Combining the safety advantages of a recombinant protein with the advantages of fully human glycosylation
Glycotope’s FSH-GEX® is a fully human glycosylated recombinant FSH (follicle-stimulating hormone), expressed in human cells and glyco-optimized FSH. FSH is responsible for follicle maturation and is administered during the onset of in vitro fertilization procedures to induce maturation of multiple oocytes for retrieval.
Disease awareness, and the opportunity
FSH-GEX® is being developed for infertility therapy, particularly for follicle maturation during in-vitro fertilization (IVF).
In single and multiple Phase I dose escalation studies FSH-GEX® was well tolerated and showed clear linearity over the tested dose levels. In the single dose and more strongly in the multiple dose study, FSH-GEX® dosed equally has a stronger effect on follicle growth than both comparator compounds Gonal-f® and Bravelle.
In a Phase 2 clinical trial, FSH-GEX® dosed at 75 IU was at least as active as 150 IU Gonal-f® in all FSH mediated parameters and endpoints. These data confirm the superior preclinical as well as Phase 1a and 1b data regarding biological activity and clinical efficacy. Furthermore, the results at a dose regimen with 150 IU FSH-GEX® applied every second day and 75 IU FSH-GEX® administered on a daily basis were fully comparable, allowing for a flexible or alternative dosing regimen with the same product.
The treatment with FSH-GEX® was safe and very well tolerated, while Gonal-f® showed the highest rate of OHSS (Ovarian hyperstimulation syndrome) during the trial. No inductions of anti-drug antibody (ADA) responses were observed in FSH-GEX® dosed patients.
Differentiation/mode of actions/specificity
Most approved preparations of FSH are derived either from human urine or recombinant sources from non-human cells. Purification of FSH from urine is a very complex process and there are safety concerns with contaminations. A generally better safety profile today makes recombinant proteins the products of choice for most patients despite higher product costs and the fact that recombinant products from non-human cells may induce immunogenic or allergic reactions due to lack of human sugar structures.