two-hander
n.— «Brad Silberling has written and directed the decidedly stripped-down “10 Items or Less,” an economical two-hander starring Morgan Freeman and “Spanglish” sensation Paz Vega.» —“10 Items or Less” by Michael Rechtshaffen Hollywood Reporter Sept. 12, 2006. (source: Double-Tongued Dictionary)
This term is listed in the Variety Slanguage glossary.