HER2 Support Group Forums - Breast cancer drug could replace traditional chemotherapy for certain patients

Promising breast cancer drug could reshape treatment

Ian Krop. Study finds drugs that can overcome drug resistance in HER2-positive breast cancer

By ALEXI COHAN | alexi.cohan@bostonherald.com | Boston Herald
PUBLISHED: June 15, 2019 at 7:23 pm | UPDATED: June 15, 2019 at 9:10 pm

A breast cancer drug with the potential to replace traditional chemotherapy is accelerating through clinical development and could soon offer patients who previously had limited options an effective treatment.

Over 400,000 people are diagnosed with HER2-positive breast cancer each year, a type of cancer that learns to resist the drugs designed to attack it. Women with HER2 can start by taking the breast cancer drug Herceptin, then often move to Kadcyla once the cancer becomes resistant.

After the disease overpowers Kadcyla, there is no standard course of action, according to Dr. Ian Krop, clinical research director of the Breast Oncology Center at Dana-Farber Cancer Institute.

That’s where the DS-8201 cancer treatment, developed by Japanese company Daiichi Sankyo, comes in.

The drug works by attaching chemotherapy to antibodies that offer a targeted attack on cancer cells and milder side effects compared to traditional chemotherapy.

Krop said that in clinical trials, 90% of patients saw some degree of tumor shrinkage. The treatment has also been seen to double survival time for advanced breast cancer patients to 20 months from 10 months.

Krop called the results “precedent-setting.”

“People run out of treatments that work eventually and then we are kind of stuck,” said Krop. “What’s really kind of special about this new drug is that it seems to start working when all the other drugs have stopped working.”

“I think this drug can definitely replace chemotherapy,” said Krop.

Clinical trials of DS-8201 started at Dana-Farber three years ago and Krop has seen the results in his own patients, some who travel a great distance for access to the treatment.

“It’s been a great experience to be involved with this because it looks like it will be a real breakthrough for these patients,” said Krop. He added that his patient’s pain levels and symptoms have improved while on the drug and CAT scans show the cancer has regressed considerably.

Krop said there are still some side effects for patients taking DS-8201, like hair loss, some nausea and some lowering of blood counts, however they are more mild than the side effects of traditional chemotherapy.

Cheryl Osimo, a breast cancer survivor and executive director of the Massachusetts Breast Cancer Coalition, knows the devastating side effects of chemotherapy all too well.

“My chemotherapy affected my vision. I lost all my hair. For some women, it affects every part of their being, every part of their body,” said Osimo. “It can be debilitating because you feel nauseous a lot.”

Osimo said, “A treatment that has milder effects and is more effective can provide people with hope, once you run out of treatment options … you become hopeless, so the more options the better.”

Daiichi Sankyo is currently accelerating its biologics license application, meaning that the drug could be approved by the Food and Drug Administration sooner than expected. Krop said it could be approved sometime in 2020.

Krop said looking toward the future, DS-8201 also has the potential to work in lung or stomach cancers.

The breakthrough drug is also expected to prompt major changes in the market as the company announced it will partner with AstraZeneca to develop and commercialize DS-8201 in many countries worldwide. The deal sees AstraZeneca paying Daiichi Sankyo up to $6.9 billion in total.