May 17, 2004 (Boston) — The humanized monoclonal antibody alemtuzumab (Campath 1H) is useful in preventing rejection in kidney transplant patients, researchers reported here Sunday.

The data were presented by researchers from the University of Pittsburgh Medical Center in Pennsylvania in a poster session at the 2004 annual meeting of the American Transplant Congress.

Lead author Amit Basu, MD, an assistant professor of surgery at Pittsburgh, told Medscape that a year ago, Pittsburgh reported success in using alemtuzumab to treat rejection in a small number of pancreatic transplants.

Alemtuzumab is most frequently used as an induction agent in transplantation, but it is rarely used in the U.S. to stem acute rejection. There have been reports in the literature, however, from antirejection studies in the U.K., Dr. Basu said.

In the Pittsburgh study, 25 kidney transplant patients with steroid-resistant rejection and 11 steroid-resistant kidney transplant patients with Banff grade 1B or worse rejection were given one to four doses of alemtuzumab. Twenty-one patients received two doses, three received three doses, and one patient received four doses.

The patients received their transplants between August 2001 and May 2003. All had received preconditioning with thymoglobulin and were given tacrolimus monotherapy. All also were receiving spaced dosing of tacrolimus as part of a weaning regimen.

After receiving alemtuzumab, 13 patients had an infectious complication or other adverse effect, including anemia, thrombocytopenia, and leukopenia. Two patients died. One had an intra-abdominal abscess, and the other had mucosinusitis that did not clear up, said Dr. Basu.

Overall, 94.4% of patients survived, and 67% of grafts survived, a salvage rate comparable to that reported in the literature with IVIG or thymoglobulin, according to the Pittsburgh researchers.

With alemtuzumab's toxicity, however, a surgeon "has to think really hard before giving it to anybody," Dr. Basu told Medscape. However, for patients with steroid-resistant rejection, it might be worth attempting, but with no more than two doses, he said.

The Pittsburgh researchers are planning a randomized controlled trial in kidney transplant patients who have steroid-resistant rejection, giving them either thymoglobulin or alemtuzumab, to further gauge effectiveness and toxicity in stemming rejection, Dr. Basu said.

Marc Clancy, MD, a kidney transplant surgeon at the Manchester Royal Infirmary in the U.K., told Medscape that the Pittsburgh results "merit direct comparison with drugs like OKT3 and thymoglobulin in a trial." He noted that there are few options for patients with steroid-resistant rejection, and that alemtuzumab seems to be at least as effective as currently available agents.

ATC 2004: Abstract 5. Presented May 16, 2004.

Reviewed by Gary D. Vogin, MD