Effect of PARP Inhibitors on Glomerular Filtration Rate

Study Overview
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Brief Summary
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The purpose of this study is to observe whether PARP inhibitors have an effect on serum creatinine level, and whether this reflects a change in creatinine secretion or a true change in kidney function.

Detailed Description
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PARPi medications interact with transporters along the renal tubules involved in the secretion of creatinine and an increase in serum creatinine is often observed in patients treated with these agents; however, it is not known whether PARP inhibitors are associated with an actual change in the glomerular filtration rate, or if the observed elevations of serum creatinine are a result of a drug effect on creatinine secretion unrelated to changes in kidney function. The investigators therefore propose a prospective observational study to examine the incidence of elevation in serum creatinine from baseline levels in patients initiated on PARP inhibitors and compare the estimated glomerular filtration rate based on creatinine to that from alternative tests. The primary purposes of this study are to: Assess the incidence of increase in serum creatinine in patients with a solid-organ cancer on treatment with a PARP inhibitor. To compare the estimated glomerular filtration rate based on serum creatinine with that of alternative biomarkers to assess whether changes in serum creatinine reflect changes in kidney function or creatinine secretion. To examine the persistence or resolution of creatinine increase and/or GFR decrease noted after discontinuation of PARPi

Official Title
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Effect of PARP Inhibitors on Glomerular Filtration Rate

Conditions
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Solid Tumor, Ovarian Cancer, Breast Cancer

Intervention / Treatment
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* Other: Kidney Function Test


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients age 18 years or older Diagnosed with any solid organ cancer Planned to receive a PARP inhibitor (olaparib, niraparib, rucaparib, veliparib, or talazoparib) Able to consent to study related procedures If unable to give informed consent, must have healthcare proxy or legally authorized representative Fluent in conversational English (Informed Consent form currently in English language) Exclusion Criteria: Patients who will not receive ongoing cancer care at Penn Medicine Major psychiatric illness or cognitive impairment that in the judgment of the study investigators or study staff would preclude study participation Any patients who are unable to comply with the study procedures as determined by the study investigators or study staff Patients on dialysis

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Individuals with solid tumors receiving PARPi<br>Kidney function will be assessed by serum creatinine, serum cystatin C, and urine creatinine clearance calculation for patients who opt-in to 24 hour urine collection. These laboratory measures will be completed by patients at the following time points: Timepoint A: Baseline (prior to PARP inhibitor initiation, at the time of standard of care clinical testing) Timepoint B: On-treatment (within 3-9 weeks of PARP inhibitor initiation, at the time of standard of care clinical testing) Timepoint C: Post-treatment (within 4 weeks of PARP inhibitor discontinuation, only for those patients with clinically significant changes in GFR based on serum creatinine, cystatin C, or 24 hour urinalysis at Timepoint B | Other: Kidney Function Test<br>* Cystatin-C measurement<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in eGFR from Baseline to On-Treatment, 3-9 weeks after PARPi Initiation (Time Point B) | Change in eGFR from baselineto on-treatment by ≥20% as measured using either cystatin C or 24h urine collection | Study labs will be obtained within 3-9 weeks after PARPi is initiated | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Within 4 Weeks of Post-discontinuation of PARPi (Time Point C) for patients with clinically significant changes in eGFR based on serum creatinine, cystatin C, or 24 hour urinalysis at Timepoint B | The percentage of patients who experience a eGFR reduction of ≥30%, and/or | Post-treatment (within 4 weeks of PARP inhibitor discontinuation, only for those patients with clinically significant changes in GFR based on serum creatinine, cystatin C, or 24 hour urinalysis at Timepoint B | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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PARPi, Kidney function, Cystatin-C