Pralatrexate: A novel synthetic antifolate for relapsed or refractory peripheral T-cell lymphoma and other potential uses

Abstract

Purpose: The pharmacology, pharmacokinetics, clinical trials, adverse effects, dosage, and economic considerations of pralatrexate (PDX) are reviewed.

Summary: Peripheral T-cell lymphoma (PTCL) comprises approximately 15–20% of all aggressive lymphomas and 5–10% of all non-Hodgkin’s lymphomas. Advanced PTCL is often refractory to traditional first-line chemotherapy regimens. PDX was developed as a synthetic folate analog antimetabolite that competitively inhibits dihydrofolate reductase (DHFR). This results in the depletion of thymidine, leading to interference with deoxyribonucleic acid synthesis and cancer cell death. PDX has a higher potency than methotrexate and edatrexate (EDX). The efficacy and safety of PDX have been demonstrated in the PROPEL trial, a prospective phase II trial in patients with relapsed or refractory PTCL. Patients with prior stem cell transplantation receiving PDX also had similar response rates (RRs). PDX was investigated on the treatment of relapsed or refractory cutaneous T-cell lymphoma, previously treated advanced non-small cell lung cancer and other solid malignancies. PDX has similar side effects to other DHFR inhibitors. The most common side effect of PDX is mucositis. The recommended dose of PDX is 30 mg/m² weekly once for 6 weeks in 7-week cycle until disease progresses or unacceptable toxicity for PTCL and may require dose reduction or discontinuation. Patients should be supplemented with oral folic acid and intramuscular vitamin B₁₂ injections.

Conclusion: PDX provides clinical benefit to patients with relapsed or refractory PTCL with durable complete and partial responses in patients who had not responded to multiple prior treatment regimens.