Safety and Efficacy of Injectable Klotho Plasmid Gene Therapy in Humans

NCT07216781 | Recruiting Phase 1

• 1 other identifier: MINICIRCLE-KLO
• Study Type: interventional
• Target: 24
• Locations: 2 countries
• Sites: 2

Brief Summary

The purpose of this study is to investigate the safety and efficacy of a gene therapy for Klotho, delivered via a nonviral plasmid in healthy adult volunteers. Additionally, this study seeks to understand the cognitive and health benefits of the Klotho gene therapy.

Conditions

Healthy Adults

Keywords

Klotho; plasmid; gene therapy

Outcome Measures

Primary Outcomes (8)

• Concentration of Serum α-Klotho Measured by Enzyme-Linked Immunosorbent Assay (pg/mL)

  Serum α-Klotho protein concentration will be quantified using a validated enzyme-linked immunosorbent assay (ELISA). Results will be reported as picograms per milliliter (pg/mL) for each participant at each time point. Higher or lower values have no inherent directionality and will be interpreted in study context.

  Measured 1 month before and 7 days before injection, then 3 days, 7 days, 1 month, 3 months, 6 months after

• Adverse Events: Number and Percentage of Participants Experiencing Treatment-Emergent Adverse Events as Assessed Patient-Reported Outcomes Version of Common Terminology Criteria for Adverse Events (PRO-CTCAE)

  Assessed through a checklist version of the PRO-CTCAE with each symptom options being none, mild, moderate, or severe. Items will be scored with 0, 1, 2, 3 respectively. Item responses will be summarized as number and percentage of participants experiencing each adverse event by system/organ class. High scores indicate highest severity of symptoms and low scores indicate no symptoms.

  Measured 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Concentration of Serum Fibroblast Growth Factor 23 (FGF23) Measured by Enzyme-Linked Immunosorbent Assay (pg/mL)

  Fibroblast Growth Factor 23 (FGF23) concentration will be quantified in serum using a validated enzyme-linked immunosorbent assay (ELISA). Results will be expressed in picograms per milliliter (pg/mL) for each participant and time point. FGF23 is a downstream effector of α-Klotho signaling and reflects activity of the phosphate-vitamin D regulatory axis.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Concentration of Intact Parathyroid Hormone Measured by Two-Site Immunoassay (pg/mL)

  Intact Parathyroid Hormone (PTH) will be measured in serum using a two-site immunoassay that detects the full-length molecule. Results will be reported in picograms per milliliter (pg/mL) per participant and time point. PTH reflects parathyroid activity within the α-Klotho-FGF23-vitamin D feedback pathway.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Concentration of Serum 1,25-Dihydroxyvitamin D (Calcitriol) Measured by Liquid Chromatography-Tandem Mass Spectrometry (pg/mL)

  Serum 1,25-dihydroxyvitamin D (calcitriol) will be quantified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Concentrations will be expressed in picograms per milliliter (pg/mL). This hormone regulates calcium and phosphate balance and is a downstream marker of α-Klotho-FGF23-PTH axis modulation.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Concentration of Serum Phosphorus Measured by Clinical Chemistry Analyzer (mg/dL)

  Serum inorganic phosphorus will be measured on a standard clinical chemistry analyzer. Results will be reported in milligrams per deciliter (mg/dL) for each participant and time point. Phosphorus levels reflect systemic phosphate homeostasis influenced by α-Klotho and FGF23 activity.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Urinary Phosphate Excretion Measured by Clinical Chemistry Assay (mg/24 h or mg/g Creatinine)

  Urinary phosphate will be assessed using a validated chemistry assay. Results will be expressed either as total phosphate excretion in milligrams per 24 hours (mg/24 h) or as the phosphate-to-creatinine ratio (mg phosphate per g creatinine). This measure reflects renal handling of phosphate and functional effects of α-Klotho on phosphate excretion.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

• Concentration of Serum Cystatin C Measured by Immunoassay (mg/L)

  Serum Cystatin C will be measured using a standardized immunoassay and reported in milligrams per liter (mg/L) for each participant and time point. Cystatin C serves as a biomarker of glomerular filtration rate and provides a mechanistic link between α-Klotho activity and renal function.

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 months, and 6 months after treatment.

Secondary Outcomes (28)

• Change From Baseline in World Health Organization Quality of Life Brief Version Domain Scores (0-100)

  Measured 1 month before, 7 days before, and then 3 days, 7 days, 1 month, 3 month, 6 months after.

• Change From Baseline in Flanker Inhibitory Control and Attention Test T-Score (Mean 50 ± 10)

  Measured 7 days before, then 3 days, 7 days, 1 month, 3 months, 6 months after treatment.

