Effect of Renal Dysfunction on Toxicity in Three Decades of Cancer Therapy Evaluation Program-Sponsored Single-Agent Phase I Studies

Impact of the 2021 CKD-EPI equation on anticancer pharmacotherapy in black and non-black cancer patients

Cancer and kidney disease disproportionately impact Black patients. The CKD-EPI2021 equation was developed to estimate glomerular filtration rate (eGFR) without using race. We assessed the impact of using CKD-EPI2021 instead of CKD-EPI2009 or Cockcroft-Gault (CG) on dosing and eligibility of anticancer drugs in Black and non-Black patients. Utilizing the National Cancer Institute Theradex database, deindexed eGFR (mL/min) was calculated for 3931 patients (8.6 % Black) using CKD-EPI2021, CKD-EPI2009, and CG. Dosing simulations based on each eGFR were performed for ten anticancer drugs with kidney function-based eligibility or dosing cutoffs. eGFR differences using CKD-EPI2021 versus CKD-EPI2009 varied between Black and non-Black patients (p < 0.001); on average, Black patients had 10.3 mL/min lower eGFR and non-Black patients had 4.2 mL/min higher eGFR using CKD-EPI2021. This corresponded to a difference in relative odds of cisplatin ineligibility using CKD-EPI2021 versus CKD-EPI2009; Black patients had 48 % higher odds of ineligibility and non-Black patients had 27 % lower odds of ineligibility using CKD-EPI2021 (p < 0.001). When using CKD-EPI2021 versus CG, eGFR differences were similar between Black and non-Black patients (p = 0.679) and relative difference in odds of cisplatin ineligibility did not vary. Using CKD-EPI2021 versus CKD-EPI2009 differentially impacts Black versus non-Black cancer patients; Black patients have lower calculated eGFR and are less likely to receive full doses of drug using CKD-EPI2021. From the historical default of CG, adopting CKD-EPI2021 would not disparately impact patients based on race, but would result in Black patients being less likely to receive full doses of drug than if CKD-EPI2009 were used.

Glomerular Filtration Rate Measurement and Chemotherapy Dosing

Many chemotherapeutic drugs used to treat malignancies undergo renal clearance. Thus, accurate knowledge of kidney function is critical to ensure proper dosing, maximize efficacy, and minimize toxicity of drugs that often have a narrow therapeutic index. Making this issue more salient is the fact that impaired kidney function, as assessed by glomerular filtration rate (GFR), is encountered commonly in patients with cancer. Recent data and expert guidelines recommend the use of the Chronic Kidney Disease-Epidemiology Collaboration equation to guide the assessment of kidney function, except when directly measured GFR is clinically necessary. Controversies regarding the measurement of kidney function include the use of race in this equation, indexing to body surface area, and dosing of medications based on stages of chronic kidney disease versus more discrete values of estimated GFR. The development of accurate, real-time GFR measures may hold great promise in allowing for more accurate dosing of these important drugs.

Inclusion of Participants with CKD and Other Kidney-Related Considerations during Clinical Drug Development: Landscape Analysis of Anticancer Agents Approved from 2015 to 2019

BACKGROUND

The US Food and Drug Administration has prioritized efforts to expand availability of therapies, including anticancer agents, for patients with CKD. US Food and Drug Administration Guidance recommends inclusion of study participants with CKD in clinical trials, improving pharmacokinetic characterization in people with decreased GFR, and using contemporary GFR assessment methods during drug development. We performed a landscape analysis of anticancer agents approved from 2015 to 2019 to evaluate inclusion of study participants with CKD and GFR assessment methods used during drug development and subsequent translation to kidney-related safety and dosing data in product labeling.

METHODS

Oncology drugs approved from 2015 to 2019 and associated pivotal trials were identified. We evaluated inclusion of study participants with CKD in pivotal trials and pharmacokinetic analyses, investigated GFR assessment methods used for pivotal trial eligibility and renal pharmacokinetic analyses, and identified kidney-related adverse drug event and dosing information.

RESULTS

A total of 55 drugs and 74 pivotal trials were included. Of the pivotal trials, 95% contained kidney-related eligibility criteria, including 68% with GFR-based eligibility. The median lower limit of GFR required for inclusion was 45 ml/min or ml/min per 1.73 m 2 . Pharmacokinetic analyses were performed in CKD stages 4-5 and hemodialysis for only 29% and 6% of drugs, respectively. Estimated creatinine clearance was used in over 60% and 80% of pivotal trials and pharmacokinetic analyses, respectively. Reporting of kidney-related adverse drug events was highly variable. Product labeling for 49% of drugs contained no kidney dosing information.

