1297P - An open-label, prospective phase II study of tislelizumab in combination with chidamide as consolidation therapy in locally advanced, unresectable, stage III NSCLC

Background

The PACIFIC trial established consolidation therapy with PD-L1 inhibitor as standard of care for patients with unresectable, stage III NSCLC and no disease progression after definitive chemoradiotherapy (CRT). PD-1 antibodies may synergize with HDAC inhibitors by inducing and activating NK cell and cytotoxic T cell (CTL) -mediated cellular immunity in previous studies. It is worth exploring new regimens to further improve survival for this population.

Methods

This was an open-label, prospective study. Patients with histologically or cytologically documented stageⅢ,locally advanced, unresectable NSCLC without progression following definitive platinum-based concurrent chemoradiation therapy (2∼4 cycles) were enrolled. After cCRT, patients received Tislelizumab 200 mg Q3W intravenously and Chidamide 30 mg twice weekly orally. The primary endpoint was safety. Secondary endpoints include 6-month and 12-month PFS rates、OS and ORR. Tumor response was assessed using RECIST V1.1.

Results

At the data cut-off April 22, 2023(median follow-up time, 23.6m), 19 patients were enrolled, mean-aged was 66.3 years (range: 53-78). Patients received combination consolidation therapy for a median of 6.37 months. Adverse events of any cause and grade occurred in 68.4% (13). 3 patients (16.7%) had Grade≥3 TRAEs. The most common Grade≥ 3 TRAEs were pneumonitis (10.5%). The confirmed ORR was 84.2% (95%CI:60.4%-96.60%). The DCR was 100%. Median PFS was 20.5 months (95%CI: 4.37m-NA), and 6-month and 12-month PFS rate were 65.7% (95%CI:38.8%-83.0%) and 58.4% (95%CI:31.5%-77.8%), respectively.

Conclusions

Tislelizumab combined with Chidamide showed encouraging antitumor activity and a favorable safety profile as consolidation therapy for locally advanced, unresectable stage III NSCLC. Further sample and longer follow-up are required to obtain more accurate results.

Table: 1297P

Incidence of TRAEs

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Beijing Cancer Prevention & Treatment Society.

Disclosure

All authors have declared no conflicts of interest.