• Change From Baseline in Dimensional Change Card Sort Test T-Score (Mean 50 ± 10)

  Measured 7 days before, then 3 days, 7 days, 1 month, 3 months, 6 months after treatment.

• Change From Baseline in Pattern Comparison Processing Speed Test T-Score (Mean 50 ± 10)

  Measured 7 days before, then 3 days, 7 days, 1 month, 3 months, 6 months after treatment.

• Change From Baseline in Picture Sequence Memory Test T-Score, Forms A and B (Mean 50 ± 10)

  Measured 7 days before, then 3 days, 7 days, 1 month, 3 months, 6 months after treatment.

Study Arms (1)

Schedule of Administration and Sample Selection

EXPERIMENTAL

This arm includes cognitive and health battery at multiple intervals pre- and post-administration of Klotho

Genetic: Injectable Plasmid Klotho Gene Therapy

Interventions

Injectable Plasmid Klotho Gene Therapy GENETIC

Injection of plasmid-delivered Klotho gene therapy

Schedule of Administration and Sample Selection

Eligibility Criteria

• Age: 23 Years - 90 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Participant is open to morphological change
• If female, participant agrees to maintain contraception
• If female, participant agrees to take a pregnancy test
• If female, participant agrees to a pregnancy waiver

You may not qualify if:

• Women of childbearing potential who are unwilling or unable to use effective contraception for the duration of the study
• History of cancer diagnosis
• Preexisting medical issues that may be exacerbated by the treatment
• Has received any gene therapy within the past 12 months
• Unwilling or unable to provide written informed consent

Sponsors & Collaborators

• Minicircle: lead

Study Sites (2)

Apeiron Center

Austin, Texas, 78701, United States

RECRUITING

GARM Clinic

Roatán, Bay Islands, Honduras

NOT YET RECRUITING

Related Publications (14)

• Urakawa I, Yamazaki Y, Shimada T, Iijima K, Hasegawa H, Okawa K, Fujita T, Fukumoto S, Yamashita T. Klotho converts canonical FGF receptor into a specific receptor for FGF23. Nature. 2006 Dec 7;444(7120):770-4. doi: 10.1038/nature05315. Epub 2006 Oct 29.

  PMID: 17086194 BACKGROUND

• Matsumura Y, Aizawa H, Shiraki-Iida T, Nagai R, Kuro-o M, Nabeshima Y. Identification of the human klotho gene and its two transcripts encoding membrane and secreted klotho protein. Biochem Biophys Res Commun. 1998 Jan 26;242(3):626-30. doi: 10.1006/bbrc.1997.8019.

  PMID: 9464267 BACKGROUND

• Masso A, Sanchez A, Bosch A, Gimenez-Llort L, Chillon M. Secreted alphaKlotho isoform protects against age-dependent memory deficits. Mol Psychiatry. 2018 Sep;23(9):1937-1947. doi: 10.1038/mp.2017.211. Epub 2017 Oct 31.

  PMID: 29086766 BACKGROUND

• Masso A, Sanchez A, Gimenez-Llort L, Lizcano JM, Canete M, Garcia B, Torres-Lista V, Puig M, Bosch A, Chillon M. Secreted and Transmembrane alphaKlotho Isoforms Have Different Spatio-Temporal Profiles in the Brain during Aging and Alzheimer's Disease Progression. PLoS One. 2015 Nov 24;10(11):e0143623. doi: 10.1371/journal.pone.0143623. eCollection 2015.

  PMID: 26599613 BACKGROUND

• Imura A, Tsuji Y, Murata M, Maeda R, Kubota K, Iwano A, Obuse C, Togashi K, Tominaga M, Kita N, Tomiyama K, Iijima J, Nabeshima Y, Fujioka M, Asato R, Tanaka S, Kojima K, Ito J, Nozaki K, Hashimoto N, Ito T, Nishio T, Uchiyama T, Fujimori T, Nabeshima Y. alpha-Klotho as a regulator of calcium homeostasis. Science. 2007 Jun 15;316(5831):1615-8. doi: 10.1126/science.1135901.

  PMID: 17569864 BACKGROUND

• Kuro-o M, Matsumura Y, Aizawa H, Kawaguchi H, Suga T, Utsugi T, Ohyama Y, Kurabayashi M, Kaname T, Kume E, Iwasaki H, Iida A, Shiraki-Iida T, Nishikawa S, Nagai R, Nabeshima YI. Mutation of the mouse klotho gene leads to a syndrome resembling ageing. Nature. 1997 Nov 6;390(6655):45-51. doi: 10.1038/36285.

