During the clinical studies conducted in previously treated patients (PTPs), 109 adverse events were reported in the course of 4160 infusions (2.6%). Only 13 events were reported by the investigator as at least remotely related to study drug. Another 7 events were nonassessable. Thus 20 events in 11 patients were considered to be either nonassessable or at least remotely related to Helixate FS (antihemophilic factor (recombinant)) administration, for an incidence of 0.5% relative to the number of infusions administered. Events that were at least remotely drug-related included: local injection site reactions (2), dizziness (2), rash (2), unusual taste in the mouth (1), mild increase in blood pressure (1), pruritus (1), depersonalization (1), nausea (1), and rhinitis (1). No FVIII inhibitors have developed in the 72 PTPs with severe hemophilia A who have received Helixate FS (antihemophilic factor (recombinant)) for a mean of 54 exposure days.
In clinical studies with previously untreated patients (PUPs) and minimally treated (MTP) pediatric patients, 18 adverse events were reported by the clinical investigators as at least possibly related to the study drug including the expected complication of inhibitor development in 8 patients (included in the 10 patients discussed under CLINICAL PHARMACOLOGY), a forearm bleed following venipuncture, constipation, adenopathy, rash, anemia and pallor in one inhibitor patient with gastroenteritis, and serous otitis media.
The following events are principally derived from post-marketing experience and publications,14 and accurate rate estimates are generally not possible. Among patients treated with its predecessor product HELIXATE, very rare cases of serious allergic reactions and anaphylactic reactions have been reported, particularly in very young patients or patients who had previously reacted to other FVIII concentrates. Individual cases of hypotension have been very rarely reported. Rare cases of urticaria have also been reported. Although such serious reactions have not been reported with the use of Helixate FS (antihemophilic factor (recombinant)) , it is likely that these may also occur. Rare cases of dyspnea have been reported with Helixate FS (antihemophilic factor (recombinant)) .