Sanofi moves further into next-gen oncology

Like Takeda with Maverick earlier this year, Sanofi must have seen something it liked in its partner Amunix. Both private biotechs have a focus on masked bispecific T-cell engagers for oncology, and both have now been snapped up by the senior pharma groups.

True, Sanofi’s association with Amunix was at arm’s length, but this took nothing away from the attractiveness of the latter’s masking technology, designed to build improved bispecifics and protein therapeutics. The focus echoes Synthorx, a biotech Sanofi bought two years ago, and Amunix marks the latest of many acquisitions for the French group.

These takeovers include other oncology players such as Kiadis, Kymab and Tidal Therapeutics, as well as Kadmon, Translate Bio, Principia and Ablynx. Before that came the $11.6bn takeout of Bioverativ, and it is through this deal that Sanofi had first-hand validation of Amunix’s technology.

Amunix had licensed its masking technology to Biogen, which in collaboration with Sobi had used it in developing the factor VIII fusion protein efanesoctocog alfa for haemophilia A. In 2017 Biogen spun out its haemophilia business into Bioverativ, which Sanofi bought a year later.

Masking attraction

This masking technology is the key attraction of Amunix, which crucially is no longer just a technology provider. It has a preclinical pipeline of oncology assets, including bispecific T-cell engagers against Her2, PSMA, EGFR and Trop2, and an IL-2 project. The last will add to the IL-2 Thor-707, which Sanofi acquired through Synthorx.

Amunix’s idea is to attach a polypeptide to otherwise standard bispecifics, cytokines or other proteins. In the case of efanesoctocog this acts to increase the half-life of factor VIII, while in oncology the purpose is to shield a bispecific or cytokine to avoid off-tumour side effects, before proteases cleave off the polypeptide in the tumour microenvironment to release a fast-cleared therapeutic.

Still, $1bn for what is effectively a preclinical technology play might seem rich, especially considering biotechs like Harpoon, Janux and Xilio, which went public on the back of similar approaches but are today worth rather less.

Evaluate Vantage understands that Amunix was preparing to IPO, and the waning valuations of the company's listed peers would not have been lost on the young biotech's backers. Venture investors including Omega Funds, Casdin Capital and Bain Capital had funded Amunix to the tune of $190m since early 2020. It is those funds that are celebrating today.