Key Takeaways:
- The new cancer medicine Tukysa (tucatinib) in conjunction with trastuzumab and capecitabine, dramatically improved outcomes for those with HER2+ advanced breast cancer that has spread to the brain.
- At 12 months, 40% of patients who were treated with tucatinib were alive and free of brain metastasis progression vs. none of the patients who were treated with a placebo
- In those with a brain metastasis that was still progressing, the average overall survival (OS) was extended from 11.6 months with a placebo to 20.7 months with medicine tucatinib
- Overall, the addition of tucatinib to medicines trastuzumab and capecitabine scaled down the probability of brain metastasis progression or death by two-thirds
- As per data presented by Nancy U. Lin, MD, Associate Chief, Division of Breast Oncology, Dana-Farber Cancer Institute, Boston, MA, at the 2020 ASCO annual meeting, Tukysa, when used in conjunction with trastuzumab and capecitabine, dramatically enhanced outcomes for patients with HER2 +Ve advanced breast cancer that has progressed to the brain.
Tukysa (tucatinib) falls under the member of the TKI drug class and is currently authorized only to treat HER2 +Ve breast cancer. It is the first TKI to show an enhancement in overall survival (OS) in patients with this kind of breast cancer.
In April 2020, the agency FDA approved tucatinib in conjunction with two medications trastuzumab and capecitabine to treat adults with advanced HER2 +ve breast cancer that cannot be eliminated by surgery or that has metastasized to other organs of the body, including the brain, and who have received at least one other anti-HER2 therapy. This approval took place on behalf of the findings of the HER2CLIMB phase 3 clinical trial.
HER2CLIMB CLINCAL TRIAL:
In this clinical trial, 612 patients who were already treated with trastuzumab, pertuzumab, and Kadcyla were randomly assigned to 1 of 2 groups. One group of 410 patients received Tukysa (tucatinib) orally twice daily, in conjunction with trastuzumab and capecitabine. A smaller group of 202 patients were taken placebo together with trastuzumab and capecitabine.
The first results from the study showed that patients who were treated with Tukysa (tucatinib) lived longer even without the cancer progressing further. These remarkable survival outcomes applied to all patients, including those who had or did not have brain metastases.
At the ASCO meeting, Dr. Nancy`s focus was on the 291 patients who had brain metastases while joining the clinical trial.
“At 12 months, 40% of those randomized to Tukysa (tucatinib) vs. 0% of those randomized to placebo were alive and free of CNS progression, and at 12 months, 70% of those randomized to Tukysa (tucatinib) were alive vs. 47% of those randomized to placebo,” Dr. Nancy noted.
The average OS, or the length of time from the beginning of treatment that half of the patients in the study were still alive, was 18.1 months with Tukysa (tucatinib) in comparison to 12 months in those who did not receive Tukysa (tucatinib), which is an enhancement of beyond 6 months.
In those with brain metastases that were becoming worse, the average OS was 11.6 months in the placebo population in comparison to 20.7 months in the Tukysa (tucatinib) population, which was beyond nine month enhancement in the average of survival for those whose cancer had progressed to the brain and was progressing.
Reference:
https://conquer-magazine.com/issues/special-issues/august-2020-asco-highlights/1329-tukysa-improves-survival-in-patients-with-her2-positive-breast-cancer-that-has-spread-to-the-brain
