Since the approval of the first therapy targeting the HER2 protein in 1998, outcomes for people with an aggressive type of breast cancer, called HER2-positive, have improved dramatically. While there are now eight approved drugs that target HER2, the disease can still outsmart each of them over time. Because of this, there is still work to be done.
In this episode of Susan G. Komen’s Breast Cancer Breakthroughs series, we join Komen Scholar alumnus Dr. Ian Krop, medical oncologist at Yale Cancer Center, and Dr. Ciara O’Sullivan, medical oncologist at Mayo Clinic, to discuss the newest advances in breast cancer research that are moving the needle for people with HER2-positive breast cancer, including an exciting clinical trial that has the potential to change the standard of care for HER2-positive metastatic breast cancer (MBC) patients.
A Critical Need for More Treatment Options
Patient Advocate Carla Lloyd was diagnosed with stage 3 HER2-positive breast cancer over 11 years ago, and like many patients today, her initial diagnosis was a mixture of good and bad news. Carla’s doctor explained to her that she had a type of breast cancer that was aggressive and grew fast due to the HER2 protein, which acts like an accelerant. Thankfully, she received a treatment that included chemotherapy and the HER2-targeted therapy drug, trastuzumab (also known as Herceptin), which attacked every HER2-covered cell in her body.
“I felt my doctor did a very good job of putting the seriousness of this type of breast cancer in layman’s terms and then reassuring me that I was going to receive targeted treatment to get after the type of cancer I had,” Carla says.
And while patients like Carla generally experience good outcomes from the current standard treatments, many still experience disease progression. As tumors evolve over time and become resistant to drugs, patients often run out of effective treatments. Because of this, only about 30% of those living with metastatic breast cancer will live longer than five years.
Another challenge is that up to 50% of people with metastatic HER2-positive breast cancer develop metastasis to the brain, which can be difficult to treat. For these reasons, breast cancer researchers are seeking new therapies that maintain long-term effectiveness and combat metastasis.
New Choices for Patients on the Horizon
In this episode of Breast Cancer Breakthroughs, Dr. Krop shares some of the new treatment approaches for metastatic HER2-postive breast cancer, including adding immunotherapy, improving first-line therapy and trying new combinations of HER2-targeted drugs. One of these ongoing trials, the HER2CLIMB-05 trial, seeks to improve first-line therapy with a new combination of HER2-targeted therapies. One of these ongoing trials, the HER2CLIMB-05 trial, seeks to improve first-line therapy with a new combination of HER2-targeted therapies.
In this trial, researchers are testing to see whether adding tucatinib to the first-line standard of care for metastatic HER2-positive breast cancer will delay progression. If successful, this trial will replace the current first-line treatment regimen that has been the standard of care for these patients for over 10 years.
Dr. O’Sullivan, a member of the HER2CLIMB-05 steering committee, is excited about what this trial could also mean for preventing brain metastases or treating existing brain metastases.
“Because tucatinib penetrates or gets effectively into the brain, which not all of the medications that we use to treat HER2-positive breast cancer can do, it looks really promising in this setting,” she says. “I’m hopeful that tucatinib, combined with trastuzumab and pertuzumab, will improve disease control and overall survival in patients with HER2-positive advanced breast cancer treated in the first-line setting.”
Delivering Hope Through Research
Eleven years after her initial diagnosis, Carla is no longer in treatment and only sees her doctor every six months for a checkup and blood work. She says that she is grateful for the relentless drive and commitment of the researchers who work very hard to make every small advance possible, which brings patients a sense of hope and order when their situation feels out of their control.
“For me, I think it starts with that respect and admiration and sheer appreciation of the researchers that bring forth those new treatments,” Carla says. “They’re managing my body that had become unmanageable for reasons I can’t understand. They develop something new and innovative that can give us hope that we will get through this disease.”