Argenx files for IPO to take autoimmune drug to phase 3

Argenx is seeking to raise up to $75 million in its Nasdaq IPO(Getty Images)

Argenx has filed to raise up to $75 million (€69 million) in a Nasdaq IPO. The European biotech is heading across the pond in search of cash to take lead candidate ARGX-113 to the cusp of a pivotal trial while also hustling cancer candidate ARGX-110 through midphase studies.

Belgian-Dutch biotech Argenx is yet to set the terms of its IPO but has detailed how it plans to use whatever proportion of its $75 million proposed maximum offering it ultimately raises. The top priority is to secure funding for further development of ARGX-113, an antibody fragment being tested in rare autoimmune diseases myasthenia gravis and primary immune thrombocytopenia. Argenx started phase 2 trials in those indications earlier this year.

A tranche of the anticipated IPO haul is earmarked for completing those studies and preparing the drug for a pivotal trial in one of the indications. Argenx expects to have top-line results from the myasthenia gravis study in the first quarter of next year, with data from the other trial due to follow in the second half of the year.

With Argenx yet to generate phase 2 data on the drug, it is asking investors to take a punt on its prospects on the basis of early-stage results. Argenx put the antibody fragment through a phase 1 trial in healthy volunteers. That trial associated ARGX-113 with 60% to 85% reductions in levels of four classes of immunoglobulin G (IgG) antibodies. Argenx is developing the drug to treat diseases associated with high levels of pathogenic IgG antibodies and thinks a 30% drop would be clinically meaningful.

Once Argenx has set aside enough cash to take ARGX-113 to the start of a pivotal trial it will put a chunk of what remains into ARGX-110. The goal is to pull in enough money to complete a phase 2 trial of the antibody in cutaneous T-cell lymphoma and a phase 1/2 study in newly-diagnosed acute myeloid leukaemia and high-risk myelodysplastic syndromes. Argenx plans to post interim data from the trials later this year.

Argenx went public in Europe in 2014, raising €40 million in the process. Since then, it has topped up its bank balance through share offerings, leaving it with €96 million in the bank at the start of the year. As it stands, no existing backers have committed to buy shares in the IPO. Argenx lists Forbion, LSP and Shire among its biggest shareholders.

Shire made a €12 million equity investment in argenx in 2014 when it expanded the collaboration it began two years earlier. Argenx also has partnerships with AbbVie, Bird Rock Bio and Leo Pharma.

By filing to list in the U.S., Argenx has added to a trickle of European biotechs that have headed to Wall Street over the past 12 months. Alzheimer’s player AC Immune netted $57.8 million in September and ObsEva pulled in close to $100 million at the start of the year. The overall flow of IPOs is well down on the boom time that came crunching to a halt in late 2015, early 2016 when offerings by Basilea Pharmaceutica, Bavarian Nordic, GenSight Biologics and others all failed to ignite.