HypoparathyroidismPhase 1/2PATTHNCT06961071
Parathyroid Allotransplant for Treatment of Hypoparathyroidism
A Phase 1/2 study testing Parathyroid Allotransplant in people with Hypoparathyroidism and Hypoparathyroidism Postprocedural, run by Peter Stock at 1 site in United States.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Hypoparathyroidism, Hypoparathyroidism Postprocedural, Hypoparathyroidism Post-surgical
- What is being tested?
- Parathyroid Allotransplant
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 3 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Jan 2026to 15 Jan 2028
- Phase
- Phase 1/2
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Inclusion Criteria Only subjects who meet all of the following criteria are eligible for enrollment.
- Subjects age 18 or older.
- Subjects who are able to provide written informed consent and to comply with study procedures.
- 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.
- No history of immunodeficiency (e.g., opportunistic infections) that could be exacerbated by immunosuppression.
- Up to date immunizations per the University of California, San Francisco (UCSF) standard of care for organ transplantation, including influenza, pneumococcal, hepatitis B, and tetanus-diptheria
Exclusion Criteria Subjects who meet any of the following criteria are not eligible for enrollment
- 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
- Intolerance to any drug that will be used as part of the IS regimen.
- Poorly controlled diabetes with an A1C of >8%.
- 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.
- Other exclusion criteria including significant renal or hepatic dysfunction
- For female subjects: Positive pregnancy test, presently breast-feeding, or unwillingness to use effective contraceptive 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.
- Active infection including hepatitis B, hepatitis C, HIV, or tuberculosis (TB). Quantiferon gold assay will be used to determine TB infection.
- Invasive aspergillus, histoplasmosis, and coccidioidomycosis infection or other opportunistic infection within 1 year prior to study entry.
- Current malignancy or treated malignancy with estimated recurrence rate >50% at 5 years, except for completely resected squamous or basal cell carcinoma of the skin
- Known active alcohol or substance abuse.
- Active infections (except mild skin and nail fungal infections).
- Active peptic ulcer disease or gastritis, symptomatic gallstones, or portal hypertension.
- Use of any investigational 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 wash-out period 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.
- 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.
- Administration of live attenuated vaccine(s) within 2 months of enrollment.
- Any medical condition that, in the opinion of the investigator, will interfere with safe study completion.
- Positive screen for polyoma (BK) viremia at time of screening.
- CKD stage 4 or 5
- Severe co-existing cardiac disease, characterized by any one of these conditions:
- Recent myocardiol infarction (MI) (within 1 year)
- 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
- Left ventricular ejection fraction < 45%
- Valvular disease requiring replacement with prosthetic valve
- Substance use that in the opinion of the investigator would interfere with compliance with the study requirements.
- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of California, San Francisco
San Francisco, California, 94143
Crystal Loucel, MPH, MS, RN, 415-476-3229, Crystal.Loucel@ucsf.edu
About this study
Official title: Parathyroid Allotransplant for Treatment of Hypoparathyroidism: PATTH
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.
- Being tested
- Parathyroid Allotransplant
- Keywords
- hypoparathyroidism, parathyroid hormone, PTH, serum calcium, phosphorus
- Medical subject headings
- Hypoparathyroidism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Parathyroid AllotransplantBiological
Parathyroid Allotransplant
| Study group | Role | What they receive |
|---|---|---|
| Parathyroid Allotransplant | Experimental | Parathyroid Allotransplant to treat hypoparathyroidism Receives: Biological: Parathyroid Allotransplant |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: From baseline to week 52 (year 1)
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.
Measured: From baseline to Year 1
Secondary outcomes (3)
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;
Measured: From baseline to week 52 (year 1)
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.
Measured: From baseline to week 52 (year 1)
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.
Measured: From baseline to week 52 (year 1)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2025
- Study start15 Jan 2026
- Primary completion15 Jan 2028 (estimated)
- Study completion15 Jan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HypoparathyroidismStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1/2
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 3 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Peter Stock
- Sponsor type
- University, hospital or other
- Collaborators
- National Institutes of Health (NIH)
- Responsible party
- Sponsor-investigator, Peter Stock, University of California, San Francisco
- Investigators
- Peter Stock, MD, PhD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06961071
- Sponsor's protocol ID
- 23-40309
- Acronym
- PATTH
- Status last verified
- Feb 2026
- First submitted
- 29 Apr 2025
- Last updated
- 27 Feb 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- 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.
Study at a glance
From the registry record, last updated by the sponsor on 27 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Parathyroid Allotransplant for Treatment of Hypoparathyroidism: PATTH
- ClinicalTrials.gov ID
- NCT06961071
- Acronym / sponsor ID
- PATTH / 23-40309
- Keywords
- hypoparathyroidism, parathyroid hormone, PTH, serum calcium, phosphorus
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 3 participants (estimated)
- Lead sponsor
- Peter StockUniversity, hospital or other
- Collaborators
- National Institutes of Health (NIH)
- Study start
- 15 Jan 2026 (actual)
- Primary completion
- 15 Jan 2028 (estimated)
- Study completion
- 15 Jan 2028 (estimated)
- First posted
- 7 May 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Parathyroid Allotransplant | Experimental | Biological: Parathyroid AllotransplantParathyroid Allotransplant to treat hypoparathyroidism |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Parathyroid AllotransplantParathyroid Allotransplant | Biological | Parathyroid Allotransplant |
Primary outcome
Levels of intact PTH
Time frame: From baseline to week 52 (year 1)
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.
Incidence of Serious Adverse Events
Time frame: From baseline to Year 1
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.
3 secondary outcomes
Dose of oral calcium supplements and calcitrol
Time frame: From baseline to week 52 (year 1)
Dose of subcutaneous parathyroid hormone (PTH) replacement therapy
Time frame: From baseline to week 52 (year 1)
PTH replacement therapy
Time frame: From baseline to week 52 (year 1)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Feb 2026.
- Individual participant dataSharing planned: 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Peter Stock, MD, PhD principal investigator
University of California, San Francisco
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Parathyroid Allotransplant in people with Hypoparathyroidism and Hypoparathyroidism Postprocedural, run by Peter Stock at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Crystal Loucel, MPH, MS, RN (415-476-3229, Crystal.Loucel@ucsf.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Levels of intact PTH (time frame: From baseline to week 52 (year 1)). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Feb 2026; AzTrials last refreshed its copy on 8 Nov 2026.