Sutro Biopharma Posts Updated Data From Ovarian Cancer Candidate

Sutro Biopharma Inc STRO announced results from a Phase 1 dose-expansion study of STRO-002 (luvelta) and interim safety data from exploratory cohort C of advanced ovarian cancer treated at the higher dose of luvelta (5.2mg/kg), along with prophylactic pegfilgrastim.
Results demonstrated that luvelta provided substantial clinical benefit, with a 37.5% overall response rate (ORR), a median duration of response (median DOR) of 5.5 months, and median progression-free survival (median PFS) of 6.1 months, regardless of starting dose.
Results also demonstrated that the higher starting dose of 5.2 mg/kg provides greater patient benefit than the lower dose of 4.3mg/kg.
Consistent with prior luvelta data, the primary adverse event from the dose-expansion cohort was predominantly asymptomatic neutropenia, with no meaningful ocular toxicity signals or complications reported.
In cohort C, an additional 15 patients with advanced ovarian cancer were enrolled and treated with prophylactic pegfilgrastim on Day 8 after each 5.2 mg/kg administration of luvelta. Initial data on neutropenia and dose delays were available on the first ten patients. This showed that patients in cohort C experienced substantial decreases in neutropenia and potential increases in dose intensity due to decreased dose delays.
Sutro plans to initiate a Phase 2/3 registration-directed study called REFRaME in the second quarter of 2023.
Price Action: STRO shares closed at $8.29 on Monday.