Cyclophosphamide 'pulses' in chronic progressive multiple sclerosis. A preliminary clinical trial.

To our knowledge, this is the first clinical trial in multiple sclerosis (MS) demonstrating the feasibility of directing immunomodulating therapy by monitoring immunologic results. Cyclophosphamide was administered at monthly intervals, escalating the dose until there was a significant reduction in both the number of blood B lymphocytes and helper/inducer (CD4) T cells of 14 patients with chronic progressive MS. The frequency and severity of adverse effects led us to conclude that the regimen is too toxic for the long-term treatment of patients with MS.