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CompletedNCT01102686Updated Feb 23, 2012

Pyrimethamine as a Treatment for Late-Onset GM2-gangliosidosis (Tay-Sachs and Sandhoff Disease)

A Phase 1/2 interventional study of Pyrimethamine and Leucovorin in Gangliosidoses, GM2, Sandhoff Disease and Tay-Sachs Disease, sponsored by The Hospital for Sick Children. Completed at 1 site in Canada. Open to participants aged 17 Years and older. Per ClinicalTrials.gov, last updated 2012-02-23.

Sponsored by The Hospital for Sick Children · Phase 1/2, Interventional, and Treatment

Phase
Phase 1/2
Study type
Interventional
Enrollment
20
Allocation
Non-randomized
Ages
17 Years and older
Sex
All
01

Study summary

The objectives of this clinical trial are to assess the safety and tolerability, as well as efficacy, of a stepwise dosing regimen of pyrimethamine, starting at 25 mg/day, given as a single dose daily for 4 weeks in patients affected with chronic Tay-Sachs or Sandhoff variants.

Read the detailed description

Patients with late-onset Tay-Sachs or Sandhoff disease will be given increasing doses of Pyr, up to but not exceeding doses used to treat malaria, over a 5-month period. We will follow the effect of the treatment on the levels of Hex A enzyme activity in white blood cells, which are considered to be a reflection of the likely enzyme activity in the brain. We will also follow some other lysosomal enzyme activities to determine if the effect is specific for Hex A. Furthermore, we will examine the effect of the treatment on the levels of GM2-ganglioside in the white blood cells. On the basis of the studies done on cultured skin cells, we expect that treatment with Pyr will increase the levels of Hex A and decrease the accumulation of GM2-ganglioside in the white blood cells.

02

Conditions studied

  • Gangliosidoses, GM2
  • Sandhoff Disease
  • Tay-Sachs Disease

Keywords

  • Late-onset GM2-gangliosidosis
  • pyrimethamine
03

In context

Gangliosidoses, GM2

26 studies on the registry are indexed under Gangliosidoses, GM2; 6 are open to participants now.

This study's planned enrollment of 20 is close to the median of 21 across 14 interventional studies indexed under Gangliosidoses, GM2.

Browse Gangliosidoses, GM2 studies →

Lead sponsor

The Hospital for Sick Children is the lead sponsor of 578 studies on the registry; 83 are open to participants now.

Of its 7 completed or terminated interventional studies of FDA-regulated products, 1 (14%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
17 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • biochemically and genetically confirmed diagnosis of GM2-gangliosidosis caused by β-hexosaminidase deficiency resulting from mutations in the HEXA or HEXB genes;
  • having HEXA or HEXB mutations shown to be responsive to pyrimethamine in vitro;
  • over 17 years of age at the time of study initiation;
  • able to understand and cooperate with the requirements of the study protocol;
  • mentally competent, have the ability to understand and willingness to sign the form;
  • able to travel to one of the three participating study sites;
  • women of must use accepted methods and must have a negative serum or urine pregnancy test within one week prior to treatment initiation;
  • fertile men must practice effective contraceptive methods during the study period, unless documentation of infertility exists;
  • laboratory values ≤2 weeks prior to randomization must show adequate hematologic, hepatic, renal, and coagulation function; and body weight >40 kg.

Exclusion criteria

Exclusion Criteria:

  • serious medical illness, significant cardiac disease or severe debilitating pulmonary disease;
  • any hematologic abnormality, especially megaloblastic anemia, leukopenia, thrombocytopenia, pancytopenia;
  • any active uncontrolled bleeding or any bleeding diathesis (e.g., active peptic ulcer disease);
  • possible folate deficiency, and those receiving therapy (such as phenytoin) affecting folate levels;
  • any complex disease that may confound treatment assessment;
  • pregnant women or women of not using reliable means of ;
  • lactating females;
  • fertile men unwilling to practice contraceptive methods during the study period;
  • unwilling or unable to follow protocol requirements;
  • known reactions, intolerance or adverse reactions to pyrimethamine;
  • evidence of active infection, or serious infection within the past month;
  • infection;
  • a history of cancer of any type;
  • receiving any other standard or treatment for any indication within the past 4 weeks prior to initiation of pyrimethamine treatment;
  • receiving immunotherapy of any type within the past 4 weeks prior to initiation of pyrimethamine treatment; or any condition or abnormality, which may, in the opinion of the investigator, compromise the safety of patients.
Terms in these criteria, in plain language(6)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

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You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Hypersensitivity

An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Non-randomized
Intervention model
Single group
Masking
None (open label)
Enrollment
20 participants (estimated)

Study arms

  • Experimental
    Pyrimethamine

    Drug: Pyrimethamine · Drug: Leucovorin

Interventions

  • Pyrimethamine will be taken orally as a single daily dose of 25 mg/day for 4 weeks, then increasing by 25 mg per dose in three four-week steps, to a final dose of 100 mg/day

  • To eliminate or minimize potential hematologic effects of Pyrimethamine, Leucovorin is to be co-administered with Pyrimethamine at a dose level of 5 mg per day, given when Pyrimethamine is administered.

06

What researchers measure

Primary outcomes

  1. Efficacy of pyrimethamine

    Changes in Hex A and Hex B, β-glucuronidase using blood assays

    Time frame: Baseline, before exposure to pyrimethamine, and Weeks 4, 8, 12, 16 and 18.

Secondary outcomes

  1. Pyrimethamine Blood levels

    Time frame: Weekly (1-18 weeks)

  2. Pyrimethamine efficacy

    Measurement of GM2 in blood samples

    Time frame: 6 months

07

Study locations

1 site
  • The Hospital for Sick Children
    Toronto, Ontario M5G 1X8, Canada
08

Timeline

Tracking since Sep 25, 2026
Not marked actual or estimatedDates not marked actual or estimated

The record gives a start of Aug 2009, a primary completion of Nov 2010 and a completion of Nov 2010. It does not say whether these dates are actual or estimated.

How these figures are worked out, and which studies are left out of them.

Registered
Oct 16, 2009
First posted
Apr 13, 2010
Start
Aug 2009
Primary completionActual
Nov 2010
CompletionActual
Nov 2010
Last update
Feb 23, 2012
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Feb 23, 2012, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT01102686
Responsible party
Sponsor
First posted
Apr 13, 2010
Start date
Aug 2009
Primary completion
Nov 2010
Completion
Nov 2010
Last update
Feb 23, 2012

Study contacts

Joe T Clarke, MD
principal investigator · The Hospital for Sick Children

Oversight

Data monitoring committee
Yes
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Feb 2012. You cannot join it, but the record below documents what was studied.

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Studies of the drug tested here: Pyrimethamine

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