Posted: Friday, March 10, 2023
Talimogene laherparepvec (T-VEC) is a modified herpes simplex virus that stimulates the immune system and is believed to enhance responses to neoadjuvant chemotherapy in individuals with triple-negative breast cancer. Results from a phase II clinical trial, conducted by Hatem Soliman, MD, and colleagues at Moffitt Cancer Center, Tampa, Florida, were published in Nature Medicine. The findings from the study, which investigated the use of T-VEC in combination with neoadjuvant chemotherapy in triple-negative breast cancer, support the continued investigation of this combination therapy.
A total of 37 patients with stage 2 to 3 triple-negative breast cancer received T-VEC plus neoadjuvant chemotherapy, and the primary endpoint was met, with estimated rate of residual cancer burden (RCB)-0 of 45.9%, and the RCB-1 descriptive rate was 65%. The 2-year disease-free rate was 89%, and immune activation during treatment seemed to correlate with response, according to the authors. Common toxicities associated with the use of T-VEC included fevers, chills, headache, fatigue, and injection-site pain. Four thromboembolic events occurred during the trial.
The researchers also analyzed levels of immune biomarkers and assessed whether these biomarkers correlated with patient responses. They discovered that most tumor samples had higher levels of T cells and activation of immune signaling pathways during the first 6 weeks of treatment. Patients who had better responses to therapy had higher levels of CD8 T cells at week 6 than patients who did not respond as well to therapy. These observations suggest that activating an immune response earlier may lead to better outcomes in patients with triple-negative breast cancer.
Disclosure: For full disclosures of the study authors, visit www.nature.com.