New drug shows promise in keeping blood cancers at bay after transplant

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Documented informed consent of the participant and/or legally authorized representative * Agreement to allow the use of archival tissue from diagnostic tumor biopsies. If unavailable, exceptions may be granted with study principal investigator (PI) approval * Age: ≥ 18 years * Eastern Cooperative Oncology Group (ECOG) ≤ 2 or Karnofsky performance status (KPS) ≥ 70 * Patients who are scheduled to receive or have already undergone allogeneic hematopoietic cell transplantation (alloHCT) from any donor type, any conditioning regimen, and regardless of GVHD prophylaxis will be include * Patients must have AML, MDS, or CMML with mIDH1 diagnosis at diagnosis (regardless of time from HCT). Note: Patient with pre-HCT disease relapse will no be included if mIDH1 is not detected after relapse * Day 30 marrow post alloHCT should show evidence of morphologic remission with \< 5% bone marrow (BM) blasts. Patients with MRD-positive status either by flow cytometry or IDH1 mutation testing will be eligible * Patients with previous therapy with IDH1 inhibitors will be included * Absolute neutrophil count (ANC) \> 1000/mm\^3 (within 28 days prior to day 1 of protocol) * Hemoglobin ≥ 8.0 gm/dL (within 28 days prior to day 1 of protocol) * Platelets ≥ 50,000/mm\^3 (within 28 days prior to day 1 of protocol) Note: Patients with lower counts can enroll if infection cytomegalovirus (CMV)/human herpes virus 6 (HHV6), etc. is being treated actively * Bilirubin ≤ 2 x upper limit of normal (ULN) (within 28 days prior to day 1 of protocol) (unless has Gilbert's disease). Patients with abnormal liver function tests (LFTs) due to active GVHD will not be eligible * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT) (serum glutamic pyruvic transaminase \[SGPT\]) ≤ 2 x ULN (within 28 days prior to day 1 of protocol). Patients with abnormal LFTs due to active GVHD will not be eligible * Creatinine clearance of ≥ 30/min/1.73 m\^2 for participants with creatinine levels above institutional normal per 24 hour urine test or the Cockcroft-Gault formula (within 28 days prior to day 1 of protocol) * Corrected QT interval (QTc) ≤ 480 ms (Note: To be performed within 28 days prior to day 1 of protocol therapy) * Seronegative for HIV antigen/antibody (Ag/Ab) combo, hepatitis C virus (HCV) (if positive, hepatitis C ribonucleic acid \[RNA\] quantitation must be performed), active hepatitis B virus (HBV) (surface antigen negative), and syphilis (rapid plasma reagin \[RPR\]) (within 28 days prior to day 1 of protocol) * Women of childbearing potential (WOCBP): negative urine or serum pregnancy test (within 28 days prior to day 1 of protocol). If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required * Agreement by females and males of childbearing potential, defined as not being surgically sterilized (men and women) or have not been free from menses for \> 1 year (women only), to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 3 months after the last dose of protocol therapy Exclusion Criteria: * Patients with more than one allogeneic HCT * History of allergic reactions attributed to compounds of similar chemical or biological composition to study agent * Active diarrhea considered clinically significant and may impair oral drug administration * Clinically significant uncontrolled illness * Uncontrolled infection requiring systemic antimicrobials * Active infection: Patients with treated viral, bacterial or fungal infections that are controlled on therapy will be allowed to participate * Participant has detectable human immunodeficiency virus (HIV) viral load within the previous 6 months (must have viral load testing prior to study enrollment if participant has a known history of HIV 1/2 antibodies) * Active hepatitis B or C, or HIV * Other active malignancy. Participants with history of prior malignancy treated with curative intent who achieved CR more than 2 years before study entry are eligible. This exclusion rule does not apply to non-melanoma skin tumors and in-situ cervical cancer * Females only: Pregnant or breastfeeding * Active grade II-IV acute GVHD per Mount Sinai Acute Graft Versus Host Disease International Consortium (MAGIC) criteria and/or requiring systemic steroids with prednisone dose equivalent of ≥ 0.25 mg/kg at end of 4 weeks. Patients with a mild form of acute GVHD involving skin, gut or liver requiring topical steroid creams or oral beclomethasone (8 mg/day), entocort, (9 mg/day) and/or solumedrol (and equivalent prednisone) will be allowed * Any other condition that would, in the investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures * Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)