Cyclophosphamide for salvage therapy of chronic graft-versus-host disease: a retrospective analysis

We retrospectively analyzed the safety and efficacy of cyclophosphamide (cyclo) for salvage treatment of chronic graft-versus-host disease (cGvHD) and cGvHD-associated (glomerulo-)nephritis at our center between 01/2010 and 11/2019. We identified 13 patients (pts) receiving cyclo for treatment of moderate (3/13) and severe (6/13) steroid-refractory cGvHD, cGvHD-associated (glomerulo-)nephritis (3/13), or vasculitis-like CNS manifestation of cGvHD (1/13). Cyclo was started on median day 509 (range 42-8193) after cGvHD onset; the median duration of application was 153 days (range 14-486) with 2/13 currently continuing treatment. The National Institute of Health organ grading and the intensity of immunosuppression (IS) were assessed at cyclo start and repeated after 3, 6, and 12 months. Response assessment was stopped at the start of any additional new IS. The median time of follow up was 407 days (range 86-1534). Best response was 1/13 CR, 6/13 PR, 4/13 SD, 1/13 MR, and 1/13 PD (ORR 54%). Significant and durable response was observed especially in cGvHD-associated (glomerulo-)nephritis (3/3). Infectious complications > CTCAE grade III were observed in 3/12 pts. During cyclo therapy, none of the pts suffered from recurrence of underlying malignancy. Overall, cyclo was relatively well tolerated and showed responses in heavily pretreated patients but requires further evaluation within clinical trials.