Oncology-focused biopharmaceutical company Citius Oncology Inc (Nasdaq:CTOR), a majority-owned subsidiary of Citius Pharmaceuticals Inc (Nasdaq:CTXR), on Tuesday reported positive topline results from a completed investigator-initiated Phase 1 clinical trial conducted by University of Pittsburgh investigators.

This study evaluated the direct T-regulatory (Treg) cell depletion activity of LYMPHIR (denileukin diftitox-cxdl) in combination with the PD-1 immune checkpoint inhibitor pembrolizumab (KEYTRUDA) in patients with recurrent or refractory gynaecologic cancers, including ovarian and endometrial malignancies.

The dose-escalation Phase 1 non-chemotherapy based clinical study aimed to establish a recommended dose of LYMPHIR in combination with pembrolizumab for a Phase 2 study. In 25 evaluable patients, no unexpected safety signals or serious immune-related adverse events were observed at any dose level.

In terms of efficacy, the trial demonstrated a 24% objective response rate (ORR) and a 48% clinical benefit rate (CBR, defined as complete response, partial response and/or stable disease for six months or greater) among 21 evaluable patients.

Full safety and clinical efficacy results are expected to be presented at an international cancer conference later this year.