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.

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Background/UNASSIGNED:gemcitabine (GEM)-based 3-week chemoradiation (3WCRT) with 36 Gy in 15 fractions. This study aimed to compare the odds of achieving surgical resection, time to progression (TTP), and overall survival (OS) of patients treated with 3WCRT with concurrent CAPE versus GEM. Methods/UNASSIGNED:A retrospective cohort study was conducted, examining medical records from a single center for patients with (B)RPC treated with 3WCRT between 1/2009-12/2020. Odd ratios (OR) of achieving surgical resection were estimated using logistic regression for univariable and multivariable analyses. Median TTP (mTTP) and median OS (mOS) were estimated using the Kaplan-Meier method. Cox proportional hazards analysis was conducted to estimate hazard ratios (HR) of progression and survival in univariable and multivariable analyses. Results/UNASSIGNED:4.0 months, 95% CI: 0.4-14.5; P=0.01), corresponding to a hazard ratio of 0.33 (95% CI: 0.14-0.81). Adjusting for covariates this effect persisted; the adjusted hazard ratio (AHR) for progression was 0.24 (95% CI: 0.08-0.77). Cox proportional hazards analysis also demonstrated that the CAPE group had superior OS compared to the GEM group in unadjusted (HR =0.13; 95% CI: 0.04-0.40) and adjusted models (HR =0.13, 95% CI: 0.03-0.52). Conclusions/UNASSIGNED:For neoadjuvant 3WCRT, this hypothesis-generating study suggests concurrent CAPE may be a more effective radiosensitizer than GEM for patients with (B)RPC.

Hepatocellular carcinoma (HCC) is the predominant form of liver cancer and a leading cause of cancer deaths worldwide. HCC is a male-dominant cancer with a male:female ratio of up to 7:1. The androgen receptor (AR) is the male hormone receptor known as a major oncogenic driver of prostate cancer. Although AR has been linked to the sexual dimorphism of HCC, clinical trials with AR-targeted agents failed to generate survival benefits. Recent studies provide new insights into the role of AR in liver tumorigenesis and therapeutic responses. Herein, we review current understanding of AR signaling in HCC and feedback mechanisms that limit response to AR blockade. New AR-targeting strategies that might improve outcomes in HCC therapies are also discussed.

INTRODUCTION/BACKGROUND:Hepatic artery infusion pump (HAIP) chemotherapy is a specialized therapy for patients with unresectable colorectal liver metastases (uCRLM). Its effectiveness was demonstrated from a high volume center, with uncertainty regarding the feasibility and safety at other centers. Therefore, we sought to assess the safety and feasibility of HAIP for the management of uCRLM at other centers. METHODS:We conducted a multicenter retrospective cohort study of patients with uCRLM treated with HAIP from January 2003 to December 2017 at six North American centers initiating the HAIP program. Outcomes included the safety and feasibility of HAIP chemotherapy. RESULTS:We identified 154 patients with HAIP insertion and the median age of 54 (48-61) years. The burden of disease was >10 intra-hepatic metastatic foci in 59 (38.3%) patients. Patients received at least one cycle of systemic chemotherapy before HAIP insertion. Major complications occurred in 7 (4.6%) patients during their hospitalization and 13 (8.4%) patients developed biliary sclerosis during follow-up. A total of 148 patients (96.1%) received at least one-dose of HAIP chemotherapy with a median of 5 (4-7) cycles. 78 patients (56.5%) had a complete or partial response and 12 (7.8%) received a curative liver resection. CONCLUSION/CONCLUSIONS:HAIP programs can be safely and effectively initiated in previously inexperienced centers with good response.