CONCLUSIONS

Study participants with CKD continue to be excluded from anticancer drug development, and GFR estimation in pivotal trials and renal pharmacokinetic analyses remains imprecise and heterogeneous. Furthermore, kidney-related safety and dosing information is scarcely and inconsistently presented.

Effect of removing race from glomerular filtration rate-estimating equations on anticancer drug dosing and eligibility: a retrospective analysis of National Cancer Institute phase 1 clinical trial participants

BACKGROUND

Kidney function assessment by estimated glomerular filtration rate (eGFR) equations, such as the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation, is important to determine dosing and eligibility for anticancer drugs. Inclusion of race in eGFR equations calculates a higher eGFR at a given serum creatinine concentration for Black patients versus non-Black patients. We aimed to characterise the effect of removing race from the CKD-EPI equation on dosing and eligibility of anticancer drugs with kidney function cutoffs.

METHODS

We did a retrospective analysis of patients enrolled in phase 1 studies sponsored by the Cancer Therapy Evaluation Program between January, 1995, and October, 2010. eGFR based on creatinine (eGFRCr) was calculated by the CKD-EPI equation and a version of the CKD-EPI equation without the race term (CKD-EPIwithout race). Estimated creatinine clearance (eClCr) was calculated by the Cockcroft-Gault equation. Dosing simulations based on each assessment of kidney function were done for ten anticancer drugs with kidney function cutoffs for dosing (oxaliplatin, capecitabine, etoposide, topotecan, fludarabine, and bleomycin) or eligibility (cisplatin, pemetrexed, bendamustine, and mitomycin) based on labelling approved by the US Food and Drug Administration or consensus guidelines. The absolute proportion of patients eligible or in each renal dosing range was calculated for each drug. Eligibility and dosing discordance rates were also calculated.

FINDINGS

Demographics and laboratory values from 340 Black patients (172 men and 168 women) were used. Median age was 57 years (IQR 47-64), median bodyweight was 78·1 kg (67·0-89·8), median body surface area was 1·91 m2 (1·77-2·09), and median serum creatinine concentration was 0·9 mg/dL (0·8-1·1). Median eGFRCr or eClCr was 103 mL/min (85-122) calculated by CKD-EPI, 89 mL/min (73-105) by CKD-EPIwithout race, and 90 mL/min (72-120) by Cockcroft-Gault. Black patients were recommended to receive dose reductions or were rendered ineligible to receive drug more frequently when using CKD-EPIwithout race than when using CKD-EPI, but at a similar rate as when using Cockcroft-Gault. The number of patients ineligible for therapy or recommended to receive any renal dose adjustment when CKD-EPIwithout race versus CKD-EPI was used increased by 72% (from 25 of 340 to 43 of 340 patients) for cisplatin, by 120% (from five to 11) for pemetrexed, by 67% (from three to five) for bendamustine, by 150% (from ten to 25) for capecitabine, by 150% (from ten to 25) for etoposide, by 67% (from three to five) for topotecan, by 61% (from 74 to 119) for fludarabine, and by 163% (from eight to 21) for bleomycin. Up to 18% of patients had discordant recommendations using CKD-EPIwithout race versus CKD-EPI.

INTERPRETATION

Removing race from the CKD-EPI equation will calculate a lower eGFR for Black patients and exclude more patients from receiving anticancer therapy, which could lead to undertreatment of Black patients with cancer and adversely affect their outcomes.

FUNDING

National Institutes of Health.

Drug dosing in cancer patients with decreased kidney function: A practical approach

Correct drug dosing of anticancer agents is essential to obtain optimal outcomes. Overdosing will result in increased toxicity, treatment interruption and possible cessation of anticancer treatment. Underdosing may result in suboptimal anti-cancer effects and may increase the risk of cancer-related mortality. As it is practical nor feasible to perform therapeutic drug monitoring for all anti-cancer drugs, kidney function is used to guide drug dosing for those drugs whose primary mode of excretion is through the kidney. However, it is not well-established what method should be utilized to measure or estimate kidney function and the choice of method does influence treatment decisions regarding eligibility for anti-cancer drugs and their dose. In this review, we will provide an overview regarding the importance of drug dosing, the preferred method to determine kidney function and a practical approach to drug dosing of anticancer drugs.

