The FDA Approves Tukysa™ for Metastatic HER2-Positive Breast Cancer

Seattle Genetics, Bothell, Washington recently issued an announcement through that the FDA approved Tukysa™ combined with capecitabine and trastuzumab for patients with metastatic HER2-positive breast cancer.

The drug combination has also proven effective in treating patients where the cancer has spread to the brain (brain metastases) and in cases where the cancer cannot be removed surgically (unresectable).

Patients whose cancer has metastasized (spread) and have received previous anti-HER2-based therapy are included in this group.

About HER2-Breast Cancer

HER2-positive breast cancer is generally more aggressive than HER2-negative breast cancer. It also has a higher rate of recurrence.

Patients develop tumors burdened with the protein HER2 or human epidermal growth factor receptor.

It is estimated that brain metastases will develop in approximately fifty percent of HER2-positive patients.

About Tukysa

Tukysa is a small molecule oral inhibitor of tyrosine kinases such as HER2, which is a protein responsible for the growth of cancer cells. Blocking the tyrosine kinases (enzymes) may prevent the growth of cancer cells. This is classified as targeted therapy.

About the HER2CLIMB Clinical Trial

Six hundred and twelve patients with advanced HER2+ breast cancer were randomly selected to engage in the HER2CLIMB trial investigating the combination of capecitabine, trastuzumab, and Tukysa. A total of forty-eight percent of enrolled patients were either diagnosed with treated or untreated brain metastases or had a history of significant brain lesions.

The cohorts included patients with metastatic or HER2-positive unresectable locally advanced breast cancer. These patients had received either a combination of ado-trastuzumab emtansine, pertuzumab, and trastuzumab or each of these drugs individually.

Primary and Secondary Endpoints

The endpoint of the trial was progression-free survival (PFS) in 480 out of 612 randomly selected patients.

Secondary outcome measures of all patients were overall survival and PFS, assessed in patients with brain metastases or who had a history of brain cancer.  Investigators also measured the percentage of patients whose cancers shrunk or dissolved after treatment (Objective Response Rate, ORR).

Trial Results

The combination of Tukysa together with capecitabine and trastuzumab reduced the risk of death by thirty-four percent when compared to capecitabine and trastuzumab alone.

The confirmed ORR with the addition of Tukysa was twice that of capecitabine and trastuzumab alone.

When patients who had brain metastases were treated with the Tukysa combination, the risk of either the progression of cancer or risk of death was reduced fifty-two percent in comparison to capecitabine and trastuzumab alone.

Adverse Events

In twenty percent of the patients receiving the Tukysa combination some of the more common adverse events included nausea, diarrhea, vomiting, abdominal pain, anemia, rash or headache.

Six percent of patients receiving the Tukysa combination experienced adverse reactions resulting in treatment discontinuation.

Two percent of the patients receiving Tukysa had fatal reactions which included sudden death, dehydration, cardiogenic shock and sepsis.

About Seattle Genetics, Inc.

Seattle Genetics is a biotechnology company based in Bothell, Washington. The company’s focus is on developing medicine that targets cancer. Seattle Genetics has offices in the European Union, California and Switzerland.

A spokesperson for the company stated that the results from the HER2CLIMB trial puts the Tukysa combination in a position of becoming the standard of care in cases of HER2-positive metastatic breast cancer.

Rose Duesterwald

Rose Duesterwald

Rose became acquainted with Patient Worthy after her husband was diagnosed with Acute Myeloid Leukemia (AML) six years ago. During this period of partial remission, Rose researched investigational drugs to be prepared in the event of a relapse. Her husband died February 12, 2021 with a rare and unexplained occurrence of liver cancer possibly unrelated to AML.

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