BioMarin Pharmaceutical has announced a stock purchase agreement to acquire LEAD Therapeutics, a drug discovery and development company with rights to a new inhibitor for the treatment of patients with rare cancers.

The acquisition will provide BioMarin with rights to LEAD’s key compound LT-673, an orally available poly (ADP-ribose) polymerase (PARP) inhibitor for the treatment of patients with rare, genetically defined cancers.

BioMarin chief executive officer Jean-Jacques Bienaime said that LT-673 provides a tremendous opportunity to apply expertise in developing therapeutics for genetic diseases to the field of oncology.

“There are attractive opportunities to treat rare cancers with PARP-sensitive mutations, as a single agent and in combination with other DNA damaging agents,” said Bienaime.

Under the terms of the stock purchase agreement, BioMarin will pay LEAD stockholders $18m up front as well as an additional $11m on acceptance of the IND filing expected by the end of 2010.

BioMarin will also pay up to $68m for the development and launch of milestones for LT-673. Subject to customary closing conditions, the acquisition is expected to be completed by mid-February 2010.