Clifton, Guy T

Abstract Purpose: Familial adenomatous polyposis (FAP) confers a significant risk of colorectal/duodenal cancer. Encapsulated rapamycin (eRapa) has demonstrated promise as FAP chemoprevention in early clinical studies. Patients and Methods: Thirty patients with FAP enrolled to three dosing regimens of eRapa (0.5 mg): cohort 1—every other day, cohort 2—daily every other week, or cohort 3—daily. The primary endpoints were safety/tolerability, pharmacokinetics, and percentage change from baseline (PCFB) in colorectal polyp burden (CPB) at 6 months. Secondary endpoints included PCFB total (TPB) and duodenal (DPB) polyp burden and change in International Society for Gastrointestinal Hereditary Tumors stage and Spigelman score at 6 and 12 months. Results: Twenty nine of thirty patients (97%) completed the 12-month study with predictable bioavailability. Low-grade adverse events were frequent but most pronounced in daily dosing. Two patients discontinued treatment related to toxicity. Cohort 1 had the largest decrease median PCFB CPB, DPB, and TPB at 6 months: −39.4 % (IQR, 108.9; P = 0.28), −33.33 % (IQR, 90; P = 0.04), and −38.6 % (IQR, 88.5; P = 0.26), respectively. At 12 months, cohort 2 had the largest decrease median PCFB CPB and TPB: −29.3 % (IQR, 67.6; P = 0.37) and −26.3 % (IQR, 49.5; P = 0.29), respectively. Intermittent dosing cohorts (1 and 2) reduced DPB at 6 months (P = 0.04) and improved TPB at 12 months (P = 0.05) compared with daily dosing. Conclusions: eRapa was safe, tolerable, and showed preliminary efficacy for FAP chemoprevention. The 0.5 mg daily every-other-week schedule will be evaluated in an upcoming phase III trial.

AbstractBackgroundCheckpoint inhibitors (CPI) in combination with cell‐based vaccines may produce synergistic antitumor immunity. The primary analysis of the randomized and blinded phase IIb trial in resected stage III/IV melanoma demonstrated TLPLDC is safe and improved 24‐month disease‐free survival (DFS) in the per treatment (PT) analysis. Here, we examine efficacy within pre‐specified and exploratory subgroups.MethodsStage III/IV patients rendered disease‐free by surgery were randomized 2:1 to TLPLDC vaccine versus placebo. The pre‐specified PT analysis included only patients completing the primary vaccine/placebo series at 6 months. Kaplan–Meier analysis was used to compare 24‐month DFS among subgroups.ResultsThere were no clinicopathologic differences between subgroups except stage IV patients were more likely to receive CPI. In stage IV patients, 24‐month DFS was 43% for vaccine versus 0% for placebo (p = 0.098) in the ITT analysis and 73% versus 0% (p = 0.002) in the PT analysis. There was no significant difference in 24‐month DFS when stratified by use of immunotherapy or CPI. For patients with resected recurrent disease, 24‐month DFS was 88.9% versus 33.3% (p = 0.013) in the PT analysis. All benefit from vaccination was in the PT analysis; no benefit was found in patients receiving up to three doses.ConclusionThe TLPLDC vaccine improved DFS in patients completing the primary vaccine series, particularly in the resected stage IV patients. The efficacy of the TLPLDC vaccine will be confirmed in a phase III study evaluating adjuvant TLPLDC + CPI versus Placebo + CPI in resected stage IV melanoma patients.