Royalty Pharma entered an agreement to acquire royalties on future worldwide sales of vosaroxin, Sunesis’ lead product candidate. Royalty Pharma will pay Sunesis $25 million for certain development milestones.

Sunesis is evaluating vosaroxin in a Phase III VALOR trial in patients with first relapsed or refractory acute myeloid leukemia (AML). Royalty Pharma will invest $25 million immediately following interim analysis of the trial in exchange for 3.6% on future sales. If the trial sample size increases, Royalty Pharma will receive 6.75% on future sales. Sunesis currently holds all worldwide commercial rights to vosaroxin.

“Royalty Pharma has a strong track record of identifying significant commercial opportunities in the pharmaceutical sector. We believe this commitment by Royalty Pharma is a validation of vosaroxin’s potential in AML and reflects the significant upside of a positive VALOR trial,” said Daniel Swisher, chief executive officer of Sunesis.

“Sunesis’ use of an adaptive trial design offers us an opportunity to invest in this promising biopharmaceutical product candidate on terms that are a win-win for both Sunesis and Royalty Pharma: Sunesis gains access to a flexible, novel financing structure and we are able to invest in vosaroxin at a time when we believe its likelihood of commercial success will be high,” said Pablo Legorreta, chief executive officer of Royalty Pharma.