Sionna Therapeutics Closes $219.2 Million Upsized IPO

In The News
February 11, 2025

Ropes & Gray represented the underwriters in Sionna Therapeutics’ initial public offering of 12,176,467 shares of its common stock at $18 per share. The closing of the upsized offering was announced on Feb.10. Sionna Therapeutics is the first Massachusetts-headquartered company to close its IPO in 2025.

Sionna is a clinical-stage biopharmaceutical company developing novel medicines that normalize the function of the cystic fibrosis transmembrane conductance regulator protein to deliver clinically meaningful benefits to cystic fibrosis patients. 

The firm also recently advised clients on life sciences IPOs for CAMP4 Therapeutics, Bicara Therapeutics and Zenas BioPharma.

The team was led by capital markets partners Tara Fisher and Tom Danielski and included life sciences regulatory & compliance partner Josh Oyster, IP transactions partner Melissa Rones, health care partner Eve Brunts, executive compensation & employee benefits partner Renata Ferrari, and data, privacy & cybersecurity partner Fran Faircloth.