Myriad Test May Find Tumor Success After Sanofi Failed
Myriad Genetics Inc. Chief Executive Officer Pete Meldrum says his lab test to pinpoint tumors with a specific genetic mutation could have helped Sanofi-Aventis SA succeed if it had been used in a study of a drug that failed in breast cancer.
Myriad, based in Salt Lake City, makes tests to identify women with a mutated BRCA gene, patients shown in past research to respond to medicines similar to Sanofi’s tumor fighter, Meldrum said in a telephone interview today.
Sanofi’s drug, BSI-201, didn’t help women live longer in a study from the third and final stage of tests generally needed for U.S. approval, the Paris-based company said yesterday. Sanofi’s treatment leads a new family of medicines known as parp inhibitors, designed to prevent cancer cells from repairing themselves after being blasted by chemotherapy. AstraZeneca Plc and Abbott Laboratories contracted to use Myriad’s BRCA test to select women for studies of their similar drugs, Meldrum said.
“I think Sanofi did make a big blunder,” said Michael Yee, an analyst with RBC Capital Markets, in a telephone interview today. “They took a gamble on a bigger breast cancer market. Abbott and AstraZeneca may have higher success because they are limiting their studies to only patients with the BRCA mutation. That’s good for Myriad because their test would be used to screen all cancer patients who would get the drug.”
Myriad fell $3.11, or 14 percent, to $19.30 at 4 p.m. in Nasdaq Stock Market composite trading, for the biggest decline since May 5.
‘Positive and Bright’
“The short-term negative is that the drugs, at least the Sanofi drug, aren’t going to be on the market as quickly as people had hoped,” Meldrum said. “I think the long term is very positive and bright for parp inhibitors and Myriad’s test.”
Most cancer drugs work by blasting DNA in the malignant cells with chemotherapy or radiation. The malignant cells can fight back by using parp enzymes to fix damaged strands of DNA within tumors. The new medicines are designed to block the enzymes, helping standard treatments to kill the cancer.
The Myriad test identifies patients with mutations in two genes, BRCA1 and BRCA2, which cause a five-fold increased risk of breast and ovarian tumors. Normal forms of these genes help block tumor formation. About 60 percent of women with mutated versions of these genes develop breast cancer, and ovarian tumors occur in 15 percent to 40 percent of BRCA-positive women.
Parp inhibitors have been shown more effective in women with mutated BRCA genes than in those who lack that trait, said Myriad’s Meldrum.
Abbott is now the most likely to succeed with a parp inhibitor for breast cancer, Yee said in a report today. Abbott’s final-stage test of its drug, called ABT-888, will only look at smaller group of patients who have the BRCA mutation, Yee said.
“The trial failure may be due to insufficient number of patients with BRCA mutations, as Sanofi tried to develop a bigger targeted drug,” Yee said. “We still think BRCA patients is a wholly viable opportunity.”
Yee said Sanofi’s drug may still be useful in breast cancer if the analysis of the results show BRCA patients responded. That would require a new study that may delay the drug for years, he said.
Abbott has completed its mid-stage trial and is still analyzing results before proceeding with the final-stage trial, said Tracy Sorrentino, a spokeswoman for the Abbott Park, Illinois-based company, in a telephone interview today.
“We have shown activity in BRCA positive breast cancer,” Sorrentino said. “Our development program is still moving ahead.”
Abbott is testing its parp inhibitor, known as veliparib, in more than 15 early-stage trials against a variety of forms of cancer, she said. The company hasn’t entered final testing for any disease.
“Patients who have lost BRCA function are likely responders for this new class of drugs, putting Myriad in a strong position,” Meldrum said in a conference call yesterday. “To capitalize on this strong position, we are developing an additional test for BRCA functionality, which we expect to launch in 2012.”
AstraZeneca, based in London, recently decided to shift its research focus for olaparib to ovarian cancer from breast malignancies, spokeswoman Sarah Lindgreen said in a telephone interview today.
Research on Hold
“We haven’t decided to abandon breast cancer studies completely.” Lindgreen said. The company was about to start the third and final stage of testing generally needed for U.S. approval, and that has been canceled for breast tumors, she said. Any breast cancer research is on hold until data from ovarian cancer trials is in, she said.
AstraZeneca’s drug could work for some patients, albeit a smaller number than the company had planned, said Amit Roy, an analyst with Nomura International Plc in London, in a telephone interview today.
An earlier AstraZeneca study showed olaparib shrank tumors in patients with the BRCA mutation, Roy said. “It will be hard for them to get high pricing for such a small population,” Roy said.
Sanofi said it is still analyzing its trial results in breast cancer. The company is also studying the drug in other hard-to-treat tumors, including lung, brain, ovarian and pancreatic malignancies.
Sanofi’s results and AstraZeneca’s trial halt in breast cancer are a “negative signal” for this family of drugs having a broad application in oncology, said Navid Malik, head of life sciences reseach at Matrix Corporate Capital LLP in London, in a telephone interview today. “Ovarian cancer is even harder to treat,” Malik said.
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