CancerReSTORENCT07364409
Autologous Transplantation of Human Cryopreserved Testis Tissue
A study testing Autologous Transplantation of Testis Tissue in people with Cancer and Hematologic Diseases, run by Herlev and Gentofte Hospital at 1 site in Denmark.
Trial summary
For pre-pubertal boys undergoing gonadotoxic therapies, freezing immature testicular tissue (ITT) containing spermatogonial stem cells (SSCs) is currently the only option to potentially preserve future fertility. Read more about this study
- Who is it for?
- Ages 40 years and older, men onlyHealthy volunteers can take part
- Conditions the study is for
- Cancer, Hematologic Diseases, Infertility, Male
- What is being tested?
- Autologous Transplantation of Testis Tissue
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 5 participants
- Where
- 1 siteDenmark
- Study dates
- 4 Nov 2024to Mar 2027
- Phase
- Interventional
- 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 40 years and older
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age ≥ 40 years
- Scheduled for an elective hydrocele or spermatocele surgery
- Willing to have a testis biopsy taken during the planned surgery
- At least one biological child, unassisted spontaneous conception
- No current or future fertility wishes
- Written informed consent for the participation in this study
Who cannot join
- Treatment with testosterone substitution
- Bleeding disorders that render surgery too high a risk
- Other contraindications to surgery
- Unable to give informed consent
- Language difficulties that could compromise the informed consent or quality of examination
Trial locations and contacts
1 site in 1 country.
Denmark1 site
Copenhagen University Hospital - Herlev and Gentofte
Herlev, Capital Region, 2730
About this study
Official title: Restoration of Spermatogenesis by Autologous Grafting of Cryopreserved Testis Tissue From Men With Non-Obstructive Azoospermia and Healthy Men With Proven Fertility
For pre-pubertal boys undergoing gonadotoxic therapies, freezing immature testicular tissue (ITT) containing spermatogonial stem cells (SSCs) is currently the only option to potentially preserve future fertility. This experimental clinical study aims to provide proof-of-concept that frozen-thawed, ectopically autotransplanted adult human testicular tissue can support spermatogenesis in healthy adult men.
Read the detailed description
As of 2025, more than 3,000 pre-pubertal boys worldwide have cryopreserved immature testicular tissue, and the number of centers offering this fertility preservation option prior to gonadotoxic therapies continues to grow. The most advanced strategy for future fertility restoration is the ectopic autologous transplantation of frozen-thawed ITT, allowing the tissue to mature, initiate spermatogenesis, and ultimately provide sperm for assisted fertility treatments.
However, the absence of human data and the preservation of ITT samples for later clinical trials have so far hindered clinical translation. To address this knowledge gap, the investigators will conduct a proof-of-concept study involving five healthy adult participants with normal spermatogenesis who have naturally conceived children and do not desire additional biological offspring.
Participants will be recruited from the Department of Urology, Copenhagen University Hospital, Herlev and Gentofte Hospital. During elective hydrocele or spermatocele surgery, testicular biopsies will be collected and cryopreserved. At a later stage, the frozen-thawed tissue fragments will be autotransplanted ectopically beneath the scrotal skin. Over a six-month period, participants will undergo regular follow-up. At the end of this period, the transplanted tissue will be retrieved and evaluated for the presence of sperm. If spermatozoa are identified, their genetic stability will also be assessed. This study will generate essential data on the safety, feasibility, and functional potential of using cryopreserved human testicular tissue for fertility restoration, thereby supporting the advancement of this approach toward clinical implementation.
- Being tested
- Autologous Transplantation of Testis Tissue
- Medical subject headings
- Neoplasms, Hematologic Diseases, Infertility, Male, Azoospermia, Nonobstructive
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Autologous Transplantation of Testis TissueProcedure or surgery
Autologous transplantation of testis tissue under the scrotal skin
| Study group | Role | What they receive |
|---|---|---|
| Autologous Transplantation of Testis Tissue | Experimental | Autologous transplantation of testis tissue under the scrotal skin Receives: Procedure: Autologous Transplantation of Testis Tissue |
What is being measured
The primary outcome is the main question the study is designed to answer.
