WASHINGTON -- The FDA has approved Allos Theraputics' pralatrexate (Folotyn) for relapsed and refractory peripheral T-cell lymphoma, a rare cancer of the immune system for which there is no other treatment.
Approval was based on results from the PROPEL trial and the drug's overall response rate. Clinical benefits, such as improved progression-free survival, have not been demonstrated.
PROPEL was an open-label, single-arm, multicenter, international trial with 109 patients, of whom 27% responded to the drug over a median of 287 days.
Nearly one fourth of the patients had not responded to prior therapies, and nearly two-thirds did not respond to their most recent prior therapy. Of those who responded to treatment during the trial, 66% did so during the first cycle.
Several grade 3 and 4 adverse effects occurred in a number of patients, including:
- Thrombocytopenia in 33%
- Mucositis in 21%
- Neutropenia in 20%
- Anemia in 17%
An FDA panel recommended the drug for approval earlier this month despite the low response rate and average response period of less than 14 weeks, largely because of the absence of other available treatments for PTCL. (See FDA Gives Nod to Two Cancer Drugs)
The FDA said those taking pralatrexate should be instructed to take supplements of folic acid daily and vitamin B12 weekly to reduce treatment toxicity.