Nektar Therapeutics said today it has granted Daiichi Sankyo Europe exclusive rights to market the registration-bound cancer drug Onzeald™ (etirinotecan pegol) in Europe, Switzerland, and Turkey.
The deal could generate up to $80 million-plus for Nektar, which retains rights to market Onzeald in the U.S. and elsewhere in the world.
Daiichi Sankyo Europe agreed to pay Nektar $20 million upfront, an additional $60 million tied to achieving European regulatory and sales milestones, plus double-digit royalties on net sales in Europe.
Onzeald, formerly NKTR-102, is being developed for advanced breast cancer and brain metastases. Onzeald has completed the Phase III BEACON clinical trial, which enrolled 852 women with locally recurrent or metastatic breast cancer, who had previously been treated with an anthracycline, taxane, and capecitabine therapies.
Nektar said it plans to submit a Marketing Authorization Application (MAA) filing this month seeking conditional approval from the European Medicines Agency (EMA) of Onzeald for advanced breast cancer and brain metastases. On May 26, the Committee for Medicinal Products for Human Use (CHMP) granted an accelerated assessment procedure for the planned Onzeald filing, which provides for an accelerated MAA review timeline.
The planned MAA filing, Nektar said, will be based upon data from a subgroup of patients from the completed Phase III study of single-agent Onzeald in patients with advanced breast cancer.
In the subgroup of 67 patients who also had a history of brain metastases, Nektar said, treatment with single-agent Onzeald resulted in an improvement in median overall survival (OS) of 5.2 months compared to treatment with a single-agent chemotherapy of physician's choice (TPC) (10 months vs. 4.8 months). TPC included a choice of ixabepilone, vinorelbine, gemcitabine, eribulin, or a taxane. In the planned primary analysis for the overall patient population in the Phase III study, the Onzeald median OS was 2.2 months longer than TPC (12.4 months vs. 10.3 months.
To satisfy the EMA's requirement for additional controlled data with the MAA for conditional approval, Nektar said it will sponsor a global, randomized Phase III trial of Onzeald in approximately 350 patients with advanced breast cancer and brain metastases. The trial will compare Onzeald to TPC, with a primary endpoint of OS. The trial will include a prespecified interim analysis for OS, to be conducted after 130 events have been observed.
Nektar said it will oversee sponsoring and funding the confirmatory trial that will support the MAA filing, with data from that trial to be used for a potential U.S. NDA filing for Onzeal.
According to Nektar, Onzeald is the first long-acting topoisomerase I inhibitor with an extended half-life and a structure that is designed to concentrate the drug in tumors. Onzeald has led to prolonged plasma SN38 exposure compared with irinotecan (elimination half-life of 37 days compared with 2 days), yet peak SN38 concentrations are at least 5 to 10 times less, which according to the company may also result in a favorable tolerability profile.