Therachon, which had raised $100m from investors including Pfizer Ventures and Novo, has agreed to be acquired by Pfizer in a deal that could potentially reach $810m.

Pharmaceutical firm Pfizer agreed yesterday to acquire portfolio company Therachon, a Switzerland-based developer of treatments for rare genetic disorders, in a deal sized at $340m upfront.

The upfront payment could be swelled by up to $470m in additional milestone payments related to the development of Therachon’s lead asset, TA-46, a treatment for a bone growth disorder called achondroplasia that causes disproportionate dwarfism.

Founded in 2014, Therachon is developing therapies for rare genetic diseases such as achondroplasia, which affects approximately 250,000…