Sanofi buys US immuno-oncology biotech Amunix for $1 billion

Sanofi has bolstered its immuno-oncology pipeline with a $1 billion agreement to acquire Amunix Pharma of the US – its fourth bolt-on deal of 2021.

South San Francisco-based Amunix specialises in T-cell engager and cytokine-based treatments for solid tumours, and is planning to advance its lead programme AMX-818 – a cell-based therapy which targets HER2-expressing cancers – into the clinic next year.

The front-loaded deal also includes $225 million in future payments tied to meeting development milestones, and adds to Sanofi's current pipeline of around 20 oncology drug candidates.

AMX-818 is a T-cell engager produced via Amunix' proprietary XPAT platform that is designed to stimulate an immunological attack on HER2-positive cancers, but only become activated in the "microenvironment" around the tumour.

The hope is that approach will kill tumour cells but avoid off-target side effects, such as the potentially cytokine-release syndrome (CRS) that is seen with CAR-T therapies.

That's all theoretical at the moment, but Amunix has presented preclinical data with AMX-818 showing that the therapy was able to shrink tumours in animal models.

The US biotech's other main platform is XTEN, which adds side chains to existing molecules to extend their activity in the body and prevent off-target effects, and has already been licensed to other drugmakers including Biogen and Merck & Co.

Sanofi's other acquisitions this year were the $3.2 billion takeover of mRNA specialist Translate Bio, firming up a longstanding alliance with the biotech, and a $1.9 billion deal to buy Kadmon Pharma and its recently-approved drug Rezurock (belumosudil) for chronic graft versus host disease (GVHD).

The Kadmon deal also included an immuno-oncology candidate – anti-PD-L1/IL-15 fusion protein KD033 – which is in early clinical development. Earlier in the year Sanofi also bought Kymab and its atopic dermatitis drug KY1005 for $1.1 billion upfront.

"The Amunix technology platform utilises a next generation smart biologics approach to precisely tailor-deliver medicines to become active only in tumour tissues while sparing normal tissues," said Sanofi's head of R&D John Reed.

The approach has the potential of "bringing the promise of more effective and safer treatment options for cancer patients," he added.

Sanofi's ambitions in immuno-oncology are spearheaded by its Regeneron-partnered PD-1 checkpoint inhibitor Libtayo (cemiplimab), and the drugmaker has been acquiring new assets that may have potential in combination therapies.