CytoDyn Initiates Phase II Trial of Leronlimab in Relapsed/Refractory Colorectal Cancer
Key Insights
CytoDyn (search) has dosed the first patient in a Phase II clinical trial evaluating leronlimab, a CCR5 (search) antagonist, in patients with relapsed/refractory microsatellite stable colorectal cancer (search).
The study is being conducted across eight clinical sites in partnership with Syneos Health, with Dr. Ben Weinberg from Georgetown University serving as lead principal investigator.
The trial builds on prior research showing potential clinical benefit of leronlimab in relapsed colorectal cancer (search) and promising survival rates in metastatic triple-negative breast cancer (search).
CytoDyn (search) Inc. has achieved a significant milestone in its oncology development program by dosing the first patient in a Phase II clinical trial evaluating leronlimab in patients with relapsed/refractory microsatellite stable colorectal cancer (search). The biotechnology company announced on June 24, 2025, that enrollment is now underway across multiple clinical sites in partnership with Syneos Health.
Clinical Trial Design and Leadership
The study is being conducted across eight clinical sites with patient enrollment and processing efforts currently underway. Dr. Ben Weinberg, MD, from Georgetown University and the MedStar Health Alliance (search), serves as the lead principal investigator for the trial.
Leronlimab is an investigational humanized IgG4 monoclonal antibody designed to bind to C-C chemokine receptor type 5 (search) (CCR5 (search)), a protein on the surface of certain immune system cells believed to play a role in numerous disease processes. CytoDyn (search) has previously studied leronlimab across multiple therapeutic areas, including oncology, infectious disease, and autoimmune conditions.
Global Disease Burden and Unmet Need
According to the World Health Organization's International Agency for Research on Cancer (IARC), colorectal cancer (search) represents the third most common cancer type worldwide and the second most common cause of cancer-related deaths globally. IARC's most recently published figures estimate approximately 1.9 million new cases of colorectal cancer and more than 900,000 deaths due to colorectal cancer worldwide each year.
The IARC has also noted that incidence rates of colorectal cancer (search) in people younger than 50 years old have been increasing for at least 20 years, with some sources dating the increase trend back 30 years or more.
Scientific Rationale and Prior Research
The current study builds on CytoDyn (search)'s prior research demonstrating the potential clinical benefit of leronlimab in patients with relapsed colorectal cancer (search). The trial will also further evaluate the potential for the company's recently announced mechanism of action for leronlimab in solid tumor oncology.
CytoDyn (search) has observed promising survival rates in prior studies of patients with metastatic triple-negative breast cancer (search). Given these results and the company's ongoing clinical investigation efforts in colorectal cancer (search), CytoDyn views its current line of scientific evaluation as the most expeditious path to determining how broadly applicable this mechanism may prove to be across various solid tumors.
Company Perspective
"Dosing the first patient in our Phase II CRC trial is a significant step forward in our mission to bring innovative treatment options to patients facing this challenging disease," said Dr. Jacob Lalezari, CEO of CytoDyn (search). "This milestone reflects the dedication of our team and clinical partners, and we look forward to advancing this study to better understand the potential impact of our therapy across solid tumor oncology."