Dose Optimization in Kidney Disease: Opportunities for PBPK Modeling and Simulation

Kidney disease affects pharmacokinetic (PK) profiles of not only renally cleared drugs but also nonrenally cleared drugs. The impact of kidney disease on drug disposition has not been fully elucidated, but describing the extent of such impact is essential for conducting dose optimization in kidney disease. Accurate evaluation of kidney function has been a clinical interest for dose optimization, and more scientists pay attention and conduct research for clarifying the role of drug transporters, metabolic enzymes, and their interplay in drug disposition as kidney disease progresses. Physiologically based pharmacokinetic (PBPK) modeling and simulation can provide valuable insights for dose optimization in kidney disease. It is a powerful tool to integrate discrete knowledge from preclinical and clinical research and mechanistically investigate system- and drug-dependent factors that may contribute to the changes in PK profiles. PBPK-based prediction of drug exposures may be used a priori to adjust dosing regimens and thereby minimize the likelihood of drug-related toxicity. With real-time clinical studies, parameter estimation may be performed with PBPK approaches that can facilitate identification of sources of interindividual variability. PBPK modeling may also facilitate biomarker research that aids dose optimization in kidney disease. U.S. Food and Drug Administration guidances related to conduction of PK studies in kidney impairment and PBPK documentation provide the foundation for facilitating model-based dose-finding research in kidney disease.

Organ Dysfunction in Patients with Advanced Melanoma Treated with Immune Checkpoint Inhibitors

BACKGROUND

Real-world data enables evaluation of immune checkpoint inhibitor (ICI) use in advanced melanoma management. We examined characteristics and outcomes of ICI-treated patients with advanced melanoma and organ dysfunction (baseline and emergent).

MATERIALS AND METHODS

This retrospective observational study used electronic health records derived from a nationwide data set to examine advanced melanoma patients treated with first-line ICIs (2011-2018). Clinical characteristics, real-world time to treatment discontinuation (rwTTD), and overall survival (OS) were analyzed for patients with normal organ function and those with organ dysfunction prior to ICI initiation. Patients with emergent dysfunction in the 90 days following ICI initiation were identified, and potentially associated characteristics were explored.

RESULTS

Of 2,407 patients included, 1,884 and 1,717 had evaluable renal and hepatic laboratory values, respectively. Patients with baseline renal dysfunction (2.4%) were older and more frequently male, and less frequently treated with ICI combinations, than patients with normal renal function. Patients with baseline hepatic dysfunction (2.8%) were similar to patients with normal hepatic function regarding demographics and treatments received. Patients with baseline organ dysfunction displayed shorter rwTTD and OS. Among patients with normal baseline organ function, 4.6% and 7.4% developed renal and hepatic dysfunction within 90 days of ICI initiation, respectively; this was associated with combination ICI treatment.

CONCLUSION

Patients with advanced melanoma and baseline organ dysfunction frequently receive ICI treatment but have poorer clinical outcomes than patients with normal organ function. Among patients with normal renal and hepatic function at ICI initiation, emergent organ dysfunction rates in this real-world cohort are similar to those reported in clinical trials.

IMPLICATIONS FOR PRACTICE

Real-world data provide an opportunity to understand treatment patterns, toxicity, and clinical outcomes among patients treated outside of clinical trials. This study confirms that patients with advanced melanoma and baseline renal or hepatic dysfunction are being treated with ICI therapy more frequently as monotherapy than in combination therapy. For those real-world patients with normal baseline organ function, emergent renal and hepatic dysfunction are both more common in patients treated with combination versus ICI monotherapy.

How to determine kidney function in cancer patients?

A precise and efficient method for estimating kidney function in cancer patients is important to determine their eligibility for clinical trials and surgery and to allow for appropriate dose adjustment of anti-cancer drugs, especially toxic drugs with a narrow therapeutic index. Since direct measurement of glomerular filtration rate (GFR) is cumbersome, several formulae have been developed to estimate kidney function. Most of these are based on serum creatinine concentration. Though the CKD-EPI formula is recognised as being the most accurate, there is an ongoing debate on which is the optimal formula for cancer patients. In this review, we provide an overview of different GFR estimating equations for kidney function and the advantages and disadvantages of each method and compare their performance in cancer patients. We discuss the importance of body surface area-indexing and propose a framework for evaluating kidney function in cancer patients.

