Faculty Bibliography

BACKGROUND:Outcomes in advanced anal squamous cell carcinoma are poor, with few treatment options and controlled clinical trials. We evaluated the efficacy and safety of pembrolizumab in patients with advanced anal squamous cell carcinoma (cohort A) from the phase 2 KEYNOTE-158 study. METHODS:Eligible patients enrolled in the ongoing non-randomised, multicohort, multicentre, phase 2 KEYNOTE-158 study, which was done across 38 centres worldwide, were aged 18 years or older; had histologically or cytologically confirmed advanced or metastatic anal squamous cell carcinoma; had previous failure of or intolerance to standard therapy or no standard therapy options; and had a PD-L1-evaluable tissue sample. Patients received pembrolizumab 200 mg intravenously every 3 weeks for 2 years, or until disease progression, unacceptable toxicity, investigator's decision to withdraw the patient from the study, or withdrawal of patient consent. The primary endpoint was objective response, as assessed by Response Evaluation Criteria in Solid Tumors version 1.1. Efficacy and safety analyses included all patients who received at least one dose of pembrolizumab. The trial is registered with ClinicalTrials.gov, NCT02628067. FINDINGS/RESULTS:Between March 3, 2016, and July 23, 2018, 163 patients were screened, of whom 112 were enrolled and treated in the anal cancer cohort. 91 (81%) patients were female, 104 (93%) had M1 disease, and 75 (67%) had PD-L1-positive tumours. The median time from first dose to data cutoff (June 27, 2019) was 34·7 months (IQR 32·5-36·4). 12 (11%, 95% CI 6-18) patients had an objective response, including 11 (15%, 8-25) of 75 patients with PD-L1-positive tumours and one (3%; 0-17) of 30 patients with PD-L1-negative tumours. 68 (61%) patients had treatment-related adverse events (20 [18%] patients had grade 3-4 adverse events), the most common of which were fatigue (17 patients), diarrhoea (13), hypothyroidism (13), and nausea (13). Serious treatment-related adverse events occurred in 12 (11%) patients. 25 (22%) patients had immune-mediated adverse events, and one (1%) had an infusion reaction. There were no treatment-related deaths. INTERPRETATION/CONCLUSIONS:Pembrolizumab monotherapy is a possible treatment option with a favourable benefit-risk ratio for patients with previously treated advanced anal squamous cell carcinoma who have no alternative satisfactory treatment options. FUNDING/BACKGROUND:Merck Sharp & Dohme.

Sarcomatoid hepatocellular carcinoma (SHCC) is a rare variant of liver cancer that lacks treatment options. The IMbrave trail demonstrated the efficacy of atezolizumab and bevacizumab (A + B) in patients with unresectable hepatocellular carcinoma but excluded patients with sarcomatoid variants. Herein, we describe a case of disease control achieved using the IMbrave regimen in a patient with sarcomatoid hepatocellular carcinoma.

INTRODUCTION/BACKGROUND:Microsatellite instability (MSI) testing and tumor mutational burden (TMB) are genomic biomarkers used to identify patients who are likely to benefit from immune checkpoint inhibitors. Pembrolizumab was recently approved by the Food and Drug Administration for use in TMB-high (TMB-H) tumors, regardless of histology, based on KEYNOTE-158. The primary objective of this retrospective study was real-world applicability and use of immunotherapy in TMB/MSI-high patients to lend credence to and refine this biomarker. METHODS:Charts of patients with advanced solid tumors who had MSI/TMB status determined by next generation sequencing (NGS) (FoundationOne CDx) were reviewed. Demographics, diagnosis, treatment history, and overall response rate (ORR) were abstracted. Progression-free survival (PFS) was determined from Kaplan-Meier curves. PFS1 (chemotherapy PFS) and PFS2 (immunotherapy PFS) were determined for patients who received immunotherapy after progressing on chemotherapy. The median PFS2/PFS1 ratio was recorded. RESULTS:MSI-high or TMB-H [≥20 mutations per megabase (mut/MB)] was detected in 157 adults with a total of 27 distinct tumor histologies. Median turnaround time for NGS was 73 days. ORR for most recent chemotherapy was 34.4%. ORR for immunotherapy was 55.9%. Median PFS for patients who received chemotherapy versus immunotherapy was 6.75 months (95% confidence interval, 3.9-10.9 months) and 24.2 months (95% confidence interval, 9.6 months to not reached), respectively (P = 0.042). Median PFS2/PFS1 ratio was 4.7 in favor of immunotherapy. CONCLUSION/CONCLUSIONS:This real-world study reinforces the use of TMB as a predictive biomarker. Barriers exist to the timely implementation of NGS-based biomarkers and more data are needed to raise awareness about the clinical utility of TMB. Clinicians should consider treating TMB-H patients with immunotherapy regardless of their histology.