A groundbreaking phase 2 clinical trial conducted at Tianjin Medical University Cancer Institute & Hospital has demonstrated promising results for patients with locally advanced nasopharyngeal cancer (NPC) in non-endemic regions, using a novel combination therapy approach.
The study, conducted between January 2019 and March 2023, evaluated the efficacy of camrelizumab immunotherapy combined with induction chemotherapy followed by concurrent chemoradiotherapy (CCRT) in 61 patients from North China.
Treatment Protocol and Response Rates
The treatment regimen consisted of two 21-day cycles of camrelizumab (200 mg) combined with docetaxel and cisplatin, followed by CCRT. After completing induction therapy, the objective response rate reached 92.8%, with 27.3% of patients achieving complete response (CR) and 65.5% showing partial response (PR) in primary tumors.
Following CCRT, the overall response rate improved to 100%, with 92.8% of patients achieving CR in primary tumors and all patients showing CR in lymph nodes. Notably, among stage T4 patients, 80% achieved CR of nasopharyngeal lesions, while all stage N3 patients demonstrated complete lymph node response.
Survival Outcomes and Maintenance Therapy
The study reported impressive survival metrics:
- 3-year disease-free survival rate: 84%
- 3-year locoregional recurrence-free survival rate: 95.8%
- 3-year distant metastasis-free survival rate: 90.9%
- 3-year overall survival rate: 89.5%
Patients who received camrelizumab maintenance therapy showed additional benefits in disease control and survival compared to those who did not continue maintenance treatment.
Safety Profile and Adverse Events
The combination therapy demonstrated a manageable safety profile. The most common treatment-related adverse events during induction therapy included:
- Leukopenia
- Neutropenia
- Lymphopenia
- Nausea
- Anemia
Grade 3 or 4 adverse events occurred in 45.6% of patients during induction therapy, with leukopenia (12.3%) and neutropenia (10.5%) being most common. During CCRT, 41.1% of patients experienced grade 3 or 4 adverse events, primarily weight loss (10.7%) and lymphopenia (8.9%).
Significance for Non-Endemic Regions
This study marks the first phase 2 trial evaluating anti-PD-1 immunotherapy combined with induction chemotherapy and CCRT in non-endemic NPC patients. The results are particularly significant given the different patient characteristics in non-endemic regions, where the proportion of keratinizing and non-keratinizing subtypes is approximately equal, unlike in endemic areas.
The treatment regimen showed particular promise for patients with high tumor burden (T4 or N3 stage), suggesting its potential as a preferred treatment strategy for advanced cases in non-endemic regions.
Future Implications
While these results are encouraging, the researchers acknowledge the need for larger randomized controlled trials to validate these findings. The study also raises important questions about the optimal duration of maintenance therapy and its cost-effectiveness, particularly in regions with varying economic conditions.
