With the acquisition, Regeneron will obtain Checkmate’s lead candidate vidutolimod, an investigational, advanced generation CpG-A oligodeoxynucleotide Toll-like receptor 9 (TLR9) agonist


Regeneron office building nearing completion. (Credit: Jim.henderson/Wikipedia)

Regeneron Pharmaceuticals has signed a definitive agreement to acquire clinical-stage biopharmaceutical company Checkmate Pharmaceuticals for about $250m.

Under the terms of the agreement, the US drugmaker will acquire all the shares of Checkmate common stock for $10.50 per share in cash.

Checkmate is a biopharmaceutical company focused on developing a unique technology that empowers the body’s own immune system to fight against cancer.

The company’s lead investigational candidate, vidutolimod, is an advanced generation CpG-A oligodeoxynucleotide Toll-like receptor 9 (TLR9) agonist.

It is administered into the tumour and is believed to induce anti-tumour T cells, along with tumour regression in patients who are previously treated with PD-1 checkpoint inhibitors.

The drug works by two complementary mechanisms, where the virus-like particle (VLP) activates an immune response, and CpG-A stimulates an anti-tumour T cell response.

In the animal models and in-vitro experiments, vidutolimod was found to activate various immune cells to help generate a strong anti-tumour T cell response.

Regeneron president and chief executive officer Leonard Schleifer said: “As we continue to advance and expand our research efforts in immuno-oncology, the acquisition of Checkmate will add a promising new modality to Regeneron’s toolkit of potential approaches for difficult-to-treat cancers.

“The unique combination of a differentiated Toll-like receptor 9 with other antibody-based oncology agents may result in increased clinical benefit and provide new treatment options for patients in need.”

The acquisition is expected to close in mid-2022, subject to certain conditions, including the tender of at least a majority of the outstanding shares of Checkmate common stock.

It is also subject to the expiration of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act, along with other customary closing conditions.

Upon completion of the tender offer, Regeneron intends to acquire all the shares that are not purchased in the tender, through a second-step merger.

Checkmate founder and chief scientific officer Art Krieg said: “We believe that the data we have generated with vidutolimod positions Checkmate at the forefront of the innate immune activator field.

“It is our hope that Regeneron’s resources and expertise will help accelerate the development of vidutolimod and realization of the full potential of our virus-like particle (VLP) platform for immunotherapy.”

Wachtell, Lipton, Rosen & Katz served as legal advisor to Regeneron on the transaction, while Centerview Partners served as financial advisor and Goodwin Procter as legal advisor to Checkmate.