Pharmacokinetics and safety of panitumumab in a patient with chronic kidney disease

Pharmacology of Tyrosine Kinase Inhibitors: Implications for Patients with Kidney Diseases

Tyrosine kinase inhibitors (TKI) have introduced a significant advancement in cancer management. These compounds are administered orally, and their absorption holds a pivotal role in determining their variable efficacy. They exhibit extensive distribution within the body, binding strongly to both plasma and tissue proteins. Often reliant on efflux and influx transporters, TKI undergo primary metabolism by intestinal and hepatic cytochrome P450 enzymes, with nonkidney clearance being predominant. Owing to their limited therapeutic window, many TKI display considerable intraindividual and interindividual variability. This review offers a comprehensive analysis of the clinical pharmacokinetics of TKI, detailing their interactions with drug transporters and metabolic enzymes, while discussing potential clinical implications. The prevalence of kidney conditions, such as AKI and CKD, among patients with cancer is explored in their effect on TKI pharmacokinetics. Finally, the potential nephrotoxicity associated with TKI is also examined.

Cancer Drug Dosing in Chronic Kidney Disease and Dialysis

Patients with malignancies have a high prevalence of kidney disease and are often treated with antineoplastic agents that undergo kidney metabolism or excretion or clearance via renal replacement therapies. Thus, the dosing of these agents, including classic chemotherapeutic drugs, targeted therapies, and immunotherapy, must take into account patients' kidney function. In this review, we will discuss the pitfalls of accurate measurement of kidney function and how kidney disease affects both pharmacodynamic and pharmacokinetic properties of drugs. Lastly, we will discuss specific agents and summarize current dosing strategies for use in patients with chronic kidney disease and end-stage kidney disease.

Augmented clearance of nivolumab is associated with renal functions in chronic renal disease model rats

The clinically approved dose of nivolumab is 240 mg Q2W. However, previous studies have shown that baseline nivolumab clearance (CL) is associated with treatment outcomes in patients with solid cancers, thus motivating researchers to identify prognostic factors and indices influencing nivolumab CL. This study used chronic kidney disease model rats to investigate whether chronic renal impairment affected nivolumab CL and explored the surrogate markers associated with nivolumab CL. We observed that the total CL for nivolumab (CL_tot) was approximately 1.42-times higher in chronic kidney disease model rats than that in sham rats with an increased urinary excretion. Additionally, CL_tot showed positive correlation with renal CL for nivolumab (CL_R), but not with extrarenal CL. Furthermore, the baseline levels of creatinine, blood urea nitrogen, creatinine CL, and urinary albumin/creatine ratio based on laboratory data were also significantly correlated with CL_R Our findings suggest that nivolumab CL increases as renal function deteriorates due to an increased excretion of nivolumab in the urine; additionally, laboratory data reflecting renal function may be a feasible index to qualitatively estimate nivolumab CL prior to nivolumab treatment under conditions of renal impairment. Significance Statement We demonstrated that nivolumab was rapidly eliminated from the circulation in chronic kidney disease model rats compared to sham rats with an increased urinary nivolumab excretion. Moreover, nivolumab clearance was significantly correlated with the baseline levels of certain laboratory parameters reflecting renal functions. These results indicate the potential applicability of baseline renal function as a prognostic index to qualitatively estimate nivolumab clearance prior to nivolumab treatment under conditions with renal impairment.

The impact of hepatic and renal function on panitumumab exposures in patients with metastatic RAS wild-type colorectal cancer

Purpose

Panitumumab is a human monoclonal antibody targeting the epidermal growth factor receptor for the treatment of wild-type RAS metastatic colorectal cancer (mCRC). Currently, no dedicated clinical studies have evaluated the effect of organ impairment on the pharmacokinetics of panitumumab. Here, we present data from late phase studies of panitumumab in patients with mCRC and analyses of the effect of hepatic or renal impairment on the exposure of panitumumab.

Methods

From three multicenter, open-label, phase 2 and phase 3 studies, 349 and 351 patients were included in hepatic and renal function subgroup analyses, respectively. Patients who received IV panitumumab and serum exposures were compared to patients with varying degrees of hepatic and renal organ dysfunction.

