ADYNOVATE SIDE EFFECTS

SIDE EFFECTS

The most common adverse reactions (≥1% of subjects) reported in the clinical studies were headache and nausea.

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in clinical trials of another drug and may not reflect the rates observed in practice.

The safety of ADYNOVATE was evaluated in 237 previously treated patients (PTPs) and 6 previously untreated patients (PUPs) with severe hemophilia A (factor VIII less than 1% of normal), who received at least one dose of ADYNOVATE in 3 completed multi-center, prospective, open label clinical studies and 4 ongoing clinical studies. The median duration of participation per subject was 401 (min-max: 3-1034) days and the median number of exposure days to ADYNOVATE per subject was 111 (min-max: 1-322).

Table 1: Adverse Reactions Reported for ADYNOVATE

Two cases of acute pancreatitis, with no precipitating cause identified in one case, were reported in adults during an extension study of the clinical trial which evaluated 137 subjects. Administration of ADYNOVATE continued and both cases resolved.

Immunogenicity

The risk of the development of factor VIII inhibitors with the use of ADYNOVATE was evaluated in 3 completed and 4 ongoing clinical trials. Subjects consisted of adolescent and adult (n= 148 with ≥150 prior EDs) and pediatric PTPs [(<6 years of age with ≥50 prior EDs (n= 32), ≥6 years of age with ≥150 prior EDs (n= 57)], and pediatric PUPs (n=6). In 191 adult and pediatric PTPs who were treated for at least 50 exposure days with ADYNOVATE, the factor VIII inhibitor frequency was 0 (95% CI of 0 to 0.019). One PUP subject from an ongoing study, who received at least one infusion of ADYNOVATE, developed neutralizing antibodies to factor VIII.

Immunogenicity also was evaluated by measuring the development of binding IgG and IgM antibodies against factor VIII, PEGylated (PEG)-factor VIII, PEG and Chinese hamster ovary (CHO) protein using validated ELISA assays. The majority of subjects (238/243) with at least one infusion of ADYNOVATE did not develop a persistent binding antibody response to any of these antigens. Twenty-eight subjects in total showed pre-existing antibodies to factor VIII (n=3), PEG-factor VIII (n=25) and/or PEG (n=3) prior to the first exposure to ADYNOVATE. Thirteen subjects who tested negative at screening developed transient antibodies against factor VIII (n= 6), PEG-FVIII (n= 8) at one or two consecutive study visits. Antibodies were transient and not detectable at subsequent visits. Five subjects showed positive results for binding antibodies at study completion or at the time of data cutoff. Binding antibodies that were detected prior to exposure to ADYNOVATE, that transiently developed during the trial or were still detectable at study completion or data cutoff could not be correlated to any impaired treatment efficacy or altered PK parameters. There was no causal relationship between observed adverse events and binding antibodies except in one subject where a causal relationship cannot be ruled out based on available data. No subject had pre-existing or treatment-emergent antibodies to CHO protein.

The detection of antibodies that are reactive to factor VIII is highly dependent on many factors, including: the sensitivity and specificity of the assay, sample handling, timing of sample collection, concomitant medications and underlying disease. For these reasons, comparison of the incidence of antibodies to ADYNOVATE with the incidence of antibodies to other products may be misleading.