Serapha Bio takes flight from Boundless merger with $230M and gene-editing prospect from China

Serapha Bio has entered into a reverse merger agreement with Boundless Bio, gaining access to a Nasdaq listing and a public platform while raising approximately $230 million in financing.

The combined company, to operate under the Serapha Bio name and trade under the ticker "AATD", will focus on SERP-01, an in vivo base editor developed in China for alpha-1 antitrypsin deficiency (AATD).

Serapha has licensed SERP-01 from Shanghai-based YolTech Therapeutics, receiving worldwide rights outside Greater China in exchange for an upfront payment and a minority equity stake; YolTech retains China rights and potential milestone payments of more than $2 billion.

The $230 million funding package consists of roughly $138 million in a prior Series A round plus about $92 million in pre-closing private investments, expected to fund the combined company into the second half of 2029, through Phase 2 completion and Phase 3 initiation for SERP-01.

Upon completion, Serapha’s pre-merger shareholders are expected to own about 96.3% of the combined company, while Boundless Bio stockholders will hold about 3.7%, with the deal expected to close in the fourth quarter of 2026.