Alvotech said that AVT03, a proposed biosimilar to osteoporosis drugs Prolia (denosumab) and Xgeva (denosumab), has demonstrated positive topline data in the AVT03-GL-C01 confirmatory patient study.

The AVT03-GL-C01 trial achieved its primary endpoints (PEs) of change from baseline in bone mass density (BMD) and a biomarker for bone resorption.

AVT03 is an investigational human monoclonal antibody that targets and binds with high affinity and specificity to the RANK ligand membrane protein.

Prolia is used to treat osteoporosis in postmenopausal women and to prevent bone loss in adults at high risk of fractures, both men and women.

Xgeva, another form of the same biologic, is indicated for preventing skeletal-related events like fractures in adults with advanced cancers affecting the bones.

 AVT03-GL-C01 is a randomised, double-blind, parallel design, repeat dose, two-arm, multicentre study. It compared the efficacy, safety, immunogenicity, and pharmacokinetic (PK) profiles of AVT03 and Prolia in nearly 532 postmenopausal women with osteoporosis to assess the clinical similarity of Alvotech’s asset.

Participants were randomly assigned to receive either three doses of AVT03 or three doses of Prolia every six months.

The trial also involved a re-randomisation phase, where patients initially receiving Prolia were further randomised to receive a third dose of either the biosimilar or the reference drug.

Findings from the trial will support extending the indications for the investigational biosimilar as a potential biosimilar to Xgeva through extrapolation.

Alvotech chief scientific officer Joseph McClellan said: “We are pleased with these results, demonstrating clinical similarity between AVT03 and the reference biologic.

“In addition, we have now obtained positive topline results from two PK studies, that show equivalent PK, safety, and tolerability of AVT03 compared to Prolia and Xgeva, respectively.

“These clinical milestones underline the capabilities of our dedicated biosimilar platform and continued diversification of our portfolio. We expect to file marketing applications for AVT03 for major global markets later this year.”

The proposed biosimilar was also assessed in the AVT03-GL-P01 and the AVT03-GL-P03 studies against Prolia and Xgeva, respectively. Both trials met their primary endpoints.

Alvotech, a biotech specialised in biosimilar medicines, plans to submit marketing applications for AVT03 later this year for major global markets.