Results

Patients

Between November 2018 and December 2019, a total of 151 HCC patients received PD-1 targeted immunotherapy in our hospital (Figure 1). The data collection cut-off time was December 31, 2019. Seventy-six patients were excluded because of incomplete data (n=63) or follow-up shorter than 6 weeks (n=13). The remaining 75 patients were divided into 3 treatment groups based on the antibody used: toripalimab (n=26), camrelizumab (n=33) and sintilimab (n=16). The demographic and laboratory characteristics at baseline are shown in Table 1. The mean duration of follow-up was 22.7 ± 12.6 weeks for all patients, 31.3 ± 7.4 weeks for toripalimab group, 15.1 ± 9.7 for camrelizumab group and 23.3 ± 14.7 for sintilimab group. The mean number of cycles of PD-1 therapy at cut-off were 4.8 ± 2.7 for all patients, 5 ± 1.9, 4 ± 3 and 5.5 ± 3.1 for toripalimab, camrelizumab and sintilimab groups respectively.

Efficacy

Seventy-five patients, who had at least one follow-up imaging result, were included in the assessment of tumor responses (Table 2). In the toripalimab group (n=26), no patient had complete response (CR), 4 patients achieved partial response (PR), and 10 patients had stable disease (SD), resulting in an objective response rate (ORR) of 15.4% and disease control rate (DCR) of 53.8%. In the camrelizumab-treated patients (n=33), the ORR and DCR was 12.1% and 78.8%, with 2, 2 and 22 patients had CR, PR and SD respectively. In the sintilimab group (n=16), 1 and 4 participants achieved CR and PR, respectively. Nine patients had stable disease and 2 showed progressive disease (PD). The ORR was 31.3% and DCR was 87.5% for this treatment group. The overall ORR and DCR of this whole cohort was 17.3% and 72.0% respectively. Amongst the three groups, the sintilimab-treated patients appeared to have the best tumor responses, and the toripalimab group the worst. However, due to the heterogeneous nature of patients and these therapies, the data generated from this small cohort do not suffice to make any statistical conclusion.
The median progression-free survival (PFS) of this whole cohort was 40.7 (95% CI, 34.7-46.7) weeks (Figure 2, Table 2); and 28.1 (95% CI, 23.0-33.2) weeks, 30.0 (95% CI, 23.3-36.8) and 49.5 (95% CI, 38.8-60.2) weeks for toripalimab, camrelizumab and sintilimab, respectively (Figure 3, Table 2). Overall, 21 (28.0%) patients had radiological disease progression during follow-up. Median time to tumor progression (TTP) was 45.7 (95% CI, 40.5-60.0) weeks for the whole population (Figure 4, Table 2), and 30.6 (95% CI, 25.6-35.7) weeks, 32.5 (95% CI, 26.1-39.0) and 54.7 (95% CI, 48.5-60.9) weeks for toripalimab, camrelizumab and sintilimab, respectively (Figure 5, Table 2). Six patients (6/75, 8.0%) died during follow-up. The median overall survival (OS) was 51.1 (95% CI, 46.4-55.9) weeks for the whole population (Figure 6), and 37.9 (95% CI, 35.9-40.0) weeks, 40.0 (95% CI, 38.6-41.4) and 52.8 (95% CI, 43.8-61.7) weeks for toripalimab, camrelizumab and sintilimab, respectively (Figure 7, Table 2).

Safety

All recorded treatment related adverse events (TRAE) are shown in Table 3. Twenty-nine patients (29/75, 38.7%) experienced at least one adverse event (AE). Overall, the most frequent AEs were rash (15/ 75, 20.0%), hypertension (12/75, 16.0%), fatigue (10/75, 13.3%), paresthesia (10/75, 13.3%) and diarrhea (8/75, 10.7%). One patient died due to myocarditis, which was probably related to camrelizumab as it erupted after one cycle of treatment. A dose delay due to adverse events was required in 2 patients (2/26, 7.7%) treated with toripalimab, 4 patients (4/33, 12.1%) treated with camrelizumab and 1 (1/16, 6.3%) receiving sintilimab. Steroids or immunosuppressive drugs were used to treat an adverse event in 10 patients (10/75, 13.3%), of which 3 (3/26, 11.5%) were treated with toripalimab, 6 (6/33, 18.2%) with camrelizumab, and 1 (1/16, 6.3%) with sintilimab.