Endocrinol Metab.  2025 Feb;40(1):146-155. 10.3803/EnM.2024.2090.

Development of a Long-Acting Follicle-Stimulating Hormone Using Serum Albumin Fab-Associated Technology for Female Infertility

• Kim D
• Cho YH
• Kang MJ
• Lee SJ
• Lee S
• Yun BH
• Chi H
• An J
• Lee K
• Han J
• Chi S
• Song MY
• Cha SH
• Lee EJ

• KMID: 2565262
• DOI: http://doi.org/10.3803/EnM.2024.2090

Abstract

Background
Recombinant human follicle-stimulating hormone (rhFSH) is commonly used to treat female infertility, but its short half-life necessitates multiple doses. Even corifollitropin alfa, with an extended half-life, requires supplementary injections of rhFSH after 7 days. This study aimed to develop and evaluate a long-acting follicle-stimulating hormone (FSH) formulation using anti-serum albumin Fab-associated (SAFA) technology to avoid additional injections and enhance ovarian function.
Methods
SAFA-FSH was synthesized using a Chinese hamster ovary expression system. Its biological efficacy was confirmed through assays measuring its ability to stimulate cyclic adenosine monophosphate (cAMP) production, estradiol synthesis, and the expression of human cytochrome P450 family 19 subfamily A member 1 (hCYP19α1) and human steroidogenic acute regulatory protein (hSTAR) in human ovarian granulosa (KGN) cells. To evaluate the effects of SAFA-FSH, we compared its impact on serum estradiol levels and ovarian weight increase with that of rhFSH in Sprague-Dawley (SD) rats using the modified Steelman-Pohley test.
Results
The results indicated that SAFA-FSH induces cAMP synthesis in KGN cells and upregulates the expression of hCYP19α1 and hSTAR in a dose-dependent manner. Female SD rats, aged 21 days, receiving daily subcutaneous human chorionic gonadotropin injections for 5 days exhibited a significant increase in serum estradiol levels and ovarian weight when administered SAFA-FSH on the first day or when given nine injections of rhFSH over 5 days. Notably, the group receiving SAFA-FSH on the first and third days demonstrated an even greater rise in serum estradiol levels and ovarian weight.
Conclusion
These findings suggest that SAFA-FSH presents a promising alternative to current rhFSH treatments for female infertility. However, further research is essential to thoroughly assess its safety and efficacy in clinical contexts.

Keyword

Follicle stimulating hormone; Female infertility; Ovulation; Gonadotropins

Figure

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  Fig. 1. The characteristics of anti-serum albumin Fab-associated (SAFA)-follicle-stimulating hormone (FSH). (A) SAFA-FSH consists of alpha and beta subunits, (B) human serum albumin binding capacity of SAFA-FSH, and (C) matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) analysis results of SAFA-FSH. hFSH, human follicle-stimulating hormone; a.u., arbitrary unit.

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  Fig. 2. Ovulation induction time course with anti-serum albumin Fab-associated (SAFA)-follicle-stimulating hormone (FSH) in SpragueDawley rats. (A) First experiment, (B) second experiment. Arrows indicate the injection cycle of each drug. Open arrows represent human chorionic gonadotropin (hCG) injections, shaded arrows represent recombinant human follicle-stimulating hormone (rhFSH) injections, and closed arrows represent SAFA-FSH injections.

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  Fig. 3. Effects of anti-serum albumin Fab-associated (SAFA)-follicle-stimulating hormone (FSH) in cell line experiments. (A) Cyclic adenosine monophosphate (cAMP) production, (B) estradiol synthesis, (C) human cytochrome P450 family 19 subfamily A member 1 (hCYP19α1) expression, and (D) human steroidogenic acute regulatory protein (hSTAR) expression in human ovarian granulosa (KGN) cells treated with indicated doses of recombinant human follicle-stimulating hormone (rhFSH) or SAFA-FSH. Data are representative of three independent experiments and are presented as mean±standard error of the mean.

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  Fig. 4. Effects of anti-serum albumin Fab-associated (SAFA)-follicle-stimulating hormone (FSH) in experimental animals. (A) Body weight, (B) serum estradiol level, (C) ovarian weight, (D) follicle count (>140 μm), and (E) representative images of ovaries stained with hematoxylin and eosin (×4). Data are presented as mean±standard error of the mean. aP<0.05, bP<0.01, cP<0.001 vs. control group; dP<0.05 vs. recombinant human follicle-stimulating hormone (rhFSH) group.

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  Fig. 5. Effects of anti-serum albumin Fab-associated (SAFA)-follicle-stimulating hormone (FSH) in the second set of experimental animals. (A) Body weight, (B) ovarian weight, and (C) representative images of ovaries. Data are presented as mean±standard error of the mean. aP<0.01 vs. control group; bP<0.01 vs. recombinant human follicle-stimulating hormone (rhFSH) group.

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Reference

1. Carson SA, Kallen AN. Diagnosis and management of infertility: a review. JAMA. 2021; 326:65–76.

2. Recent advances in medically assisted conception: report of a WHO Scientific Group. World Health Organ Tech Rep Ser. 1992; 820:1–111.

