Abstract 447P
Background
KN-048 lacks data on the Chinese population, and also there is limited information regarding the use of pembrolizumab in locally curable R/M HNSCC. This study aims to investigate the efficacy and safety of pembrolizumab in two populations.
Methods
Data comes from 19 hospitals in China. R/M HNSCC pts who received pembrolizumab monoterapy or combination with chemotherapy/targeted therapy from July 2020 to January 2024 were reviewed by searching the hospital HIS/medical record system. The primary endpoint was OS, secondary endpoints include time of pembrolizumab treatment (TOPT), safety, etc. Investigators also explored the impact of different biomarkers on survival. This study used IBM SPSS Statistics 29 to analyze the data.
Results
Total 291 pts were included. Basline was shown in the table. 22.5% of pts experienced Immune-related adverse events (irAEs), with G1-4 myelosuppression was the most common (36.8%). The main irAEs of G3-4 were myelosuppression (10.9%) and pneumonia (7.2%). The median follow-up time was 18.5 months (m). The results showed that the mOS of whole pts was not reach. Surgery or RT option (Yes - Arm 1, No - Arm 2) was related to OS in Cox analysis. mOS of Arm 1 vs Arm 2 was NR vs 19.6 mo (HR=2.33, 95%CI:1.52-3.56, p<0.001), and 18mo-OS of Arm 1 was 74.7%. In Arm 1, PS=0 has better TOPT than PS=1-2 (5.6m vs 2.5m, HR=1.73, 95%CI:1.14-2.64, p=0.01). Smoking was significantly associated with worse OS (NR vs 14.3m, HR=1.98, 95%CI:1.20-3.27, p=0.008) and TOPT (5.1m vs 2.5m, HR=1.56, 95%CI:1.10-2.30, p=0.026) in Arm 2. In univariate analyses, tumor shrinkage reached CR/PR was significantly better with OS and TOPT in both of Arm 1 and Arm 2. Pts with CPS ≥ 20 and 1-19 both had significantly better OS and TOPT than those with CPS <1. (Table). Table: 447P
| Characteristics | N (%) | |
| PS | 0 | 84 (28.7) |
| 1 | 198 (67.6) | |
| 2 | 9 (3.1) | |
| Smoking | Yes | 134 (46.0) |
| Sex | M | 219 (75.2) |
| Age | >=65 | 96 (32.9) |
| Location | Oral | 194 (66.6) |
| Oropharyngeal | 28 (9.6) | |
| Laryngeal | 26 (8.9) | |
| Hypopharyngeal | 21 (7.2) | |
| Nasal sinus | 15 (5.1) | |
| Unknown | 7 (2.4) | |
| Previous therapy | Surgery | 242 (83.1) |
| RT | 148 (50.8) | |
| Chemotherapy | 122 (41.9) | |
| CPS | >=20 | 52 (17.9) |
| 1-19 | 44 (15.1) | |
| <1 | 10 (3.4) | |
| Unknow | 185 (63.6) | |
| p16 (Oropharyngeal - 20 tested) | Postive | 9 (45.0) |
| Disease status | Only local recurrence | 114 (39.2) |
| Only metastasis | 91 (31.3) | |
| Local recurrence and metastasis | 73 (25.1) | |
| Newly diagnosed disease | 13 (4.4) | |
| Surgery or RT option | Yes | 144 (49.4) |
| Treatment | Monotherapy | 51 (17.5) |
| Chemotherapy | 197 (67.7) | |
| Target therapy | 26 (8.9) | |
| Others | 17 (5.8) |
Conclusions
Pembrolizumab showed good efficacy and safety in the Chinese population with R/M HNSCC. The data of the two Arms still need to be further explored separately.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.