After licensing out tremelimumab to AZ, Pfizer pays for another CTLA-4 mAb

Five years ago Pfizer ($PFE) gave much of the development rights to its CTLA-4 monoclonal antibody tremelimumab to AstraZeneca’s ($AZN) biologics arm--but today it has decided it wants to jump back into developing this cancer class after signing a deal worth $250 million with OncoImmune.

The U.S. Big Pharma has earmarked up to a quarter of a billion dollars in upfront and milestone payments to the Rockville, MD-based biotech for an option on its preclinical CTLA-4 candidate ONC-392.

Under the deal, Pfizer said in a statement that it plans to watch how well ONC-392 does “up until a certain agreed-upon time” (which has not been disclosed) to see whether or not it wants the option to exclusively license ONC-392--as well as any other OncoImmune anti-CTLA4 antibodies.

Should it take up this option, it would then run all the R&D and marketing side of things for the drug, while paying from mid-single up to low-double digits royalties, and other payments, to the private and little-known OncoImmune.

The protein CTLA-4, expressed on the surface of activated T lymphocytes, is the focus of this med, and was designed by the biotech to help reduce the immune related toxicities while “retaining potent anti-tumor immunity.”

Pfizer is no stranger to CTLA-4 mAb development as it once ran its own R&D programs for a similar med in the form of tremelimumab, before giving up much of its rights (outside of combo therapies) to MedImmune back in the fall of 2011.  

AstraZeneca’s biologics arm has however hit barriers in its recent development project with the drug, after it flunked a solo challenge for mesothelioma. It has however had better luck when combined with other treatments, such as AstraZeneca’s PD-L1 candidate durvalumab.

In fact, the London-HQ’d co is now pursuing combo studies with the med for non-small cell lung cancer (NSCLC), squamous cell carcinoma of the head and neck, bladder, pancreatic, gastric and liver cancers.