Treatment of T-cell Leukemia/Lymphoma in Children and Young Adults With the Memorial Sloan Kettering Cancer Center New York IIB Protocol.

We described the Memorial Sloan Kettering Cancer Center New York IIB (MSK-NYII) protocol pilot in 1993, for the treatment of acute lymphoblastic leukemia (ALL) in children at high risk of early relapse. We now report MSK-NYII for the treatment of T-ALL/T-lymphoma over a 15-year period. A review of all patient charts identified 63 treated from 1/1/2000-12/31/2015, with a median follow-up of 9.9 years. Further follow-ups were confounded by the COVID pandemic. Remissions (CR) were defined as <5% marrow blast count on Day 28 and resolution of extramedullary disease. Forty-four had T-ALL, and 19 had stage III/IV lymphoblastic lymphoma (T-LL). Median age at diagnosis was 13.6 years (range 0.4 to 23.7). At diagnosis central nervous system (CNS) leukemia was present in 7/63 patients (11%), cranial nerve palsy in 3 (5%), CNS2 [<5cells/µL cerebrospinal fluid with blasts seen on cytospin] in 11 (17%), testicular enlargement in 3 (5%), and mediastinal mass in 45 (71%). On Day 8, 37 T-ALL (86%) were rapid early responders with <25% marrow blasts. 54 patients had an examination, cerebrospinal fluid, and marrow evaluation on day 28. Remission was demonstrated in 53 (98%) after prior marrow and CNS disease. The 19 T-lymphoma patients had no evidence of disease on day 28. Four relapses in marrow were recorded during therapy. Second remissions were able to be achieved. One patient died without having relapsed and is counted as an event in the event-free survival (EFS) analysis. Four patients, including 3 after the second CR transplant, died during follow-up. One unusual case of T-ALL recurred as T-LL of the colon 5.5 years after diagnosis, 3.5 years after therapy discontinuation. Fifteen years after diagnosis 88% (95% CI=78%-98%) survived event-free, and 91% (95% CI=82%-100%) survived. Twenty-five patients received irradiation. Three had RT to the testes, 3 had cranial RT for cranial nerve palsies, and 19 had cranial radiation for either CNS leukemia, CNS2, or for initial white blood cell >100,000/ µL. The MSK-NYIIB protocol, with a 94% 5-year and 88% 15-year EFS, is an effective therapy for the treatment of T-ALL/lymphoma, with similar toxicity to other high-risk regimens.