Aadi Bioscience, Inc. reported results from a planned interim analysis on the first third of participants in the ongoing tumor-agnostic PRECISION1 trial evaluating nab-sirolimus in patients with TSC1 or TSC2 inactivating alterations. The interim analysis includes data from the first third of trial participants (n=40) with a minimum of 4.5 months of follow-up, including investigator-assessed response and safety analyzed separately in each of the TSC1 and TSC2 arms. Nine different tumor types were enrolled in the TSC1 arm and 13 tumor types were enrolled in the TSC2 arm. Efficacy of nab-sirolimus in patients with tumors harboring pathogenic inactivating alteration in TSC1: Of the 22 patients enrolled, 19 patients received = 1 post baseline scan and were evaluable for efficacy.

Observations included: A 26% Overall Response Rate (ORR) including 5 partial responses (PR) with 4 confirmed responses and 1 unconfirmed response (uPR); All responses were ongoing at the time of data cutoff. The patient with uPR remains on treatment and is awaiting a confirmatory scan; 9 patients had stable disease (SD), 3 of which were greater than or equal to six months in duration, resulting in a clinical benefit rate of 42% (5 PR + 3 SD = 6 mos); Patients were heavily pre-treated with median of 3 prior lines of therapy; Median time to response was 1.4 months; Responses were seen across four different epithelial carcinomas; 60% of responders experienced > 50% tumor reduction. Efficacy of nab-sirolimus in patients with tumors harboring pathogenic inactivating alteration in TSC2: Of the 18 patients enrolled, all 18 patients received = 1 post baseline scan and were evaluable for efficacy.

Observations included: An 11% ORR including 2 PRs with 1 confirmed and 1 uPR; 12 patients had SD, 3 of which were greater than or equal to six months resulting in a clinical benefit rate of 28% (2 PR + 3 SD = 6 mos); Patients were heavily pre-treated with median of 3.5 prior lines of therapy; 50% had = 5 prior lines of therapy; Responses were seen in one epithelial carcinoma and one sarcoma. No new safety signals were observed, and no grade four treatment-related events or deaths occurred. One patient discontinued the study due to grade two pneumonitis that completely resolved after discontinuation of therapy.

Across both arms, the safety profile was consistent with the nab-sirolimus label and the mTOR inhibitor drug class. 80 patients are currently enrolled in the PRECISION1 trial, supporting the two-thirds interim analysis expected in the third quarter of 2024. The ORR analysis in this cohort will be based on independent radiological review with a minimum of six months of follow-up for all patients.

The trial is expected to be completed by the end of 2024 with results anticipated in early 2025.