Results

The C_max and C_trough values for patients with mild (n = 119) and moderate (n = 4) hepatic impairment were within the range of serum concentrations of panitumumab for the normal hepatic function subgroup. The distributions of serum concentration of panitumumab in patients with mild (n = 85) or moderate (n = 19) renal impairment were similar to the serum concentrations of panitumumab in the normal renal function subgroup. Population pharmacokinetic modeling and covariate analysis results were also consistent with lack of any significant effect of renal or hepatic impairment on the pharmacokinetics of panitumumab. Additionally, real-world evidence from case studies of patients with mCRC and severe hepatic or renal impairment, which is a rare patient population to study, indicated lack of clinically relevant differences in exposure of panitumumab compared with patients with mCRC and normal hepatic or renal function.

Conclusions

Mild-to-moderate hepatic or renal dysfunction had no clinically meaningful impact on the pharmacokinetics of panitumumab in patients with mCRC. No dose adjustments for panitumumab are warranted in patients with mCRC with mild-to-moderate hepatic or renal dysfunction.

Trial registration

ClinicalTrials.gov; NCT00083616, NCT00089635, NCT00113763

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-021-04319-w.

Panitumumab: A Review of Clinical Pharmacokinetic and Pharmacology Properties After Over a Decade of Experience in Patients with Solid Tumors

Panitumumab is a fully human monoclonal antibody that binds to the epidermal growth factor receptor (EGFR), thereby inhibiting the growth and survival of tumors expressing EGFR. Panitumumab received approval in the USA in 2006 for the treatment of wild-type RAS (defined as wild-type in both KRAS and NRAS) metastatic colorectal cancer. Over the last 10 years, the pharmacokinetic and pharmacodynamic profile of panitumumab has been studied to further evaluate its safety, efficacy, and optimal dosing regimen. In this review, we summarize the key clinical pharmacokinetic and pharmacology data for panitumumab, and considerations for its use in special populations. Panitumumab has a nonlinear pharmacokinetic profile and its approved dosing regimen (6 mg/kg every 2 weeks) is based on body weight; dose adjustments are not needed based on sex, age, or renal or hepatic impairment. Drug interactions do not occur when panitumumab is combined with chemotherapy drugs including irinotecan, paclitaxel, and carboplatin. The level of tumor EGFR expression was found to have no effect on panitumumab pharmacokinetics or efficacy. The incidence of anti-panitumumab antibodies is low; when anti-panitumumab antibodies are produced, they do not affect the efficacy, safety, or pharmacokinetics of panitumumab. In summary, the pharmacokinetic and pharmacodynamic profile of panitumumab is well suited for standard dosing, and the approved body weight-based dosing regimen maintains efficacy and safety in the treatment of wild-type RAS metastatic colorectal cancer across a broad range of patients.

Panitumumab-Associated Drug-Induced Immune Thrombocytopenia in a Patient with Colorectal Cancer

Severe thrombocytopenia is a rare adverse event of panitumumab. Here, we report the first patient with metastatic colorectal cancer who developed severe thrombocytopenia, diagnosed as panitumumab-associated drug-induced immune thrombocytopenia (DITP). A clinical diagnosis of DITP can be obtained by excluding other causes of thrombocytopenia and is confirmed by the recovery of thrombocytopenia after the discontinuation of the suspected drug. Treatment includes permanent discontinuation of the suspected drug. Re-exposure should be avoided. It should be kept in mind that panitumumab can induce DITP in the case of a new, sudden, unexpected, and isolated drop in platelet count after excluding other causes of thrombocytopenia.

Distinguishing Features of Cetuximab and Panitumumab in Colorectal Cancer and Other Solid Tumors

Cetuximab and panitumumab are two distinct monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR), and both are widely used in combination with chemotherapy or as monotherapy to treat patients with RAS wild-type metastatic colorectal cancer. Although often considered interchangeable, the two antibodies have different molecular structures and can behave differently in clinically relevant ways. More specifically, as an immunoglobulin (Ig) G1 isotype mAb, cetuximab can elicit immune functions such as antibody-dependent cell-mediated cytotoxicity involving natural killer cells, T-cell recruitment to the tumor, and T-cell priming via dendritic cell maturation. Panitumumab, an IgG2 isotype mAb, does not possess these immune functions. Furthermore, the two antibodies have different binding sites on the EGFR, as evidenced by mutations on the extracellular domain that can confer resistance to one of the two therapeutics or to both. We consider a comparison of the properties of these two antibodies to represent a gap in the literature. We therefore compiled a detailed, evidence-based educational review of the known molecular, clinical, and functional differences between the two antibodies and concluded that they are distinct therapeutic agents that should be considered individually during treatment planning. Available data for one agent can only partly be extrapolated to the other. Looking to the future, the known immune activity of cetuximab may provide a rationale for this antibody as a combination partner with investigational chemotherapy plus immunotherapy regimens for colorectal cancer.