Shionogi Provides Updates on Zatolmilast, an Investigational Drug for Fragile X Syndrome, Including Recent Changes to Study Protocol to Increase Access for Participants and Families

OSAKA, Japan, July 18, 2024 - Shionogi & Co., Ltd. (Head Office: Osaka, Japan; Chief Executive Officer: Isao Teshirogi, Ph.D.; hereafter "Shionogi") today announced progress on the development program for zatolmilast (BPN14770), an investigational drug for Fragile X syndrome (FXS), the leading cause of inherited intellectual disabilities, like autism spectrum disorder.¹ Zatolmilast was discovered by Tetra Therapeutics Inc., (hereafter “Tetra”), which was acquired by Shionogi in 2020.

Zatolmilast is the first and only selective PDE4D inhibitor being investigated for FXS.² There are currently no pharmacological agents approved by the U.S. Food and Drug Administration (FDA) to treat FXS.³

The FDA recently granted Fast Track designation to zatolmilast, reflecting the significant unmet medical need for FXS. The FDA previously granted zatolmilast Rare Pediatric Disease Designation and Orphan Drug Designation. The European Commission granted Orphan Medicinal Product designation for zatolmilast in FXS earlier this year. These designations are designed to facilitate the development and expedite the review of potential new therapies that treat serious conditions and fulfill an unmet medical need.

“My husband and I have spent the past 30 years raising and directing funds to support early-stage research in Fragile X syndrome. This is a full circle moment for us as our organization funded the early development of zatolmilast,” said Katie Clapp, President and Co-Founder of the FRAXA Research Foundation, a non-profit organization dedicated to funding research for FXS. “It’s important to realize that this progress is possible because of the families that participate in clinical trials. I hope more families will consider participating in clinical research to help our loved ones, not only today, but also for future generations.”

Tetra is currently enrolling participants in zatolmilast clinical studies at 15 sites across the U.S., with additional sites anticipated this year.^4-6 The studies are evaluating the safety and efficacy of zatolmilast in males aged 9 to 45 years with FXS.^4-6 Tetra recently completed several protocol amendments to make the clinical trials more accessible for people living with FXS and their families,^7-9 including:

“I’ve been working on Fragile X syndrome and with the community for more than 30 years. Enrolling participants in late-stage (Phase 2b/3) clinical studies of zatolmilast is a significant step in our efforts to bring a potential treatment option to families,” said Elizabeth Berry-Kravis, MD, PhD, clinical trial investigator and professor of pediatrics, neurological sciences and biochemistry at Rush University Medical Center in Chicago. “If the positive Phase 2 trial data can be replicated, this investigational drug has the potential to improve cognition and could offer people living with Fragile X syndrome and their families the first cognitive treatment developed specifically for this rare genetic disorder.”

In addition to supporting FRAXA, Tetra has supported the National Fragile X Foundation since 2017. This year, Tetra and Shionogi are sponsors of the National Fragile X Foundation International Fragile X Conference taking place July 25-28 in Orlando, Florida. The conference brings together people living with FXS and their families, caregivers, friends and professionals to learn from one another during the FXS journey.

In a Phase 2 randomized, double-blind, placebo-controlled, two-way crossover trial that included 30 adult males with FXS, the primary endpoint of safety was demonstrated. An exploratory analysis of the efficacy of zatolmilast showed improvement in cognition, specifically in language domains including picture vocabulary and oral reading recognition.² Clinically meaningful improvements in daily functioning were also observed.² The most commonly reported adverse events were vomiting and upper respiratory tract infections. However, rates were similar between the active and placebo arms.² No participants discontinued the study due to adverse events.²

Zatolmilast is being evaluated in a pivotal Phase 2b/3 program in the U.S., with two randomized, double-blind, placebo-controlled studies of 150 participants each.^4-6 The first, Study 204 (NCT05163808), includes adolescent males ages 9-17.⁴ The second, Study 301 (NCT05358886), includes adult males ages 18-45.⁵ The zatolmilast clinical program also includes Study 302 (NCT05367960), an open-label extension study, that may last for up to two years, available to participants after completing Study 204 or Study 301.⁶

Primary endpoints for the studies include cognitive assessment of the efficacy of zatolmilast, as measured by the cognition crystallized composite score of the National Institutes of Health Toolbox Cognitive Battery (NIH-TCB), a calculated score from a series of tests to assess the patients’ change from baseline of the Picture Vocabulary and Oral Reading domains of the NIH-TCB. Secondary endpoints include assessments of language, daily function, caregiver and clinician improvement scales and other domains from the NIH-TCB, as well as further determination of the investigational drug’s safety and tolerability.^4-6

Learn about the zatolmilast clinical program at https://tetratherapeutics.com/clinical-trials/.

Zatolmilast is an investigational drug. Safety and efficacy have not been established. There is no guarantee that zatolmilast will be approved by any health authority.

