A Phase 4 interventional study of Conversion to extended-release tacrolimus and Maintenance of immediate-release tacrolimus in Kidney Transplant Recipients and Old Age, sponsored by Massachusetts General Hospital. Recruiting at 1 site in United States. Open to participants aged 65 Years and older. Per ClinicalTrials.gov, last updated 2026-05-28.
Sponsored by Massachusetts General Hospital · Phase 4, Interventional, and Prevention
The objective of this randomized controlled study is to assess the neurocognitive outcomes between individuals using immediate-release (IR) tacrolimus (Prograf®) and those who were converted to extended-release tacrolimus (Envarsus XR) among older kidney transplant recipients (KTRs).
158 studies on the registry are indexed under Tremor; 44 are open to participants now.
This study's planned enrollment of 92 is above the median of 33 across 109 interventional studies indexed under Tremor.
Browse Tremor studies →Massachusetts General Hospital is the lead sponsor of 2,586 studies on the registry; 447 are open to participants now.
Of its 222 completed or terminated interventional studies of FDA-regulated products, 168 (76%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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.
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.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
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.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Bilirubin
A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.
Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients who are randomized to this group will receive extended-release tacrolimus (Envarsus XR) at 80 percent of their total daily dose of IR tacrolimus (Prograf) before the switch. Tacrolimus trough level will be obtained 3-4 weeks after the conversion to ensure appropriate dosage.
Drug: Conversion to extended-release tacrolimus
Patients in the IR tacrolimus (Prograf) maintenance group will continue with their current dose of IR tacrolimus (Prograf) before enrollment unless the drug trough levels deviate from the therapeutic range.
Drug: Maintenance of immediate-release tacrolimus
Conversion from immediate-release tacrolimus (Prograf) to extended-release tacrolimus (Envarsus XR) as a part of the maintenance immunosuppressive treatment
Also known as: Envarsus XR
Continuing immediate-release tacrolimus (Prograf) as a part of the maintenance immunosuppressive treatment
Also known as: Prograf
The difference in changes of neurocognitive function in intermediate-term (Total cognition composite, standard score)
Neurocognitive functions will be assessed across multiple cognitive domains using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3. The NIHTB-CB version 3 encompasses seven tests to assess attention, executive function, language, memory, and processing speed. The total cognition composite will be derived by averaging normalized scores. The results will be reported in Standard Scores \[SS; mean of 100, standard deviation (SD) of 15\] adjusting the age of the subject. The investigators will compare the changes in standard score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in intermediate-term (Fluid composite, standard score)
The fluid composite score will be obtained using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3, similarly as described above. The fluid cognition composite will be derived by averaging normalized scores. The results will be reported in Standard Scores \[SS; mean of 100, standard deviation (SD) of 15\] adjusting the age of the subject. The investigators will compare the changes in standard score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in intermediate-term (Crystallized composite, standard score)
The crystallized composite score will be obtained using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3, similarly as described above. The crystallized cognition composite will be derived by averaging normalized scores. The results will be reported in Standard Scores \[SS; mean of 100, standard deviation (SD) of 15\] adjusting the age of the subject. The investigators will compare the changes in standard score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in intermediate-term (Total cognition composite, T score)
The total composite score will be obtained using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3, similarly as described above. The total cognition composite will be derived by averaging normalized scores. The results will be reported in T scores (mean of 50 and SD of 10) with adjustments for age, gender, education, and race/ethnicity. The investigators will compare the changes in T score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in intermediate-term (Fluid composite, T score)
The fluid composite score will be obtained using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3, similarly as described above. The fluid cognition composite will be derived by averaging normalized scores. The results will be reported in T scores (mean of 50 and SD of 10) with adjustments for age, gender, education, and race/ethnicity. The investigators will compare the changes in T score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in intermediate-term (Crystallized composite, T score)
The crystallized composite score will be obtained using the NIH toolbox-Cognitive battery (NIHTB-CB) version 3, similarly as described above. The crystallized cognition composite will be derived by averaging normalized scores. The results will be reported in T scores (mean of 50 and SD of 10) with adjustments for age, gender, education, and race/ethnicity. The investigators will compare the changes in T score from baseline between the two intervention groups.
