Study definitions of successful tolerance, partial response study failure, and relapse
| Successful tolerance . | Negative inhibitor titer, FVIII recovery ≥ 66% of expected, and FVIII recovery ≥ 6 h . |
|---|---|
| Partial response | After 33 mo of ITI, negative inhibitor titer but persistently abnormal recovery or half-life; responding clinically to FVIII replacement without an anamnestic increase in inhibitor titer |
| Study failure | Failure of the inhibitor to decline by ≥ 20% over any 6-mo period after the first 3 mo of immune tolerance induction (ITI); or failure to achieve tolerance or partial response after 33 mo on ITI; or withdrawal from the study for any reason before tolerance was achieved |
| Relapse | Inhibitor recurrence during the 12-mo follow-up period on prophylaxis after tolerance was achieved, as evidenced by recurrent positive Bethesda titer or a decline in FVIII recovery or half-life below study limits |
| Successful tolerance . | Negative inhibitor titer, FVIII recovery ≥ 66% of expected, and FVIII recovery ≥ 6 h . |
|---|---|
| Partial response | After 33 mo of ITI, negative inhibitor titer but persistently abnormal recovery or half-life; responding clinically to FVIII replacement without an anamnestic increase in inhibitor titer |
| Study failure | Failure of the inhibitor to decline by ≥ 20% over any 6-mo period after the first 3 mo of immune tolerance induction (ITI); or failure to achieve tolerance or partial response after 33 mo on ITI; or withdrawal from the study for any reason before tolerance was achieved |
| Relapse | Inhibitor recurrence during the 12-mo follow-up period on prophylaxis after tolerance was achieved, as evidenced by recurrent positive Bethesda titer or a decline in FVIII recovery or half-life below study limits |
From the consensus proceedings from the Second International Conference on Immune Tolerance Therapy, Bonn, Germany, 1997 (unpublished).