A Phase II Trial of the WEE1 Inhibitor Adavosertib in SETD2-Altered Advanced Solid Tumor Malignancies (NCI 10170).

PURPOSE:Evaluate the efficacy of WEE1 inhibitor adavosertib in patients (pts) with solid tumor malignancies (cohort A) and clear cell renal cell carcinoma (ccRCC; cohort B). PATIENTS AND METHODS:NCT03284385 was a parallel cohort, Simon two-stage, phase II study of adavosertib (300 mg QDAY by mouth on days 1-5 and 8-12 of each 21-day cycle) in pts with solid tumor malignancies harboring a pathogenic SETD2 mutation. The primary endpoint was objective response rate (ORR). Correlative assays evaluated loss of H3K36me3 by immunohistochemistry (IHC), a downstream consequence of SETD2 loss, in archival tumor tissue. RESULTS:Eighteen pts were enrolled (9/cohort). Median age was 60 years (range 45 - 74). The median duration of treatment was 1.28 months (range 0 - 24+). No objective responses were observed in either cohort; accrual was halted following stage 1. Minor tumor regressions were observed in 4/18 (22%) evaluable pts. Stable disease (SD) was the best overall response in 10/18 (56%) pts, including three pts with SD >4 months. One pt with ccRCC remains on treatment for >24 months. The most common adverse events (AE) of any grade were nausea (59%), anemia (41%), diarrhea (41%), and neutropenia (41%). Nine pts (50%) experienced a Grade ≥ 3 AE. Of 8 evaluable archival tissue samples, 6 (75%) had loss of H3K36me3 by IHC. CONCLUSIONS:Adavosertib failed to exhibit objective responses in SETD2-altered ccRCC and other solid tumor malignancies though prolonged stable disease was observed in a subset of pts. Combination approaches may yield greater depth of tumor response.