Faeth Therapeutics (NASDAQ:FTH) reported preliminary Phase 2 clinical results showing a confirmed objective response rate of 33% for its investigational PIKTOR treatment combined with paclitaxel in patients with advanced endometrioid endometrial cancer.
The biotechnology company also reported a disease control rate of 83% and preliminary median progression-free survival of 7.4 months in its ongoing PIK-201 trial.
Based on the findings, Faeth plans to advance PIKTOR into a Phase 3 registrational study, subject to regulatory discussions.
Phase 2 Trial Reports 33% Confirmed Response Rate
The open-label, single-arm PIK-201 study is evaluating PIKTOR, an oral combination of serabelisib and sapanisertib, alongside paclitaxel in patients with advanced endometrial cancer carrying mutations in the PI3K/AKT/mTOR pathway.
The trial is being conducted in collaboration with The GOG Foundation.
As of the October 30, 2026 data cutoff, confirmed objective responses were observed in 12 of 36 efficacy-evaluable patients, representing a response rate of 33%.
Among patients with a PIK3CA mutation, the confirmed response rate reached 44%, with seven responses among 16 patients.
The disease control rate, which includes complete responses, partial responses and stable disease, was 83%.
Across all 42 treated patients, preliminary median progression-free survival was estimated at 7.4 months, while the six-month progression-free survival rate was 62%.
Sixteen patients remained on treatment at the data cutoff.
Safety Results Show 5% Treatment Discontinuation Rate
Faeth reported that the PIKTOR and paclitaxel combination was generally tolerated, although 64% of patients experienced treatment-related adverse events of Grade 3 or higher.
Neutropenia was the most frequently reported severe treatment-related adverse event, occurring at Grade 3 or higher in 26% of patients.
Treatment-related hyperglycemia occurred in 12% of patients, including one Grade 3 event, while stomatitis was reported in 21%, also including one Grade 3 event.
Two patients, representing 5% of the study population, discontinued treatment because of treatment-related adverse events. No treatment-related deaths were reported.
Nearly half of the participants had diabetes or prediabetes at baseline, while 76% had distant metastases.
Patients had received a median of two previous lines of therapy, and 98% had previously undergone immunotherapy.
Faeth Plans Phase 3 Development
Faeth said the preliminary findings support further evaluation of PIKTOR in a Phase 3 registrational trial.
Chief Executive Officer Anand Parikh said the company believes targeting multiple components of the PI3K/AKT/mTOR pathway could provide a treatment approach for patients with advanced endometrial cancer.
The company intends to proceed with Phase 3 planning following discussions with regulatory authorities.
The Phase 2 study remains ongoing, and the reported efficacy and safety findings are preliminary.
As a single-arm trial without a control group, PIK-201 does not establish how the treatment compares directly with other available therapies.
PIKTOR remains investigational and is also being developed for potential use in breast cancer.