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Background: PD-1 and CTLA-4 inhibitors are associated with several adverse events including a spectrum of immune-related adverse effects (irAEs). Neurologic irAEs are uncommon occurrences with varied presentations. We describe two separate cases of ipilimumab associated meningoencephalomyelitis and demyelinating polyneuropathy with unusual presentations., Case Presentation: Two melanoma patients were treated with ipilimumab in the adjuvant setting. The first patient developed a meningoencephalitis following 3 doses of ipilimumab. MRI imaging of the brain confirmed leptomeningeal enhancement although cerebrospinal fluid (CSF) analyses were negative for malignant cells consistent with meningoencephalomyelitis. Although she initially improved following treatment with steroids and intravenous immunoglobulin, she subsequently relapsed. She was successfully treated with infliximab and made a complete neurological recovery. A second patient developed progressive lower extremity weakness following two doses of ipilimumab. MRI imaging of the spine confirmed diffuse nerve root enhancement consistent with acute inflammatory demyelinating polyneuropathy (AIDP). He was treated with high dose steroids with resolution of neurological symptoms. Both patients remain disease free., Conclusions: Neurological irAEs are uncommon adverse events in the context of CTLA-4 and/or PD-1 inhibitor therapy. Care must be taken to distinguish these from leptomeningeal disease. Early recognition of neurological irAEs is critical for the initiation of specific anti-inflammatory agents to prevent and potentially reverse neurological sequelae.

PurposeCombination programmed cell death protein 1/cytotoxic T-cell lymphocyte-4-blockade and dual BRAF/MEK inhibition have each shown significant clinical benefit in patients with BRAFV600-mutant metastatic melanoma, leading to broad regulatory approval. Little prospective data exist to guide the choice of either initial therapy or treatment sequence in this population. This study was conducted to determine which initial treatment or treatment sequence produced the best efficacy.Patients and methodsIn a phase III trial, patients with treatment-naive BRAFV600-mutant metastatic melanoma were randomly assigned to receive either combination nivolumab/ipilimumab (arm A) or dabrafenib/trametinib (arm B) in step 1, and at disease progression were enrolled in step 2 to receive the alternate therapy, dabrafenib/trametinib (arm C) or nivolumab/ipilimumab (arm D). The primary end point was 2-year overall survival (OS). Secondary end points were 3-year OS, objective response rate, response duration, progression-free survival, crossover feasibility, and safety.ResultsA total of 265 patients were enrolled, with 73 going onto step 2 (27 in arm C and 46 in arm D). The study was stopped early by the independent Data Safety Monitoring Committee because of a clinically significant end point being achieved. The 2-year OS for those starting on arm A was 71.8% (95% CI, 62.5 to 79.1) and arm B 51.5% (95% CI, 41.7 to 60.4; log-rank P = .010). Step 1 progression-free survival favored arm A (P = .054). Objective response rates were arm A: 46.0%; arm B: 43.0%; arm C: 47.8%; and arm D: 29.6%. Median duration of response was not reached for arm A and 12.7 months for arm B (P < .001). Crossover occurred in 52% of patients with documented disease progression. Grade ≥ 3 toxicities occurred with similar frequency between arms, and regimen toxicity profiles were as anticipated.ConclusionCombination nivolumab/ipilimumab followed by BRAF and MEK inhibitor therapy, if necessary, should be the preferred treatment sequence for a large majority of patients.

Background: Preclinical and translational evidence suggest BRAF/MEK inhibitors modulate the tumor microenvironment (TME), providing rationale for combination with immunotherapy. Methods: This investigator-initiated, phase I trial evaluated pembrolizumab, vemurafenib, and cobimetinib in patients with untreated, BRAFV600E/K mutant advanced melanoma. The first 4 patients received vemurafenib with pembrolizumab, and the next 5 patients received vemurafenib and cobimetinib with pembrolizumab. Primary endpoints: safety and maximum tolerated dose of the triplet. Secondary endpoints: objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and quality of life (QoL). The trial was closed after enrollment of 9 (planned 30) patients due to dose-limiting toxicity (DLT). Study NCT02818023 was approved by the IRB, and all patients provided informed consent. Results: Patients received a median of 6 cycles of therapy. 8 of 9 experienced drug-related grade 3/4 AEs. DLTs included dermatitis (n=8), hepatitis (n=1), QTc prolongation (n=1), and arthralgias (n=1 each). QoL assessments identified a clinically significant decrease in self assessed QoL at 1 year compared to baseline (0.38 v 0.43). Median PFS was 20.7 months and median OS was 23.8 months for vemurafenib with pembrolizumab. Median PFS and OS were not reached for patients receiving triple therapy. ORR in the overall cohort was 78% (7/9). 2 patients experienced a complete response, 5 had a partial response, 1 had stable disease, and 1 had progressive disease. 4 patients had ongoing responses at data analysis. Peripheral blood flow cytometry identified significantly decreased PD1 expression on CD4+ T-cells at 3 and 9 weeks compared to baseline, not corresponding to clinical response. Conclusions: Triple therapy with vemurafenib, cobimetinib and pembrolizumab is associated with high response rates but significant adverse events, leading to early study closure. [ABSTRACT FROM AUTHOR]