Journey to replace in vivo bioassay by In Vitro Potency Assays for Follicular stimulating Hormone (FSH)

Adi Kozminsky-Atias, Development Department, BTG (a Ferring company), Beer Tuvia, Israel (adat@ferring.com)

Regulatory authorities are increasingly advocating for the replacement of animal-based testing with in vitro methods, encouraging the pharmaceutical industry to adopt more ethical and scientifically advanced approaches. For over two decades, gonadotropin drugs have been routinely tested using the compendial Steelman–Pohley bioassay, which measures ovarian weight gain in immature rats to determine potency.

Driven primarily by ethical considerations aligned with the 3Rs principles (Replacement, Reduction, and Refinement), and secondarily by the potential for improved efficiency and cost-effectiveness, the company initiated a transition to an in vitro potency assay. A fully automated, cell-based assay was developed and validated to quantify potency by measuring the dose-dependent increase in cyclic AMP (cAMP) following FSH receptor activation. To support global regulatory submissions, a manual version of the assay for drug product (DP) was also developed, validated, and successfully transferred.

To bridge the transition from the in vivo to the in vitro method, an extensive comparative study was conducted. This study evaluated the ability of both assay formats to detect structural variants, impurities, and glycan modifications using forced degradation and spiked samples. In addition, release and stability batches were tested in both formats. The results demonstrated that the in vitro assay provided robust and reliable discrimination capabilities and had comparable results.

This strategic approach led to the successful regulatory approval of the in-house in vitro potency assay for recombinant human FSH (r-hFSH) in over 70 countries, replacing the in vivo bioassay for both drug substance (DS) and drug product (DP) batch release and stability testing.

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Short Biography of Presenting Author

Adi Kozminsky-Atias is currently Heading the Biological Assay development group in BTG, a Ferring Company, which includes managing a highly skilled team focused on development of potency, immunoassays and other biological impurities assays. Previously, she was a lead scientist in the biological assay team at BTG, a Ferring Company, where she focused on the development, optimisation, transfer and validation of a wide range of potency of biological products in support of early clinical phases through to commercialization and post approval changes. Adi also has experience for over 5 years as a cmc project manager for biopharmaceutical products and additional 3 year in Discovery. She holds a PhD in Cell and Molecular Biology and Biochemistry from the Ben- Gurion University, Israel and has overall of 15 years' experience in pharmaceutical industry.