Table 1.
Naturally occurring and commercially available recombinant follitropin preparations and nomenclature.
| Generic Name | Brand name examples | Characteristics |
|---|---|---|
| Urofollitropin (Fertinex) |
Fertinex (HP-FSH) immunoaffinity (8.5–13.5 IU/ug) Metrodin (87 IU/mg) (discontinued in US) Bravelle (2%LH)(discontinued in US), Menopure, Ferring (available in US) |
From post-menopausal urine; more acidic forms than recombinant FSH. Isoelectric point (pI <4.0, 40% of preparation and higher than 4.0 (74%) in highly purified preparations); both α2,3 and α2,6 sialylation) and reduced sulfated glycans compared to pituitary FSH, less core (~23.9%) fucose and less bisecting glycans than pituitary FSH. |
| Pituitary FSH | Not commercially used | Derived from human pituitary gland; both α2,3 and α2,6 sialylation and with sulfated glycans, 44–53% core fucose. |
| Follitropin alpha | Gonal-F® EMD Serono of Merck KGaA,Germany (13.6 IU/ug) Bemfola® Finox Biotech, Sweden (US rights obtained by Gedeon Richter Plc. Ovaleap® Teva Pharma, Israel Cinnal-f®Cinnagen, Iran |
Derived through recombinant DNA technology and expressed in Chinese hamster ovary (CHO) cells. Isoelectric point (pI = 4–5) 91% >4.0 so profile more basic than urinary FSH, with only α2,3 linked sialic acid, 30-36% core fucose. Only Gonal F is currently available in US. |
| Follitropin beta | Follistim® Organon, (available in US) Puregon® Merck |
Derived through recombinant DNA technology and expressed in Chinese hamster ovary (CHO) cells. Isoelectric point (pI = 3.5–5.5) profile more acidic than follitropin alpha, α2,3 linked sialic acid.; 13.7% core fucose. |
| Follitropin delta | Rekovelle® Ferring, Switzerland | Derived through recombinant DNA technology and expressed in human cells. Contains both α2,3 and α2,6 sialylation patterns. |
| Follitropin epsilon | Glyco Express Glycotope, Berlin | Derived through recombinant technology and expressed in human cells. Similar as above but with some differences. |
Naturally occurring follitropin from human pituitaries is not used commercially but has been the gold standard for many biochemical and biological studies as well as a comparator for recombinant follitropin. Urinary follitropin is available commercially. Recombinant follitropin Gonal-F®, and biosimilars Bemfola®, Ovaleap® and Cinnal-f® are grouped into one class called follitropin Alpha. The follitropin Beta class includes Follistim® and Puregon®. Follitropin Delta included the follitropin Rekovelle® which is produced using a human cell line and results in a product that possesses sialic acid2,6 as well as sialic acid2,3 capped Gal. Follitropin Epsilon is also produced in a human cell line but is in a different group because it is claimed to have different glycosylation to Rekovelle® and it is not yet commercially available. Isolelectric profile as reported in (4) and fucose as reported in (5).