Efficacy and safety of renal tubule cell therapy for acute renal failure

Abstract

The mortality rate for patients with acute renal failure (ARF) remains unacceptably high. Although dialysis removes waste products and corrects fluid imbalance, it does not perform the absorptive, metabolic, endocrine, and immunologic functions of normal renal tubule cells. The renal tubule assist device (RAD) is composed of a conventional hemofilter lined by monolayers of renal cells. For testing whether short-term (up to 72 h) treatment with the RAD would improve survival in patients with ARF compared with conventional continuous renal replacement therapy (CRRT), a Phase II, multicenter, randomized, controlled, open-label trial involving 58 patients who had ARF and required CRRT was performed. Forty patients received continuous venovenous hemofiltration + RAD, and 18 received CRRT alone. The primary efficacy end point was all-cause mortality at 28 d; additional end points included all-cause mortality at 90 and 180 d, time to recovery of renal function, time to intensive care unit and hospital discharge, and safety. At day 28, the mortality rate was 33% in the RAD group and 61% in the CRRT group. Kaplan-Meier analysis revealed that survival through day 180 was significantly improved in the RAD group, and Cox proportional hazards models suggested that the risk for death was approximately 50% of that observed in the CRRT-alone group. RAD therapy was also associated with more rapid recovery of kidney function, was well tolerated, and had the expected adverse event profile for critically ill patients with ARF.

Figures

Figure 1.

Kaplan-Meier estimates of survival between patients in the RAD and conventional CRRT groups.

Figure 2.

Kaplan-Meier estimates of time to renal recovery in the RAD and CRRT-alone groups.

Figure 3.

Schematic of the extracorporeal perfusion circuit for renal cell therapy. Flow rates approximate those used clinically. The hemofilter perfusion PUMP system used the BBraun's (Bethlehem, PA) Diapact System; the RAD perfusion system used an Alaris (San Diego, CA) intravenous pump for the pre-RAD ultrafiltrate line and a Minntech (Minneapolis, MN) blood pump for the post-RAD blood line. Qb, blood flow; Qf, rate of fluid filtration.