SAT668 Can We Treat Osteoporosis, Obesity And Neurodegeneration With A Single FSH-blocking Drug?

Abstract Disclosure: A.R. Pallapati: None. J. Gimenez-Roig: None. S. Rojekar: None. F. Korkmaz: None. D. Sant: None. O. Barak: None. F. Sultana: None. O. Moldavski: None. A. Gumerova: None. H.S. Kannangara: None. U. Cheliadinova: None. C.J. Rosen: None. J.N. Caminis: None. M. Meseck: None. V.E. Demambro: None. S.L. Sims: None. S. Gera: None. R. Witztum: None. S. Miyashita: None. V. Ryu: None. M. Saxena: None. T. Frolinger: None. A. Macdonald: None. S. Kim: None. G. Pevnev: None. D. Lizneva: None. T. Yuen: None. M. Zaidi: None. Pharmacological and genetic studies suggest that FSH is an actionable target for diseases affecting millions, notably osteoporosis, obesity and Alzheimer’s disease (AD). Blocking FSH action prevents bone loss (1, 2), fat accrual (3) and AD-like features in mice (4). We recently developed a first-in-class, humanized, epitope-specific FSH blocking antibody that binds to a 13-amino-acid-long sequence of FSHβ—MS-Hu6—with a KD of 7.52 nM (5). We showed that MS-Hu6 binds specifically to FSHβ, without binding to LH and TSH. For efficacy studies, we have blocked FSH action using either MS-Hu6 or the parent murine antibody, Hf2, targeted to the same epitope. Using our Good Laboratory Practice platform (Code of Federal Regulations, Title 21, Part 58), we report that FSH blockade prevents obesity, osteoporosis and AD in mice. We injected 20-week-old C57BL/6 male mice on a high-fat diet with a range of doses of Hf2 or vehicle s.c. five-days-a-week for 8 weeks. Hf2 (100 µg/mouse/day) reduced the increase in fat mass by 33% starting week 3, with a 7% reduction in in body weight. In separate studies, MS-Hu6 not only caused beiging of white adipose tissue in UCP1-reporter ThermoMice (IVIS imaging), but also improved bone density and microstructure (micro-CT) by elevating bone formation (dynamic histomorphometry). The increase in bone mass and improved microstructure were replicated in Cliff Rosen’s lab using C57BL6 mice 24 weeks post-ovariectomy. Novel Object Recognition testing of AD-prone, ovariectomized 3xTg mice showed a deficit in recognition memory, which was reversed after 8 weeks of Hf2 (100 µg/mouse/day for 5-days-a-week) exposure. Biodistribution studies using 89Zr-labelled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone, bone marrow, fat depots and brain tissue. MS-Hu6 displayed a β phase t½ of 7.5 days in humanized Tg32 mice. In monkeys, an acute single injection of MS-Hu6 did not affect vitals, and biochemical parameters remained within the normative range. We tested 215 variations of excipients using a range of physicochemical techniques, including protein thermal shift, size exclusion chromatography, dynamic light scattering, Fourier-transform infrared spectroscopy, circular dichroism spectroscopy, and differential scanning calorimetry, to yield a formulation with thermal, colloidal, monomeric and structural stability at an ultra-high concentration (100 mg/mL) with acceptable viscosity, clarity and turbidity parameters. MS-Hu6 showed the same “humanness” as human IgG1 in silico and was non-immunogenic in ELISPOT assays for IL-2 and IFNγ in human PBMC cultures. In conclusion, MS-Hu6 is efficacious, durable and manufacturable, and is therefore poised for human testing as a multipurpose therapeutic for obesity, osteoporosis, and perhaps for AD. 1Cell, 2006; 2PNAS, 2018,; 3Nature, 2017; 4Nature, 2022; 5. PNAS, 2020, eLife, 2022. Presentation: Saturday, June 17, 2023