Estimation of Kidney Function in Oncology: Implications for Anticancer Drug Selection and Dosing

Estimation of kidney function in patients with cancer directly affects drug dosing, agent selection, and eligibility for clinical trials of novel agents. Overestimation of kidney function may lead to overdosing or inappropriate agent selection and corresponding toxicity. Conversely, underestimation of kidney function may lead to underdosing or inappropriate agent exclusion and subsequent therapeutic failure. It would seem obvious that the most accurate estimates of kidney function should be used to reduce variability in decision making and ultimately, the therapeutic outcomes of toxicity and clinical benefit. However, clinical decision making is often more complex. The Cockcroft-Gault formula remains the most universally implemented estimator of kidney function in patients with cancer, despite its relative inaccuracy compared with the Chronic Kidney Disease Epidemiology Collaboration equation. The Chronic Kidney Disease Epidemiology Collaboration equation is a more precise estimator of kidney function; however, many currently used kidney function cutoff values were determined before the development of the Chronic Kidney Disease Epidemiology Collaboration equation and creatinine assay standardization using Cockcroft-Gault estimates. There is a need for additional studies investigating the validity of currently used estimates of kidney function in patients with cancer and the applicability of traditional anticancer dosing and eligibility guidelines to modern and more accurate estimates of kidney function. In this review, we consider contemporary calculation methods used to estimate kidney function in patients with cancer. We discuss the clinical implications of using these various methods, including the potential influence on drug dosing, drug selection, and clinical trial eligibility, using carboplatin and cisplatin as case studies.

Dose adjustment of cisplatin, etoposide, and ifosfamide according to kidney function: a retrospective analysis and implications for medication safety

Clearance of cisplatin, etoposide, and ifosfamide depends on kidney function and dosages should be adjusted in patients with renal impairment. However, there is still limited data on the adherence of physicians to dosing recommendations for these drugs in cancer patients with renal impairment. Three thousand four hundred forty-eight prescriptions to 369 patients, treated in the Comprehensive Cancer Center of a German university hospital, were retrospectively evaluated. The administered relative doses of cisplatin, etoposide, and ifosfamide were compared with relative doses recommended at the time of prescription according to the patients' creatinine clearance. Cisplatin is contraindicated according to two German summary of product characteristics (SmPC) in patients with a creatinine clearance < 60 mL/min. Nevertheless, 37 cisplatin prescriptions were made for this group of patients (i.e., 2.0% of all cisplatin prescriptions). According to one German SmPC (valid in the year of data analysis), etoposide dosage should be reduced in patients with a creatinine clearance from 15 to 50 mL/min, while it is contraindicated below 15 mL/min. Thirteen etoposide prescriptions were without dose reduction in patients with creatinine clearance from 15 to 50 mL/min (1.5% of all etoposide prescriptions); one patient received etoposide with creatinine clearance below 15 mL/min. In 8.9% of ifosfamide prescriptions, patients did not receive a reduced dose in spite of respective recommendations. Dosages of cisplatin, etoposide, and ifosfamide are not always adjusted as recommended in patients with renal impairment. Consistent international dosing recommendations (e.g., in SmPCs), preferentially included in clinical decision support systems, should be developed to tackle this problem.

A survey of renal impairment pharmacokinetic studies for new oncology drug approvals in the USA from 2010 to early 2015: a focus on development strategies and future directions

The US Food and Drug Administration (FDA) issued a guidance document in 2010 on pharmacokinetic (PK) studies in renal impairment (RI) on the basis of observations that substances such as uremic toxins might result in altered drug metabolism and excretion. No specific recommendations for oncology drugs were included. We surveyed the publicly available FDA review documents of 29 small molecule oncology drugs approved between 2010 and the first quarter of 2015. The objectives were as follows: (i) summarize the impact of RI on PK at the time of the initial new drug application; (ii) identify limitations of the guidance; and (iii) outline an integrated approach to study the impact of RI on these drugs. Our survey indicates that the current FDA guidance does not appear to provide clear strategic or decision pathways for RI studies in terms of small molecule oncology drugs. The FDA review documents indicate an individualized approach to the review because of the complex pharmacologic nature of these drugs and patient populations. Overall, the strategy for carrying out a RI study during clinical development or as a postmarketing study requires integration with the totality of data, including mass balance, absolute bioavailability, drug–drug interaction, hepatic dysfunction, population PK, exposure–response analysis, the therapeutic window for best guidance, and determination of the optimal doses for special oncology populations.