3. Hull MG, Glazener CM, Kelly NJ, Conway DI, Foster PA, Hinton RA, et al. Population study of causes, treatment, and outcome of infertility. Br Med J (Clin Res Ed). 1985; 291:1693–7.

4. Kim JH, Alzahrani HS, Lee SR, Kim SH, Chae HD. Outcomes of fertility preservation for female cancer patients in a single tertiary center. Yonsei Med J. 2023; 64:497–504.

5. Kim SY. Diagnosis and treatment of hypopituitarism. Endocrinol Metab (Seoul). 2015; 30:443–55.

6. Patil M. Gonadotrophins: the future. J Hum Reprod Sci. 2014; 7:236–48.

7. Carvalho BR. Corifollitropin alfa for controlled ovarian stimulation in assisted reproductive technologies: state of the art. Rev Bras Ginecol Obstet. 2023; 45:43–8.

8. Beckers NG, Macklon NS, Devroey P, Platteau P, Boerrigter PJ, Fauser BC. First live birth after ovarian stimulation using a chimeric long-acting human recombinant follicle-stimulating hormone (FSH) agonist (recFSH-CTP) for in vitro fertilization. Fertil Steril. 2003; 79:621–3.

9. Kim D, Lee S, Cho YH, Kang MJ, Ku CR, Chi H, et al. Long-acting recombinant human follicle-stimulating hormone (SAFA-FSH) enhances spermatogenesis. Front Endocrinol (Lausanne). 2023; 14:1132172.

10. Verbost P, Sloot WN, Rose UM, de Leeuw R, Hanssen RG, Verheijden GF. Pharmacologic profiling of corifollitropin alfa, the first developed sustained follicle stimulant. Eur J Pharmacol. 2011; 651:227–33.

11. Ai A, Tang Z, Liu Y, Yu S, Li B, Huang H, et al. Characterization and identification of human immortalized granulosa cells derived from ovarian follicular fluid. Exp Ther Med. 2019; 18:2167–77.

12. Steelman SL, Pohley FM. Assay of the follicle stimulating hormone based on the augmentation with human chorionic gonadotropin. Endocrinology. 1953; 53:604–16.

13. Zhang YL, Guo KP, Ji SY, Liu XM, Wang P, Wu J, et al. Development and characterization of a novel long-acting recombinant follicle stimulating hormone agonist by fusing Fc to an FSH-β subunit. Hum Reprod. 2016; 31:169–82.

14. Devroey P, Boostanfar R, Koper NP, Mannaerts BM, Ijzerman-Boon PC, Fauser BC, et al. A double-blind, non-inferiority RCT comparing corifollitropin alfa and recombinant FSH during the first seven days of ovarian stimulation using a GnRH antagonist protocol. Hum Reprod. 2009; 24:3063–72.

15. Baird DT. A model for follicular selection and ovulation: lessons from superovulation. J Steroid Biochem. 1987; 27:15–23.

16. Fauser BC, Van Heusden AM. Manipulation of human ovarian function: physiological concepts and clinical consequences. Endocr Rev. 1997; 18:71–106.

17. Homburg R, Insler V. Ovulation induction in perspective. Hum Reprod Update. 2002; 8:449–62.

18. Devroey P, Fauser BC, Platteau P, Beckers NG, Dhont M, Mannaerts BM. Induction of multiple follicular development by a single dose of long-acting recombinant follicle-stimulating hormone (FSH-CTP, corifollitropin alfa) for controlled ovarian stimulation before in vitro fertilization. J Clin Endocrinol Metab. 2004; 89:2062–70.

19. Oguz SH, Yildiz BO. An update on contraception in polycystic ovary syndrome. Endocrinol Metab (Seoul). 2021; 36:296–311.

20. Kelly AC, Jewelewicz R. Alternate regimens for ovulation induction in polycystic ovarian disease. Fertil Steril. 1990; 54:195–202.

21. Kim JH, Jung MH, Hong SH, Moon N, Kang DR. Age-adjusted prevalence and characteristics of women with polycystic ovarian syndrome in Korea: a nationwide population-based study (2010-2019). Yonsei Med J. 2022; 63:794–8.

22. White DM, Polson DW, Kiddy D, Sagle P, Watson H, Gilling-Smith C, et al. Induction of ovulation with low-dose gonadotropins in polycystic ovary syndrome: an analysis of 109 pregnancies in 225 women. J Clin Endocrinol Metab. 1996; 81:3821–4.

23. Homburg R, Howles CM. Low-dose FSH therapy for anovulatory infertility associated with polycystic ovary syndrome: rationale, results, reflections and refinements. Hum Reprod Update. 1999; 5:493–9.

24. Orvieto R, Homburg R. Chronic ultra-low dose follicle-stimulating hormone regimen for patients with polycystic ovary syndrome: one click, one follicle, one pregnancy. Fertil Steril. 2009; 91(4 Suppl):1533–5.