Drug interactions with sunitinib

Severe tyrosine-kinase inhibitor induced liver injury in metastatic renal cell carcinoma patients: two case reports assessed for causality using the updated RUCAM and review of the literature

Background

Sunitinib and pazopanib are both oral small molecule multityrosine kinase inhibitors (MTKI) used in the treatment of renal cell carcinoma (RCC). Hepatotoxicity or “liver injury” is the most important adverse effect of pazopanib administration, but little is known about the underlying mechanism. Liver injury may also occur in patients treated with sunitinib, but severe toxicity is extremely rare. Herein we report two new cases of severe liver injury induced by MTKI. Both cases are unique and exceptional. We assessed both cases for drug-induced liver injury (DILI) using the updated score Roussel Uclaf causality assessment method (RUCAM). The literature on potential pathogenic mechanisms and precautionary measures is reviewed.

Case presentation

A case of a metastatic RCC (mRCC) patient treated with pazopanib who had manifestation of severe liver injury is presented. These manifestations consisted of grade 4 alanine aminotransferase (ALT) increase and grade 4 hyperbilirubinemia. Alternate causes of acute or chronic liver disease were excluded. The patient gradually recovered from the liver injury and refused any further therapy for mRCC. The patient was diagnosed with acute myeloid leukemia (AML) two years later and eventually succumbed to the disease. The second case describes a mRCC patient treated with sunitinib for 3,5 years and fatal liver failure after 2 weeks of clarithromycin co-medication for acute bronchitis.

Conclusions

Liver injury has been commonly observed in TKI-treated patients with unpredictable course. Management requires regular routine liver enzyme-monitoring and the collaboration of medical oncologist and hepatologist. There is an unmet medical need for a risk stratification and definition of predictive biomarkers to identify potential genetic polymorphisms or other factors associated with TKI-induced liver injury. Any potential unrecommended concomitant therapy has to be avoided.

Association of sunitinib concentration and clinical outcome in patients with metastatic renal cell carcinoma treated with a 2-week-on and 1-week-off schedule

WHAT IS KNOWN AND OBJECTIVE

Sunitinib is used as a first-line therapy for metastatic renal cell carcinoma. The primary aim of this study was to determine the optimal total sunitinib (sunitinib plus N-desethyl sunitinib) trough concentration for the alternative dosing schedule: 2-week-on and 1-week-off schedule (2/1 schedule).

METHODS

Patients with metastatic renal cell carcinoma treated with the 2/1 schedule of sunitinib, whose total sunitinib concentrations were available, were recruited for this study. Out of 19 patients, 17 whose sunitinib dosage was not changed until the measurement of drug concentration were eligible for the analysis of the relationship between total sunitinib concentration and clinical outcome. Individual pharmacokinetic parameters in 19 patients were estimated via the Bayesian analysis.

RESULTS

The onset of severe (grade ≥3) adverse effects among 17 patients during 3 weeks as a first course of sunitinib therapy was observed in 7 (41.2%) patients. The median total sunitinib concentration in patients with severe adverse effects was significantly higher compared with that in patients without severe adverse effects [median: 119 (113-131) vs. 87.8 (77.4-102) ng/mL, p = 0.01]. According to the receiver operating characteristic analysis of the onset of severe adverse effects, the cut-off value of the total sunitinib concentration was 108 ng/mL. Patients with a total sunitinib concentration lower than 108 ng/mL had a longer time to first dose reduction or withdrawal due to adverse effects compared with those with a total sunitinib concentration of 108 ng/mL or higher (p = 0.03). The probability without treatment failure was not significantly different between the two concentration groups. In addition, the estimated sunitinib apparent oral clearance (CL/F) was significantly lower in the severe adverse effects group. Our simulation demonstrated that 0.67-time dose is needed for patients with approximately 90.0 ng/mL of sunitinib concentration on day 7 to maintain the concentration at the same level as the patients with higher CL/F.

WHAT IS NEW AND CONCLUSION

Maintaining the total sunitinib trough concentrations of less than 108 ng/mL is safe to avoid the onset of serious adverse effects without increasing the treatment failure in patients with metastatic renal cell carcinoma treated with the 2/1 schedule of sunitinib.

