ClinicalTrials.gg
RecruitingNCT06961071PATTHUpdated Feb 27, 2026

Parathyroid Allotransplant for Treatment of Hypoparathyroidism

A Phase 1/2 interventional study of Parathyroid Allotransplant in Hypoparathyroidism, Hypoparathyroidism Postprocedural and Hypoparathyroidism Post-surgical, sponsored by Peter Stock. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-27.

Sponsored by Peter Stock · Phase 1/2, Interventional, and Treatment

From the registry’s dates

  • Started Jan 2026; still recruiting 9 months later.
Phase
Phase 1/2
Study type
Interventional
Enrollment
3
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

This study is being done to see if transplanting parathyroid tissue into the forearm will help hypo-parathyroid patients achieve parathyroid hormone (PTH) levels that would help normalize their serum calcium and phosphorus levels. The parathyroid tissue used in this study will come from cadaveric tissues that were donated at the time of the death of the donor(s).

Read the detailed description

The company that makes the parathyroid hormone NATPARA will no longer be making the product by the end of 2024 which is one of the reasons the investigators are doing this study: to see if parathyroid transplantation is another way to treat hypoparathyroidism. This procedure is investigational and one of the first times the procedure is being done in humans. It is not approved by the FDA.

02

Conditions studied

  • Hypoparathyroidism
  • Hypoparathyroidism Postprocedural
  • Hypoparathyroidism Post-surgical

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Keywords

  • hypoparathyroidism
  • parathyroid hormone
  • PTH
  • serum calcium
  • phosphorus
03

In context

Hypoparathyroidism

128 studies on the registry are indexed under Hypoparathyroidism; 30 are open to participants now.

This study's planned enrollment of 3 is below the median of 50 across 77 interventional studies indexed under Hypoparathyroidism.

Browse Hypoparathyroidism studies →

Lead sponsor

Peter Stock is the lead sponsor of 2 studies on the registry; 1 is open to participants now.

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

04

Who can participate

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

Eligibility criteria

Inclusion Criteria Only subjects who meet all of the following criteria are eligible for enrollment.

  1. Subjects age 18 or older.
  2. Subjects who are able to provide written and to comply with study procedures.
  3. Clinical history and laboratory data compatible with HypoPT as defined by hypocalcemia and documented PTH levels either inappropriately normal or below the normal range on two occasions greater than 2 weeks apart and 12 months after surgery, requiring treatment with activated vitamin D (≥0.5 mcg calcitrol) and oral calcium (≥800mg) daily, or currently on PTH (1-84), PTH (1-34), palopegteriparatide or other recombinant parathyroid hormone replacement injections with ongoing symptomatology due to hypocalcemia and variable degree of biochemical control.
  4. No history of immunodeficiency (e.g., opportunistic infections) that could be exacerbated by .
  5. Up to date immunizations per the University of California, San Francisco (UCSF) standard of care for organ transplantation, including influenza, pneumococcal, , and tetanus-diptheria

Exclusion Criteria Subjects who meet any of the following criteria are not eligible for enrollment

  1. Presence of donor specific anti-HLA antibodies detected by Luminex Single Antigen/specificity bead assay including weakly reactive antibodies that would not be detected by a flow cross match
  2. Intolerance to any drug that will be used as part of the IS regimen.
  3. Poorly controlled diabetes with an of >8%.
  4. Blood Pressure (BP): systolic blood pressure (SBP) > 140mmHg or DBP >90 mmHg despite treatment with antihypertensive agents. If the BP is greater than 140/90 chart review and discussion with the patient will be done to establish that BP is in good control.
  5. Other exclusion criteria including significant renal or hepatic dysfunction
  6. For female subjects: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective measures for the duration of the study and 4 months after discontinuation. For male subjects: intent to procreate during the duration of the study or within 4 months after discontinuation or unwillingness to use effective measures of contraception. Oral contraceptives, Norplant®, Depo-Provera®, and barrier devices with spermicide are acceptable contraceptive methods; condoms used alone are not acceptable.
  7. Active infection including hepatitis B, , , or tuberculosis (TB). Quantiferon gold assay will be used to determine TB infection.
  8. Invasive aspergillus, histoplasmosis, and coccidioidomycosis infection or other opportunistic infection within 1 year prior to study entry.
  9. Current or treated malignancy with estimated recurrence rate >50% at 5 years, except for completely resected squamous or basal cell carcinoma of the skin
  10. Known active alcohol or substance abuse.
  11. Active infections (except mild skin and nail fungal infections).
  12. Active peptic ulcer disease or gastritis, symptomatic gallstones, or portal hypertension.
  13. Use of any agents within 4 weeks of screening or 5 half-lives of the investigational product/ medication, whichever is longer. Investigational products with prolonged invivo effects will require a that aligns with the biochemical and physiologic effects of the agent prior to the initiation of this protocol. If the half life of the experimental agent is not known, participation in the study will be addressed with the study team and documented in the study record.
  14. Any investigational agents/products that could potentially interfere with the safety and/or efficacy of the procedure being studied will be addressed with the study team and documented in the study record.
  15. Administration of (s) within 2 months of enrollment.
  16. Any medical condition that, in the opinion of the investigator, will interfere with safe study completion.
  17. Positive screen for polyoma (BK) viremia at time of screening.
  18. CKD stage 4 or 5
  19. Severe co-existing cardiac disease, characterized by any one of these conditions:

