ter-199 and Chromosome-Deletion

As opposed to the treatment landscape for myelodysplastic syndromes (MDS) two decades ago, potential therapies now abound for the treatment of lower-risk and higher-risk populations. In lower-risk patients, decision tools can be used to determine the likelihood of response to erythropoiesis stimulating agents (ESAs), which have demonstrated survival advantages in retrospective studies in patients with MDS, and whether these patients should be treated initially with ESAs or non-growth factor ("active") therapies. Lenalidomide has shown good activity in transfusion-dependent patients with the del(5q) cytogenetic abnormality and modest activity in other lower-risk patients. In higher-risk patients, the DNA methyltransferase inhibitors produce complete and partial responses in 20% to 30% of patients, and for the first time, the MDS drug azacitidine has demonstrated a survival advantage when compared with conventional therapies. Newer therapies stimulate platelet production and target novel pathways, while a panoply of combination studies are underway or recently completed and that likely represent the next frontier in MDS therapy.

Topics: Azacitidine; Benzoates; Blood Transfusion; Bone Marrow Diseases; Chromosome Deletion; Chromosomes, Human, Pair 5; Clinical Trials as Topic; Combined Modality Therapy; Decitabine; DNA-Cytosine Methylases; Glutathione; Hematinics; Humans; Hydrazines; Immunologic Factors; Lenalidomide; Myelodysplastic Syndromes; Pyrazoles; Randomized Controlled Trials as Topic; Receptors, Fc; Recombinant Fusion Proteins; Risk; Thalidomide; Thrombopoietin

Ezatiostat, a glutathione S-transferase P1-1 inhibitor, promotes the maturation of hematopoietic progenitors and induces apoptosis in cancer cells.. Ezatiostat was administered to 19 patients with non-deletion(5q) myelodysplastic syndrome (MDS) at one of two doses (2000 mg or 2500 mg/day) in combination with 10 mg of lenalidomide on days 1-21 of a 28-day cycle. No unexpected toxicities occurred and the incidence and severity of adverse events (AEs) were consistent with that expected for each drug alone. The most common non-hematologic AEs related to ezatiostat in combination with lenalidomide were mostly grade 1 and 2 fatigue, anorexia, nausea, diarrhea, and vomiting; hematologic AEs due to lenalidomide were thrombocytopenia, neutropenia, and anemia. One of 4 evaluable patients (25%) in the 2500/10 mg dose group experienced an erythroid hematologic improvement (HI-E) response by 2006 MDS International Working Group (IWG) criteria. Four of 10 evaluable patients (40%) in the 2000 mg/10 mg dose group experienced an HI-E response. Three of 7 (43%) red blood cell (RBC) transfusion-dependent patients became RBC transfusion independent, including one patient for whom prior lenalidomide monotherapy was ineffective. Three of 5 (60%) thrombocytopenic patients had an HI-platelet (HI-P) response. Bilineage HI-E and HI-P responses occurred in 3 of 5 (60%), 1 of 3 with HI-E and HI-N (33%), and 1 of 3 with HI-N and HI-P (33%). One of 3 patients (33%) with pancytopenia experienced a complete trilineage response. All multilineage responses were observed in the 2000/10 mg doses recommended for future studies.. The tolerability and activity profile of ezatiostat co-administered with lenalidomide supports the further development of ezatiostat in combination with lenalidomide in MDS and also encourages studies of this combination in other hematologic malignancies where lenalidomide is active.

Topics: Aged; Aged, 80 and over; Antineoplastic Agents; Chromosome Deletion; Chromosomes, Human, Pair 5; Drug Therapy, Combination; Female; Glutathione; Glutathione Transferase; Humans; Lenalidomide; Male; Maximum Tolerated Dose; Middle Aged; Myelodysplastic Syndromes; Prognosis; Thalidomide

Treatment options for patients with lower risk non-del(5q) myelodysplastic syndromes (MDS) who fail erythroid stimulating agents are restricted to one of the hypomethylating drugs with an expected response rate of approximately 50%. Ezatiostat HCl, an agent with the potential for producing multi-lineage responses in this population is currently in clinical investigation phase. This case report describes a 77 year old male who received less than two cycles of therapy with ezatiostat HCl which had to be aborted due to intolerable side effects, but which produced a sustained normalization of all three blood counts. This trilineage response has now lasted for more than a year. Interestingly, the patient began with a del(5q) abnormality and responded briefly to lenalidomide. Upon relapse of the anemia, a bone marrow showed the disappearance of the del(5q) but the appearance of a new clonal abnormality t(2;3). Given that the patient had a complete cytogenetic response to a truncated exposure to lenalidomide followed by a trilineage response to an even briefer course of ezatiostat HCl suggests a potential role for ezatiostat HCl in del(5q) patients who relapse following lenalidomide.

Topics: Administration, Oral; Aged; Antineoplastic Agents; Chromosome Deletion; Chromosomes, Human, Pair 2; Chromosomes, Human, Pair 3; Chromosomes, Human, Pair 5; Erythroid Cells; Glutathione; Hemoglobins; Humans; Lenalidomide; Male; Myelodysplastic Syndromes; Remission Induction; Thalidomide; Treatment Outcome