Chimerix Pays $30M+ for Rights to Orphan Leukemia Drug

Durham-based Chimerix,has committed $30 million and 10 million shares of its common stock to buy exclusive worldwide rights to a leukemia drug under development by Cantex Pharmaceuticals Inc. 

The deal gives Chimerix the chance to finish developing the drug CX-01 from Cantex, a former North Carolina company now based in Florida. Chimerix said it intends to move quickly into Phase 3 development of CX-01 to treat acute myeloid leukemia (AML). 

CX-01 has received fast track and orphan drug designations from the U.S. Food and Drug Administration for the AML indication. Chimerix said the treatment has had “strong, consistent clinical data with an attractive safety profile.” 

In Phase 2 clinical trials, Chimerix said CX-O1 demonstrated compelling complete response rates. In combination with standard chemotherapy it improved event-free and overall survival, compared to standard chemo alone. 

Mike Sherman, CEO of Chimerix, said in the announcement that, “With more than 21,000 new cases of AML diagnosed annually in the U.S. alone and a five-year survival rate of less than 30 percent, the patient need is clear. CX-01’s mechanism of action, targeting multiple proteins involved in protecting and supporting the growth of cancer cells, provides opportunities for potential development across a range of hematologic malignancies.”

He added, “This transaction exemplifies our commitment to pursuing and accelerating programs where we can quickly address unmet patient needs with a meaningful clinical benefit.”

The company said CX-01 is a new chemical entity derived from unfractionated heparin with very low anticoagulant activity.  CX-01 targets key protein pathways important for AML blast cell migration to the bone marrow and retention of these cells in the marrow where they are protected from chemotherapy. 

CX-01 also binds with proteins involved in chemotherapy resistance and the delay in platelet recovery after chemotherapy. Together, these activities are understood to sensitize AML blasts to chemotherapy and improve clinical responses. These mechanisms of action support potential for development in myelodysplastic syndrome, multiple myeloma, and lymphomas. 

Other financial terms of the deal include:

• No additional payments owed Cantex until first approval.
• Milestones for first approval in the U.S., EU and Japan totaling $105 million.
• Milestones for subsequent approvals in the U.S., EU and Japan totaling $97.5 million.
• Sales milestones for achievement of certain revenue amounts totaling $385 million.
• Tiered royalties on net sales starting at 10 percent and ending in high-teens.

Chimerix said it expects to start a Phase 3 registrational trial in mid-2020.