Clovis Oncology Inc (CLVS.O) said it will suspend the development of an experimental cancer compound after it proved no better than standard chemotherapy in improving overall survival of metastatic pancreatic cancer patients.
The stock fell 42 percent to its lowest in nearly a year, making it the top percentage loser on the Nasdaq on Monday. It was down 34 percent at $14.30 at 1044 ET.
"We did not have high conviction in (the drug) CO-101, but others on Street may have had higher expectations leading to the larger decline (in Clovis' share price)," Leerink Swann analyst Marko Kozul said.
The failure of Clovis' cancer drug comes days after bigger rival Celgene Corp (CELG.O) said its approved lung and breast cancer drug Abraxane improved survival in patients with pancreatic cancer.
Celgene's shares rose about 10 percent on Monday morning.
Clovis Chief Executive Patrick Mahaffy said on a conference call with analysts that the study results were "even more unambiguous than we could have imagined".
The company tested the compound, CO-101, against the standard cancer therapy gemcitabine.
Median survival in patients on both Clovis's drug and the standard therapy was about six months - "entirely consistent with the survival results from other gemcitabine studies in metastatic pancreatic cancer," Clovis said.
The company said that it now plans to focus resources on its experimental lung cancer treatment, codenamed CO-1686, and expects to report early stage data from a study on the compound in June 2013, followed by efficacy data later in the same year.
Clovis, which listed on the Nasdaq last November, is also developing a drug to treat breast cancer. (Reporting by Zeba Siddiqui in Bangalore; Editing by Don Sebastian, Roshni Menon)