ASU Autism Reserarch Center | MTT Results Phases 1 and 2 05-31-23

Current Availability of the FMT procedure for the treatment of Autism in the US - Sept 2024

Fecal Microbiota Transplantation (FMT), also known as human probiotic infusion, bacteriotherapy, and fecal transplant, is a powerful infusion of healthy colon flora which has been used historically to treat patients with a variety of gut conditions, including clostridium difficile, aka C difficile infection, inflammatory bowel disease (crohn’s disease and ulcerative colitis), irritable bowel syndrome, autoimmune disease, dysbiotic gut flora and other lower GI conditions.

FMT treatments are currently only approved for use in the united states by the U.S. FDA for people with the aformentioned conditons and/or life-threatening severe diarrhea. The FDA does not allow FMT to be used for any other conditions in the united states until more research has been completed.

FMT may reduce a patient's autistic symptoms by as much as 50%.

The Institute of predictive and personalized medicine (IPPM), in Slovakia, offers administration of the FMT for the treatment of autism.

MTT vs FMT (Fecal Microbiota Therapy)

FMT (Fecal Microbiota Transplant) was introduced to repair the gut microbiota after its depletion in patients suffering from recurrent Clostridioides difficile infections. It is a simple treatment that typically involves one administration of healthy donor stool via colonoscopy or capsules.

MTT (Microbiota Transplant Therapy) is a complex treatment regimen designed to restructure rather than merely repair the gut microbiome. It involves conditioning to remove harmful bacteria followed by a course of multiple treatments with highly purified microbiota derived from select healthy donors. The microbiota is contained in capsules or powder that can be suspended in a liquid carrier such as milk or yogurt.

Current Progress on the MTT procedure - Sept 2025

The Autism Research Team at ASU is currently finishing up research on a type of intensive FMT which they call Microbiota Transplant Therapy (MTT). The current goal is submittal of their application for FDA approval by the end of the first quarter 2026.

MTT involves first using an antibiotic to kill pathogenic bacteria, then a bowel cleanse to remove remaining bacteria and the antibiotic, and then seven to eight weeks of full-spectrum microbiota, using gut bacteria from people who are neurotypical. The treatment involves 10 weeks of intense daily therapy.

So far, no patient has shown any serious adverse effects.

The approach is based on pioneering research by Dr. Thomas Borody with the Centre for Digestive Diseases in Australia, who first used this method to successfully treat his patients with autism, and Professors Alex Khoruts and Michael Sadowsky at the University of Minnesota, who developed the methods for producing purified microbiota.

“[The FDA has] granted us fast-track status for the treatment,” explains Prof. Adams, “and we [have] moved on to Phase 2.”

This second phase began in 2017 and looks at 84 adults with autism. Originally a federally funded study, the pandemic intervened, delaying the research and slashing funding.

By the end of treatment, there was an 80 percent reduction in symptoms of the gastrointestinal disorder and a 25 percent reduction in autism symptoms. The improvements remained when the researchers performed a follow-up exam eight weeks after treatment ended.

The U.S. FDA requires trial Phases 1, 2, and 3 prior to considering drugs for approval.

If the ASU team submits their application for FDA approval of the MTT (Microbiota Transfer Therapy) procedure during the 2026 holiday season, the timeline for potential approval will depend on several factors, including the type of FDA review the application receives and whether any expedited pathways are applicable.

Standard FDA Review Timelines

Under the Prescription Drug User Fee Act (PDUFA), the FDA aims to review standard New Drug Applications (NDAs) within approximately 10 months from the date of submission. Therefore, if the MTT application follows the standard review process, approval could be expected around late 2027.

Expedited Review Options-

If the MTT procedure qualifies for expedited programs due to its potential to address unmet medical needs in autism treatment, the FDA offers several pathways:

Priority Review: Reduces the FDA review period to 6 months.
Accelerated Approval: Allows earlier approval based on surrogate endpoints, with confirmatory trials required post-approval.
Fast Track Designation: Facilitates more frequent communication with the FDA and eligibility for rolling review.

If the MTT application is granted any of these designations, the approval timeline could be shortened, potentially leading to approval by mid-2027.

New Initiatives to Shorten Review Times

A 2025 pilot called the Commissioner’s National Priority Voucher (CNPV) that can compress reviews to ~1–2 months for a very small number of selected applications. There’s no indication MTT would be eligible, but I’m flagging it for completeness.

