OncoGenex Pharmaceuticals has announced its wholly owned subsidiary, OncoGenex Technologies, executed a termination agreement with Teva under which OncoGenex will regain rights to custirsen, an investigational compound currently in phase III clinical development as a treatment for prostate and lung cancers. This transfer of rights occurs in connection with the termination of the 2009 collaboration agreement between OncoGenex and Teva.

"OncoGenex is excited to move forward with the clinical investigation of custirsen in patients with advanced cancers who desperately need new treatment options," said Scott Cormack, president and CEO of OncoGenex. "The finalization of this agreement gives OncoGenex control of custirsen's development, including the ability to move forward with plans to modify the ENSPIRIT trial design and statistical analysis plan to enable the trial to continue with fewer patients, increased confidence in success and shorter time to regulatory submission."

The agreement between the two parties to terminate the collaboration includes a $23.2 million payment from Teva.

This payment reflects a $27 million advance reimbursement amount less $0.8 million for expenses incurred by Teva in 2015 prior to the termination date as well as a $3 million holdback amount that may be used to settle additional expenses incurred by Teva related to the continued development of custirsen as well as certain indemnity claims. One half of the then remaining balance of the holdback amount will be released to OncoGenex in October 2015 with a further half of the then remaining amount paid in January 2016. Any final remaining amount will be released in April 2016.

In addition, OncoGenex will take over responsibility for all custirsen expenses, including those related to the ENSPIRIT trial, as well as manufacturing and regulatory activities for custirsen programs that were previously managed by Teva.