35 Participants Needed

SYNB1934 for Phenylketonuria

(SYNPHENY-3 Trial)

Recruiting at 21 trial locations
KH
NS
AK
AK
Overseen ByAneal Khan, MD
Age: 18+
Sex: Any
Trial Phase: Phase 3
Sponsor: Synlogic
Must be taking: Sapropterin, Sepiapterin
Pivotal Trial (Near Approval)This treatment is in the last trial phase before FDA approval
Prior Safety DataThis treatment has passed at least one previous human trial

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests SYNB1934v1, a new treatment for people with high blood phenylalanine (Phe) levels. The goal is to find the best dose that reduces Phe levels by at least 20% without causing side effects.

Will I have to stop taking my current medications?

The trial requires that you continue your current diet, sapropterin, sepiapterin, and large neutral amino acids without changes during the study. However, you cannot take Palynziq® (pegvaliase-pqpz) within 1 month of screening or any systemic antibiotics within 28 days prior to the first dose.

Are You a Good Fit for This Trial?

Adults with Phenylketonuria (PKU) who haven't been able to control their blood Phe levels using current treatments can join. They should be on a stable diet and treatment for at least 1 month, agree to not change their diet or PKU management during the trial, and use contraception if applicable. Pregnant women, those on recent investigational drugs, antibiotics, or specific PKU therapies like Palynziq®, are excluded.

Inclusion Criteria

I am using birth control during and for 2 weeks after the study.
I can maintain my current diet and supplements throughout the study.
I have PKU and my blood Phe levels are too high despite current treatments.
See 4 more

Exclusion Criteria

Acute or chronic medical, surgical, psychiatric, or social condition or laboratory abnormality that may increase patient risk associated with study participation, compromise adherence to study procedures and requirements, and, in the judgment of the investigator, would make the patient inappropriate for enrollment
I am allergic to E. coli Nissle, SYNB1934v1 ingredients, or cinnamon and cannot tolerate certain acid-reducing medications.
I have received gene therapy for PKU.
See 5 more

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Dose-escalating, open-label period (DEP)

Participants receive escalating doses of SYNB1934v1 to determine an individually titrated dose (iTD)

Up to 15 weeks
Weekly visits for dose escalation and monitoring

Randomized withdrawal period (RWP)

Participants are randomized to receive SYNB1934v1 or placebo to assess efficacy and safety

4 weeks
Visits at Weeks 1, 3, and 4 for blood Phe level measurement

Open-label extension (OLE)

Participants may continue receiving SYNB1934v1 with dose adjustments based on tolerability

Up to 36 months

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

  • Placebo
  • SYNB1934
Trial Overview The study tests SYNB1934v1's effectiveness in managing PKU over three parts: initial dose finding up to 15 weeks; a double-blind phase where participants randomly get either SYNB1934v1 or placebo for four weeks; followed by an open-label extension lasting up to three years.
How Is the Trial Designed?
4Treatment groups
Experimental Treatment
Placebo Group
Group I: RWP (Part 2, SYNB1934v1)Experimental Treatment1 Intervention
Participants who completed the DEP were randomized 1:1 to receive SYNB1934v1 at their iTD established in the DEP orally immediately after meals. Participants remained on this dose of SYNB1934v1 for the duration of the RWP; doses of SYNB1934v1 were not permitted to be modified during the RWP.
Group II: OLE (Part 3, SYNB1934v1)Experimental Treatment1 Intervention
Participants completed a dose ramp to their iTD guided by tolerability, as described for the DEP, including the full dose-ramp schedule. The iTD in the OLE may have been different from the iTD in the DEP or RWP. The investigator may have escalated the dose of SYNB1934v1 up to 1 × 10\^12 live cells based on tolerability; multiple attempts to escalate to a higher dose level were permitted per investigator discretion.
Group III: DEP (Part 1, SYNB1934v1)Experimental Treatment1 Intervention
Participants received SYNB1934v1 orally immediately after meals on the following dose-ramp regimen: Dose level 1 (Days 1-9): 3 × 10\^11 live cells partial dose up to 3 times daily (TID); Dose level 2 (Weeks 4-6): 6 × 10\^11 live cells up to TID; Dose level 3 (Weeks 7-9): 1 × 10\^12 live cells up to TID.
Group IV: RWP (Part 2, Placebo)Placebo Group1 Intervention
Participants who completed the DEP were randomized 1:1 to receive placebo orally immediately after meals. Participants remained on the same dose of placebo for the duration of the RWP; doses of placebo were not permitted to be modified during the RWP.

Find a Clinic Near You

Who Is Running the Clinical Trial?

Synlogic

Lead Sponsor

Trials
10
Recruited
460+
Unbiased ResultsWe believe in providing patients with all the options.
Your Data Stays Your DataWe only share your information with the clinical trials you're trying to access.
Verified Trials OnlyAll of our trials are run by licensed doctors, researchers, and healthcare companies.
Back to top
Terms of Service·Privacy Policy·Cookies·Security