Abstract
PURPOSE: An unmet treatment need remains for relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL), including the follicular lymphoma (FL), mantle cell lymphoma (MCL), and marginal zone lymphoma (MZL) subtypes. The PI3K/AKT/mTOR pathway is dysregulated and associated with poor prognosis in NHL. The AKT inhibitor capivasertib has preclinical activity in hematologic malignancy models. PATIENTS AND METHODS: NCT05008055 was a modular, open-label, multicenter phase II study that examined oral capivasertib monotherapy in patients with R/R B-cell NHL who had received ≥2 prior lines of therapy. Patients had R/R FL (cohort 1A), MZL (cohort 1B), or MCL (cohort 1C). Capivasertib 480 mg twice daily was administered orally 4 days on/3 days off. The primary objective was to determine the objective response rate (ORR) by blinded independent central review. RESULTS: Thirty patients were enrolled (of 272 planned). The ORR for patients with R/R FL, MZL, and MCL were 18.8% (three of 16), 33.3% (one of three), and 30% (three of 10), respectively; 62.5% (10 of 16) of patients with R/R FL had stable disease. Baseline tumor PTEN expression was deficient/undetectable in the two patients who had a complete response and three of five patients who had a partial response. The most common capivasertib-related adverse events (AE) were diarrhea (63.3%), nausea (20%), vomiting (13.3%), and hyperglycemia (10%). Capivasertib-related grade ≥3 AE or serious AE were observed in nine and three patients, respectively. CONCLUSIONS: The study was terminated early with a small sample size, limiting interpretation, although antitumor activity was limited. Future studies of capivasertib in hematologic malignancies would likely require biomarker-directed patient selection and/or combination therapy.