Hope for rare disease: new drug shows promise in Long-Term study
NCT ID NCT06657859
First seen Jun 27, 2026 · Last updated Sep 16, 2026 · Updated 10 times
Summary
This study is for people with PMM2-CDG, a rare genetic disorder, who have already taken the experimental drug GLM101 in a previous trial. The goal is to see if GLM101 is safe and effective over a longer period. Participants will receive weekly infusions of GLM101 at the same dose as before. The study will monitor side effects and changes in movement and coordination.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- GLM101 (given intravenously)
- What this could lead to
- If successful, this could show that GLM101 is safe and helps control symptoms of PMM2-CDG over the long term, offering a treatment option for this rare disease.
- What could go wrong
- This is an early-phase, open-label extension study with no placebo group, so results may be less reliable. The drug may still cause side effects or not work as hoped.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
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Phase 2
Tests whether the treatment actually works, and watches for side effects, in a larger group.
- Participants
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About 90 people
The number the study aims to enrol. It can still change while the study runs.
- Started
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Sep 2024
- Expected to finish
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Oct 2029
An estimate. End dates often move.
- Lead sponsor
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A company
The lead sponsor is a pharmaceutical, biotech, or medical-device company.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
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2 years and older
- Sex
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Anyone
- Healthy volunteers
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Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Is willing and able to provide informed consent/assent, directly or through a legally authorized representative. 2. Has successfully completed the Treatment Period with GLM101 in a previous clinical study. 3. At least 2 years of age, at the time of signing the informed consent form (ICF). 4. Molecularly confirmed diagnosis of PMM2-CDG. Diagnosis is defined as biallelic pathogenic and/or likely pathogenic variants, or, in the case of variants of uncertain pathogenicity, demonstration of bi-allelic variants AND phosphomannomutase-2 (PMM2) enzyme activity consistent with a diagnosis of PMM2-CDG. Historical diagnosis including from a prior parent trial is permitted; 5. Male or female participant has appropriate measures in place to prevent pregnancy: * If the participant is a female of childbearing potential (i.e. fertile, following menarche and until becoming post-menopausal unless permanently sterile (permanent sterilization methods include hysterectomy, bilateral salpingectomy and bilateral oophorectomy)) or becomes of childbearing potential during the study, she must not be pregnant (confirmed by a negative serum pregnancy test), is using a medically accepted method of contraception (abstinence, a hormonal contraceptive associated with inhibition of ovulation in conjunction with a barrier method, or use of an intrauterine device), and must agree to continue using this method for 50 days after the last infusion of GLM101. Note: True abstinence: defined as refraining from heterosexual intercourse during the entire period of risk associated with the study treatments. The reliability of sexual abstinence needs to be evaluated in relation to the duration of the clinical trial and the preferred and usual lifestyle of the participant. Periodic abstinence (such as calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception. * If the participant is a female of non-childbearing potential, she must be pre-pubertal, surgically sterile, or must have an ovarian dysfunction confirmed by a follicle stimulating hormone (FSH) \>40 IU/L and absence of menses for 12 months without an alternative medical cause. * If the participant is a sexually active (or becomes sexually active during the study) male with female partners, the sexually mature, nonsterile male participant agrees to use a medically acceptable method of contraception (abstinence, the partner taking a hormonal contraceptive in conjunction with a male condom, or use by the partner of an intrauterine device with a male condom) and agrees to continue using this method for 50 days after the last infusion of GLM101. Males are considered surgically sterile if they have undergone bilateral orchiectomy or vasectomy at least 3 months prior to Screening. 6. If the participant is male, he must agree to refrain from donating sperm during the study and 50 days after the last infusion of GLM101. 7. Is willing and able to comply with this protocol. Exclusion Criteria: Participants who meet any of the following criteria will be excluded from participation in the study: 1. Has any other condition that would, in the opinion of the Investigator, potentially compromise the safety or compliance of the participant or preclude the participant's successful completion of the study. 