164P - TQB2450 plus anlotinib combined with paclitaxel and cisplatin as first-line treatment of advanced esophageal squamous cell carcinoma (ESCC): a single-arm, multicenter phase II trial

Background

Immunotherapy combined with chemotherapy as first-line treatment in advanced ESCC has been the standard of care. Previously results demonstrated anlotinib, whether combined with chemotherapy as first-line regimen or monotherapy as second-line treatment, had encouraging efficacy and manageable toxicity in advanced ESCC. TQB2450 is a humanized anti-PD-L1 monoclonal antibody, which could recovery T-cells activity and enhance immune responses by preventing the binding of PD-L1 to PD-1 and B7.1 receptors on the surface of T cells. Here, we conducted a phase II trial to evaluate the efficacy and safety of anlotinib combined with TQB2450, cisplatin and paclitaxel as first-line therapy in advanced ESCC.

Methods

Eligible patients (pts) with advanced ESCC who had not previous systemic therapy received TQB2450 (1200mg, iv, d1, q3w) plus anlotinib (10mg, po, d1∼14, q3w) combined with paclitaxel (135mg/m², iv, d1, q3w) and cisplatin (60∼75mg/m², iv, d1∼3, q3w) for 4 to 6 cycles as initial therapy. Patients, who did not have progressive disease (PD), continued received anlotinib (10mg, po, d1∼14, q3w) and TQB2450 (1200mg, iv, d1, q3w) as maintenance treatment until PD or unacceptable toxicity. The primary endpoint was PFS. Secondary endpoints were iPFS (iRECIST), ORR (RECIST 1.1), DCR, DOR and safety.

Results

As of 31 May, 2022, 38 pts were enrolled with a median age of 64 years (range 41-74), male (78.9%) and ECOG PS 1 (78.9%). Of 25 evaluable pts, 1 pts had complete response, 20 pts reached partial response and 4 pts had stable disease. The ORR was 84.0% (95%Cl 63.9%-95.5%) and the DCR was 100.0% (95%Cl: 86.3%-100.0%). Median PFS was not reached. ≥ Grade 3 treatment-related adverse events (TRAEs) was 57.9% (22/38), which mainly included neutropenia (42.1%), leukopenia (18.4%) and hypertension (18.4%). 11 pts (28.9%) suffered from serious AEs. AEs led to discontinuation of TQB2450 in 7.9% and anlotinib in 7.9% of enrolled patients.

Conclusions

TQB2450 plus anlotinib combined with paclitaxel and cisplatin showed significant efficacy and manageable toxicities as first-line treatment in advanced ESCC, which might provide a new treatment strategy for those.

Clinical trial identification

NCT05013697.

Legal entity responsible for the study

The authors.

Funding

Chia Tai-Tianqing Pharmaceutical Co., Ltd.

Disclosure

All authors have declared no conflicts of interest.