Merck invests $700M in bispecific, targeting autoimmune and cancer opportunities against Amgen

Merck & Co. has made a bold move in the blood cancer market by paying $700 million upfront to acquire global rights to Curon Biopharmaceutical’s CD3xCD19 bispecific antibody. This strategic deal positions Merck as a formidable competitor to Amgen and AstraZeneca in oncology, and to Cullinan Therapeutics in autoimmune diseases. The mechanism of action for CD3 and CD19 plays a crucial role in the bispecific antibody industry. Amgen's Blincyto, which targets these two proteins, was approved by the FDA in 2014 for treating acute lymphoblastic leukemia (ALL). Although Blincyto has a significant lead in the market, emerging companies have identified potential weaknesses in its approach and are exploring untapped opportunities, particularly in autoimmune diseases.

Merck's engagement with Curon involves an upfront payment and up to $600 million in additional milestone payments contingent on development and regulatory success. In return, Merck gains rights to CN201, a promising phase 1/2 candidate. Curon, a biotech firm based in China, recently presented data from two clinical trials involving CN201. These trials demonstrated early signs of efficacy in treating non-Hodgkin lymphoma (NHL) and ALL. Notably, some patients who had not responded to multiple previous therapies achieved complete responses.

Curon has engineered the bispecific antibody CN201 to minimize cytokine release syndrome (CRS) without sacrificing effectiveness. In the clinical trials for NHL and ALL, CRS occurred in 7% and 31% of patients, respectively, primarily after the first dose. Most CRS cases were mild, although one ALL patient experienced a grade 3 reaction.

Merck intends to continue investigating CN201 for its potential in treating B-cell malignancies. AstraZeneca, which acquired its own CD3xCD19 bispecific antibody, AZD0486, for $100 million upfront in 2022, is also advancing its clinical trials. A phase 2 trial for AZD0486 in NHL is slated to begin this year, and early-phase studies in ALL and NHL are already underway.

Interest in targeting CD19 has surged recently, particularly in the context of autoimmune diseases. Researchers have shown promising results with a CAR-T candidate in lupus, and another study tested Blincyto in patients with multidrug-resistant rheumatoid arthritis, yielding dramatic responses, according to Amgen’s chief scientific officer Jay Bradner.

Cullinan has made autoimmune diseases the focal point of its CD3xCD19 bispecific project and plans to submit an application to study the candidate in systemic lupus erythematosus, with rheumatoid arthritis to follow. Merck appears poised to challenge Cullinan by investigating CN201’s potential as a novel and scalable treatment option for autoimmune diseases.

In summary, Merck's acquisition of Curon's CD3xCD19 bispecific antibody CN201 marks a significant strategic move in the competitive landscape of oncology and autoimmune diseases. With ongoing and future clinical trials, Merck aims to capitalize on the therapeutic potential of CN201, positioning itself as a key player alongside industry giants like Amgen, AstraZeneca, and Cullinan Therapeutics.