Efficacy

Nerlynx (neratinib) Efficacy in Breast Cancer

Nerlynx (neratinib) is an oral kinase inhibitor specifically designed to block a group of enzymes that promote cell growth, including those in HER2-positive breast cancer. The efficacy of Nerlynx in breast cancer was demonstrated in the ExteNET study, a large international, double-blind, placebo-controlled, phase III trial. The trial included patients with HER2-positive early-stage breast cancer who had completed adjuvant trastuzumab therapy. The results showed that Nerlynx significantly improved 2-year invasive disease-free survival (iDFS) compared to placebo, reducing the risk of breast cancer recurrence or death by 34%. This benefit was observed across various patient subgroups, indicating its potential as an extended adjuvant therapy for HER2-positive breast cancer patients.

Despite the positive outcomes, the use of Nerlynx is associated with a high incidence of diarrhea, which can be severe. Patients are usually co-prescribed antidiarrheal medications to manage this side effect. Ongoing studies continue to evaluate the long-term benefits and optimal duration of Nerlynx therapy in the adjuvant setting, as well as its efficacy in combination with other treatments for breast cancer.

Tukysa (tucatinib) Efficacy in Breast Cancer

Tukysa (tucatinib) is another oral kinase inhibitor that targets HER2-positive breast cancer. Its efficacy was notably demonstrated in the HER2CLIMB trial, a randomized, double-blind, placebo-controlled, global phase II trial. The study included patients with HER2-positive metastatic breast cancer, including those with brain metastases. The results indicated that Tukysa, in combination with trastuzumab and capecitabine, significantly improved progression-free survival (PFS) and overall survival (OS) compared to the placebo group. The addition of Tukysa to the treatment regimen reduced the risk of disease progression or death by 46% and the risk of death by 34%.

Importantly, Tukysa has shown activity in patients with brain metastases, a group that has historically been challenging to treat. The data suggested that Tukysa can cross the blood-brain barrier and provide clinical benefit to this patient population. The safety profile of Tukysa is generally manageable, with diarrhea, palmar-plantar erythrodysesthesia syndrome, and elevated liver enzymes being the most common adverse events. Ongoing research is focused on further defining Tukysa's role in the treatment landscape of HER2-positive breast cancer, including its use in earlier lines of therapy and in combination with other agents.