Sequential MRD assessments in 22 patients on I-M. All 22 patients were positive at diagnosis at a level of >100 000 tumor cells/million total cells. Six patients who were MRD (−) prior to I-M became MRD (+) with subsequent follow-up, 2 reverting back to MRD (−) status; of the 4 pts with persistent MRD (+) disease, 1 had clinical progression and the others maintain clinical response though MRD was not rechecked in these patients.