We tested the safety and efficacy of a dose‐modified The Cancer and Leukemia Group B 10403 regimen using reduced doses of pegylated (PEG)‐asparaginase (ASP) and corticosteroids (RD‐10403) in 30 patients with Philadelphia‐chromosome negative ALL who were ≥50‐year‐old and younger adults with significant metabolic or hepatic co‐morbidities. The gene discussed is ASPG; the disease is acute lymphoblastic leukemia.