Merck & Co. said Tuesday it has called for an early halt to a Phase 3 trial of Lynparza in colorectal cancer, after independent data monitors calculated that the medicine, when given alone or alongside Roche’s drug Avastin, won’t extend survival in patients with metastatic disease.
The trial aimed to determine whether the drug, which is co-owned by AstraZeneca, can help patients who have stabilized or gone into remission following treatment with Avastin and chemotherapy. The trial tested both Lynparza alone and with Avastin against an Avastin-chemo combination, to determine how well the Lynparza regimens might be able to delay disease progression or death.
Avastin is already used as an initial therapy for advanced coloretal cancer, as well as for those whose disease progresses.
Success could have allowed the two drugmakers to expand the market opportunity for Lynparza into a new disease.
Merck paid AstraZeneca $1.6 billion for partial rights to Lynparza in 2017. The Food and Drug Administration has since approved the drug for use in several ovarian and breast cancer settings as well as for certain pancreatic and prostate tumors. Analysts at SVB Securities have predicted the drug could reach nearly $10 billion in yearly sales in 2028.
The setback in colorectal cancer is a blow to those projections, however, and comes five months after a combination of Lynparza and Merck’s top-selling cancer drug, Keytruda, failed to extend survival in prostate cancer patients.
Lynparza was AstraZeneca’s second biggest money-maker in 2021, accounting for $2.3 billion in product sales — the company equally shares gross profits with Merck. Passing the $2 billion sales milestone triggered a $200 million collaboration fee from the Merck partnership.
The drug’s continued growth is essential to achieving AstraZeneca’s long-term plans of getting to $40 billion in sales by 2023, a promise made nearly eight years ago when fending off an acquisition bid from Pfizer. AstraZeneca had $37 billion in total sales in 2021.
The National Institutes of Health is recruiting colorectal cancer patients for a study that tests a combination of Lynparza and another AstraZeneca cancer drug, called Imfinzi, that’s similar to Keytruda.