First-line treatment with HDACis plus tislelizumab combined with chemotherapy in advanced NSCLC: a single-arm phase II study.

BACKGROUND

Immune checkpoint inhibitors in combination with chemotherapy have been a common first-line treatment for non-small cell lung cancer (NSCLC), but they do not work for all patients. HDAC inhibitors (HDACis) may synergize with progressive disease (PD)-1 antibodies by inducing and activating cellular immunity. In this phase II study, we assessed the efficacy and tolerability of chidamide and tislelizumab in combination with chemotherapy in NSCLC patients.

METHODS

This was a single-arm, prospective study. Driver-gene negative locally advanced and metastatic NSCLC patients without prior systemic treatment were enrolled. Patients received chidamide, tislelizumab, and chemotherapy for 4-6 cycles and were then maintained by tislelizumab and chidamide. The primary endpoint was objective response rate (ORR), and secondary endpoints included disease control rate (DCR), progression-free survival (PFS), duration of response, overall survival (OS) and safety.

RESULTS

Twenty patients were enrolled in the study and most of them were PD-L1 1%-49% and PD-L1 < 1%. At the data cutoff, ORR was 80% (95% CI, 56.3-94.3), and DCR was 100%. The median follow-up was 23.4 months, the median PFS was 11.0 months (95% CI, 9.1-12.9m), and the median OS was 17.5 months (95% CI, 9.2-25.8m). Eleven patients (55.0%) had ≥ Grade 3 treatment-related adverse events (TRAEs). The most common ≥ Grade 3 TRAEs were leukopenia (25.0%) and neutropenia (20.0%). No patients died from treatment-related adverse events.

CONCLUSIONS

The combination of HDACi and tislelizumab with chemotherapy showed promising antitumor effects and manageable toxicity. More studies are needed to further confirm these results.

CLINICALTRIALS.GOV IDENTIFIER: ChiCTR2000041542.