The effects of continued azacitidine treatment cycles on response in higher risk patients with myelodysplastic syndromes: an update

Oral hypomethylating agents: beyond convenience in MDS

Oral hypomethylating agents (HMAs) represent a substantial potential boon for patients with myelodysplastic syndrome (MDS) who have previously required between 5 and 7 visits per month to an infusion clinic to receive therapy. For patients who respond to treatment, ongoing monthly maintenance visits represent a considerable burden to quality of life, and for those who are early in therapy, these sequential visits may tax transportation and financial resources that would be optimally distributed over the treatment cycle to facilitate transfusion support. The availability of oral HMAs may support the optimal application of these agents by contributing to adherence and lessening the burden of therapy, potentially encouraging patients to stay on longer-term treatment. Distinct pharmacokinetic profiles for the recently approved oral HMAs (oral azacitidine and decitabine-cedazuridine) result in differential toxicity profiles and have prompted their clinical trial development in lower- and higher-risk MDS, respectively.

Azacitidine adverse effects in patients with myelodysplastic syndromes

Azacitidine is now considered one of the standard-of-care agents for patients with high-risk myelodysplastic syndromes who are not candidates for high-dose chemotherapy. Considering the mechanism of action of the agent, it is critical to maintain adequate dose intensities for prolonged periods of time in order for treatment to be effective. Therefore, aggressive prevention as well as treatment of side effects is critical. The drug mainly causes hematological toxicity that is managed with growth factor support, blood transfusions, and dose and schedule adjustment. Nonhematological side effects are mainly gastrointestinal and cutaneous in nature, and can be easily managed with symptomatic treatment and correct administration techniques.

Management and supportive care measures for adverse events in patients with myelodysplastic syndromes treated with azacitidine*

OBJECTIVE

Myelodysplastic syndrome (MDS) treatment can initially worsen patients' clinical condition and they may discontinue therapy before achieving benefit. We present previously unpublished data from two large phase III trials describing common adverse events (AEs) associated with azacitidine and methods to manage them.

METHODS

In the Cancer and Leukemia Group B (CALGB) 9221 study, patients with any French-American-British (FAB) subtype of MDS were randomized to azacitidine or best supportive care (BSC). After 56 d, patients randomized to BSC with disease progression could cross over to receive azacitidine. In the AZA-001 study, patients with higher-risk MDS (FAB-defined refractory anemia with excess blasts (RAEB), RAEB in transformation, or chronic myelomonocitic leukaemia and IPSS int-2 or high) were randomized to azacitidine or to conventional care regimens (CCR), which included low-dose ara-C, BSC, or intensive chemotherapy. In both studies, azacitidine dose was 75 mg/m(2)/d SC for 7 d every 28 d. AEs were graded per National Cancer Institute's Common Toxicity Criteria version 2.0 (AZA-001) or CALGB Expanded CTC (CALGB 9221).

RESULTS

In safety-evaluable patients in AZA-001 (N = 175) or CALGB 9221 (N = 150), the most common AEs with azacitidine included hematologic (eg, cytopenias) and non-hematologic administration-related events (eg, injection-site reactions and gastrointestinal disorders). Most AEs were transient and resolved during ongoing therapy (> 83%). Hematologic AEs, most frequently observed during early treatment cycles, decreased during subsequent cycles and were usually managed with dosing delays (23-29%). Gastrointestinal symptoms were primarily managed with anti-emetics and laxatives.

CONCLUSION

Hematologic and non-hematologic AEs with azacitidine decreased in frequency as treatment continued. Awareness of the onset, duration and management of AEs can facilitate treatment, permitting patients to continue therapy for maximum benefit.

How much? How frequent? How long? A clinical guide to new therapies in myelodysplastic syndromes

Advances in the treatment of myelodysplastic syndromes (MDSs) over the last decade have given patients and their hematologists a multitude of treatment options. Therapeutic options now exist that reduce disease-related symptoms, improve quality of life, and alter the natural history of the disease. Three drugs are now specifically Food and Drug Administration-approved for treatment of MDS: (1) azacitidine, (2) decitabine, and (3) lenalidomide. Clinical results with each of these agents, plus results with immunosuppressive therapy, are reviewed to guide clinical decision making. Although each therapy has made a substantial impact in improving the care of patients with MDS, unfortunately MDS treatment in 2010 ultimately fails in most patients, but these therapies provide a foundation on which we can build to further improve outcomes.

The role of azacitidine in the management of myelodysplastic syndromes (MDS)

Myelodysplastic syndromes (MDS) are a group of common bone marrow disorders characterized by ineffective hematopoiesis, peripheral cytopenias, and a propensity for transformation to acute myeloid leukemia (AML). For many years, the main treatment option for MDS was best supportive care which alleviates symptoms but has no effect on the natural course of the disease. The recent approval of the demethylating agent azacitidine represents a significant advance in the treatment of MDS. The results of two randomized trials with azacitidine have shown an overall response rate between 40% and 60%, an improved quality of life, a reduced risk of transformation to AML and a definite survival advantage compared to best supportive care or low-dose chemotherapy. Current data on azacitidine and its place in the treatment of MDS are reviewed.