Argenx pens $2.2bn deal to buy autoimmune biotech Forte

Netherlands- and Belgium-based biotech argenx has agreed to buy US biotech Forte Biosciences for up to $2.2 billion, bolstering its autoimmune disease pipeline.

The $77-per-share deal follows an earlier investment in Dallas, Texas-based Forte by argenx, which participated in the US firm's $150 million public offering in April, and represents an 86% premium to Forte's average share price in recent weeks.

Shares in Forte shot up earlier this month after it reported positive phase 1b results for lead candidate FB102, an anti-CD122 antibody, in vitiligo. The autoimmune skin-lightening disorder is the lead indication for FB102, and it is also being developed for coeliac disease, with phase 2 results due later this year, while studies in other autoimmune indications like alopecia areata are also planned.

FB102 is potentially a first-in-class drug that targets pathogenic T-cell and natural killer (NK) cell activity in autoimmune disorders, and is being billed by both argenx and Forte as a "pipeline-in-a-product."

Funding for the deal will come entirely from argenx's cash reserves, driven by sales of its flagship Vyvgart/Vyvgart Hytrulo (efgartigimod alfa) franchise for generalised myasthenia gravis, a rare neuromuscular autoimmune disorder, and chronic inflammatory demyelinating polyneuropathy (CIDP), revenues of which grew 90% to $4.2 billion last year.

Efforts by the company to expand the indications for FcRn blocker Vyvgart have run into some problems, however, including failed trials in thyroid eye disease, pemphigus, and primary immune thrombocytopenia (ITP), so buying Forte will give argenx the opportunity to advance on a broader front whilst retaining its focus on autoimmunity.

argenx's pipeline also includes complement C2 inhibitor empasiprubart – in mid- to late-stage testing for CIDP, delayed graft function in kidney transplants, and multifocal motor neuropathy (MMN) – as well as MuSK activator adimanebart in mid-stage clinical testing for neuromuscular disorders spinal muscular atrophy (SMA) and congenital myasthenic syndromes (CMS) and anti-IgA drug ARGX-121, due to start phase 2 in IgA nephropathy (IgAN) before year-end.

"The addition of FB102 to our portfolio aligns perfectly with the argenx playbook: compelling biology, strong clinical validation, and broad potential to address patient need," said Karen Massey, the company's chief executive.

The acquisition will also help argenx meet its Vision 2030 strategy, which hinges on 50,000 patients on treatment with its medicines, across 10 labelled indications, and five new molecules in phase 3 trials.

It is expected to close in the third quarter of this year, subject to customary closing conditions.