    1. Recent myocardiol infarction (MI) (within 1 year)
    2. Evidence of ischemia on functional cardiac exam within the last year. These include persantine thallium stress test and/or coronary angiogram which will be performed in any patient with a history of an MI
    3. \< 45%
    4. Valvular disease requiring replacement with prosthetic valve
  20. Substance use that in the opinion of the investigator would interfere with compliance with the study requirements.
  21. Past or current medical problems or findings from medical history, physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.
Terms in these criteria, in plain language(12)

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

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

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.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

HbA1c

A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.

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.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

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.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

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.

Washout period

A planned gap after a treatment, so that its effects can lessen before the study treatment or a study assessment. Ask the study team and the doctor who prescribed it before changing any medicine.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

LVEF (left ventricular ejection fraction)

The share of blood the heart’s main pumping chamber (the left ventricle) pushes out with each beat, measured by an echocardiogram (heart ultrasound) or a MUGA scan. About 50–70% is normal.

05

Study design

Phase
Phase 1 / Phase 2
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
3 participants (estimated)

Study arms

  • Experimental
    Parathyroid Allotransplant

    Parathyroid Allotransplant to treat hypoparathyroidism

    Biological: Parathyroid Allotransplant

Interventions

  • BiologicalParathyroid Allotransplant

    Parathyroid Allotransplant

06

What researchers measure

Primary outcomes

  1. Levels of intact PTH

    The primary efficacy endpoint is attainment of levels of intact PTH levels that are in the normal range and at least double the baseline intact PTH level at one year following the PTG transplant from a single donor.

    Time frame: From baseline to week 52 (year 1)

  2. Incidence of Serious Adverse Events

    The primary safety endpoints are the incidence of serious adverse events related to the transplant procedure or immunosuppression, incidence of post- transplant infections and malignancies, incidence of de novo sensitization.

    Time frame: From baseline to Year 1

Secondary outcomes

  1. Dose of oral calcium supplements and calcitrol

    in patients on conventional Ca and calcitriol supplementation, a 50% reduction in the pre-transplant oral dose of calcium supplements and calcitrol with maintenance of stable serum calcium in the normal;

    Time frame: From baseline to week 52 (year 1)

  2. Dose of subcutaneous parathyroid hormone (PTH) replacement therapy

    for patients on subcutaneous PTH replacement therapy, a 50% reduction in the dose of PTH replacement therapy with maintenance of serum calcium in the normal target range.

    Time frame: From baseline to week 52 (year 1)

  3. PTH replacement therapy

    Discontinuation of PTH replacement therapy while maintaining serum calcium in the normal target range while taking 1000 mg or less of elemental calcium in the form of calcium supplements.

    Time frame: From baseline to week 52 (year 1)

Other outcomes

  1. Quality of Life measurement

    An exploratory endpoint is the improvement in one or more quality of life measurements comparing baseline with one-year post-transplant using the Medical Outcomes Study Short Form 36 (SF36) survey and the Hypoparathyroidism Experience Scale (HPES).

    Time frame: From baseline to Year 1

07

Study locations

1 of 1 sites recruiting
08

References and documents

Individual participant data

Plan to share: Yes — The study protocol, informed consent, clinical study report, and de-identified individual participant data (IPD) collected in this trial will be made available to other researchers.

Supporting information: Study protocol, Informed consent form, Clinical study report

Time frame: Upon completion of the clinical study report and publication of the trial outcomes.

Access criteria: Researchers may contact Dr. Peter Stock, MD, PhD at UCSF by contacting the primary contact listed in this CT.GOV record.

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Started Jan 2026 (actual). Primary completion is estimated for Jan 2028, 24 months after the start.

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

Registered
Apr 29, 2025
First posted
May 7, 2025
StartActual
Jan 15, 2026
Primary completionEst.
Jan 15, 2028
CompletionEst.
Jan 15, 2028
Last update
Feb 27, 2026
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 27, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT06961071
Lead sponsor
Peter Stock
Responsible party
Peter Stock (Professor of Surgery (MD, PhD), University of California, San Francisco) — Sponsor-investigator
First posted
May 7, 2025
Start date
Jan 15, 2026
Primary completion
Jan 15, 2028 (estimated)
Completion
Jan 15, 2028 (estimated)
Last update
Feb 27, 2026

Study contacts

Crystal Loucel, MPH, MS, RN
Contact
Crystal.Loucel@ucsf.edu
415-476-3229
Rodney Rogers
Contact
Rodney.Rogers@ucsf.edu
415-514-6454
Peter Stock, MD, PhD
principal investigator · University of California, San Francisco

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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