GTx could earn another €42 million (about $56.89 million) in milestone payments from Ipsen as part of the companies’ expanded partnership for GTx’ selective estrogen receptor modulator, toremifene. The amended deal relates to development and commercialization of toremifene 80 mg for the reduction of fractures in advanced prostate cancer patients on androgen-deprivation therapy and toremifene 20 mg for the prevention of prostate cancer in high-risk patients with high-grade prostatic intraepithelial neoplasia (HGPIN).
The reworked deal also gives Ipsen first right of negotiation (under specific conditions) to the oral LH inhibitor, GTx-758, in its licensed toremifene territories. GTx-758 is currently in Phase II development for the first-line treatment of men with advanced prostate cancer.
GTx submitted an initial toremifene NDA for the fracture-reduction indication in 2008. In October 2009, FDA’s complete response letter requested a second Phase III trial. GTx anticipates starting this study later this year once an agreement has been reached with the FDA on a final study protocol required for marketing approval.
GTx and Ipsen signed their original toremifene collaboration back in 2006, with GTx paying $30 million up front. Terms of the expanded agreement provide for Ipsen to pay GTx up to €42 million on the initiation, enrollment, and progression of a second toremifene 80 mg Phase III trial. In return, Ipsen gets the right to either co-promote toremifene 80 mg in the U.S. or to receive double-digit royalties on net sales of the drug in the U.S.
The French firm also receives additional licensed territories for marketing toremifene products outside Europe, including Australia and certain countries in North Africa, the Middle East, and Asia (excluding Japan). Ipsen will in addition be relieved from previous contractual obligations relating to the payment of potential milestones tied to European approval of toremifene 80 mg.
“This new agreement with GTx gives us expanded market reach and rights for toremifene,” state Stéphane Thiroloix, evp corporate development at Ipsen. “It will strengthen Ipsen’s franchise in hormone-dependent cancers and broaden our drug range in the oncology area.”