New data presented at the European Society for Medical Oncology (ESMO) 2024 conference demonstrated that immunotherapy may improve long-term survival rates across various cancer types, including advanced melanoma, early-stage triple-negative breast cancer, and muscle-invasive bladder cancer.
The phase II CheckMate 067 trial, a study of immunotherapy with an anti–PD-1-based therapy in patients with advanced melanoma, reported a median overall survival of 71.9 months (approximately 6 years) in patients receiving combination immunotherapy with nivolumab plus ipilimumab. This represented the longest follow-up to date, with a minimum of 10 years of observation. The patients who showed no disease progression for at least 3 years after initial response to anti–PD-1-based immunotherapy demonstrated a 10-year melanoma-specific survival rate of 96%.
A study on early-stage triple-negative breast cancer reported statistically significant and clinically meaningful improvements in overall survival with immunotherapy plus chemotherapy administered prior to surgery, followed by continued immunotherapy postsurgery. The 5-year overall survival rate was 86.6% in the immunotherapy group compared with 81.2% in the placebo group. Given the aggressive nature of triple-negative breast cancer and its historical lack of response to common breast cancer treatments because of the absence of estrogen and progesterone receptors and normal HER2 levels, this finding marked a significant advancement.
The phase III NIAGARA study in patients with muscle-invasive bladder cancer demonstrated improved outcomes with immunotherapy (durvalumab) plus chemotherapy administered prior to radical cystectomy, followed by continued immunotherapy. Key findings included significantly longer event-free survival (hazard ratio [HR] = 0.68, 95% confidence interval [CI] = 0.56–0.82, P < .001) and improved overall survival (HR = 0.75, 95% CI = 0.59–0.93, P = .0106). Notably, immunotherapy did not compromise the ability to perform radical cystectomy, with completion rates of 88% in the immunotherapy group and 83% in the comparator arm.
In the CheckMate 067 trial, a small percentage of patients showing a good initial response to anti–PD-1-based immunotherapy, with no disease progression for at least 3 years, had died of melanoma at 10 years. The researchers suggested that there is potential for cure in patients responsive to these treatments.
"For patients who show no disease progression beyond three years, these longer-term results demonstrate that most of them never progress," noted Dr. Marco Donia, Associate Professor of Clinical Oncology at the National Center for Cancer Immune Therapy of Denmark, Copenhagen University Hospital Herlev.
In the triple-negative breast cancer study, the researchers revealed that the combination of chemotherapy and immunotherapy prior to surgery, followed by continued immunotherapy after surgery, might lead to a sensitization of triple-negative breast cancer to immunotherapy.
"At ESMO 2024, we are seeing many studies in different cancers showing that immunotherapy can work for a long time," indicated Dr. Alessandra Curioni-Fontecedro, Professor of Oncology at the University of Fribourg and Director of Oncology at the Hospital of Fribourg, Switzerland.
While these findings highlighted the promise of immunotherapy in cancer treatment across multiple tumor types, challenges remain. The researchers emphasized the need for more research on resistance mechanisms to immunotherapy and how to overcome them. Collaborative efforts between researchers and pharmaceutical companies are essential to address this issue and improve treatment outcomes for patients.