Egrifta (Tesamorelin) Side Effects: Severity Distribution by Patient Phenotype

Does the label give severity grades by phenotype?

No. The Egrifta SV and Egrifta WR labels present adverse reactions as overall percentages for 543 tesamorelin-treated and 263 placebo-treated HIV-infected adults during the initial 26-week phase [1][2]. The table lists each reaction by name and does not break rates out by prediabetes, age, sex, CD4 count, or antiretroviral regimen. The approved population is HIV-infected adults with lipodystrophy and excess abdominal fat [1].

What rates did the trials report?

The most common reactions, each above 5%, were arthralgia, injection-site erythema, injection-site pruritus, pain in extremity, peripheral edema, and myalgia [1]. In the labels' combined table, arthralgia was 13% vs 11% on placebo, peripheral edema 6% vs 2%, and myalgia 6% vs 2% [1]. Separately, the injection-site reaction warning gives an incidence of 25% on tesamorelin vs 14% on placebo in the first 26 weeks [1].

Hypersensitivity reactions occurred in 4% of patients treated in the clinical trials and included pruritus, erythema, flushing, urticaria, and rash [1]. The label says patients should seek prompt medical attention and treatment should be discontinued immediately if a hypersensitivity reaction is suspected [1].

Glucose intolerance and diabetes are labeled risks. HbA1c at least 6.5% from baseline to week 26 occurred in 5% of tesamorelin patients vs 1% on placebo, with a hazard ratio of 3.3 (95% CI 1.4 to 9.6) [1]. The label says to evaluate glucose before starting and to monitor during treatment, and to monitor patients with diabetes for retinopathy [1].

Tesamorelin stimulates growth hormone production and raises IGF-1. Among patients treated for 26 weeks, 47% had IGF-1 above 2 SDS and 36% above 3 SDS; among those treated for 52 weeks, 34% and 23% [1]. The label says the effects of prolonged IGF-1 elevation are unknown and that discontinuation should be considered for persistent elevations, such as above 3 SDS, particularly if the fat-loss response is not robust [1].

Fluid retention is another labeled risk. It can appear as edema, arthralgia, or carpal tunnel syndrome; the label describes these as transient or resolving with discontinuation [1]. The label also warns that pharmacologic growth hormone has been linked to increased mortality in acute critical illness and says to consider discontinuing tesamorelin in critically ill patients [1].

Which phenotypes are named?

For side-effect rates, none. The label names groups for contraindications and monitoring, not for a severity distribution: pregnancy, active malignancy, disruption of the hypothalamic-pituitary axis, and known hypersensitivity to tesamorelin or excipients are contraindications [1]. It says there is no information on use in patients older than 65, that safety and effectiveness in children are not established, and that pharmacokinetics in renal or hepatic impairment are not established [1]. It also asks prescribers to weigh the higher background cancer risk in people with HIV [1].

The label says all treated patients should have periodic glucose monitoring, with retinopathy monitoring for those with diabetes, but it does not report separate side-effect rates for that group [1]. For sex, the 412-patient pivotal trial was 86% men [3]; the labels' adverse-reaction table is not split by sex [1].

Can post-market reports fill the gap?

No. FDA's adverse event dashboard states that reports cannot be used to estimate incidence and do not establish causation [4]. They cannot provide a phenotype-specific severity distribution.