A phase I clinical study of naked DNA expressing two isoforms of hepatocyte growth factor to treat patients with critical limb ischemia.

BACKGROUND

The purpose of the present phase I clinical trial was to evaluate the safety, tolerability, and preliminary efficacy of naked DNA therapy expressing two isoforms of hepatocyte growth factor (pCK-HGF-X7) in critical limb ischemia (CLI) patients.

MATERIALS AND METHODS

Twenty-one patients with CLI were consecutively assigned to receive increasing doses (cohort I: 4  mg; cohort II: 8  mg; cohort III: 12  mg; and cohort IV: 16  mg) of pCK-HGF-X7, which was administered into the ischemic calf and/or thigh muscle at days 1 and 15. A safety and tolerability evaluation and measurement of pain severity score using a visual analog scale (VAS), ulcer status, transcutaneous oxygen (TcPO(2) ) and ankle-brachial index (ABI) were performed throughout a 3-month follow-up period.

RESULTS

No serious adverse events were observed in any of the 21 patients for the 3-month follow-up period. A significant reduction in pain was observed in the treated patients, with the mean VAS decreasing from 5.95-1.64 (p  <  0.001). The mean ABI value increased from 0.49-0.63 (p  =  0.026) at 3-month follow-up. The mean TcPO(2) value on the dorsum of the foot, the anterior calf and posterior calf significantly increased from 28.25-39.28  mmHg (p  =  0.012), from 22.00-30.63  mmHg (p  =  0.046) and 32.05-47.19  mmHg (p  =  0.001) at 3-month follow-up, respectively. Wound healing improvement was observed in the six of nine patients that had an ulcer at baseline.

CONCLUSIONS

These results support the performance of a phase II randomized controlled trial with pCK-HGF-X7.