Summary

Depending on the review pathway:

Standard Review: Approval by late 2027.
Expedited Review: Approval could occur by mid-2027.
CNPV Program: If eligible, approval might be possible as early as early 2027.

The exact timeline will depend on the specifics of the application and the FDA's assessment of the MTT procedure's potential impact on autism treatment.

If they already have Fast Track designation from the FDA, that speeds up some parts of the process — but it doesn’t guarantee approval in a fixed, short time. It mostly helps by enabling things like rolling review, more frequent communication with the FDA, and earlier issue-resolution.

Here’s how the timeline could look under Fast Track, assuming a submission is accepted around the holidays of 2026:

Key Features of Fast Track That Affect the Timeline

The FDA must decide whether to grant the Fast Track designation within 60 days of receiving the request.
Once Fast Track status is granted, the sponsor can use rolling review, meaning they can submit parts of the application as they become ready rather than waiting for the entire thing. That can shave off time.
Fast Track allows for more frequent interactions with the FDA, which helps address questions, deficiencies, or missing data earlier rather than later. That reduces delays.

Estimated Timeline Under Fast Track

Let’s assume:

The ASU team files a complete application (or Biologics License Application / whatever regulatory pathway is needed) around December 2026.
All the required clinical data, manufacturing, safety, etc., are in order (i.e. no major surprises or rejection/refusal to file letters).
They maintain good communication and respond quickly to any FDA questions.

Then, under Fast Track, the review could be expected to take on the order of 6-10 months after the application is accepted by the FDA for review — possibly shorter if they also qualify for Priority Review or Accelerated Approval.

So, approval (if everything goes smoothly) could occur sometime between mid-2027 and late-2027

Caveats / What Could Delay Things

If the FDA identifies gaps in data during review, the sponsor may need to provide additional studies, which adds time.
Manufacturing, safety, or efficacy concerns could require new trials or additional analyses.
If Fast Track is combined with Priority Review, the deadline for FDA action is shorter (see below).

If Also Qualified for Priority Review

If in addition to Fast Track, they obtain Priority Review, the FDA’s goal is to act on the marketing application within 6 months as opposed to the standard 10 months.

So if the ASU team both has Fast Track and qualifies for Priority Review, then a best‐case approval might be around 6 months from when the full application is accepted for review — potentially pushing approval to around mid-2027 if the application is accepted around late 2026 and everything is in order.

I searched ASU’s domain for “priority review” and did not find any credible instances where ASU (asu.edu) explicitly refers to a “priority review” in the context of FDA regulatory approval.

Since ASU doesn’t appear to state that they have Priority Review (based on what I found), here’s what the timeline would look like if they did combine Fast Track + Priority Review assuming the submission happens around the holidays of 2026, and everything goes smoothly.

Fast Track + Priority Review: What That Means

Fast Track speeds up development by allowing rolling submission of parts of the application as they are completed, more frequent FDA interactions, early identification and resolution of issues. It enables rolling review and more frequent FDA interaction, which can shorten pre-acceptance and issue-resolution time.
Priority Review means once the FDA accepts the full application, review must be completed in a shortened timeframe (usually 6 months instead of the standard ~10 months under the PDUFA goal for standard review). FDA goal to act within 6 months of filing acceptance (vs ~10 months standard).

Projected Timeline under Fast Track + Priority Review

Here’s a possible schedule, assuming ideal conditions, full data, no major issues:

Step	Approximate timing
Submit application	Late Dec 2026
FDA “filing acceptance” (starts review clock)	Late Jan–Feb 2027
Priority Review clock (6 months)	Feb → Aug 2027
Potential approval (if no major issues)	~ Aug 2027

Projected Timeline for Availability in the Clinics

If FDA approval lands in August 2027, early-adopter centers could start offering MTT in roughly 1–3 months (Oct–Nov 2027), with broader, insurance-supported availability building through mid- to late-2028.

Putting it together for an Aug 2027 approval:

Oct–Nov 2027: Initial availability at select centers (self-pay or early coverage).
Q1–Q2 2028: Coding and more payer policies in place (J-code window + coverage decisions), enabling wider clinic uptake.
Q2–Q4 2028: Broad U.S. clinic availability if manufacturing, training, and coverage progress normally. (Inference from the above timelines.)

Exact timing will still depend on manufacturing scale-up, distribution, site training, and payer determinations for an autism indication, but the precedent suggests the 1–3 months to first use and ~6–12 months to broad access pattern is realistic.