XtalPi (HKG:2228) entered into a partnership with an international biopharmaceutical company to develop an oral small-molecule therapy targeting a G protein-coupled receptor, according to a Tuesday Hong Kong bourse filing.

The agreement carries a potential value of more than $400 million, including an upfront payment, research funding, development and commercial milestone payments, and future royalties.

Under the deal, the partner will fully fund XtalPi's early-stage research and development work.

Shares of the firm were down over 2% in late morning trade on Wednesday.