- OncoMed Pharmaceuticals is discontinuing development of one of its monoclonal antibodies, tarextumab, after the drug missed primary and secondary endpoints of a mid-stage study evaluating it in patients with small cell lung cancer (SCLC).
- The randomized, double-blinded Phase 2 PINNACLE trial evaluated 145 patients with the disease who received chemotherapy and either placebo or tarextumab plus etoposide. Median progression-free survival (PFS) was 5.6 months in the treatment arm versus 5.5 months in the placebo, whereas overall response rates were 68.5% and 70.8%, respectively.
- Tarextumab aims to inhibit two signaling pathways, called NOTCH2 and NOTCH3, which research suggests can promote cancer development when they malfunction. OncoMed CEO Paul Hastings said in a Monday morning investor call his company is shelving another NOTCH-focused candidate, brontictuzumab, as well, which is in Phase 1b testing in colorectal cancer patients.
This is the second mid-stage failure the West Coast biotech has faced in as many weeks. On April 10, the company announced another treatment, demcizumab didn't significantly improve progression free survival for a specific group of metastatic pancreatic cancer patients.
Following the earlier news, OncoMed stock fell more than 40%. Shares tumbled further in Monday morning trading by about another 20% to $3.90 apiece.
"We're going to take a little bit of time and put our heads down and look at this pipeline and how to prioritize it, and look at the discovery efforts we have ongoing as well as the clinical programs," OncoMed CEO Paul Hastings said in a Monday investor call.
Hastings also disclosed the company has $156.9 million in cash, and is trying to bring in more to push certain programs toward earning milestone payments, such as those programs targeting the R-spondin 3 protein (RSPO3), the Delta-like 4 protein (DLL4), and the T-cell immunoglobulin and ITIM domain (TIGIT).
OncoMed saw a partnership with Bayer fizzle last week, but the company still has strategic alliances with GlaxoSmithKline, which holds the right to license and develop treatments targeting the NOTCH signaling pathway, and Celgene, which holds similar rights, but for demcizumab, navicixizumab — the DLL4 candidate — and up to four other programs targeting the RSPO signaling pathway.
According to its most recent 10-K filing with the Securities and Exchange Commission, OncoMed could rake in milestone payments as high as $721 million for demcizumab, $505 million for navicixizumab and $440 million for anti-RSPO3 treatments.
That line up of "biobucks" isn't mollifying investors, however, who sold off OncoMed shares heavily on Monday morning.