Efficacy

Efficacy of Kadcyla (trastuzumab emtansine) in Breast Cancer

Kadcyla (trastuzumab emtansine) is a targeted therapy drug used in the treatment of HER2-positive breast cancer. This medication is designed to combine the HER2 targeting properties of trastuzumab with the chemotherapy agent DM1 (emtansine), allowing for direct delivery of the cytotoxic agent to the cancer cells. Clinical trials have demonstrated that Kadcyla significantly improves survival rates in patients with metastatic HER2-positive breast cancer, particularly those who have previously received trastuzumab and a taxane, separately or in combination. In a pivotal trial, Kadcyla extended progression-free survival (the time during and after treatment that a patient lives with the disease without it getting worse) compared to the standard therapy.

Kadcyla is also approved for use as an adjuvant treatment for HER2-positive early breast cancer in patients who have residual invasive disease after neoadjuvant taxane and trastuzumab-based treatment. In this setting, Kadcyla has been shown to improve invasive disease-free survival, reducing the risk of recurrence of breast cancer or death compared to trastuzumab alone. The use of Kadcyla in earlier stages of breast cancer aims to provide a more effective treatment option to prevent disease progression and improve long-term outcomes.

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

Enhertu (fam-trastuzumab deruxtecan-nxki) is another novel agent for the treatment of HER2-positive breast cancer. It is an antibody-drug conjugate that combines a HER2-targeted antibody with a topoisomerase inhibitor payload, delivered directly to the cancer cells. Enhertu has shown substantial efficacy in the treatment of patients with HER2-positive metastatic breast cancer who have received two or more prior anti-HER2-based regimens. Clinical trials have reported that Enhertu significantly improves progression-free survival and overall survival in this patient population, with a notable percentage of patients achieving objective response rates, meaning their tumors shrank or disappeared after treatment.

Furthermore, Enhertu has been studied in patients with HER2-low expressing breast cancer, which is defined as tumors with low levels of HER2 that do not qualify as HER2-positive. In this subset of breast cancer, Enhertu has demonstrated promising efficacy, expanding the potential therapeutic options for a broader group of breast cancer patients. The drug has been granted accelerated approval for this indication based on the response rates and duration of response observed in clinical trials, with continued approval contingent upon verification and description of clinical benefit in confirmatory trials.