Efficacy

Efficacy of Enhertu (fam-trastuzumab deruxtecan-nxki) in Breast Cancer

Enhertu (fam-trastuzumab deruxtecan-nxki) is a novel antibody-drug conjugate that has shown significant efficacy in the treatment of breast cancer, particularly in patients with HER2-positive metastatic breast cancer. This targeted therapy combines an anti-HER2 antibody with a cytotoxic chemotherapy agent, allowing for the direct delivery of the chemotherapy to the cancer cells overexpressing the HER2 protein. Clinical trials have demonstrated that Enhertu significantly improves progression-free survival (PFS) and overall survival (OS) in patients with HER2-positive metastatic breast cancer who have previously received two or more anti-HER2-based regimens.

The pivotal phase II study, DESTINY-Breast01, revealed that Enhertu led to a robust objective response rate (ORR) in a majority of patients, with a notable number achieving complete response. The durability of the response was also a key finding, with many patients maintaining their response for an extended period. These results have positioned Enhertu as an important treatment option for patients with HER2-positive breast cancer who have exhausted other therapeutic options.

Efficacy of Tukysa (tucatinib) in Breast Cancer

Tukysa (tucatinib) is an oral tyrosine kinase inhibitor that is used in combination with trastuzumab and capecitabine for the treatment of adult patients with advanced unresectable or metastatic HER2-positive breast cancer, including those with brain metastases. Tukysa has been shown to be effective in inhibiting the growth of HER2-positive cancer cells. The drug's efficacy was demonstrated in the pivotal HER2CLIMB trial, where it significantly improved PFS and OS in patients with HER2-positive metastatic breast cancer, including those with brain metastases, who had received previous anti-HER2 therapies.

In the HER2CLIMB trial, the addition of Tukysa to trastuzumab and capecitabine resulted in a 46% reduction in the risk of disease progression or death compared to trastuzumab and capecitabine alone. Moreover, the trial showed that Tukysa could cross the blood-brain barrier and was effective in treating brain metastases, a common and challenging complication in HER2-positive breast cancer patients. This finding is particularly significant as it addresses an unmet need in the treatment of this patient population, offering hope for improved outcomes.