Clovis Oncology Inc (CLVS): Double Data, Double Stock Price

Plenty of data was presented at the American Society for Clinical Oncology meeting over the weekend, causing the first set of ASCO pops, but Clovis Oncology Inc (NASDAQ:CLVS) looks like the clear winner, more than doubling today as the company presented data on its two cancer drugs rucaparib and CO-1686.

Solid data with competition
Rucaparib produced a clinical benefit in 89% of patients with ovarian cancer in a phase 1 trial. More impressive, seven out of seven patients with a mutation in BRCA saw disease control .

Rucaparib is an inhibitor of poly ADP-ribose polymerase, or PARP. Inhibiting PARPs function causes DNA damage, which should be repaired by the BRCA complexes. It makes sense, then, that tumors with BRCA mutations would respond better to rucaparib. Clovis Oncology Inc (NASDAQ:CLVS) plans to move into a new trial in the second half of the year to potentially identify other mutations beyond BRCA that might make the tumors sensitive to rucaparib.

Clovis Oncology Inc (NASDAQ:CLVS) isn’t the only one developing a PARP inhibitor, though. BioMarin Pharmaceutical Inc. (NASDAQ:BMRN)s presented data at ASCO for BMN673, where 82% of patients with BRCA mutations had a clinical benefit. There were 28 patients in that part of the trial, so the data could be more reproducible than rucaparib’s seven out of seven. BioMarin Pharmaceutical Inc. (NASDAQ:BMRN) also has solid data for breast tumors with BRCA mutations. Shares of BioMarin Pharmaceutical Inc. (NASDAQ:BMRN) actually fell a little today, but I think the data were widely expected to be positive, so there’s likely a little “sell the news” going on.

TESARO Inc (NASDAQ:TSRO) is also up today after announcing that it established a partnership with clinicians to run the phase 3 development of its PARP inhibitor, niraparib. The trial will enroll about 300 breast cancer patients with BRCA mutations, comparing niraparib to investigators’ choice of other breast cancer treatments.

And there are quite a few other PARP inhibitors in the clinic, so competition could be fierce if rucaparib makes its way through development and onto the market.