Hansa Medical AB announced preliminary data showing that IdeS has very good efficacy in a phase 2 study with 8 highly sensitized patients on the waiting-list for kidney transplantation. Data analysis shows that IdeS rapidly decreases anti-HLA antibodies to levels acceptable for transplantation, thereby increasing the probability of finding a compatible donor. This is demonstrated by a significant reduction of percentage panel reactivity after treatment.

In addition, essentially all IgG was cleaved within 24 hours after dosing in all patients. IdeS was considered safe and well tolerated in HLA sensitized dialysis patients awaiting kidney transplantation. The phase 2 IdeS study was a single arm, single centre, ascending dose study at Uppsala University Hospital, Sweden.

Eight sensitized dialysis patients were included and they received 0.12 or 0.25 mg/kg body weight of intravenous IdeS once or twice within 2 days. IgG was rapidly and efficiently cleaved within minutes after IdeS treatment. Antibodies to HLA, measured with single-antigen bead analysis and T- and B-cell panel reactive antibody analysis, reached levels acceptable for transplantation within hours of treatment.

IdeS had an acceptable safety and tolerability profile in the intended category of patients; myalgia and increased susceptibility to infection were identified as potential side effects. Susceptibility to infection is expected in connection with immunosuppressive treatments. Hansa Medical has previously reported about one patient in the study who was made eligible for kidney transplantation by treatment with IdeS and successfully transplanted with a deceased donor.

IdeS treatment converted the positive cross-match tests (both FACS-CXM and CDC-CXM) negative, thereby making the transplantation possible.