Time frame: 12 month
The difference in changes of neurocognitive function in short-term (Total cognition composite, standard score)
Same as described above
Time frame: 3 month
The difference in changes of neurocognitive function in short-term (Fluid composite, standard score)
Same as described above
Time frame: 3 month
The difference in changes of neurocognitive function in short-term (Crystallized composite, standard score)
Same as described above
Time frame: 3 month
The difference in changes of neurocognitive function in short-term (Total cognition composite, T score)
Same as described above
Time frame: 3 month
The difference in changes of neurocognitive function in short-term (Fluid composite, T score)
Same as described above
Time frame: 3 month
The difference in changes of neurocognitive function in short-term (Crystallized composite, T score)
Same as described above
Time frame: 3 month
The changes in quality of life, measured by SONG-LP questionnaire
The Standardized Outcome in Nephrology-Life Participation (SONG-LP) questionnaire will evaluate each participant's engagement in significant life domains in correlation with the intervention. This questionnaire assesses life participation in the areas of leisure, family, work, and social activities through four simple questions. The score ranges from 4 to 20, with a higher score indicating greater engagement in life activities. The difference in changes of total score from baseline between the two intervention groups will be obtained.
Time frame: 3 month and 12 month
The changes in tremor, measured by QUEST questionnaire
Quality of Life in Essential Tremor (QUEST) questionnaire will be used to assess tremors subjectively. This questionnaire comprises 30 items contributing to the five dimensions: physical/activities of daily living, psychosocial, communication, hobbies/leisure, and work/finances. The investigators will also obtain self-rated tremor severity in various body parts. The score ranges from 0 to 120, with a higher score indicating a greater impact on their QOL from tremor. The investigators will compare the changes in total score and the score on each scale from baseline between the two intervention groups.
Time frame: 3 month and 12 month
The changes in sleep quantity, measured by a wearable device
The investigators will assess each participant's sleep quantity using wearable devices. The participants will be instructed to wear the device continuously for 14 days at pre-specified time points during the study period. Sleep quantity will be represented by the total amount of time spent asleep. The difference in changes in sleep quantity from baseline will be compared between the two intervention groups.
Time frame: 3 month and 12 month
The changes in sleep quality, measured by a wearable device
The investigators will objectively assess each participant's sleep quality using wearable devices. The participants will be instructed to wear the device continuously for 14 days at pre-specified time points during the study period. Sleep quality will be measured as a percentage of time spent in deep sleep and REM sleep to the total sleep time. A higher percentage indicates a better sleep quality. The changes in sleep quality from baseline will be compared between the two intervention groups.
Time frame: 3 month and 12 month
Subgroup analysis of primary and secondary outcomes based on age group
The investigators will analyze the differential impact of the intervention in participants aged 75 years and older, compared to those under 75 years old.
Time frame: At 3 month and 12 month
Subgroup analysis of primary and secondary outcomes based on gender
The investigators will perform a subgroup analysis for each outcome based on gender to determine whether the treatment effect varies between males and females.
Time frame: At 3 month and 12 month
Subgroup analysis of primary and secondary outcomes based on education level
The investigators will analyze the differential impact of the intervention in participants with Bachelor's degree holders, compared to those without Bachelor's degree holders.
Time frame: At 3 month and 12 month
Subgroup analysis of primary and secondary outcomes based on the baseline cognitive function
The investigators will perform a subgroup analysis for each outcome based on baseline cognitive function to determine whether the treatment effect varies according to baseline cognitive function. Participants with a baseline NIHTB-CB total composite T score ≤ 43 (corresponding to the lower 25th percentile adjusted for age, gender, education, and race/ethnicity) will be separately analyzed to those with a score \> 43.
Time frame: At 3 month and 12 month
Plan to share: Yes — As part of our commitment to transparency and promoting further scientific research, the investigators plan to share individual participant data (IPD) from this clinical trial. The data will be made available to qualified researchers upon request, subject to appropriate data use agreements and ethical considerations. Specifically, the following data will be shared: Demographic Information: Age, sex, race. Outcomes Data: Information related to primary and secondary endpoints Adverse Events: Data on reported adverse events and serious adverse events. All data will be available in a de-identified format to protect participant confidentiality via ClinicalTrials.gov.
Supporting information: Study protocol
Time frame: The individual participant data (IPD) and supporting information will be made available to qualified researchers 6 months after the publication of the primary study results. Data will be accessible for a minimum of 5 years from the date of publication or study completion, whichever occurs later, to ensure ample time for further research and analysis.
Access criteria: Access to individual participant data (IPD) will be granted to qualified researchers conducting non-commercial, scientifically valid research. Researchers must: Submit a formal data access request, including a research proposal and ethical review approval. Sign a data use agreement outlining the terms of data use, including confidentiality and non-re-identification. Provide documentation of ethical approval from an Institutional Review Board or equivalent.
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Studies of the drug tested here: Tacrolimus
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