Ex vivo evaluation of pidotimod activity on cell-mediated immunity.

The activity of pidotimod ((R)-3-[(S)-(5-oxo2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) on immunological parameters was evaluated in a double-blind trial, involving two Research Centres. 16 patients with a primary or metastatic neoplasm, 16 elderly patients under immunodeficiency conditions and 11 healthy volunteers were enrolled in the present study. The patients, randomized within each centre, were assigned to one of the following treatments lasting 15 days: one vial i.m. of pidotimod 50 mg, 100 mg, 200 mg twice a day, respectively; one vial i.m. of physiological saline twice a day. The lymphocyte PHA-stimulation test evidenced a significant variability due to the different treatment groups (p = 0.004). The analysis of the stimulation index (SI), computed from the mean c.p.m. before and after PHA-stimulation, showed a significant difference, dose-independent, between saline and active treatment (p = 0.002). The SI analysis, on the basis of the data of the allogenic stimulation test (mixed lymphocyte culture), confirmed the difference between saline and active treatment (p = 0.05) with a significant linear component in the time-effect curve (p = 0.001) but not in the dose-effect curve. A 12% increase in CD 3 lymphocytes compartment was observed with pidotimod 400 mg/day. The drug was well tolerated by all the patients included in the study.

Ex vivo evaluation of pidotimod activity in patients with chronic obstructive pulmonary disease.

The aim of this study was to evaluate the activity of pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl)carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) on 52 patients affected with chronic obstructive pulmonary disease (COPD). The study was carried out in a randomized, parallel, double-blind trial, followed by incomplete blocks design. Pidotimod 800 mg was administered orally twice a day for 30 days. The follow-up period was 5 weeks. Our results show that in patients with COPD pidotimod potentiates T-cell activity. The effects on T-cells appear after 15 days of treatment and last for 5 weeks after the end of therapy. Since other studies demonstrated that pidotimod displays an immunopotentiating activity also on macrophages and granulocytes, the drug is useful to increase the immune defense during infections. The drug has a good compliance and is well tolerated also during long-term treatment.