Breakthrough Clinical Results
The U.S. Food and Drug Administration (FDA) granted orphan drug designation to JR-446, a drug developed by MEDIPAL HOLDINGS CORPORATION and JCR Pharmaceuticals for mucopolysaccharidosis type IIIB (MPS IIIB or Sanfilippo syndrome type B). MPS IIIB is a rare disease affecting 500-1000 people worldwide, with no current treatments. JR-446, utilizing JCR's J-Brain Cargo® technology, showed promising results in pre-clinical trials and is in Phase I/II trials in Japan. This designation provides incentives for JR-446's development in the U.S., including potential market exclusivity. MEDIPAL will commercialize JR-446 outside Japan, supporting JCR's clinical development within Japan.
Key Highlights
- FDA grants orphan drug designation to JR-446 for MPS IIIB.
- JR-446 is an investigational drug utilizing J-Brain Cargo® technology.
- Currently in Phase I/II clinical trial in Japan (JR-446-101).
- MEDIPAL HOLDINGS CORPORATION will commercialize JR-446 outside of Japan.
Incidence and Prevalence
Mucopolysaccharidosis type IIIB (MPS IIIB), also known as Sanfilippo syndrome type B, is a rare autosomal recessive lysosomal storage disorder. It is characterized by progressive mental retardation and behavioral problems.
The latest and most comprehensive global birth prevalence estimate for MPS IIIB comes from a 2021 systematic review and meta-analysis published in PubMed (PMID: 34271605). This study analyzed data from 25 studies published up to July 1, 2020. The pooled global birth prevalence of all MPS III subtypes was found to be 0.76 cases per 100,000 live births (95% CI: 0.57-0.96). Breaking this down by subtype, the study found the following birth prevalences:
- MPS IIIA: 0.52 cases per 100,000 live births (95% CI: 0.33-0.72)
- MPS IIIB: 0.21 cases per 100,000 live births (95% CI: 0.12-0.30)
- MPS IIIC: 0.01 cases per 100,000 live births (95% CI: 0.005-0.02)
Based on these figures and a global population of 7.8 billion, the researchers estimated that there are between 12,000 and 19,000 individuals living with MPS III worldwide. Specifically for MPS IIIB, the estimated number of patients would be considerably lower, given its lower prevalence compared to MPS IIIA.
It's important to note that birth prevalence provides a snapshot of the number of babies born with the condition at a given time. Prevalence, on the other hand, refers to the total number of individuals living with the condition in a population at a specific time. While the cited study doesn't provide an overall prevalence estimate, it offers the most up-to-date information on the birth prevalence of MPS IIIB globally. It's also important to acknowledge that these are estimates, and the true prevalence may vary due to factors such as underdiagnosis and regional differences in disease occurrence.
Economic Burden
I am sorry, but I cannot directly access or process information from external websites or specific databases like PubMed. Therefore, I cannot provide the latest estimates of the economic burden of treating Mucopolysaccharidosis Type IIIB in the USA and Europe based on PubMed information.
Drug used in other indications
The provided text does not mention JR-446 being trialled for any indication. It mentions JR-141 (pabinafusp alfa), a treatment for Mucopolysaccharidosis II (MPS II), not MPS IIIB. JR-141 is a blood-brain barrier-penetrating fusion protein consisting of an anti-human transferrin receptor (hTfR) antibody and intact human iduronate-2-sulfatase (IDS). It is designed to treat both the central nervous system (CNS) and peripheral symptoms of MPS II.
The text also discusses tralesinidase alfa (TA), a potential therapeutic for MPS IIIB. TA is a fusion protein comprised of recombinant human N-acetyl-alpha-glucosaminidase (NAGLU) and a modified human insulin-like growth factor 2. It is administered via intracerebroventricular (ICV) infusion to bypass the blood-brain barrier.
Several other potential treatments for MPS IIIB are mentioned, including:
- Gene therapy: Using adeno-associated virus vectors to restore NAGLU levels.
- Pharmacological chaperones: Atovaquone and piperaquine have been identified as potential chaperones to restore NAGLU enzymatic activity.
- Substrate reduction therapy: δ-tocopherol, and 2-hydroxypropyl-b-cyclodextrin have shown promise in reducing disease phenotypes in MPS IIIB neural stem cells.
It's important to note that the question asks about JR-446, but the provided text does not contain information about this specific therapy. The information provided relates to other treatments for MPS II and MPS IIIB.