Sperm retrieval
The primary outcome of interest is the retrieval of viable sperm by testicular sperm extraction (TESE) from the transplanted testicular tissue
Measured: Sperm retrieved yes/no at 6 months post transplantation
Secondary outcomes (3)
Genetic Stability of retrieved Spermatozoa
If spermatozoa are retrieved, the genome will be sequenced to assess gentic stability of sperm retrieved after autotransplantation of frozen-thawed testicular tissue
Measured: Assessed in sperm retrieved 6 months after transplantation
Histology of engrafted testicular Tissue
The autotransplanted and retrieved testicular tissue and potentially sperm will be assessed and characterized histopathologically
Measured: Tissue retrieved 6 months after transplantation
Safety of subcutaneous Transplantation
Complications at any point during the study period will be recorded and classified according to Clavien-Dindo
Measured: From obtaining the testicular biopsy until full healing from the procedure for retrieving the transplanted tissue, up to 3 months after tissue retrieval
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2026
- Study start4 Nov 2024
- Primary completion17 Dec 2025
- Study completionMar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for CancerStudies 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 N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 5 participants (actual)
Sponsor and investigators
- Lead sponsor
- Herlev and Gentofte Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Elena von Rohden, MD, Herlev and Gentofte Hospital
- Investigators
- Elena von Rohden, MD, Principal investigator, Department of Urology, Copenhagen University Hospital - Herlev and Gentofte
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07364409
- Sponsor's protocol ID
- H-24039098
- Other IDs
- 2096-00027B, P-2024-17175
- Acronym
- ReSTORE
- Status last verified
- Oct 2025
- First submitted
- 13 Dec 2025
- Last updated
- 23 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Risk of re-identification of individual participants due to small sample size
Study at a glance
From the registry record, last updated by the sponsor on 23 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Restoration of Spermatogenesis by Autologous Grafting of Cryopreserved Testis Tissue From Men With Non-Obstructive Azoospermia and Healthy Men With Proven Fertility
- ClinicalTrials.gov ID
- NCT07364409
- Acronym / sponsor ID
- ReSTORE / H-24039098
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 5 participants (actual)
- Lead sponsor
- Herlev and Gentofte HospitalUniversity, hospital or other
- Collaborators
- University of Copenhagen, Copenhagen University Hospital, Rigshospitalet
- Study start
- 4 Nov 2024 (actual)
- Primary completion
- 17 Dec 2025 (actual)
- Study completion
- Mar 2027 (estimated)
- First posted
- 23 Jan 2026 (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.
For pre-pubertal boys undergoing gonadotoxic therapies, freezing immature testicular tissue (ITT) containing spermatogonial stem cells (SSCs) is currently the only option to potentially preserve future fertility. This experimental clinical study aims to provide proof-of-concept that frozen-thawed, ectopically autotransplanted adult human testicular tissue can support spermatogenesis in healthy adult men.
Detailed description
As of 2025, more than 3,000 pre-pubertal boys worldwide have cryopreserved immature testicular tissue, and the number of centers offering this fertility preservation option prior to gonadotoxic therapies continues to grow. The most advanced strategy for future fertility restoration is the ectopic autologous transplantation of frozen-thawed ITT, allowing the tissue to mature, initiate spermatogenesis, and ultimately provide sperm for assisted fertility treatments.
However, the absence of human data and the preservation of ITT samples for later clinical trials have so far hindered clinical translation. To address this knowledge gap, the investigators will conduct a proof-of-concept study involving five healthy adult participants with normal spermatogenesis who have naturally conceived children and do not desire additional biological offspring.
Participants will be recruited from the Department of Urology, Copenhagen University Hospital, Herlev and Gentofte Hospital. During elective hydrocele or spermatocele surgery, testicular biopsies will be collected and cryopreserved. At a later stage, the frozen-thawed tissue fragments will be autotransplanted ectopically beneath the scrotal skin. Over a six-month period, participants will undergo regular follow-up. At the end of this period, the transplanted tissue will be retrieved and evaluated for the presence of sperm. If spermatozoa are identified, their genetic stability will also be assessed. This study will generate essential data on the safety, feasibility, and functional potential of using cryopreserved human testicular tissue for fertility restoration, thereby supporting the advancement of this approach toward clinical implementation.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Autologous Transplantation of Testis Tissue | Experimental | Procedure: Autologous Transplantation of Testis TissueAutologous transplantation of testis tissue under the scrotal skin |
Who may qualify
- Ages
- 40 years and older
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Age ≥ 40 years
- Scheduled for an elective hydrocele or spermatocele surgery
- Willing to have a testis biopsy taken during the planned surgery
- At least one biological child, unassisted spontaneous conception
- No current or future fertility wishes
Key exclusion criteria (5 listed)
- Treatment with testosterone substitution
- Bleeding disorders that render surgery too high a risk
- Other contraindications to surgery
- Unable to give informed consent
- Language difficulties that could compromise the informed consent or quality of examination
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 |
|---|---|---|
| Autologous Transplantation of Testis TissueAutologous transplantation of testis tissue under the scrotal skin | Procedure or surgery | Autologous Transplantation of Testis Tissue |
Primary outcome
Sperm retrieval
Time frame: Sperm retrieved yes/no at 6 months post transplantation
The primary outcome of interest is the retrieval of viable sperm by testicular sperm extraction (TESE) from the transplanted testicular tissue
3 secondary outcomes
Genetic Stability of retrieved Spermatozoa
Time frame: Assessed in sperm retrieved 6 months after transplantation
Histology of engrafted testicular Tissue
Time frame: Tissue retrieved 6 months after transplantation
Safety of subcutaneous Transplantation
Time frame: From obtaining the testicular biopsy until full healing from the procedure for retrieving the transplanted tissue, up to 3 months after tissue retrieval
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 23 Jan 2026.
- Individual participant dataSharing planned: No. Risk of re-identification of individual participants due to small sample size
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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. This study is not recruiting at the moment.
Elena von Rohden, MD principal investigator
Department of Urology, Copenhagen University Hospital - Herlev and Gentofte
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Autologous Transplantation of Testis Tissue in people with Cancer and Hematologic Diseases, run by Herlev and Gentofte Hospital at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 5 exclusion criteria. 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: under way, not looking for participants, as of the sponsor's last update on 23 Jan 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 Denmark. 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.
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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Sperm retrieval (time frame: Sperm retrieved yes/no at 6 months post transplantation). 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 23 Jan 2026.