A new treatment strategy for triple-negative breast cancer (TNBC) has demonstrated encouraging outcomes in a phase 1 clinical trial conducted at Roswell Park Comprehensive Cancer Center. The study, which combined chemotherapy with a novel immunotherapy approach, achieved a high rate of complete remission without the severe immune-related side effects often associated with other immunotherapy regimens.
The clinical trial, led by Dr. Shipra Gandhi, enrolled nine patients with early-stage TNBC. TNBC, accounting for 10-20% of all breast cancers, is known for its aggressive nature and high mortality rate, even when diagnosed early. The results, published in The Journal for ImmunoTherapy of Cancer, indicate a significant step forward in addressing this challenging disease.
High Remission Rate Without Severe Side Effects
Of the nine patients, five achieved complete remission, and one experienced near-complete remission, resulting in an overall remission rate of approximately 66%. This outcome is comparable to the current standard regimen that combines neoadjuvant chemotherapy with pembrolizumab. However, the Roswell Park regimen distinguishes itself by the absence of immune-related adverse events, a significant advantage given the potentially serious and sometimes fatal nature of these side effects.
"We are very excited with these promising results from our study of a new treatment combination for patients with this most highly aggressive form of breast cancer, triple-negative breast cancer," said Dr. Gandhi. She emphasized the need for validation in a larger study due to the small initial patient cohort.
Chemokine Modulatory Regimen (CKM) Details
The treatment involved neoadjuvant chemotherapy with paclitaxel, combined with a chemokine modulatory regimen (CKM). The CKM therapy included rintatolimod, interferon alfa-2b, and celecoxib. Patients also received doxorubicin and cyclophosphamide. This combination aims to prevent tumor cell growth and enhance the body's immune response against the cancer.
The rationale behind the CKM regimen is based on the observation that higher numbers of cytotoxic T lymphocytes (CTLs) in a patient’s tumor after neoadjuvant chemotherapy correlate with a greater likelihood of complete remission. The researchers found that administering rintatolimod and interferon alpha together increased beneficial chemokines that attract CTLs while suppressing undesirable chemokines that attract regulatory T cells (Tregs), which can limit the immune system’s ability to fight the tumor. The study also showed that the CKM regimen triggered the production of beneficial chemokines in tumor tissue but not in healthy tissue.
Scientific Rationale
According to Dr. Pawel Kalinski, the scientific lead of the research, the study was informed by the understanding that a robust presence of cytotoxic T lymphocytes (CTLs) within a patient's tumor following neoadjuvant chemotherapy is indicative of a higher likelihood of complete remission. The team demonstrated that the combined administration of rintatolimod and interferon alpha effectively elevated the levels of beneficial chemokines, which are responsible for attracting CTLs. Simultaneously, this combination suppressed undesirable chemokines that attract regulatory T cells (Tregs), which can hinder the immune system's tumor-fighting capabilities. Their work also demonstrated that the CKM regimen triggered production of beneficial chemokines in tumor tissue but not in healthy tissue. The clinical trial results reflected the results of the preclinical work; patients’ tumors contained higher numbers of CTLs after the chemotherapy/immunotherapy combination was administered.
Future Directions
While these initial results are promising, further research is necessary to confirm the efficacy and safety of this novel treatment approach in a larger and more diverse patient population. The ongoing studies will help determine the optimal use of the CKM regimen in the treatment of triple-negative breast cancer and potentially other types of cancer.
