Outcomes of patients with resected stage III/IV acral or mucosal melanoma, treated with adjuvant anti-PD-1 based therapy.

IMPORTANCE: Acral (AM) and mucosal melanomas (MM) are rare subtypes with a poor prognosis. In those with advanced disease, anti-PD-1 (PD1) therapy has reduced activity compared to that seen in non-acral cutaneous melanoma. OBJECTIVE: To determine the efficacy of adjuvant PD1 in resected AM or MM. DESIGN: An international, retrospective cohort study SETTING: Data up to November 2021 collected from 20 centres across 10 countries. PARTICIPANTS: One hundred and ninety four patients with resected stage III or IV1 AM or MM who received adjuvant PD1 were included and compared to matched patients from the Melanoma Institute Australia (MIA) database using a propensity score matching analysis. MAIN OUTCOMES AND MEASURES: Recurrence-free survival (RFS), distant metastasis-free survival (DMFS) and overall survival (OS) were investigated. RESULTS: Forty five of 139 (32%) AM and 9 of 55 (16%) MM patients completed adjuvant therapy. The main reason for early treatment cessation in both groups was disease recurrence: 51 (37%) and 30 (55%) in the AM and MM groups, respectively. In the AM group adjuvant PD1 was associated with a longer RFS [HR-0.69 (0.52-0.92, p = 0.0127)], DMFS [HR0.58 (0.38-0.89, p = 0.0134)] and OS [HR of 0.59 (0.38-0.92, p-value 0.0196)] when compared to the historical cohort. In the MM group there was no statistical difference in RFS [HR1.36 (0.69-2.68,p-value 0.3799], DMFS or OS. CONCLUSION AND RELEVANCE: After adjuvant PD1, both AM and MM have a high risk of recurrence. Our data suggests a benefit to using adjuvant PD1 therapy in resected AM but not in resected MM. Additional studies to investigate the efficacy of adjuvant PD1 for MM are needed.

Efficacy and safety of 'Second Adjuvant' therapy with BRAF/MEK inhibitors after local therapy for recurrent melanoma following adjuvant PD-1 based immunotherapy.

BACKGROUND: Anti-PD-1 antibodies and BRAK/MEK inhibitors (BRAF/MEKi) reduce the risk of recurrence for patients with resected stage III melanoma. BRAFV600-mutated (BRAFmut) melanoma patients who recur with isolated disease following adjuvant therapy may be suitable for 'second adjuvant' treatment after local therapy. We sought to examine the efficacy and safety of 'second adjuvant' BRAF/MEKi. PATIENTS AND METHODS: Patients with BRAFmut melanoma treated with adjuvant PD-1 based immunotherapy who recurred, underwent definitive local therapy and were then treated with adjuvant BRAF/MEKi were identified retrospectively from 13 centres (second adjuvant group). Demographics, disease and treatment characteristics and outcome data were examined. Outcomes were compared to BRAFmut patients who did not receive 'second adjuvant' therapy (no second adjuvant group). RESULTS: 73 patients were included; 61 who received 'second adjuvant' therapy and 12 who did not. Most initially recurred on PD-1 therapy (66%). There were no differences in characteristics between groups. 92% of second adjuvant group received dabrafenib and trametinib and median duration of therapy was 11.8 months (0.4, 34.5). 72% required dose adjustments, 23% had grade 3 + toxicity and 38% permanently discontinued drug due to toxicity. After median 26.1 months (1.9, 56.3) follow-up, recurrence-free survival (RFS) was improved in second adjuvant group versus no second adjuvant group (median 30.8 vs 4 months, HR 0.35; p = 0.014), largely driven by a delay in early recurrence, with no difference in overall survival (p = 0.59). CONCLUSION: This is the first study examining outcomes of 'second adjuvant' targeted therapy for melanoma, after failure of adjuvant PD-1 based immunotherapy. Data suggest a short-term improvement in RFS, but at the cost of toxicity. Alternative strategies and more data on sequencing adjuvant therapies are required to improve outcomes.

Management of infliximab refractory immune checkpoint inhibitor gastrointestinal toxicity: a multicenter case series.

BACKGROUND: Immune checkpoint inhibitor (ICI) gastrointestinal toxicity (gastritis, enteritis, colitis) is a major cause of morbidity and treatment-related death. Guidelines agree steroid-refractory cases warrant infliximab, however best management of infliximab-refractory ICI gastrointestinal toxicity (IRIGItox) is unknown. METHODS: We conducted an international multicenter retrospective case series. IRIGItox was defined as failure of symptom resolution ≤grade 1 (Common Terminology Criteria for Adverse Events V.5.0) following ≥2 infliximab doses or failure of symptom resolution ≤grade 2 after one dose. Data were extracted regarding demographics, steroid use, response to treatment, and survival outcomes. Toxicity was graded at symptom onset and time of infliximab failure. Efficacy of infliximab refractory therapy was assessed by symptom resolution, time to resolution and steroid wean duration. Survival outcomes were examined based on immunosuppressive therapy received. RESULTS: 78 patients were identified: median age 60 years; 56% men; majority melanoma (N=70, 90%); 60 (77%) received anti-cytotoxic T-lymphocyte-associated protein 4 alone or in combination with anti-programmed cell death protein-1 and most had colitis (N=74, 95%). 106 post-infliximab treatments were given: 31 calcineurin inhibitors (CNIs); 27 antimetabolites (mycophenolate, azathioprine); 16 non-systemic immunomodulatory agents (eg, mesalazine or budesonide); 15 vedolizumab; 5 other biologics (anti-interleukin-12/23, 16, Janus kinase inhibitors) and 7 interventional procedures (including colectomy); 5 did not receive post-infliximab therapy. Symptom resolution was achieved in most (N=23/31, 74%) patients treated with CNIs; 12/27 (44%) with antimetabolites; 7/16 (44%) with non-systemic immunomodulation, 8/15 (53%) with vedolizumab and 5/7 (71%) with interventional procedures. No non-vedolizumab biologics resulted in toxicity resolution. CNIs had the shortest time to symptom resolution (12 days) and steroid wean (43 days); however, were associated with poorer event-free survival (6.3 months) and overall survival (26.8 months) than other agents. Conversely, vedolizumab had the longest time to toxicity resolution and steroid wean, 66 and 124 days, but most favorable survival data: EFS 24.5 months; median OS not reached. Six death occurred (three due to IRIGItox or management of toxicity; three with persisting IRIGItox and progressive disease). CONCLUSIONS: IRIGItox causes major morbidity and mortality. Management is heterogeneous. CNIs appear most likely to result in toxicity resolution in the shortest time period, however, are associated with poorer oncological outcomes in contrast to vedolizumab.