# Marvel says MB-204 normalised autism-linked behaviours in Shank3 mice that its parent Parkinson's drug did not - Published: 2026-11-10 - Author: [BiotechNews.io](https://biotechnews.io/author/biotechnews-io.md) - Topics: [News](https://biotechnews.io/news.md) - About: [Marvel Biosciences Corp.](https://marvelbiotechnology.com/) - Based on: [Marvel Announces Final Shank3 Data: MB-204 Highly Effective at Reversing Autism Behaviours](https://www.globenewswire.com/news-release/2026/11/10/3399262/0/en/marvel-announces-final-shank3-data-mb-204-highly-effective-at-reversing-autism-behaviours.html), GlobeNewswire, 2026-11-10 - Based on: [Meta-analysis of SHANK Mutations in Autism Spectrum Disorders: a gradient of severity in cognitive impairments](https://pubmed.ncbi.nlm.nih.gov/25188300/), PLoS Genetics, 2014-09-04 - Based on: [22q13.3 deletion syndrome](https://medlineplus.gov/genetics/condition/22q133-deletion-syndrome/), MedlinePlus Genetics, U.S. National Library of Medicine - Based on: [Marvel Biosciences Advances MB-204 Toward First-in Human Testing, Selects CMAX as Phase I Clinical Trial Site](https://marvelbiotechnology.com/2243-2/), Marvel Biosciences, 2026-10-19 - Source: https://biotechnews.io/news/mb-204-autism-shank3-mouse-data/ - Publication: Biotech News - Publisher: Connectively (Terkel, Inc.) - Editorial policy: https://biotechnews.io/editorial-policy/ - AI use: Connectively's automated system wrote this article with AI from a press release issued by Marvel Biosciences on November 10, 2026, linked under Sources. Statements about the company and its products are the company's. The illustration was generated with AI. The article was assembled and published automatically, without an editor's review. Report errors to corrections@connectively.us. Marvel Biosciences said on November 10, 2026, that its MB-204 autism candidate returned six behavioural measures to normal in a Shank3 mouse model of Phelan-McDermid syndrome. The Calgary company says the data supports taking the drug into its first Phase 1 trial. ## Key points - Marvel Biosciences (TSXV: MRVL, OTCQB: MBCOF) reported mouse data for MB-204 from a Shank3 model study run with Dr. Julie Le Merrer and Dr. Jerome Becker at the iBraiN Institute. - According to the company, the higher MB-204 dose brought six measured behaviours back to the levels of normal mice, while istradefylline, the Parkinson's drug MB-204 is derived from, did not on those six. - Both MB-204 at the higher dose and istradefylline brought repetitive grooming and same-arm returns in a Y-maze back to normal levels, Marvel says. - The mice were given MB-204 by mouth at 1 or 2.5 mg/kg and tested one to three hours later, against istradefylline at 1 mg/kg. - Marvel says it is preparing a Phase 1 trial and, in October 2026, named CMAX Clinical Research in Adelaide, Australia, as the trial site. ## What is the Shank3 model, and why does it matter for autism research? It reproduces in mice the loss of SHANK3, the gene behind many features of Phelan-McDermid syndrome. A 2014 meta-analysis in [PLoS Genetics](https://pubmed.ncbi.nlm.nih.gov/25188300/) found SHANK3 mutations in 0.69% of people with autism and in up to 2.12% of those with moderate to profound intellectual disability. [MedlinePlus Genetics](https://medlineplus.gov/genetics/condition/22q133-deletion-syndrome/) describes Phelan-McDermid syndrome, also called 22q13.3 deletion syndrome, as causing developmental delay, absent or delayed speech and often autism, and counts more than 2,200 people diagnosed worldwide. Because the model is built on one known gene, it lets researchers test whether a drug changes behaviours tied to a defined genetic form of autism, the kind of patient grouping [personalized medicine](https://biotechnews.io/insight/personalized-medicine-progress/) is built on. ## What did Marvel report for MB-204? Marvel says the higher dose