Citius Pharmaceuticals and Citius Oncology Unveil Promising Early Results of Pembrolizumab and LYMPHIR™ Combo for Recurrent Cancer

Citius Pharmaceuticals, Inc. ("Citius Pharma") and Citius Oncology, In., have revealed promising early-stage results from an ongoing Phase I clinical trial. The trial is investigating the safety and effectiveness of combining pembrolizumab with LYMPHIR™ in patients with recurrent solid tumors. These initial findings were shared through a poster titled "T-regulatory Cell Depletion with E7777 (denileukin diftitox-xcdl) Combined with Pembrolizumab in Patients with Recurrent Solid Tumors: Phase I Trial," presented at the Society for Immunotherapy of Cancer (SITC) 2024 Annual Meeting, which took place from November 8-10, 2024. 

The study is led by Dr. Haider Mahdi, Assistant Professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at the University of Pittsburgh. Its goal is to determine the most effective dose for upcoming trials and examine how a treatment regimen combining pembrolizumab and LYMPHIR affects the tumor's immune microenvironment.

PD-1 inhibitors, like pembrolizumab, are a class of immune checkpoint inhibitors that target the PD-1 protein on T cells. This action allows the immune system to better detect and destroy cancer cells. Pembrolizumab, created by Merck and marketed as KEYTRUDA®, is the top-selling PD-1 inhibitor globally and holds the title of the most prescribed drug, with sales reaching $25 billion in 2023.

Mahdi said, “We have seen promising results in patients with heavily pre-treated recurrent or metastatic gynecologic tumors and will enroll three additional patients before completing the Phase I portion of this study. We will further investigate in patients with gynecologic tumors and those with other solid tumor histologies. We want to explore the impact of this therapy on Tregs, host immune-effector cells and the tumor microenvironment."

Dr. Myron Czuczman, Chief Medical Officer of Citius Pharmaceuticals and Citius Oncology, mentioned, "The preliminary results from this Phase I trial of patients with recurrent gynecological cancers are highly encouraging. This novel chemo-free immunomodulatory combination regimen has been well tolerated, including at the highest dosage. This efficacy data strongly suggests that LYMPHIR may have the ability to improve and prolong the anti-tumor activity of immune checkpoint inhibitors. To date, this unique regimen has not been associated with significant immune-related adverse events. Moreover, of the 15 evaluable patients, one third experienced a clinical benefit with a median of more than 12 months of progression free survival.”

He further added, "There is reason to be optimistic about the potential of LYMPHIR to boost a patient's response to pembrolizumab by temporarily depleting Tregs that modulate the tumor microenvironment, without triggering an autoimmune response from the patient's body. We believe the positive signals from this data support expanding the research in a Phase II study to further evaluate the combination's benefits across a broader range of solid tumor types.”