Intermittent granulocyte colony-stimulating factor for neutropenia management in patients with relapsed or refractory...

Neutropenia is a major dose-limiting toxicity associated with lenalidomide in relapsed/refractory multiple myeloma (MM). The optimal dosing schedule of granulocyte colony-stimulating factor (G-CSF) is unclear. We developed an intermittent G-CSF schedule (4-6 doses per cycle) initiated upon onset of grade 3-4 neutropenia. Of 216 patients with relapsed/refractory MM treated at our center with lenalidomide/dexamethasone on an Expanded Access Program, there was a high incidence of grade 3-4 neutropenia (61%) and grade 3-4 infections (37%). Despite intermittent G-CSF use in 117 patients, recurrent grade 3-4 neutropenia was common (59%), and dose reductions were required in 40% of G-CSF recipients, most due to thrombocytopenia. G-CSF recipients had a longer duration on therapy and achieved a higher rate and depth of response. Intermittent G-CSF may be an effective approach for lenalidomide dose-preservation, which may lead to improved outcomes, although it does not prevent infections or thrombocytopenia-related dose limitations.