Individual patient-mutated clone size in response to EPAG. (A) UPN1, a 30-year-old woman diagnosed 8 years before EPAG treatment and failing multiple IST cycles, had mutations in SETBP1 and RUNX1 detected at baseline before EPAG. At the time of detection of monosomy 7 at 3 months, the percentage of variant alleles for both genes increased concurrently with the monosomy 7 clone, suggesting the transformed monosomy 7 clone also harbored the abnormal genetic variants. (B) UPN24, an 8-year-old boy with super SAA, responded to EPAG and remained stable. Analysis at baseline did not detect mutations, but at the primary end point of 6 months, 2 RUNX1 mutations and 1 SETBP1 mutation were detected. Bone marrow morphology and karyotype have remained normal for >3 years, including after EPAG was discontinued for a robust response.