Pharma, BioPharma

Sanofi’s $1B Amunix acquisition aims for targeted, safer T cell engagers for cancer

In acquiring Amunix, Sanofi becomes the latest big pharmaceutical company to strike a deal to gain access to technology that improves the safety and efficacy of T cell engager cancer therapies. Sanofi agreed to pay $1 billion up front to buy preclinical Amunix.

 

When it comes to treating solid tumors, T cell engagers have fallen short due to dangerous toxicity in healthy tissues despite a design that’s supposed to be targeted in effect. Drug research has advanced several different approaches intended to improve the safety and efficacy of this drug class and Sanofi is committing $1 billion to acquire Amunix Pharmaceuticals in a bet that the preclinical-stage biotech can overcome hurdles that have kept T cell engagers from finding broader adoption.

The $1 billion sum is an upfront payment. Mountain View, California-based Amunix could earn up to $225 million more if it achieves development milestones. With the deal, Amunix’s five drug candidates will join a Sanofi cancer drug pipeline that the pharmaceutical giant says now has about 20 molecules in development. But the technology underpinning Amunix’s drugs is just important to Sanofi, if not more so.

Bispecific T cell engagers are antibodies that bind to two targets, one on a T cell and the other on a cancer cell. The physical link of the T cell to the cancer cell sparks the immune activity that kills tumors. Amgen’s blinatumomab, marketed under the name Blincyto, is currently the only commercially available T cell engager, with an FDA approval that covers use of the drug in treating certain types of leukemia. However, a black box warning on the drug’s label cautions that the drug may spark problems including cytokine release syndrome, as well as potentially life-threatening toxic effects in the brain.

Amunix aims to avert the toxic effects of T cell engagers with technology that “masks” the therapy until it reaches its target. According to the biotech, these masks enable biologic drugs to circulate in the body undetected, becoming active only at disease-specific locations. These drugs are engineered to be long lasting in their inactive state; when activated, Amunix says these molecules convert to half-life agents that do their cancer-killing work and then are rapidly cleared from the body. Amunix contends these features could overcome the toxicity problems that prevent use of bi-specific antibodies to treat solid tumors.

The most advanced Amunix drug candidate, AMX-818, is a masked T cell engager that targets the cancer protein HER2. It’s being developed to address a range of solid tumors expressing that target. The drug is currently undergoing the preclinical research that could support the filing of an investigational new drug application.

In acquiring Amunix, Sanofi becomes the latest big pharma company to strike a deal with a smaller biotech to gain access to new T cell engager technology. Last week, Bristol Myers Squibb agreed to pay $150 million up front for rights to Immatics’ lead drug program, a Phase 1-ready “T cell engaging receptor” that’s designed to recruit T cells to recognize and destroy cancer cells.

Earlier in the year, Takeda Pharmaceutical acquired Maverick Therapeutics, its T cell engager research partner of the past four years. Maverick’s lead program targets solid tumors expressing the protein EGFR. Merck is in the chase for better T cell engagers via an alliance with Janux Therapeutics, a biotech that went public in June, raising more than $193 million. Janux has said it plans to file an investigational new drug application for its most advanced program in the first half of 2022. Both Maverick and Janux say their respective technologies enable a T cell engager to circulate in the body but activate only at the site of the cancer.

Founded in 2006, Amunix spent most of its history supporting the drug research of larger companies. Merck and Roche are among the companies that have licensed Amunix’s technology. Sanofi also has a licensing agreement with Amunix, but not for a cancer drug. The Amunix technology is part of efanesoctocog alfa, an experimental Sanofi treatment in late-stage development for hemophilia A. Amunix’s XTEN technology extends the time that the biological therapy lasts in circulation.

In Tuesday’s announcement of the Amunix acquisition, Sanofi said XTEN can be applied to a range of existing and experimental drugs. In addition to improving T cell engagers, Amunix is also applying its technology to therapies that hit cytokines, signaling proteins that regulate immune responses. Use of cytokine therapies has been limited by their toxicity, but Amunix said its technology can be used to preferentially activate cytokines in the tumor microenvironment. The company’s most advanced cytokine program focuses on the cytokine interleukin 12.

Photo: Nathan Laine/Bloomberg, via Getty Images

Shares0
Shares0