  PMID: 9363890 BACKGROUND

• Imura A, Iwano A, Tohyama O, Tsuji Y, Nozaki K, Hashimoto N, Fujimori T, Nabeshima Y. Secreted Klotho protein in sera and CSF: implication for post-translational cleavage in release of Klotho protein from cell membrane. FEBS Lett. 2004 May 7;565(1-3):143-7. doi: 10.1016/j.febslet.2004.03.090.

  PMID: 15135068 BACKGROUND

• Gupta S, Moreno AJ, Wang D, Leon J, Chen C, Hahn O, Poon Y, Greenberg K, David N, Wyss-Coray T, Raftery D, Promislow DEL, Dubal DB. KL1 Domain of Longevity Factor Klotho Mimics the Metabolome of Cognitive Stimulation and Enhances Cognition in Young and Aging Mice. J Neurosci. 2022 May 11;42(19):4016-4025. doi: 10.1523/JNEUROSCI.2458-21.2022. Epub 2022 Apr 15.

  PMID: 35428698 BACKGROUND

• Dubal DB, Yokoyama JS, Zhu L, Broestl L, Worden K, Wang D, Sturm VE, Kim D, Klein E, Yu GQ, Ho K, Eilertson KE, Yu L, Kuro-o M, De Jager PL, Coppola G, Small GW, Bennett DA, Kramer JH, Abraham CR, Miller BL, Mucke L. Life extension factor klotho enhances cognition. Cell Rep. 2014 May 22;7(4):1065-76. doi: 10.1016/j.celrep.2014.03.076. Epub 2014 May 10.

  PMID: 24813892 BACKGROUND

• Davidsohn N, Pezone M, Vernet A, Graveline A, Oliver D, Slomovic S, Punthambaker S, Sun X, Liao R, Bonventre JV, Church GM. A single combination gene therapy treats multiple age-related diseases. Proc Natl Acad Sci U S A. 2019 Nov 19;116(47):23505-23511. doi: 10.1073/pnas.1910073116. Epub 2019 Nov 4.

  PMID: 31685628 BACKGROUND

• Chen CD, Podvin S, Gillespie E, Leeman SE, Abraham CR. Insulin stimulates the cleavage and release of the extracellular domain of Klotho by ADAM10 and ADAM17. Proc Natl Acad Sci U S A. 2007 Dec 11;104(50):19796-801. doi: 10.1073/pnas.0709805104. Epub 2007 Dec 3.

  PMID: 18056631 BACKGROUND

• Castner SA, Gupta S, Wang D, Moreno AJ, Park C, Chen C, Poon Y, Groen A, Greenberg K, David N, Boone T, Baxter MG, Williams GV, Dubal DB. Longevity factor klotho enhances cognition in aged nonhuman primates. Nat Aging. 2023 Aug;3(8):931-937. doi: 10.1038/s43587-023-00441-x. Epub 2023 Jul 3.

  PMID: 37400721 BACKGROUND

• Arking DE, Krebsova A, Macek M Sr, Macek M Jr, Arking A, Mian IS, Fried L, Hamosh A, Dey S, McIntosh I, Dietz HC. Association of human aging with a functional variant of klotho. Proc Natl Acad Sci U S A. 2002 Jan 22;99(2):856-61. doi: 10.1073/pnas.022484299. Epub 2002 Jan 15.

  PMID: 11792841 BACKGROUND

• Abraham CR, Mullen PC, Tucker-Zhou T, Chen CD, Zeldich E. Klotho Is a Neuroprotective and Cognition-Enhancing Protein. Vitam Horm. 2016;101:215-38. doi: 10.1016/bs.vh.2016.02.004. Epub 2016 Mar 22.

  PMID: 27125744 BACKGROUND

Central Study Contacts

Mac Davis

CONTACT

512-630-0882; mac@minicircle.io

Study Design

• Study Type: interventional
• Phase: phase 1
• Allocation: NA
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: SINGLE GROUP
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Model Details: Non-placebo-controlled trial

Study Record Dates

• First Submitted: September 30, 2025
• First Posted: October 15, 2025
• Study Start: October 6, 2025
• Primary Completion: August 1, 2026
• Study Completion: August 1, 2026
• Last Updated: February 17, 2026

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Data will be made available upon publication and will be available indefinitely.
• Access Criteria: Data will be made available to anyone who wishes to access it in an online repository at Vivli (https://vivli.org/). The types of data shared will include de-identified data of pre- and post-treatment values for the following measures: serum Klotho levels; kidney and blood safety panels; questionnaires and adverse event reporting data (all check box questions; however, any open-ended answer data will reviewed to ensure they cannot be used to identify an individual participant - final judgments will be made by the study central coordinator); RIAS-2 scores; all NIH-toolbox measures; Kernel brain data; epigenetic age.

Locations

US (1); HO (1)