BACKGROUND:
Guadecitabine is a next-generation hypomethylating agent whose active metabolite decitabine decitabine: It works by reducing the amount of methylation in the body. Methylation is a process that acts like a switch to turn off or “silence” genes in certain cells. When these genes (called tumor suppressor genes) are turned off, MDS cells and cancer cells can grow freely. Decitabine is approved by the U… has a longer in-vivo exposure time than intravenous decitabine. More effective hypomethylating agents are needed for the treatment of myelodysplastic syndromes myelodysplastic syndromes: (my-eh-lo-diss-PLASS-tik SIN-dromez) A group of disorders where the bone marrow does not work well, and the bone marrow cells fail to make enough healthy blood cells. Myelo refers to the bone marrow. Dysplastic means abnormal growth or development. People with MDS have low blood cell count for at… . In the present study, we aimed to compare the activity and safety of two doses of guadecitabine in hypomethylating agent treatment-naive or relapsed or refractory refractory: Not responsive to treatment or cure. For example, refractory anemia is a low red blood cell count that doesn't respond to standard treatments. patients with intermediate-risk or high-risk myelodysplastic syndromes.
METHODS:
This phase 2 part of the phase 1/2, randomised, open-label study enrolled patients aged 18 years or older from 14 North American medical centres with International Prognostic Scoring System International Prognostic Scoring System: A system that turns patient data into a score. The score tells how quickly a myelodysplastic syndrome (MDS) case is progressing and helps predict what may happen with the patient's MDS in the future. Also called IPSS. intermediate-1-risk, intermediate-2-risk, or high-risk myelodysplastic syndromes, or chronic myelomonocytic leukaemia. They were either hypomethylating agent treatment-naive or had relapsed or refractory disease after previous hypomethylating agent treatment as determined by the investigators' judgment. Eligible patients had Eastern Cooperative Oncology Group performance status of 0-2. Patients were randomly assigned (1:1) using a computer algorithm for dynamic randomisation to subcutaneous guadecitabine 60 or 90 mg/m2 on days 1-5 of a 28-day treatment cycle. Treatment was stratified by previous treatment with hypomethylating agents and neither patients nor investigators were masked. The primary endpoint was overall response (a composite of complete response, partial response, marrow complete response, and haematological improvement) assessed in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT01261312.
FINDINGS:
Between July 9, 2012, and April 7, 2014, 105 patients were enrolled: 55 (52%) were allocated to guadecitabine 60 mg/m2 (28 patients were treatment-naive and 27 had relapsed or refractory disease after previous hypomethylating agent treatment) and 50 (48%) patients to 90 mg/m2 (23 patients were treatment-naive and 27 had relapsed or refractory disease). Three (3%) patients of 105 did not receive study treatment and were excluded from analyses. Median follow-up was 3·2 years (IQR 2·8-3·5). The proportion of patients achieving an overall response did not significantly differ between dose groups (21 of 53 [40%, 95% CI 27-54] with 60 mg/m2 and 27 of 49 [55%, 95% CI 40-69] with 90 mg/m2; p=0·16). 25 of 49 (51%, 95% CI 36-66) patients who were treatment-naive and 23 of 53 (43%, 30-58) patients with relapsed or refractory disease achieved an overall response. The most common grade 3 or worse adverse events in both groups, regardless of relationship to treatment, were thrombocytopenia thrombocytopenia: (throm-buh-sie-tuh-PEE-nee-uh) A condition in which there is a shortage of platelets in the bloodstream. This results in a low platelet count. Bleeding and bruising often occur with thrombocytopenia. (22 [41%] of 53 patients in the 60 mg/m2 group and 28 [57%] of 49 in the 90 mg/m2 group), neutropaenia (21 [40%] and 25 [51%]), anaemia (25 [47%] and 24 [49%]), febrile neutropaenia (17 [32%] and 21 [43%]), and pneumonia (13 [25%] and 15 [31%]). Seven (7%) of 102 patients died due to adverse events (three with 90 mg/m2 and four with 60 mg/m2), and all except one were in the relapsed or refractory cohort. Two deaths were deemed treatment related (septic shock with 60 mg/m2; pneumonia with 90 mg/m2).
INTERPRETATION:
Guadecitabine was clinically active with acceptable tolerability in patients with intermediate-risk and high-risk myelodysplastic syndromes. Responses and overall survival in the relapsed or refractory cohort offer the potential of a new therapeutic option for patients for whom currently available hypomethylating agents are not successful. We therefore recommend guadecitabine at a dose of 60 mg/m2 on a 5-day schedule for these patients.
FUNDING:
Astex Pharmaceuticals and Stand Up To Cancer.