Skip to main content
Premium Trial:

Request an Annual Quote

Seagen Eyeing HER2 Breast Cancer Indication for Tukysa-Kadcyla Based on Positive Phase III Data

NEW YORK – Seagen on Wednesday said that it plans to discuss positive results from a Phase III trial of Tukysa (tucatinib) with Genentech's Kadcyla (trastuzumab emtansine) in metastatic HER2-positive breast cancer with the US Food and Drug Administration.

Tukysa and Kadcyla are both anti-HER2 therapies; the former is a tyrosine kinase inhibitor that blocks the HER2 protein on cancer cells, and the latter is an antibody-drug conjugate that attaches to HER2 receptors on cancer cells and releases a cytotoxic payload.

In the HER2CLIMB-02 trial, Seagen is comparing the dual HER2-targeted treatment combination's activity against Kadcyla and placebo in patients with HER2-positive metastatic or unresectable breast cancer who have received a taxane and trastuzumab in any setting. The Bothell, Washington-based company said the trial met its primary endpoint by showing that patients on the Tukysa-containing regimen had longer progression-free survival than those on just Kadcyla. Overall survival data are not yet mature in the study.

"We are encouraged by these results for Tukysa in combination with Kadcyla in metastatic HER2-positive breast cancer including in patients with brain metastases," Roger Dansey, president of R&D and chief medical officer at Seagen, said in a statement. "We plan to present the HER2CLIMB-02 data at an upcoming medical meeting and discuss the results with the FDA."

Tukysa in combination with Genentech's first-generation HER2-targeted drug Herceptin (trastuzumab) and capecitabine is approved in the US for treating patients with unresectable or metastatic HER2-positive breast cancer including those with brain metastases who have received one or more anti-HER2-based regimens.

The FDA also granted accelerated approval to the Tukysa-Herceptin combination in January for patients with metastatic colorectal cancer whose tumors are RAS wild-type and HER2-positive and who have received prior chemotherapy. The FDA approved the regimen based on data from the Phase II MOUNTAINEER trial, in which 38 percent of 84 advanced colorectal cancer patients on Tukysa-Herceptin experienced tumor shrinkage.