614MO - A phase II study of Becotatug (JMT101) in combination with osimertinib (Osi) in patients (pts) with classical EGFR-mutated non-small cell lung cancer (NSCLC) (BOOSTER Study)

Background

Becotatug (Beco) is a humanized IgG1 monoclonal antibody targeting EGFR. Previous study of Beco combined with Osi has shown encouraging efficacy in advanced NSCLC harboring EGFR ex20ins mutations (Zhao et al. Nature Communications, 2023 ;Zhang et al. ELCC 2024 137MO). Here we report the results of Beco combined with Osi in pts with classical EGFR-mutated advanced NSCLC.

Methods

Pts with advanced NSCLC harboring classical EGFR mutations were enrolled. This trial has four cohorts according to the prior treatments (Cohort 1: treatment naïve pts; Cohort 2: pts resistant to 1^st or 2^nd generation EGFR-TKI therapy and without T790M mutation; Cohort 3: pts who were resistant to 3^rd generation EGFR-TKI, but has not received chemotherapy; Cohort 4: pts who had failed both prior 3^rd generation EGFR-TKI and platinum-containing double-agent chemotherapy). Eligible pts received three dosing regimens, including Beco 6 mg/kg (Q2W) + Osi 80 mg (QD) (R1), Beco 6 mg/kg (Q2W) + Osi 160 mg (QD) (R2) and Beco 6 mg/kg (Q3W) + Osi 80 mg (QD) (R3). The aim of the study was to evaluate the safety and efficacy of Beco in combination with Osi.

Results

A total of 161 pts with median age of 59 years were enrolled into 4 cohorts. In treatment naïve pts, the ORR was 78.8% and PFS was 20.8M (not matured). Treatment-related adverse events (TRAEs) occurred in 160 pts (99.4%), with similar rates across cohorts. Sixty-seven (41.6%) pts reported grade ≥3 TRAEs, with an incidence of ≥5% of grade ≥3 TRAEs being rash (8.1%). Safety was similar in the Osi group at different dose levels. The efficacy data is shown in the table. The correlation analysis between PK/biomarkers and efficacy will be presented later. Table: 614MO

N, number of pts; NE, not evaluable. Data cutoff date: Mar 19, 2024.

Conclusions

Beco in combination with Osi showed encouraging antitumor activity and manageable safety in treatment naïve pts with advanced NSCLC harboring classical EGFR mutations.

Clinical trial identification

NCT06391944.

Editorial acknowledgement

Legal entity responsible for the study

Shanghai JMT-Bio Pharmaceutical Co., Ltd.

Funding

Shanghai JMT-Bio Pharmaceutical Co., Ltd.

Disclosure

J. Hao, X. Yang, X. Wan, M. Li, Y. Yang: Financial Interests, Personal, Full or part-time Employment: CSPC Pharmaceutical Group Limited. All other authors have declared no conflicts of interest.