Biotech firm Septerna on Thursday said it raised $288 million in its initial public offering that has been upsized twice, a sign of upbeat investor sentiment for the capital-intensive sector.

Septerna sold 16 million shares in the offering at $18 a piece.

Earlier in the day, the drug developer had already upsized the offering to nearly 15.3 million shares, from 10.9 million shares and said it aimed to sell at $18 a piece versus an earlier target range of $15 and $17 a share.

Goldman Sachs-backed Septerna would be valued around $750 million.

Drug developers have achieved resounding success in the fall U.S. IPO market, with all the $100-million plus offerings since September upsized.

Robust debuts by drug developers Bicara Therapeutics , MBX Biosciences, BioAge Labs and Upstream Bio are also encouraging potential candidates in the sector to move ahead with their listings.

Septerna's lead experimental candidate, SEP-786, is being developed to treat hypoparathyroidism — a condition in which the body produces insufficient levels of parathyroid hormone that disrupts calcium levels in the blood and bones.

The drug is in an early-stage study, with data expected in mid-2025.

"Despite being in early stages, their pipeline is diversified, spanning multiple large markets, including immunology, metabolic diseases and obesity, providing several paths to potential success," said IPOX research analyst Lukas Muehlbauer.

Septerna is developing G-protein-coupled receptor (GPCR) therapies. GPCR is a class of proteins that serve as a main conduit for chemicals to get past a cell's membrane and be taken up by a cell.

Goldman owns a 5.4% stake in Septerna, which is also backed by venture capital firm Third Rock Ventures.

"While this IPO shows investors will back select early-stage companies, they likely remain selective based on factors such as the quality of existing institutional investors and clear commercial opportunities," Muehlbauer said.

Septerna will list on the Nasdaq under "SEPN".

(Reporting by Arasu Kannagi Basil and Pretish M J in Bengaluru; Editing by Shailesh Kuber, Shilpi Majumdar and Rashmi Aich)