Theratechnologies has received a Complete Response Letter (CRL) from the US Food and Drug Administration (FDA), denying approval for its F8 formulation of tesamorelin to treat HIV.

The CRL was issued in response to the company's supplemental biologics licence application.

The FDA's letter highlighted issues primarily related to chemistry, manufacturing and controls. Its inquiries focused on the microbiology, assays, impurities and stability of the lyophilised product and the final reconstituted drug.

The regulator had also sought additional data to assess the potential immunogenicity risk associated with the proposed formulation.

The company will respond to the FDA's inquiry and expects to seek regulatory clearance for this newer version of tesamorelin.

Despite the setback, the current commercial availability of EGRIFTA SV, the F4 formulation of tesamorelin, remains unaffected.

EGRIFTA SV is approved for reducing excess abdominal fat in adult patients with HIV infection and lipodystrophy.

It will continue to be marketed by Theratechnologies in the US.

The growth hormone-releasing factor analogue induces endogenous growth hormone production and release by acting on pituitary cells in the brain.

Hyperglycaemia, hypersensitivity reactions, reactions at the injection site, arthralgia and myalgia were among the reported adverse reactions linked to EGRIFTA SV.

The company develops and markets new therapies that meet unmet medical needs.

Theratechnologies senior vice-president and chief medical officer Christian Marsolais stated: “While we are disappointed to receive a Complete Response Letter from the FDA for the F8 formulation of tesamorelin containing questions that were not raised during the review process, we plan to address these new comments as swiftly as possible.

“We remain focused on bringing this new formulation of tesamorelin to market as part of our commitment to innovate and simplify treatments for people with HIV.”