Clovis Oncology Inc.’s experimental drug shrunk tumors in 82 percent of women with a certain type of deadly ovarian cancer, results that offer new promise for patients and promise to heat up the rivaly between the small Colorado biotech and U.K. drug giant AstraZeneca Plc.
In a midstage study of 204 patients, rucaparib shrunk tumors in 32 of 39 patients with BRCA mutations. Four women in that group had their tumors disappear, known as a complete response. The study data was released Saturday at the American Society of Clinical Oncology’s meeting in Chicago.
The drug also stopped patients’ cancer from progressing for a median of 9.4 months in those with BRCA mutations, and for 7.1 months in those with the similar mutations. In non-mutated patients, rucaparib delayed progression for 3.7 months.
Clovis Chief Executive Officer Patrick Mahaffy said he plans to file the drug for approval with U.S. regulators next year, setting up a competition with AstraZeneca, which already has a similar drug for sale.
“The data are really compelling,” Mahaffy said in a phone interview. “We’re getting into the category where we can claim best-in-class status for rucaparib.”
About 60 percent of women with ovarian cancer have a mutation to a gene called BRCA, or similar mutations. Clovis’s drug rucaparib targets those defects by blocking a protein cancer cells use to repair themselves. Without it, they die.
AstraZeneca’s drug Lynparza uses the same mechanism and was approved in the U.S. in December. In a study of 137 patients with BRCA mutations, it shrank tumors in 34 percent of the women, and responses lasted a median of 7.9 months. Analysts estimate Lynparza will have sales of $483 million a year by 2020.
Rare and Deadly
Ovarian cancer is both rare and deadly. It makes up 3 percent of cancers affecting women, and five years after diagnosis with advanced disease only 17 percent of patients are still alive, according to the American Cancer Society. There are few targeted treatments.
The biggest distinction between the two drugs may be the number of patients they treat, Mahaffy said. Lynparza is only approved for patients with inherited BRCA mutations, about 15 percent of cases, while rucaparib could also be effective in the larger group women who develop BRCA mutations and similar defects.
“This is a really big step forward for ovarian cancer,” Mahaffy said.
Clovis, cofounded by Mahaffy in 2009 and based in Boulder, is also competing with AstraZeneca in lung cancer, a far more common disease. About 221,000 new cases will be diagnosed in the U.S. this year, and it is the most common cause of cancer death, according to the American Cancer Society.
Lung Cancer Competition
In a study released Sunday, Clovis’s lung cancer drug rociletinib shrank tumors in 60 percent of EGFR-positive patients who had failed other treatments. The cancer didn’t return or start growing again in the patients for a median of eight months, the company said in a statement.
The EGFR mutation appears in about 15 percent of Western lung cancer patients and in as many as 40 percent of Asians. AstraZeneca and Clovis both hope to have their drugs approved by the end of the year.
The companies are also testing the lung cancer drugs as an initial treatment, which could expand the potential market to $3 billion a year.
In Clovis’s trial, the median progression-free survival -- a measure of how long patients went without their cancer getting worse -- was shorter than the 13.1 months the company reported in April.
The updated results come from a larger, sicker group of patients, including some whose cancer had spread to the brain, said Jonathan Goldman, an oncologist at the University of California, Los Angeles, and one of the study’s investigators.
Progression-free survival for patients without brain tumors was 10.3 months, according to the study.
AstraZeneca last reported data for its drug, AZD9291, at the European Lung Cancer Congress in April, and said it had a median progression-free survival of 13.5 months. That was from a smaller data set, and a different mix of patients, Mahaffay said.
“In the toughest test a lung cancer drug can face, our drug has come out very well,” Mahaffy said.
The results from the ovarian and lung studies may increase interest from potential buyers for Clovis, which had an initial public offering of shares in 2011 and has yet to bring a drug to the market. In an April note, Goldman Sachs Group Inc. analyst Terence Flynn said the odds of a takeover were at least 30 percent.
Mahaffy has developed two other medical companies that were bought: Pharmion Corp., which was sold to Celgene Corp. in 2008, and NeXstar Pharmaceuticals Inc., which was purchased by Gilead Sciences Inc. in 1999.
He said he had no plans to sell Clovis and can market its products independently. “We are fully capable of managing it on our own,” he said.