of MB-204 brought four social-contact measures and two of the three Y-maze measures back to the levels seen in normal mice, and that istradefylline did not normalise those six. The table sets out each measure as the company reported it. | Measure (as reported by Marvel) | MB-204, higher dose | MB-204, lower dose | Istradefylline | |---|---|---|---| | Number of nose contacts | Normal | Similar to istradefylline | Not normal (p<0.001) | | Number of paw contacts | Normal | Similar to istradefylline | Not normal (p<0.05) | | Average length of nose contacts | Normal | Normal | Not normal (p<0.001) | | Average length of paw contacts | Normal | Normal | Not normal (p<0.05) | | Y-maze spontaneous alternations | Normal | Normal | Not normal (p<0.001) | | Y-maze alternate arm returns | Normal | Normal | Not normal (p<0.01) | | Y-maze same arm returns (repetitive) | Normal | Normal | Normal | | Grooming episodes (repetitive) | Normal | Normal | Normal | The doses were 1 and 2.5 mg/kg of MB-204 by mouth and 1 mg/kg of istradefylline, which Marvel calls the highest dose that does not affect movement; mice were tested one to three hours after dosing. > "We look forward to testing MB-204 for the first time in patients as we prepare for our Phase 1 clinical trial." > > — Dr. Mark Williams, Chief Science Officer, Marvel Biosciences ## How does MB-204 work? MB-204 is a fluorinated derivative of istradefylline, which Marvel describes as the only clinically approved adenosine A2a antagonist. The company points to a growing body of research suggesting that blocking the adenosine A2a receptor could help in autism and other neurological conditions, and says it is also studying MB-204 in Rett and Fragile X syndromes. ## What does the Shank3 result mean for biotech watchers? Our analysis: the result Marvel leads with is the head-to-head against its parent drug, since a derivative earns its place by doing something the approved compound does not, and the company reports that on six measures. Shank3 joins the Rett, Fragile X and Oprm1 mouse models Marvel listed in its [October 19 release](https://marvelbiotechnology.com/2243-2/), so four genetically distinct models now stand behind one compound. The next test is in people, at the CMAX unit in Adelaide, the stage where [drug discovery](https://biotechnews.io/insight/innovations-in-drug-discovery/) programmes first check safety in humans. ## Frequently asked questions ### Has MB-204 been tested in people yet? Not yet. Marvel says it is preparing the Phase 1 trial in which MB-204 will be given to people for the first time. ### Where will MB-204's first human trial take place? Marvel named CMAX Clinical Research in Adelaide, Australia, as the Phase 1 site on [October 19, 2026](https://marvelbiotechnology.com/2243-2/). ### Who ran the Shank3 mouse study? Marvel says the study was carried out with Dr. Julie Le Merrer and Dr. Jerome Becker at the iBraiN Institute. ### Which other conditions is Marvel studying MB-204 in? Besides autism linked to Shank3, Marvel says it is investigating MB-204 in Rett syndrome and Fragile X syndrome, and names depression and Alzheimer's disease as other areas where A2a blockers could be useful. ## Sources - Marvel Biosciences press release on the final Shank3 data: press release from Marvel Biosciences via GlobeNewswire, 10 November 2026. - [Meta-analysis of SHANK Mutations in Autism Spectrum Disorders](https://pubmed.ncbi.nlm.nih.gov/25188300/): Leblond and colleagues, PLoS Genetics, September 2014. - [22q13.3 deletion syndrome](https://medlineplus.gov/genetics/condition/22q133-deletion-syndrome/): MedlinePlus Genetics, U.S. National Library of Medicine. - [Marvel selects CMAX as Phase I clinical trial site](https://marvelbiotechnology.com/2243-2/): Marvel Biosciences news release, 19 October 2026. - [Marvel Biosciences](https://marvelbiotechnology.com/): the company's website.