Pharmacokinetic and pharmacodynamic comparison of two "pegylated" interferon alpha-2 formulations in healthy male volunteers: a randomized, crossover, double-blind study.

BACKGROUND: Interferon (IFN) alpha conjugation to polyethylene glycol (PEG) results in a better pharmacokinetic profile and efficacy. The aim of this study was to compare the pharmacokinetic, pharmacodynamic and safety properties of a new, locally developed, 40-kDa PEG-IFN alpha-2b preparation with a reference, commercially available PEG-IFN alpha-2a in healthy male volunteers. METHODS: A randomized, crossover, double-blind study with a 3-weeks washout period, was done. A single 180 micrograms PEG-IFN alpha-2 dose was administered subcutaneously in both groups. Sixteen apparently healthy male subjects were included. Serum PEG-IFN concentration was measured during 336 hours by an enzyme immunoassay (EIA). Other clinical and laboratory variables were used as pharmacodynamic and safety criteria. RESULTS: The pharmacokinetic comparison by EIA yielded a high similitude between the formulations. In spite of a high subject variability, the parameters' mean were very close (in all cases p > 0.05): AUC: 53623 vs. 44311 pg.h/mL; Cmax: 333 vs. 271 pg/mL; Tmax: 54 vs. 55 h; half-life (t1/2): 72.4 vs. 64.8 h; terminal elimination rate (lambda): 0.011 vs. 0.014 h(-1); mean residence time (MRT): 135 vs. 123 h for reference and study preparations, respectively. There were no significant differences with respect to the pharmacodynamic variables either: serum neopterin and beta-2 microglobulin levels, stimulation of 2'5' oligoadenylate synthetase expression, and serum IFN antiviral activity. A strong Spearman's rank order correlation (p < 0.01) between the pharmacokinetic and pharmacodynamic concentration-time curves was observed. Both products caused similar leukocyte counts diminution and had similar safety profiles. The most frequent adverse reactions were leukopenia, fever, thrombocytopenia, transaminases increase and asthenia, mostly mild. CONCLUSIONS: Both formulations are fully comparable from the pharmacokinetic, pharmacodynamic, and safety profiles. Efficacy trials can be carried out to confirm clinical similarity.

Enemas de factor de crecimiento epidérmico para inducir la remisión de la colitis ulcerosa izquierda / Epidermal growth factor enemas for induction of remission in left-sided ulcerative colitis

Introducción: la colitis ulcerosa es una enfermedad inflamatoria crónica de etiología poco conocida, que afecta la mucosa del colon. El efecto positivo del factor de crecimiento epidérmico fue reportado en estudio previo con uso de enema para tratamiento de la manifestación izquierda leve o moderada de la enfermedad. Este antecedente sirvió de base para evaluar la eficacia y perfil de seguridad de una solución viscosa del producto.Métodos: fueron aleatorizados 31 pacientes hacia tres grupos de tratamiento diario durante 14 días. Doce recibieron enemas de 10 mg de factor de crecimiento epidérmico en 100 mL de solución viscosa, mientras nueve fueron tratados con enemas placebo conteniendo solamente solución viscosa. Ambos grupos recibieron además 1,2 g diarios de mesalacina oral. El tercer grupo incluyó 10 pacientes con mesalacina en enemas de 3g / 100 mL. La variable principal de eficacia fue la respuesta clínica al finalizar las dos semanas de tratamiento, definida como la disminución de, al menos tres puntos, el índice basal de actividad de la enfermedad acompañada de mejoría endoscópica o histológica.Resultados: se alcanzó remisión de la enfermedad en todos los pacientes que recibieron factor de crecimiento epidérmico y en seis de los grupos mesalacina enema y placebo. Todas las comparaciones entre grupos mostraron superioridad estadísticamente significativa para el factor de crecimiento epidérmico, único producto que logró la reducción significativa del índice de actividad de la enfermedad y de la presencia e intensidad de los síntomas digestivos en los pacientes luego del tratamiento. Ningún evento adverso fue reportado.Conclusiones: estos resultados son consistentes con las anteriores evidencias moleculares y clínicas que señalan al factor de crecimiento...

Introduction: ulcerative colitis is a little known chronic inflammatory disease in colonic mucosa. The positive effect of epidermal growth factor was shown in a previous report, with enema use for treatment of mild to moderate left-sided manifestation of the disease. This evidence provided the basis for evaluating the efficacy and safety profile of a viscous solution of this product. Methods: thirty-one patients were randomized to three groups for daily medications during 14 days. Twelve received one 10 mg enema of epidermal growth factor dissolved in 100 mL of viscous solution whereas nine were treated with placebo enema; both groups also received 1.2 g of oral mesalamine per day. The other group included ten patients with 3 g / 100 mL of mesalamine enema. Primary end point was clinical responses after two weeks of treatment, defined as a decreased of, at least three points from baseline, the Disease Activity Index and endoscopic or histological evidences of improvement. Results: remission of disease was observed in all patients in the epidermal growth factor group, and six in both, mesalamine enema and placebo group. All the comparisons between groups showed statistically significant superiority for epidermal growth factor, the only product with significant reduction in disease activity index as well as the presence and intensity of digestive symptoms in patients after treatment. None adverse event was reported. Conclusions: the results agree with previous molecular and clinical evidences, indicating that the epidermal growth factor is effective to reduce disease activity and to induce remission. A new study involving more patients should be conducted to confirm the efficacy of the epidermal growth factor enemas