- Merrimack Pharmaceuticals announced Monday morning that its Phase 2 CARRIE trial failed to meet its primary or secondary endpoints in patients with untreated metastatic pancreatic cancer.
- Merrimack's drug, MM-141 or istiratumab, was given with a regimen of nab-paclitaxel and gemcitabine in patients with high serum levels of free Insulin-like Growth Factor-1 (IGF-1) and compared to the nab-paclitaxel and gemcitabine regimen alone.
- Based on the study results, Merrimack has opted not to devote additional resources to the development of MM-141. The Phase 2 results will be presented at an upcoming medical meeting.
While Merrimack is downplaying the failure of the asset, investors were not as optimistic about the company's other prospects.
Shares of the Cambridge-based biotech fell nearly 35% in morning trading to trade near $6 apiece — well off the previous close of $9.15 and its 52-week high of $15.40.
Merrimack had been touting its "mission is to transform cancer care through the smart design" of targeted therapies. It bases its approach on treatments with a specific biomarker that can help with patient selection. While biomarkers are thought to be the future of cancer drug development, the study results are further evidence that solving the cancer riddle is not as simple.
Now that MM-141 missed in pancreatic cancer patients, the company will turn toward two other assets. MM-121, or seribantumab, is being tested in Phase 2 studies for metastatic breast cancer and non-small cell lung cancer.
Both studies are enrolling patients with high tumor expression of heregulin, the signal for the HER3 receptor that MM-121 targets. Topline results for the NSCLC study are expected in the second half of the year. The drug, however, previously fell short in NSCLC previously.
Merrimack will also put more resources into its Phase 1 asset MM-310, which targets the EphA2 receptor. Safety data is expected before the end of the year.
These two drugs, along with MM-141, were Merrimack's attempt at a turnaround. The company sold off its commercialized pancreatic drug Onivyde (irinotecan) to Ipsen in early 2017 for $575 million upfront due to weak sales. At the time, the biotech cut its staff and used the money from the sale to pay down debt.