At the same time, MM-111, consisting of human anti-HER2 and anti-HER3 scFv linked by modified HSA [152], is currently held in reserve by Elevation Oncology, which acquired it from Merrimack in 2019 after a negative phase 2 trial in HER2-positive gastric and esophageal tumors (NCT01774851), but currently pushes development of seribantumab (MM-121, a monospecific HER3-monocloncal antibody also acquired from Merrimack at the same time) for tumors harboring NRG1-fusion. The gene discussed is ERBB3; the disease is neoplasm of esophagus.