Lenalidomide on alternative days is effective in myelodysplastic syndrome with 5q- deletion

Lenalidomide is the treatment of choice in low-risk patients with myelodysplastic syndrome (MDS) and 5q- deletion, at the standard dose of 10 mg for 21 d of every 28-d cycle (Giagounidis et al, 2008). The main response criteria is to achieve blood transfusion independence and recent data reported a response rate of more than 60% in this subset of patients (Ja¨dersten & Hellstro¨m-Linderberg, 2009). Nevertheless this effective treatment frequently induce severe (World Health Organization grade III–IV) neutropenia (55% of treated patients) and thrombocytopenia (44% of patients) at least during the initial 2–3 months. Another problem to be considered is the high cost of this standard therapy, as recently highlighted (Stone, 2009). One way to reduce toxicity has been reported by lowering the standard dose from 10 to 5 mg/d for 21 d (Giagounidis et al, 2008), but this schedule did not substantially affect the cost, because of the tablets’ unit price. On this particular issue we would like to report our pivotal experience in six patients treated with lenalidomide at 10 mg on alternative days for 21 d every 28 d. Our intent was to maintain the same efficacy, reduce treatment-related toxicity and also lower the cost of treatment. Moreover, there are no published data to date about the target plasma concentration of lenalidomide required to effectively inhibit the del 5q clone.