RESUMO
BACKGROUND: HP802-247 is a new-generation, allogeneic tissue engineering product consisting of growth-arrested, human keratinocytes (K) and fibroblasts (F) delivered in a fibrin matrix by a spray device. OBJECTIVE: To identify the preferred dose of HP802-247 based on cell concentration and K/F ratio. METHODS: A multicenter, randomized, double-blind, placebo-controlled, explorative phase II study of 6 different doses of HP802-247 administered once per week for 12 consecutive weeks in chronic venous leg ulcers. RESULTS: HP802-247 was safe and well tolerated and showed increasing efficacy dependent on cell concentration and K/F ratio, in line with in vitro growth factor release data. The mean complete closure rate at week 12 for all patients treated with HP802-247 was 40%, and for placebo it was 33%. In contrast to placebo, all HP802-247 dose groups improved from week 12 to 24. CONCLUSION: As an integral part of a rational tissue engineering product development, this explorative trial identified the preferred dose of HP802-247 for further clinical studies.