ERBB2 and gastroesophageal junction adenocarcinoma: In patients with unresectable metastatic/locally advanced gastroesophageal junction adenocarcinoma (GEA), the simultaneous targeting of HER2 and PD-1 (margetuximab + retifanlimab) or HER2 and PD-1/LAG-3 (margetuximab + tebotelelimab) resulted in the opportunity to enhance the antitumor response compared to treatment with either agent alone, and currently available data for the coadministration of margetuximab with either retifanlimab or tebotelimab suggested a well-tolerated potential for synergistic antitumor activity, thus supporting the mahogany assay in patients with GEA [79].