Phase 2 study of futibatinib in patients with gastric or gastroesophageal junction cancer harboring FGFR2 amplifications

Abstract

Background and aims

Aberrant fibroblast growth factor receptor (FGFR)-driven signaling, predominantly arising from FGFR2 amplification, plays a key role in gastric cancer pathogenesis. This open-label, phase 2 study evaluated the efficacy and safety of futibatinib, an irreversible FGFR1–4 inhibitor, in patients with gastric or gastroesophageal junction (GEJ) cancer harboring FGFR2 amplifications.

Methods

Patients were treated with futibatinib 20 mg orally once daily in a 28-day cycle. The primary endpoint was objective response rate (ORR) per independent central review. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety.

Results

Among 28 treated patients, the ORR per independent central review was 17.9 %, comprising five patients with a partial response (median duration of response, 3.9 months), and an additional nine patients with stable disease for a disease control rate of 50.0 %. Median PFS per independent central review and median OS were 2.9 and 5.9 months, respectively. The most common treatment-related adverse events (any grade) were hyperphosphatemia (89.3 %), decreased appetite (32.1 %), and increased aspartate aminotransferase (21.4 %). Only one (3.6 %) patient discontinued study treatment due to an adverse event.

Futibatinib demonstrated modest antitumor activity with a safety profile consistent with previous reports in patients with gastric or GEJ cancer harboring FGFR2 amplifications, potentially warranting further investigation.