Citius Oncology reports promising early data for LYMPHIR combination at ASCO

Citius Oncology (NASDAQ:CTOR) showcased positive early-stage clinical trial results, demonstrating the potential of its targeted immune therapy LYMPHIR to enhance the efficacy of checkpoint inhibitors in treating recurrent or refractory gynecologic cancers.

The data, derived from an investigator-initiated Phase 1 study led by researchers at the University of Pittsburgh Medical Center (UPMC) Magee-Womens Hospital, was featured as a poster presentation at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting.

The trial examined the safety and preliminary anti-tumor activity of LYMPHIR (denileukin diftitox-cxdl) administered in tandem with the PD-1 immune checkpoint inhibitor pembrolizumab.

Among the 21 efficacy-evaluable patients in the study—a heavily pre-treated cohort battling recurrent or metastatic solid tumors, primarily gynecologic malignancies—the dual-immunotherapy regimen achieved a 24% overall response rate.

Furthermore, the combination delivered a 48% clinical benefit rate, meaning nearly half of the evaluable participants achieved stable disease or tumor shrinkage.

For the subset of patients experiencing a clear clinical benefit, the median progression-free survival reached 20.5 months, signaling a durable response in a difficult-to-treat oncology segment where conventional treatments face significant resistance challenges.

The combination therapy also demonstrated a favorable and manageable tolerability profile, with investigators reporting no new or unexpected safety signals during the evaluation window.

LYMPHIR's primary mechanism of action relies on transiently depleting immunosuppressive regulatory T-cells within the tumor microenvironment.

Management notes that by clearing these protective barriers, the agent effectively helps address immune resistance and enhance the surrounding therapeutic response of checkpoint inhibitors.

Based on the encouraging clinical signals and stable baseline safety metrics achieved during this initial phase, a Phase 2 expansion is planned to continue testing the chemo-free immunomodulatory approach.