A randomized multicenter comparison of basiliximab and muromonab (OKT3) in heart transplantation:: SIMCOR study

Background: Antilymphocytic antibodies have been long used for the prevention of acute rejection early after heart transplantation (HTx), but their adverse effects have limited their widespread use. Our aim was to evaluate the safety, tolerability, and efficacy of the novel anti-CD25 antibody basiliximab (BAS) compared with muromonab (OKT3). Patients and methods: In this multicenter study, 99 patients were randomly assigned to receive either BAS or OKT3 in the early post-HTx period. The primary endpoint was safety and tolerability. Specific safety variables were predefined for a better comparison of adverse effects. Secondary endpoints concerning anti-rejection efficacy were also evaluated. Results: No adverse events related to study medication were found in the BAS group, whereas 23 were observed among patients receiving OKT3 (P < 0.0001). The proportion of patients with predefined adverse events day 4 post-HTx was much higher with OKT3 than with BAS (43% vs. 4%; P < 0.0001). Fever, acute pulmonary edema, hypotension, and other complications accounted for most of the difference. At 1-year follow-up, biopsy-proven rejection episodes grade >= 3A had occurred in 39.6% of BAS patients versus 40.4% of OKT3 patients (P=0.87). There were no differences in terms of severity and timing of acute rejection episodes. The number of infectious episodes, complications not related to study medication, and actuarial survival were similar in both groups. Conclusion: In this HTx study, induction therapy with BAS was safer and better tolerated than OKT3, without significant differences in efficacy outcomes.