Modernizing Clinical Trial Eligibility Criteria: Recommendations of the American Society of Clinical Oncology–Friends of Cancer Research Organ Dysfunction, Prior or Concurrent Malignancy, and Comorbidities Working Group

Purpose

Patients with organ dysfunction, prior or concurrent malignancies, and comorbidities are often excluded from clinical trials. Excluding patients on the basis of these factors results in clinical trial participants who are healthier and younger than the overall population of patients with cancer.

Methods

ASCO and Friends of Cancer Research established a multidisciplinary working group that included experts in trial design and conduct to examine how eligibility criteria could be more inclusive. The group analyzed current eligibility criteria; conducted original data analysis; considered safety concerns, potential benefits, research, and potential hurdles of this approach through discussion; and reached consensus on recommendations regarding updated eligibility criteria that prioritize inclusiveness without compromising patient safety.

Results

If renal toxicity and clearance are not of direct treatment-related concern, then patients with lower creatinine clearance values of > 30 mL/min should be included in trials. Inclusion of patients with mild to moderate hepatic dysfunction may be possible when the totality of the available nonclinical and clinical data indicates that inclusion is safe. Ejection fraction values should be used with investigator assessment of a patient’s risk for heart failure to determine eligibility. Patients with laboratory parameters out of normal range as a result of hematologic disease should be included in trials. Measures of patient functional status should be included in trials to better assess fit versus frail patients.

Conclusion

Expanding inclusion of these patients will increase the number and diversity of patients in clinical trials and result in a more appropriate population of patients.

Risks and benefits of phase I liver dysfunction studies: should patients with severe liver dysfunction be included in these trials?

Introduction The goal of organ dysfunction Phase I trials is to characterize the safety and pharmacokinetics of novel agents in cancer patients with liver or kidney dysfunction, but the clinical benefit is not well established. Methods We reviewed 170 patients across 15 liver dysfunction studies at our institution, grouped based on the NCI-Organ Dysfunction Working Group criteria or Child-Pugh Score. Results The median survival for the entire cohort was two months and just one month amongst patients with severe liver dysfunction. Patients with normal or mild liver dysfunction, absence of tumor in liver, good performance status, higher serum albumin and lower bilirubin, aspartate transaminase and alkaline phosphatase had improved survival by univariate analysis. Serum albumin and liver function classification remained significant by multivariate analysis. Conclusion Given poor survival of patients with liver dysfunction, we need better criteria, such as albumin levels, for optimally selecting patients for liver dysfunction studies.

The renal safety and efficacy of combined gemcitabine plus cisplatin and gemcitabine plus carboplatin chemotherapy in Chinese patients with a solitary kidney after nephroureterectomy

PURPOSE

The renal safety of cisplatin-based chemotherapy has not been investigated in patients with urothelial carcinoma of the upper urinary tract (UUT-UC) who retain a solitary kidney after nephroureterectomy. This study aimed to assess and compare the renal safety and efficacy of gemcitabine-cisplatin (GP) and gemcitabine-carboplatin (GC) in these patients.

METHODS

The medical records of patients diagnosed with urothelial carcinoma at the Sun Yat-Sen University Cancer Center between January 2005 and December 2015 were retrospectively reviewed. The creatinine clearance (CrCl) and estimated glomerular filtration rate (eGFR) were used to assess renal function and were calculated using different formulas.

RESULTS

A total of 71 patients were enrolled in this study; 48 patients were on GP, and 23 were on GC. The renal function indicators (CrCl and eGFR) were all significantly lower after GP chemotherapy than at baseline, a phenomenon that was not observed in the GC group. Severe nephrotoxicities (SNTs) were reported in 12 patients on GP (25%) and zero on GC. SNT risk factors included a more than 20% decrease in eGFR after one GP cycle and the presence of diabetes (all p < 0.05). Among patients treated with first-line palliative chemotherapy (n = 32), GC (n = 13) patients had an ORR of 46.2%, which was not significantly different from GP patients (36.8%, n = 19), whereas GC patients tended to have a shorter OS than GP patients (9.2 vs. 29 months, p = 0.200).

CONCLUSIONS

Our results confirm that GP has an adverse impact on the renal function of patients with UUT-UC who retain a solitary kidney, but it can be safely administered to the majority of these patients without inducing SNT. In specific patients, GC is an alternative to GP that has comparable efficacy and favourable renal toxicity.