Bayer Ends Partnership with OncoMed on Compounds That Inhibit Cancer Stem Cell Pathways

Bayer Ends Partnership with OncoMed on Compounds That Inhibit Cancer Stem Cell Pathways

Bayer Pharma has decided not to exercise its option to license two cancer stem cell pathway inhibitors from OncoMed, effectively ending their partnership in this area.

OncoMed developed the first-in-class Wnt pathway inhibitors vantictumab (OMP-18R5) and ipafricept (OMP-54F28) while the companies were collaborating in immuno-oncology.

The decision means OncoMed will retain worldwide development and commercialization rights to the two investigational compounds and to all other Wnt pathway biologics that were developed under the collaboration. Bayer’s decision is unlikely to change the small molecule program the partnership developed.

Vantictumab targets the Wnt cancer stem cell pathway. The compound reduced the frequency of cancer developing in stem cells, pre-clinical trial studies have shown. It also prompted cancer stem cells to differentiate into less aggressive cell types that are also more susceptible to chemotherapy.

Researchers said combinations of vantictumab and already approved therapies have shown promise against pancreatic, breast, lung, melanoma, ovarian, and other cancers. Vantictumab appears to be particularly compatible with taxane-based chemotherapies, the team said.

Two Phase 1b clinical trials of vantictumab are under way. One (NCT01973309) will be testing a combination of vantictumab and a standard-of-care chemotherapy known as Taxol (paclitaxel) in HER2-negative breast cancer. The other (NCT02005315) will be evaluating a combination of vantictumab, Gemzar (gemcitabine) and Abraxane (protein-bound paclitaxel) in advanced pancreatic cancer. Both trials are in the patient-recruitment phase.

Ipafricept selectively binds Wnt ligands that activate Wnt signaling. It displays anti-tumor activity in pancreatic, breast, ovarian, colorectal, and other cancers, studies have shown. A ligand is a molecule that produces a signal by binding to a site on a protein.

Two Phase 1b trials of ipafricept are under way. One (NCT02050178) is assessing a combination of ipafricept, Gemzar and Abraxane in pancreatic cancer. The other (NCT02092363) is evaluating a combination of ipafricept, Paraplatin (carboplatin) and Taxol in ovarian cancer. Both studies also are in the recruitment phase.

A Phase 1a trial indicated that ipafricept can modulate Wnt pathway activity as a stand-alone therapy. It was also well tolerated, the study showed.

Interim data from the clinical trials was presented at the 2016 annual meeting of the American Society of Clinical Oncology and the 2016 congress of the European Society for Medical Oncology.

OncoMed said it will continue to develop demcizumab (OMP-21M18), navicixizumab (OMP-305B83), rosmantuzumab (OMP-131R10) and anti-TIGIT (OMP-313M32) in collaboration with Celgene Corporation; Tarextumab (OMP-59R5), now in Phase 2 development, with GlaxoSmithKline (GSK); and brontictuzumab (OMP-52M51) and GITRL-Fc (OMP-336B11) independently.

“Under our collaboration with Bayer, we have received over $90 million in up-front and milestone payments that have fully funded the development of vantictumab and ipafricept. While we had looked forward to collaborating with the Bayer team on the late-stage development of these biotherapeutics, we are very pleased to have worldwide rights to two promising Phase 2-ready assets,” Paul J. Hastings, chairman and chief executive officer of OncoMed, said in a press release. “We will be conducting an internal portfolio review and prioritization as we determine next steps for all our programs, including vantictumab and ipafricept.”