibitor (ICI) therapy. Guidelines recommend corticosteroid (CS) treatment; however, the average treatment duration for ir-D/C remains poorly defined.

Methods: All advanced melanoma patients treated with ICI therapy at the Royal Marsden Hospital between 2011 and 2016 were reviewed to identify ir-D/C cases alongside clinical variables. 

Results: 117 any-grade ir-D/C episodes occurred in 109 (21%) patients out of a total of 519 patients treated (ipilimumab=77 episodes, anti-PD1=17 (nivolumab or pembrolizumab), ipilimumab and nivolumab=23 (ipi+nivo)) (seven patients had ir-D/C more than once on different lines of treatment) and greater than/=grade 3 ir-D/C occurred most frequently (63/519 patients (12%) vs 29/519 (5%) grade 1, and 25/519 (5%) grade 2). Median onset (days) of all-grade ir-D/C after starting ICI therapy was 41 for ipilimumab (IQR 24 to 59, n=77), 91 for anti-PD1 (IQR 46 to 355, n=17) and 45 for ipi+nivo (IQR 24 to 67, n=23). In 71/117 (61%) patients, ir-D/C episodes were treated with CS (17% grade 2; 79% grade 3/4): 54 being steroid-responsive; 17 being steroid-refractory and received additional anti-tumor necrosis factor (TNF) treatment. Median grade 3 ir-D/C CS duration was similar across treatments, averaging 58 days. Median overall CS duration (days) was longer in the grade 3/4 D/C steroid-refractory group (94 vs 45 days). Infection developed in 11/71 (15%) CS recipients and in 6/17 (35%) anti-TNF recipients. In 65/117 (55%) patients, ir-D/C episodes were investigated with flexible sigmoidoscopy. Of these patients, 38/65 (58%) had macroscopic colitis and 12/65 (18%) had microscopic colitis. The steroid-refractory group had more macroscopic changes, 13/17 (76%), than the steroid-responsive group, 22/41 (54%). 

Conclusion: Rates of grade 3 ir-D/C were higher than reported in clinical trials. The 58-day median duration of CS therapy for grade 3 ir-D/C places a significant number of patients at risk of complications. We demonstrate that microscopic colitis is an important subgroup, advocating biopsies in ir-D/C even with macroscopically normal bowel.

For what it's worth. - c

Late addition.  Not really news, but ~

Workup and Management of Immune-Mediated Colitis in Patients Treated with Immune Checkpoint Inhibitors.  Singh, Marshall, He.  Oncologist. 2020 Mar;25.

As the use of immune checkpoint inhibitors for several different malignancies becomes more mainstream, their side-effect profile raises new challenges. In 2011, the Food and Drug Administration approved the first checkpoint inhibitor for the treatment of advanced melanoma, and since then, checkpoint inhibitors have demonstrated efficacy in many other tumor types. Given the frequent use of immune checkpoint inhibitors in a wide range of cancers today, the diagnosis and management of their immune-mediated toxicities need special attention. One of the most common is immune-mediated colitis. Workup and management of immune-mediated colitis can be challenging and is the purpose of this review. KEY POINTS: Rate of immune mediated colitis differ from different kind of immune checkpoint inhibitor treatment. To work up immune-mediated colitis, tests to rule out infectious etiologies of diarrhea, colonoscopy and abdominal image will help to differentiate immune mediated colitis from colitis from other etiology. Patients with mild colitis can be managed with supportive therapies alone, but more severe cases may require immunomodulators such as steroid. Refractory cases may require tumor necrosis factor (TNF) inhibitors, such as infliximab in addition to steroid treatment.

- c