Septerna may be yet to disclose “any meaningful clinical data,” but the biotech clearly thinks there will be investor appetite for its G protein-coupled receptors (GPCRs).
The South San Francisco-based biotech first disclosed its ambition to go public at the start of the month but has now attached some numbers to that plan. The idea is to sell 10.9 million shares priced between $15 and $17 apiece, according to a Securities and Exchange Commission filing this morning.
Assuming the final share price falls in the middle of this range, the IPO is expected to bring $157.9 million in net proceeds—rising to $182.3 million if underwriters take up their 30-day option to acquire a further 1.6 million shares at the same price.
Using a platform for isolating functional native GPCR proteins outside of cells, Septerna has discovered a small molecule that could offer hypoparathyroidism patients an oral alternative to lifelong injections. The biotech believes its lead asset, SEP-786, is the only clinical-stage oral small-molecule PTH1R agonist around.
PTH1R has historically proven tough to drug with small molecules, leading other companies to develop injectable peptides to activate the receptor, such as Ascendis Pharma with Yorvipath and AstraZeneca with eneboparatide. SEP-786 has been generally well tolerated in preclinical tests and has showed potent and selective activation of PTH1R in human, dog and rat receptor in vitro models, according to Septerna.
The biotech admitted in its filing that “we have not yet generated any meaningful clinical data on any of the product candidates being developed using our platform,” but that should change with the expected readout from an ongoing phase 1 trial of SEP-786 in mid-2025.
Septerna is allocating $54 million of the IPO proceeds to continue SEP-786’s clinical journey into a phase 2 study. A further $24 million is earmarked for taking its chronic spontaneous urticaria program led by SEP-631 into phase 1.
Septerna is joining a renewed trickle of biotech IPOs that began in late summer and included Bicara Therapeutics, Zenas BioPharma and MBX all going public on the same day last month.