Allos Therapeutics, Inc announced the initiation of patient enrolment in a phase I, open-label, multi-centre study of the company's novel antifolate PDX (pralatrexate) with vitamin B12 and folic acid supplementation in patients with relapsed or refractory cutaneous T-cell lymphoma (CTCL).
"Based on our experience with PDX in patients with peripheral T-cell lymphoma, we're excited to initiate this study in patients with cutaneous T- cell lymphoma and view this effort as a natural progression of our PDX development program in haematological malignancies," said Pablo J Cagnoni, MD, chief medical officer of Allos. "Therapies currently used to treat cutaneous T-cell lymphoma fail to produce durable remissions in the majority of patients with advanced disease."
In this study, patients with either relapsed or refractory cutaneous T- cell lymphoma will receive PDX as part of a weekly schedule for two or three weeks followed by one week of rest. Patients will receive starting doses of PDX at 30 mg/m2, with dose reduction in subsequent cohorts based on toxicity. Up to 56 evaluable patients will be enrolled in the study with the objective of determining the optimal dose and safety profile of PDX in this population. A total of 20 of these patients will be enrolled at what is determined to be the optimal dose and schedule. Steven Horwitz, MD, Assistant Attending Physician, Lymphoma Service, Memorial Sloan-Kettering Cancer Centre, will serve as the study chair.
"Given the evidence of activity observed to date with PDX in patients with aggressive T-cell lymphomas, coupled with the common cell lineage between PTCL and CTCL, there is a strong clinical rationale to pursue development of PDX in this setting," said Dr Horwitz.
The cutaneous T-cells lymphomas are comprised of a number of non-Hodgkins T-cell lymphomas, including mycosis fungoides and Sezary syndrome, which have their primary manifestations in the skin. According to the Lymphoma Research Foundation, CTCL comprises about 2 per cent to 3 per cent of the estimated 63,000 new cases of non-Hodgkin's lymphoma diagnosed annually.
PDX is a novel, small molecule chemotherapeutic agent that inhibits dihydrofolate reductase, or DHFR, a folic acid (folate)-dependent enzyme involved in the building of nucleic acid, or DNA, and other processes. PDX was rationally designed for efficient transport into tumour cells via the reduced folate carrier, or RFC-1, and effective intracellular drug retention. We believe these biochemical features, together with preclinical and clinical data in a variety of tumours, suggest that PDX may have a favourable safety and efficacy profile relative to methotrexate and certain other DHFR inhibitors.