Mylan Copycat Breast Cancer Drug Comparable to Roche’s Herceptin

  • Biosimilar version of Herceptin has similar response, safety
  • Drug appeared effective in women with advanced breast cancer

Mylan NV’s copycat version of Roche Holding AG’s breast cancer drug Herceptin appeared just as potent in a trial as the brand-name medicine that generates $6.8 billion a year, raising the possibility that a less expensive treatment option is on the horizon in the U.S.

The study, presented at the American Society of Clinical Oncology meeting in Chicago, found 69.6 percent of women with advanced breast cancer that were given Mylan’s drug responded to treatment, compared with 64 percent on Herceptin. The risk of serious side effects were also similar, with no differences found in dangerous immune system responses or weakening of the heart muscle.

The results, including early findings that the rates of progression in both groups were identical after six months, are encouraging, said lead researcher Hope Rugo, director of breast oncology clinical trials program at the University of California in San Francisco.

“The availability of alternatives will make the drug more accessible to people around the world,” she said in a telephone interview.

Cutting Costs

The drug is for women who suffer from a variant of breast cancer that is fueled by HER2, a growth-promoting protein that leads it to spread faster and more aggressively, she said. Herceptin has improved the chance of survival in those cancers, and a copycat version, known as a biosimilar, will cut the cost, Rugo said.

Mylan has already introduced a biosimilar version of Herceptin in India, where more than 5,000 patients have received it, Rugo said. While the U.S. patent doesn’t expire until 2019, Mylan President Rajiv Malik said May 3 the drugmaker plans to file for Food and Drug Administration approval in the next few months. Roche officials declined to comment.

Breast cancer is the most common tumor type in women and the second most deadly after lung cancer, killing 40,000 women in the U.S. each year, according to the American Cancer Society. About one in five carry the genetic variant that causes excessive production of HER2, and Herceptin was the first drug approved in 1998 to directly target those cancers.

Herceptin improved the outlook for women with HER2 positive breast cancer so much that it’s one of the few medicines in oncology that has brand name power, said Don Dizon, clinical co-director of gynecologic oncology at Massachusetts General Hospital and chair of ASCO’s cancer communications committee. Oncologists may be slow to embrace a biosimilar version, particularly for women with early stage disease, for whom treatment may provide a cure, he said.

The study included 500 women with advanced disease given either Herceptin or MYL-1401O, plus chemotherapy, and tracked tfor six months. The researchers continue to monitor the women to determine if there are any differences in overall survival or the length of time it takes for the disease to progress. Earlier studies showed Herceptin may prolong survival by five months to eight months in women with advanced disease.

  • For more ASCO coverage, see NSE ASCO16