Pralatrexate is an effective treatment for relapsed or refractory transformed mycosis fungoides: A subgroup efficacy analysis from the PROPEL study

Background: Transformed mycosis fungoides (tMF) is an aggressive disease, with poor prognosis and a median survival of 24 months. Patients And Methods: In the Pralatrexate in Patients With Relapsed or Refractory Peripheral T-cell Lymphoma (PROPEL) study, 12 patients with tMF were treated with a median of 10 pralatrexate doses (starting dose of 30 mg/m ² ) administered weekly for 6 weeks in a 7-week cycle. The median number of prior systemic therapies was 3. Results: This retrospective analysis showed that the objective response rate in this subgroup was 25% (n = 3) per independent central review and 58% (n = 7) per investigator assessment, with this discrepancy likely attributed to challenges with photodocumentation of cutaneous lesions. The median duration of response and the median progression-free survival were 2.2 and 1.7 months, respectively, per central review, whereas median duration of response was 4.4 months, and median progression-free survival was 5.3 months per investigator assessment. Median survival was 13 months. Grade 1-3 mucositis was reported in 7 (58%) patients. Grade 4 adverse events were fatigue (n = 1) and thrombocytopenia (n = 1). Pralatrexate was well tolerated, with no toxicity-related discontinuations. Conclusions: Based on these results, pralatrexate may be a treatment option for patients with relapsed or refractory tMF.