Avalyn Pharma, a Boston-based biotech, priced its upsized initial public offering at $300 million, selling over 16.5 million shares at $18 apiece. The company is set to start trading as AVLN on the Nasdaq Thursday.

The IPO marks a significant capital raise for the clinical-stage firm, which focuses on developing inhaled therapies for respiratory diseases. The upsized offering signals strong investor demand despite a volatile market for biotech IPOs.

Avalyn sold more than 16.5 million shares at $18 each, generating $300 million in gross proceeds. The pricing came in above the previously expected range, reflecting robust interest from institutional investors.

The fresh capital is expected to fund advancement of Avalyn's pipeline, including its lead candidate for pulmonary fibrosis. Proceeds could also support expansion of clinical trials and manufacturing capabilities.

Analysts will watch the stock's first-day performance for clues about biotech IPO appetite. The offering follows a cautious period for new listings in the sector.