Citius Oncology has announced positive topline results from an investigator-initiated Phase I clinical trial evaluating the combination of LYMPHIR (denileukin diftitox-cxdl) and Keytruda (pembrolizumab) in patients with recurrent or refractory gynecologic cancers. The study was conducted by researchers at the University of Pittsburgh.

The trial assessed the ability of LYMPHIR to deplete regulatory T cells (Tregs) when combined with the PD-1 immune checkpoint inhibitor Keytruda. The treatment was tested in patients with relapsed or treatment-resistant gynecologic malignancies, including Ovarian Cancer and Endometrial Cancer, where therapeutic options remain limited.

The dose-escalation Phase I trial aimed to determine the recommended dose of LYMPHIR in combination with pembrolizumab for a future Phase II study. Among 25 evaluable patients enrolled in the study, investigators reported no unexpected safety signals or serious immune-related adverse events at any tested dose levels.

Preliminary efficacy results also showed promising outcomes. Among 21 evaluable patients, the combination therapy achieved an objective response rate of 24 percent and a clinical benefit rate (CBR) of 48 percent. Clinical benefit included patients who achieved complete response, partial response or stable disease lasting at least six months.

Researchers observed signs that combining LYMPHIR with Keytruda may enhance anti-tumour immune responses, particularly in heavily pretreated patients who had previously exhausted standard treatment options.

According to company officials, the favourable safety profile and early efficacy signals support further investigation of the therapy combination in larger studies. The results are expected to guide the design of a Phase II clinical trial evaluating the regimen in patients with recurrent gynecologic cancers.

Detailed findings from the trial, including safety and efficacy analyses, are expected to be presented at an international oncology conference later this year.