UK approval for Seagen’s oral HER2 inhibitor Tukysa

Seagen’s oral HER2 drug Tukysa has been granted authorisation by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA) for the treatment of HER2-positive advanced breast cancer.

The MHRA has cleared Tukysa (tucatinib) as an add-on therapy to Roche’s anti-HER2 antibody Herceptin (trastuzumb) plus Xeloda (capecitabine) for adults patients with HER2-positive locally-advanced or metastatic breast cancer who have previously received at least two anti-HER2 treatment regimens.

In the HER2CLIMB trial, which the MHRA approval is based on, Tukysa plus Herceptin and Xeloda achieved a 46% reduction in the risk of disease progression or death compared to the two Roche drugs given alone.

Tukysa also met two secondary objectives in the trial, with a 34% reduction in the risk of death, and a 52% fall in the risk of disease progression or death in patients whose cancer had metastasised into the brain at the time they were enrolled in the study.

“The Tukysa combination is a landmark therapy for patients with HER2-positive metastatic breast cancer with or without brain metastases, extending overall survival in these patients after two prior anti-HER2-treatment regimens,” said Clay Siegall, chief executive officer at Seagen.

“We are pleased Tukysa is now authorised in the UK, and we look forward to further collaborating with the national reimbursement bodies to ensure it is available to adult patients,” he added.

Last week, the European Commission also approved Tukysa in the HER2-positive advanced breast cancer setting.

The EC approval for Tukysa is valid in Northern Ireland, while the MHRA authorisation covers England, Scotland and Wales.

The oral HER2 inhibitor is also approved in the US for the treatment of HER2-positive advanced cancer.

The US Food and Drug Administration (FDA) approved Seagen’s drug as part of Project Orbis, an initiative of the US FDA Oncology Center of Excellence that provides a framework for concurrent submission and review of oncology medicines among international partners.

In 2019, Seagen announced that it had initiated another trial of Tukysa – the HER2CLIMB-02 study – that will compare Tukysa to placebo in combination with Kadcyla (ado-trastuzumab emtansine) in HER2-positive advanced breast cancer.

The study will include patients with brain metastases and those who have had prior treatment with taxanes and Herceptin in any setting.