A new fully human recombinant FSH (follitropin epsilon): two phase I randomized placebo and comparator-controlled pharmacokinetic and pharmacodynamic trials

Abstract

Study question: What are the differences and similarities of pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of the novel recombinant human FSH follitropin epsilon expressed in the human cell line GlycoExpress compared with a Chinese hamster ovary (CHO) derived compound and a urinary derived product?

Summary answer: Overall follitropin epsilon, with a fully human glycosylation, shows a comparable PK profile at single-dose as well as multiple-dose administration compared to recombinant CHO-derived FSH as well as urinary derived FSH, whereas the PD properties differ from product to product with follitropin epsilon being most active in PD parameters.

What is known already: Recombinant FSH produced in CHO and FSH obtained from the urine of postmenopausal women show comparable PK and PD properties. However, more recently a comparative study of a recombinant FSH produced in the human cell line PerC6 and a CHO-derived FSH preparation revealed differences in PK and PD properties of the molecule.

Study design, size, duration: Both studies were randomized, placebo- and comparator-controlled, single-blind phase I studies in healthy pituitary-suppressed female volunteers aged 18 and 40 years. The single-dose, dose escalation study included 19 women (April 2011 to September 2011) with three ascending dose levels per subject or placebo/comparators with a 14-day washout phase between dosings. The multiple-dose study included 57 women (October 2011 to April 2012) in five cohorts with three dose levels versus placebo and two comparators. Randomization to the respective treatment was performed after successful downregulation of the pituitary gland prior to Investigational Medicinal Product dosing.

Participants/materials, setting, methods: In the single-dose study, 12 subjects received follitropin epsilon (25, 75, 150 and 300 IU) in three of four possible ascending doses and seven subjects received one dose of two comparators (150 IU Bravelle and 150 IU Gonal-f) and placebo in random order in each treatment period. In the multiple-dose study, 30 subjects received follitropin epsilon (75 IU or 150 IU once daily [QD], or 150 IU every other day [QAD], 10 subjects each) and 27 subjects received 150 IU Gonal-f, 150 IU Bravelle, or placebo for 7 days (11/10/6 subjects). Blood samples for measuring PK as well as PD parameters were collected systematically before, during and after dosing. Adverse events (AEs) and other relevant safety parameters were recorded. Data were summarized using descriptive statistics.

Main results and the role of chance: The single- and multiple-dose PK parameters maximum concentration (Cmax) and area under the concentration-time curve (AUC0-last) increased in a linear fashion with increasing dose levels of follitropin epsilon. Follitropin epsilon showed PK characteristics comparable to the comparators indicating that well established treatment schemes could be applied. There was a dose-response effect of single and multiple doses of follitropin epsilon on follicular growth, which was shown for the biomarker inhibin B as well as for the mean number and size of follicles. Multiple doses of 75 IU follitropin epsilon given daily, as well as 150 IU follitropin epsilon every second day, showed a follicle growth comparable with 150 IU Gonal-f given daily, while in case of daily administration of 150 IU Bravelle only weak follicle stimulation was observed. Multiple doses of 150 IU follitropin epsilon induced a much higher follicle growth compared to the same dose of Gonal-f. All single and multiple follitropin epsilon doses tested were safe and well tolerated, and overall there were no relevant differences between follitropin epsilon and the comparators in terms of safety. The average number of AEs increased with increasing dose levels. No clinically relevant abnormalities were reported for any of the other safety parameters assessed. No follitropin epsilon anti-drug antibodies were observed.

Limitations, reasons for caution: The studies were conducted as a single-blind design. Hormone levels or other parameters assessed in serum are generally not considered as being subject to bias. Other assessments directly performed by the investigators, such as transvaginal ultrasound assessments, may have been subject to personal bias. No prospective calculations of statistical power had been made, as is common practice for first in human and early phase I studies in healthy volunteers.

Wider implications of the findings: These early development studies showed that follitropin epsilon exhibits comparable PK characteristics, as well as inducing stronger PD effects in terms of follicle growth and serum inhibin B, than the comparators. Follitropin epsilon induced a dose-dependent increase in follicular growth. The results warrant further studies with this new fully human recombinant FSH.

Study funding/competing interest(s): The studies were sponsored by GLYCOTOPE GmbH, Berlin, Germany. K.A-E. is an employee of QPS-Netherlands, B.V., which received funding for the studies from Glycotope GmbH; I.D. and C.K. are employees of Dinox B.V., which received funding for the studies from Glycotope GmbH; L.S. and S.G. are employees and shareholders of Glycotope GmbH; B.D. and K.E. are employees of Glycotope GmbH.

Trial registration number: www.clinicaltrials.gov: NCT01354886 (single-dose); NCT01477073 (multiple-dose).

Trial registration date: The single-dose trial was registered on 11 May 2011 while the multiple-dose trial was registered on 09 November 2011.

Date of first subject's enrolment: First subject was enroled in the single-dose trial in 27 April 2011 and in the multiple-dose trial in 02 October 2011.

Keywords: ART; FSH; FSH-GEX; IVF; estradiol; follitropin epsilon; glycosylation; inhibin B; pharmacodynamics; pharmacokinetics.