Inhibition and induction of CYP enzymes in humans: an update

The cytochrome P450 (CYP) enzyme family is the most important enzyme system catalyzing the phase 1 metabolism of pharmaceuticals and other xenobiotics such as herbal remedies and toxic compounds in the environment. The inhibition and induction of CYPs are major mechanisms causing pharmacokinetic drug–drug interactions. This review presents a comprehensive update on the inhibitors and inducers of the specific CYP enzymes in humans. The focus is on the more recent human in vitro and in vivo findings since the publication of our previous review on this topic in 2008. In addition to the general presentation of inhibitory drugs and inducers of human CYP enzymes by drugs, herbal remedies, and toxic compounds, an in-depth view on tyrosine-kinase inhibitors and antiretroviral HIV medications as victims and perpetrators of drug–drug interactions is provided as examples of the current trends in the field. Also, a concise overview of the mechanisms of CYP induction is presented to aid the understanding of the induction phenomena.

Model-based assessment of pharmacokinetic changes of sunitinib, tacrolimus, and everolimus in a patient with metastatic renal cell carcinoma after renal transplantation

The safety of the coadministration of sunitinib with tacrolimus and everolimus with regard to therapeutic drug monitoring has not been demonstrated. Here, we report a patient who showed high sunitinib concentrations, in addition to pharmacokinetic changes in tacrolimus and everolimus after sunitinib therapy. A living-donor renal transplant patient treated with tacrolimus and everolimus was diagnosed with pulmonary and pleural metastases of renal cell carcinoma. The patient received sunitinib therapy (37.5 mg/day, 2 weeks on and 1 week off). This patient exhibited a high total sunitinib concentration (sunitinib, 105.8 ng/mL; N-desethyl sunitinib, 27.9 ng/mL) on day 10 postinitiation and experienced grade 3 diarrhea. The observed sunitinib concentrations were a little higher than those reported in the 421C>A polymorphism of the ATP-binding cassette subfamily G member 2 gene carrier. The observed concentrations of both tacrolimus and everolimus gradually decreased compared with the Bayesian-predicted values after the onset of sunitinib therapy, and the doses of tacrolimus and everolimus were increased. Careful therapeutic drug monitoring of sunitinib, tacrolimus, and everolimus concentrations is necessary during combination therapy, especially after episodes of diarrhea.

Association between clinically relevant toxicities of pazopanib and sunitinib and the use of weak CYP3A4 and P-gp inhibitors

PURPOSE

Sunitinib and pazopanib, two tyrosine kinase inhibitors (TKI), may be targets of potential pharmacokinetic drug-drug interactions (P-PK-DDIs). While strong cytochrome P4503A (CYP3A4) inhibitors or inducers should cause a clinically relevant modification in plasma TKI concentrations, the effect of weak inhibitors is unknown. The objective of this study was to evaluate the association between weak P-PK-DDI and clinically relevant toxicity in real life.

PATIENTS AND METHODS

This was a single-center retrospective study including patients treated with sunitinib or pazopanib for any malignancies, for whom a PK-DDI analysis was performed before starting TKI. The primary endpoint was the correlation between P-PK-DDIs and a dose decrease after 1 month of treatment. The secondary endpoint was the correlation between PK-DDIs and drug withdrawal due to toxicity.

RESULTS

Seventy-six patients were assessed. A P-PK-DDI with weak CYP3A4 or P-gp inhibition was found in 14 patients. In patients with P-PK-DDI or without, the dose was reduced during the first month in 57.1% and 17.7% (p = 0.003) and the drug withdrawn in 42.8% and 11.3% (p = 0.011), respectively. In multivariate analysis, a significant correlation was found between P-PK-DDI (CYP3A4 and P-gp inhibitors) and dose reduction, and between drug withdrawal and PK-DDI (CYP3A4 inhibitors).

CONCLUSION

P-PK-DDI was correlated with dose reduction and drug withdrawal due to toxicity. The causality of this relationship warrants to be assessed; therefore, therapeutic drug monitoring is necessary in patients treated with TKI.

