First-Line Nivolumab Plus Low-Dose Ipilimumab for Microsatellite Instability-High/Mismatch Repair-Deficient Metastatic Colorectal Cancer: The Phase II CheckMate 142 Study.

PURPOSE: Nivolumab received US Food and Drug Administration approval as a single agent or in combination with ipilimumab in patients with microsatellite instability-high/mismatch repair-deficient (MSI-H/dMMR) metastatic colorectal cancer (mCRC) that progressed following treatment with a fluoropyrimidine, oxaliplatin, and irinotecan based on CheckMate 142. Presented are results of nivolumab plus low-dose ipilimumab in the first-line therapy cohort from the phase II CheckMate 142 study. PATIENTS AND METHODS: Patients with no prior treatment in the metastatic setting for MSI-H/dMMR CRC were treated with nivolumab every 2 weeks plus low-dose ipilimumab every 6 weeks until disease progression. The primary end point was objective response rate (investigator assessment; RECIST v1.1). RESULTS: Median age of treated patients was 66 years (N = 45). Median follow-up was 29.0 months. Objective response rate and disease control rate were 69% (95% CI, 53 to 82) and 84% (95% CI, 70.5 to 93.5), respectively, with 13% complete response rate. Median duration of response was not reached; 74% of responders had ongoing responses at data cutoff. Median progression-free survival and median overall survival were not reached with minimum follow-up of 24.2 months (24-month rates, 74% and 79%, respectively). Clinical benefit was observed regardless of baseline demographic and tumor characteristics, including BRAF or KRAS mutation status. In a post hoc analysis, of 14 patients who discontinued treatment and did not receive subsequent therapy, 10 remained progression-free. Patient-reported outcomes were stable over the treatment period. Grade 3-4 treatment-related adverse events occurred in 22% of patients; 13% discontinued because of any-grade treatment-related adverse events. CONCLUSION: Nivolumab plus low-dose ipilimumab demonstrated robust and durable clinical benefit and was well tolerated as a first-line treatment for MSI-H/dMMR mCRC. Based on these promising data, randomized studies are warranted.

Overview of Causality Assessment for Drug-Induced Liver Injury (DILI) in Clinical Trials.

Causality assessment for suspected drug-induced liver injury (DILI) during drug development and following approval is challenging. The IQ DILI Causality Working Group (CWG), in collaboration with academic and regulatory subject matter experts (SMEs), developed this manuscript with the following objectives: (1) understand and describe current practices; (2) evaluate the utility of new tools/methods/practice guidelines; (3) propose a minimal data set needed to assess causality; (4) define best practices; and (5) promote a more structured and universal approach to DILI causality assessment for clinical development. To better understand current practices, the CWG performed a literature review, took a survey of member companies, and collaborated with SMEs. Areas of focus included best practices for causality assessment during clinical development, utility of adjudication committees, and proposals for potential new avenues to improve causality assessment. The survey and literature review provided renewed understanding of the complexity and challenges of DILI causality assessment as well as the use of non-standardized approaches. Potential areas identified for consistency and standardization included role and membership of adjudication committees, standardized minimum dataset, updated assessment tools, and best practices for liver biopsy and rechallenge in the setting of DILI. Adjudication committees comprised of SMEs (i.e., utilizing expert opinion) remain the standard for DILI causality assessment. A variety of working groups continue to make progress in pursuing new tools to assist with DILI causality assessment. The minimum dataset deemed adequate for causality assessment provides a path forward for standardization of data collection in the setting of DILI. Continued progress is necessary to optimize and advance innovative tools necessary for the scientific, pharmaceutical, and regulatory community.