Merck has officially completed its acquisition of CN201, an investigational bispecific antibody, from Curon Biopharmaceutical. This strategic move aims to bolster Merck's pipeline in B-cell malignancies and autoimmune diseases. CN201 is currently undergoing Phase I and Phase Ib/II clinical trials for the treatment of relapsed or refractory non-Hodgkin lymphoma (NHL) and B-cell acute lymphocytic leukemia (ALL). Early trial data suggests a favorable safety profile and effective B-cell depletion, potentially leading to sustained clinical benefits.
CN201: A Novel Approach to B-Cell Depletion
CN201 is designed to actively deplete B-cells, making it a potential therapeutic option for both B-cell malignancies and autoimmune conditions. Dean Y. Li, president of Merck Research Laboratories, expressed enthusiasm about building on Curon's foundational work. The bispecific antibody targets CD19, a protein expressed on B-cells, and CD3, a protein on T-cells, to bring these cells together to kill the B-cells.
Phase I Trial Results
The Phase I trial employed a 3+3 dose-escalation design, enrolling adults with CD19+ relapsed or refractory B-NHL. The study focused on assessing safety, tolerability, maximum-tolerated dose, and preliminary anti-tumor activity. A total of 58 patients received either fixed or step-up doses of CN201, and no maximum tolerated dose was reached. Common adverse events included decreased white blood cells, neutropenia, and lymphopenia. Cytokine release syndrome (CRS) occurred in 7% of patients, with all cases classified as mild.
In higher doses, CN201 demonstrated an objective response rate (ORR) of 77%, with a complete remission (CR) rate of 22%. Among patients with indolent B-NHL, the ORR was 91% and the CR rate was 45.5%, including a patient who had previously failed CAR T-cell therapy, highlighting the potential of CN201 in challenging cases.
Financial Implications and Future Milestones
As part of the acquisition, Merck is recording a pre-tax charge of approximately $750 million, expected to be included in their third-quarter non-GAAP results. Curon Biopharmaceutical is eligible for up to an additional $600 million upon achieving specific milestones related to drug development and regulatory approval. This agreement underscores the potential value and impact of CN201 in treating B-cell associated diseases.
