Sanofi to acquire US-based Principia for USD 3.7 billion

The transaction is Hudson's second big bolt-on purchase since becoming CEO last year, having paid $2.5 billion in December for Synthorx that is developing immuno-oncology treatments.

Principia's most-advanced candidate, rilzabrutinib, is in Phase 3 trials against pemphigus, which can cause blisters or pus-filled bumps on the skin and mucous membranes and is caused when the immune system mistakenly makes antibodies that attack the body.

Phase 3 trials are on tap to use another drug candidate for multiple forms of multiple sclerosis.

"This acquisition advances our ongoing R&D transformation to accelerate development of the most promising medicines," Hudson said in a statement.

In buying Principia's rilzabrutinib for pemphigus and potentially other autoimmune diseases, Hudson aims to challenge Roche, whose Rituxan since 2018 has secured U.S. and European approvals against pemphigus, which historically was treated with high doses of corticosteroids.

Sanofi shares edged up 0.2%, bucking a slight fall in France's CAC-40 index, as analysts viewed the deal as positive. Sanofi shares are down 5% this year, less than a third of the CAC-40's 17% drop.

The deal "fits within the strategy of deploying firepower across numerous bolt-on deals," wrote brokerage Jefferies, which rates Sanofi a "buy".

Evercore is the financial advisor to Sanofi on the deal. Centerview Partners LLC and BofA Securities are advising Principia.