Patient characteristics
A total of 89 HCC patients received additional camrelizumab due to UP after initial TACE treatment in our hospital between May 2019 and January 2021. Of those, 28 were excluded due to concurrent ablation, resection, radiotherapy, or systemic therapies, 11 were excluded due to camrelizumab discontinuation, and 9 patients were excluded because they were lost to follow-up. Finally, 41 patients were included in this study (Figure 1). The situation I, II, and III of UP occurred in 11, 13, and 17 patients, respectively. A total of 150 TACE sessions were performed before the addition of camrelizumab, with a median TACE procedure of 3 (range, 1-19) per patient. The overall patient characteristics are shown in Table 1. In addition, 15 patients (36.6%) died during the observation period of the study.
Addition of camrelizumab to TACE
The 41 patients received 280 camrelizumab therapy sessions, with a median of 5 sessions (range, 1–17) per patient. Twenty-three patients received camrelizumab combined with TACE (hereafter, camrelizumab-TACE), in whom 52 combined TACE procedures were performed, with a median of 2 procedures (range, 1-6) per patient. The remaining 18 patients received camrelizumab alone due to TACE contraindications.
Tumor response
Imaging results 2-3 months after intervention indicated that 1 patient (2.4%) achieved CR, 9 patients (22.0%) achieved PR, and 15 patients (36.6%) achieved SD. Thus, the ORR is 24.4% and the DCR is 61.0%. Imaging results 6 months after intervention showed CR in 1 patient (2.4%), PR in 4 patients (9.8%), and SD in 19 patients (46.3%). Therefore, ORR was 12.2% and DCR was 58.5%.
Progression‑free survival
The median follow-up period from camrelizumab initiation to the study's end point was 7 months (range, 4–14 months). Of the 41 patients, 33 (80.5%) develop disease progression after addition of camrelizumab. The median PFS in this study was 6 months (95% CI: 3.8 months, 8.2 months) (Figure 2). Univariate analysis (Table 1) indicated that combination therapy and platelet-to-lymphocyte ratio (PLR) were significantly associated with PFS (P<0.05). At multivariable analysis (Table 2), combination therapy (camrelizumab-TACE) was significantly in connection with better PFS (P=0.003).
Subgroup analysis by treatment modalities
In this study, 23 patients received camrelizumab-TACE, and 18 patients received camrelizumab alone. The median PFS was 8 months (95% CI: 5.8 months, 10.2 months) and 3 months (95% CI: 2.7 months, 3.3 months) in the camrelizumab-TACE and camrelizumab subgroups (Figure 3), respectively, with a statistically significant difference between them (P<0.001).
Adverse events
Twenty-one (51.2%) patients developed post-embolization syndrome, including fever (n=18), abdominal pain (n=15), nausea and vomiting (n=10) within one week after TACE. After symptomatic treatment during hospitalization, the symptoms of all patients were relieved or significantly improved. In addition, there were no TACE related severe AEs such as liver abscess and biloma, and no allergic events occurred during camrelizumab injection.
During the follow-up period, 17 (41.5%) patients developed at least one type of AEs after treatment with camrelizumab (Table 3), and no patients developed severe AEs (more than grade III). Grade I/II AEs included reactive cutaneous capillary endothelial proliferation (RCCEP) (n=14), hypothyroidism (n=6), asthenia (n=2), rash (n=1), myositis (n=1), and pneumonitis (n=1). Of noted, the 2 patients with pneumonia and myositis who received glucocorticoids and were temporarily interrupted from camrelizumab demonstrated significant improvement in symptoms, and then resumed camrelizumab therapy. No treatment-related mortalities occurred.