Gastroesophageal adenocarcinomas are a diverse group of diseases that we are starting to reclassify more and more on the basis of biomarker profiles, such as microsatellite status, human epidermal growth factor receptor 2 (HER2) and programmed death-ligand 1 (PD-L1) positivity, and molecular signatures based on next-generation sequencing results. Recently, fibroblast growth factor receptor 2 (FGFR2), particularly the FGFR2b form, emerged as a potential future biomarker for treatment selection. FGFR2b as a biomarker is present in a significant proportion of upper gastrointestinal tumors.
The phase 2 FIGHT trial1 evaluated the role of bemarituzumab, an anti-FGFR2 antibody, in combination with chemotherapy during first-line treatment of advanced gastroesophageal adenocarcinoma. The primary endpoint of this trial was progression-free survival (PFS). This trial enrolled 155 patients with upper gastrointestinal tumors with FGFR2b overexpression (defined as at least 2+ by immunohistochemistry) or amplification on next-generation sequencing. About 30% of patients with HER2 nonpositive tumors (ie, those that would not qualify for treatment with the targeted agent trastuzumab) were eligible for participation. In the FIGHT trial, patients were randomized in a 1:1 ratio to receive either standard chemotherapy (folinic acid, fluorouracil, and oxaliplatin [FOLFOX]) or chemotherapy plus bemarituzumab. Patients in the experimental group were allowed to receive one dose of standard FOLFOX chemotherapy while biomarker testing was ongoing.
With a median follow-up time of 10.9 moths, PFS was numerically prolonged in the bemarituzumab group (9.5 vs 7.4 months), but it did not reach statistical significance (P = .073). Overall survival (OS) was improved in the experimental group (not reached vs 12.9 months; P = .027). With a longer follow-up of 12.5 months, in post hoc exploratory analysis, OS was significantly longer in the experimental group (19.2 vs 13.5 months; hazard ratio 0.60, P = .027). The rate of serious adverse events was similar between the two groups. However, it is important to note ocular toxicities associated with bemarituzumab treatment. Corneal adverse events were seen in 67% of patients in the experimental group, with 24% of patients experiencing grade 3 events. Moreover, 26% of patients discontinued bemarituzumab because of corneal adverse events.
Overall, this phase 2 trial demonstrated that FGFR2b is emerging as an important biomarker and target in patients with advanced gastroesophageal adenocarcinoma. Ongoing phase 3 trials (FORTITUDE-101 with FOLFOX [NCT05052801] and FORTITUDE-102 with FOLFOX and nivolumab [NCT05111626]) hopefully will confirm the early results seen in the FIGHT trial. Awareness and early attention to treatment-associated toxicities will be critical for the potential future incorporation of bemarituzumab into clinical practice.
A study by Ramos‐Santillan and colleagues explored whether the order of treatment modalities matter in the management of early-stage gastric cancer. Typically, perioperative chemotherapy (both neoadjuvant and adjuvant) is used during treatment of early-stage gastric cancer, which is usually defined as at least cT2N0 or cTxN+ disease. In this study, multivariable Cox regression analyses were performed on propensity score-matched cohorts. The study analyzed outcomes of 11,984 patients who were identified using the US National Cancer Database and treated between 2005 and 2014. The results revealed that patients who had stage I disease had better outcomes with upfront resection followed by adjuvant therapy. Patients with stage III disease did better with a neoadjuvant approach, whereas patients with stage II disease had similar outcomes regardless of chemotherapy timing. This research has the limitations inherent to the retrospective nature of the analysis and lack of prospective enrollment and controls. However, it does suggest that there may be a fraction of patients who should be treated with upfront resection. For incorporation of this change into standard practice, the question of therapy sequencing should be answered in a randomized prospective trial that incorporates the most updated systemic therapy (fluorouracil, leucovorin, oxaliplatin, and docetaxel [FLOT]) into its design.
Chemotherapy continues to play a critical role during first-line treatment of advanced esophageal and gastric adenocarcinoma. Triple chemotherapy regimens have been known to have increased efficacy in this setting, but their use has been limited by associated toxicities. A study by Nguyen and colleagues evaluated the TCX regimen (paclitaxel, carboplatin, and capecitabine) during first-line treatment of advanced gastric cancer. This regimen is similar to other triple chemotherapy regimens, such as FLOT and DCF (docetaxel, cisplatin, and fluorouracil), which have proven activity in this disease. This prospective phase 2 trial enrolled 83 patients. The median PFS (9.3 months) and OS (17 months) compared favorably with historical references. The regimen had expected adverse events, with cytopenias and fatigue being the most frequently reported. On the basis of the reported safety and efficacy, TCX has potential to be used as a chemotherapy backbone in future trials, but larger trials are needed to confirm the phase 2 trial results.
Wainberg ZA, Enzinger PC, Kang YK, et al. Bemarituzumab in patients with FGFR2b-selected gastric or gastro-oesophageal junction adenocarcinoma (FIGHT): A randomised, double-blind, placebo-controlled, phase 2 study. Lancet Oncol. 2022 Oct 13. Doi: 10.1016/S1470-2045(22)00603-9