Biopharmaceutical company Citius Pharmaceuticals Inc (Nasdaq: CTXR) and its majority-owned subsidiary Citius Oncology Inc.(Nasdaq: CTOR) on Monday announced positive preliminary data from a Phase I trial of pembrolizumab and LYMPHIR in patients with recurrent solid tumors.

The study, presented at the Society for Immunotherapy of Cancer 2024 Annual Meeting, showed a 27% overall response rate (ORR) and a 33% clinical benefit rate (CBR), with a median progression-free survival (PFS) of 57 weeks.

Led by Dr Haider Mahdi at the University of Pittsburgh, the trial aims to determine the optimal dose and assess the combination's impact on tumor immune microenvironments. Notably, two patients who responded positively had prior anti-PD-1 therapy failures, suggesting enhanced efficacy when LYMPHIR is combined with immune checkpoint inhibitors.

Among 21 participants, four achieved partial responses and one had stable disease for over six months. Safety data indicated tolerability with most adverse events linked to the patients' underlying conditions. Only one instance of dose-limiting toxicity (capillary leak syndrome) was reported.

LYMPHIR, an FDA-approved IL-2 receptor-directed cytotoxin for CTCL, is expected to see increased market demand, valued at over USD400m.

Citius Pharmaceuticals continues to advance its late-stage pipeline, including Mino-Lok and CITI-002, reinforcing its position in critical care and oncology markets.