2. Diagnosis of congenital disorder of glycosylation (CDG) other than PMM2; Diagnosis is defined as biallelic pathogenic and/or likely pathogenic variants, or, in the case of variants of uncertain pathogenicity, demonstration of bi-allelic variants AND the defined CDG enzyme activity consistent with a diagnosis of the CDG other than PMM2 CDG. 3. If not enrolling directly from a parent study (i.e., more than 28 days from Final Treatment visit in a parent study to date of consent), has an active infection requiring parenteral antibiotics, antivirals, or antifungals or treatment with systemic steroids within 7 days prior to Screening; 4. ALT or AST \>3× ULN OR total bilirubin \>2× ULN or INR \>1.5 (if no anti-coagulation treatment) or INR \> 4 (if participant on anti-coagulation treatment) considered clinically significant; 5. Has a history of liver transplant; 6. Has a history of drug or alcohol use disorder within the 12 months prior to Screening; 7. If not enrolling directly from a parent study (i.e., if more than 28 days from Final Treatment visit in a parent study to date of consent), has had a major surgical procedure within 30 days prior to Screening; 8. Has laboratory value(s) outside the laboratory reference range considered clinically significant and not related to PMM2-CDG; 9. If female, has a positive serum pregnancy test during Screening. 10. If female, and breastfeeding. 11. Is currently participating in another interventional clinical study or has completed another clinical study with an investigational drug or device (other than GLM101) within 30 days or 5 half-lives before GLM101 infusion. 12. Has a hypersensitivity to anti-histamine pre-medication. 13. Has a history of a severe allergic reaction to any drug or excipients of GLM101 (as listed in the GLM101 IB); 14. If not enrolling directly from a parent study (i.e., if more than 28 days from Final Treatment visit in a parent study to date of consent), has serology positive for hepatitis B surface antigen or hepatitis C antibody during Screening; 15. Has a QTc ≥ 450 ms, or other clinically significant ECG abnormalities; 16. Has uncontrolled cardiovascular, hepatic, pulmonary, gastro-intestinal, endocrine, metabolic, ophthalmologic, immunologic, psychiatric or other significant disease; 17. Weight exceeds 120 kg. 18. Persons who have been committed to an institution by virtue of an order issued either by the judicial or the administrative authorities. 19. Participant is unwilling or unable to comply with scheduled visits, study drug administration plan, laboratory tests, other study procedures, and study restrictions.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
How to take part
Only the study team decides who joins. These are the ways to reach them.
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The places running it
15 sites in 8 countries. The list below names each one and where it is.
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The official record
The full official record for this study. This one lists no contact details, but it is the first place any would appear.
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A doctor treating you
A doctor who knows your case can contact a study site on your behalf, and can tell you whether this study is worth pursuing at all.
Contacts and locations
Locations
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AP-HP Hopital Universitaire Necker-Enfants Malades
Paris, 75015, France
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Azienda Ospedaliero Universitaria Pisana
Pisa, 56126, Italy
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Azienda Ospedaliero Universitaria Policlinico G. Rodolico-San Marco - Presidio Ospedaliero G. Rodolico
Catania, 95124, Italy
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Birmingham Children's Hospital
Birmingham, B4 6NH, United Kingdom
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Great Ormond Street Hospital for Children
London, WC1N 3JH, United Kingdom
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Hospital Sant Joan de Déu
Esplugues de Llobregat, 08950, Spain
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Hospital Universitario 12 de Octubre
Madrid, 28041, Spain
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Hospital Universitario 12 de Octubre - Unidad Pediatrica de Investigacion y Ensayos Clinicos (UPIC)
Madrid, 28041, Spain
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Seattle Children's Hospital
Seattle, Washington, 98105, United States
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The Children's Hospital of Philadelphia (CHOP)
Philadelphia, Pennsylvania, 19104, United States
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The Icahn School of Medicine at Mount Sinai
New York, New York, 10029, United States
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Unidade Local de Saúde de Santo António, E.P.E
Porto, 4099-001, Portugal
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Universitaetsklinikum Münster
Münster, 48149, Germany
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University of Minnesota
Minneapolis, Minnesota, 55455, United States
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Vseobecna fakultni nemocnice v Praze
Prague, 128 08, Czechia
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