Somavert (Pegvisomant) - Side Effects and Adverse Reactions

ADVERSE REACTIONS

LABORATORY CHANGES

Elevations of serum concentrations of ALT and AST greater than ten times the ULN were reported in two subjects (0.8%) exposed to SOMAVERT in pre-approval clinical studies (see PRECAUTIONS, Liver Tests [LTs]).

GENERAL

Nine acromegalic patients (9.6%) withdrew from pre-marketing clinical studies because of adverse events, including two patients with marked transaminase elevations (see PRECAUTIONS, Liver Tests [LTs]), one patient with lipohypertrophy at the injection sites, and one patient with substantial weight gain. The majority of reported adverse events were of mild to moderate intensity and limited duration. Most adverse events did not appear to be dose dependent. Table 5 shows the incidence of treatment-emergent adverse events that were reported in at least two patients treated with SOMAVERT and at frequencies greater than placebo during the 12-week, placebo-controlled study.

IMMUNOGENICITY

In pre-marketing clinical studies, approximately 17% of the patients developed low titer, non-neutralizing anti-GH antibodies. Although the presence of these antibodies did not appear to impact the efficacy of SOMAVERT, the long-term clinical significance of these antibodies is not known. No assay for anti-pegvisomant antibodies is commercially available for patients receiving SOMAVERT.