Fragile X syndrome is the leading cause of inherited intellectual disabilities, like autism spectrum disorder.¹ FXS is known to have a greater effect on males than females because the mutation of the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene is carried on the X chromosome.¹ The most important clinical abnormality associated with FXS is global developmental delay and intellectual disability.¹⁰ Other common symptoms of FXS include behavioral problems, attention deficits and anxiety.¹ FXS can cause challenges across many aspects of daily life, such as impacting individuals’ ability to care for themselves and communicate with others.¹¹

Tetra Therapeutics, a Shionogi Group Company, is a clinical stage biotechnology company focused on developing a portfolio of therapeutic products to address unmet needs in central nervous system diseases and disorders. In addition to advancing the zatolmilast clinical program, Tetra also has a PDE4B inhibitor in pre-clinical development. Tetra Therapeutics is headquartered in Kalamazoo, Michigan. For more information, visit tetratherapeutics.com/clinical-trials/.

Shionogi is committed to the research and development of innovative medicines that address unmet medical needs for people worldwide. Rare diseases often have limited treatment options and affect daily lives of individuals and families around the world.¹² In the U.S., Shionogi is advancing clinical programs for rare diseases and disorders including Fragile X syndrome and Pompe disease. For more information, see our pipeline here: https://www.shionogi.com/us/en/innovation/pipeline.html.

Shionogi & Co., Ltd. is a leading global research-driven pharmaceutical company dedicated to bringing benefits to patients based on its corporate philosophy of "supplying the best possible medicine to protect the health and well-being of the patients we serve." Shionogi has discovered and developed novel antibiotics, medicines for HIV and influenza, and currently markets medicines for infectious diseases and central nervous system disorders. Shionogi’s global pipeline includes research programs in infectious disease, pain/CNS, metabolic disorders, rare disease, oncology and stroke. For more information, visit https://www.shionogi.com/global/en.

For Further Information, Contact:

SHIONOGI Website Inquiry Form: https://www.shionogi.com/global/en/contact.html

U.S. Media Contact: ShionogiCommunications@shionogi.com

SEU Press Office: pressoffice@shionogi.eu

1. Fragile X Syndrome (FXS). Cleveland Clinic. Accessed June 11, 2024. Available at: https://my.clevelandclinic.org/health/diseases/5476-fragile-x-syndrome.

2. Berry-Kravis EM, Harnett MD, Reines SA, et al. Inhibition of phosphodiesterase-4D in adults with fragile X syndrome: a randomized, placebo-controlled, phase 2 clinical trial. Nat Med 27, 862–870 (2021). https://doi.org/10.1038/s41591-021-01321-w.

3. Alusi G, Berry-Kravis E, Nelson D, Orefice LL, Booker SA. Emerging Therapeutic Strategies for Fragile X Syndrome: Q&A. ACS Chem Neurosci. 2022 Dec 21;13(24):3544-3546. doi: 10.1021/acschemneuro.2c00674. Epub 2022 Dec 7. PMID: 36475635; PMCID: PMC9782331.

4. ClinicalTrials.gov. A Randomized Study of BPN14770 in Male Adolescents (Aged 9 to <18 Years) With Fragile X Syndrome. Identifier: NCT05163808.

5. ClinicalTrials.gov. Safety and Efficacy Study of BPN14770 in Subjects With Fragile X Syndrome. Identifier: NCT05358886.

6. ClinicalTrials.gov. An Open-Label Extension Study of BPN14770 in Subjects With Fragile X Syndrome. Identifier: NCT05367960.

7. BPN14770-CNS-204. Tetra Therapeutics. Accessed June 24, 2024. Available at: https://tetratherapeutics.com/clinical-trials/bpn14770-cns-204/.

8. BPN14770-CNS-301. Tetra Therapeutics. Accessed June 24, 2024. Available at: https://tetratherapeutics.com/clinical-trials/bpn14770-cns-301/.

9. BPN14770-CNS-302. Tetra Therapeutics. Accessed June 24, 2024. Available at: https://tetratherapeutics.com/clinical-trials/bpn14770-cns-302/.

10. Ciaccio C, Fontana L, Milani D, et al. Fragile X syndrome: A review of clinical and molecular diagnoses. Ital J Pediatr. 19, 43(1): 39 (2017). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5395755/.

11. Fragile X Syndrome: Learning What Families Need. The Centers for Disease Control and Prevention. Accessed June 11, 2024. Available at: https://www.cdc.gov/fragile-x-syndrome/articles/learning-what-families-need.html.

12. Han Q, Fu H, Chu X, Wen R, Zhang M, You T, Fu P, Qin J, Cui T. Research advances in treatment methods and drug development for rare diseases. Front Pharmacol. 2022 Oct 12;13:971541. doi: 10.3389/fphar.2022.971541. PMID: 36313320; PMCID: PMC9597619.