October 7, 2016
By Mark Terry, BioSpace.com Breaking News Staff
Boulder, Colorado-based Clovis Oncology presented efficacy and safety data for rucaparib at the 2016 ESMO Congress held in Copenhagen, disappointing investors. Although the data was not all negative, it was mixed, and hopeful investors responded with a drop in stock prices.
Rucaparib is a small molecule inhibitor of PARP1, PARP2 and PARP3 being developed to treat ovarian cancer, specifically in tumors with BRCA mutations and other DNA repair deficiencies beyond BRCA.
“These results demonstrate that rucaparib may represent an important option for women with multiply relapsed BRCA-mutated ovarian cancer based on its encouraging efficacy and tolerability,” said Rebecca Kristeleit, with The University College of London, Cancer Institute, London, UK, in a statement. “In my opinion, rucaparib has the hallmarks of an important new therapeutic option for ovarian cancer patients.”
Analysts and investors aren’t as convinced. John Carroll, writing for Endpoints News, said, “The biotech reported a 54 percent objective response rate for the drug for BRCA-mutated ovarian cancer, with nine (9%) complete responders and 48 (45%) partial responders. Boring down into the data, investigators also reported zero response among the 7 percent of the patients who were platinum-refractory, a 25 percent response rate for platinum-resistant patients and 66 percent for platinum-sensitive responses.”
At least one concern is how the drug compares to competitors, such as Tesaro ’s niraparib or AstraZeneca ’s Lynparza.
The data presented was part of the data set submitted with its New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) in August. The PDUFA date is February 23, 2017.
PARPi is a fairly new mechanism for oncology drugs, and is at least partially why Pfizer acquired Medivation . Several other companies are interested in PARPi, including Celgene , Merck , Amgen , Sanofi and AstraZeneca .
So far, the various PARPi drugs are being tested in different types of cancers or in different populations. That makes it hard to compare the various drugs or for anyone to determine which ones are “best in class,” if any of them are. Max Nisen, recently writing in Bloomberg Gadfly, said, “That may not stop the drugmakers and their potential acquirers from hoping their drug is the one PARP inhibitor to rule them all—a blockbuster that will ride multiple approvals to multi-billion-dollar sales. Others might believe their drugs are close enough to best that they could still net a significant return.”
Although Clovis dropped from $35.17 at the opening of trading today, it is currently at $30.63. That’s fairly minor compared to when it was trading at $105.89 on November 10, 2015 and dropped to $30.24 on November 16, 2015.
Carroll writes, “The painful reception for the Boulder, CO-based biotech’s data today underscore some serious issues at Clovis Oncology. The company was forced to restate its data submitted for an approval of rociletinib, prompting an embarrassing and devastating drop in the number of responses that the biotech had claimed for their drug. An FDA panel subsequently rejected the drug, prompting Clovis to restructure and lay off staffers.”
So the company is focusing hard on rucaparib, although it will have to compete with Lynparza, and potentially niraparib. And Pfizer picked up talazoparib, another PARP inhibitor, when it bought Medivation. Rucaparib’s PDUFA date in February is ahead of Tesaro, but a lot rides on the successful approval of this drug.