Targeted Therapy for Advanced Thyroid Cancer: Kinase Inhibitors and Beyond

The treatment of advanced thyroid cancer has undergone rapid evolution in the last decade, with multiple kinase inhibitor drug approvals for each subtype of thyroid cancer and a number of other commercially available drugs that have been studied for this indication. Although most of the US Food and Drug Administration (FDA)-approved drugs are antiangiogenic multikinase inhibitors-vandetanib, cabozantinib, sorafenib, lenvatinib-there are two FDA indications that are mutation specific-dabrafenib/trametinib for BRAF-mutated anaplastic thyroid cancer and larotrectinib for NTRK-fusion thyroid cancer. Furthermore, other mutation-specific drugs, immunotherapies, and novel strategies for advanced thyroid cancer are under investigation. Understanding the molecular basis of thyroid cancer, the drugs of interest for treatment of advanced thyroid cancer, and how these drugs can be administered safely and in the appropriate clinical scenario are the topics of this review.

Pharmacogenetic-Based Interactions between Nutraceuticals and Angiogenesis Inhibitors

Background: Angiogenesis inhibitors (AIs) have become established as an effective cancer treatment. Whereas their interactions with antineoplastic drugs have extensively been investigated, little is known of the effect of their co-administration with nutraceuticals/dietary supplements (N/DSs), which are often self-prescribed. N/DSs comprise a wide range of products such as herbs, nutrients, vitamins, minerals, and probiotics. Assessment of their interactions with cancer drugs, particularly AIs, is hampered by the difficulty of gauging the amount of active substances patients actually take. Moreover, there is no agreement on which approach should be used to determine which N/DSs are most likely to influence AI treatment efficacy. We present a comprehensive review of the metabolic routes of the major AIs and their possible interactions with N/DSs. Methods: The PubMed and Cochrane databases were searched for papers describing the metabolic routes of the main AIs and N/DSs. Results: Data from the 133 studies thus identified were used to compile a diagnostic table reporting known and expected AI-N/DS interactions based on their metabolization pathways. AIs and N/DSs sharing the cytochrome P450 pathway are at risk of negative interactions. Conclusions: Recent advances in pharmacogenetics offer exceptional opportunities to identify prognostic and predictive markers to enhance the efficacy of individualized AI treatments. The table provides a guide to genotyping patients who are due to receive AIs and is a promising tool to prevent occult AI-N/DS interactions in poor metabolizers. N/DS use by cancer patients receiving AIs is a topical problem requiring urgent attention from the scientific community.

A favorable outcome of advanced dermatofibrosarcoma protuberans under treatment with sunitinib after imatinib failure

While traditional cytotoxic agents play a limited role in advanced dermatofibrosarcoma protuberans (DFSP), the treatment of sunitinib for patients with advanced DFSP after imatinib failure is not well defined. The objective of this case report was to analyze the relationship between molecular mechanisms and clinical outcomes of sunitinib treatment in patients with advanced DFSP after imatinib failure. In this case report, a 37-year-old man suffered from advanced DFSP progression after surgical operation, microwave ablation, and chemotherapy. The immunohistochemistry in this patient revealed abundant expression of platelet-derived growth factor receptor-beta on tumor cells, which is one of the drug targets of sunitinib. The nucleotide sequence analysis revealed COL1A1-PDGFB fusion transcripts in this patient. Thus, we treated the patient with sunitinib, a multi-targeted tyrosine kinase inhibitor, after imatinib failure. After treatment with sunitinib, the patient exhibited a partial response and 9 months’ progression-free survival without significant adverse drug effects. In our case, the patient with advanced DFSP experienced a favorable outcome in 9-months’ progression-free survival and a significant improvement of quality of life without serious side effects after sunitinib treatment. Therefore, sunitinib could serve as another treatment option for patients with advanced DFSP.

Sex-Divergent Clinical Outcomes and Precision Medicine: An Important New Role for Institutional Review Boards and Research Ethics Committees

The efforts toward individualized medicine have constantly increased in an attempt to improve treatment options. These efforts have led to the development of small molecules which target specific molecular pathways involved in cancer progression. We have reviewed preclinical studies of sunitinib that incorporate sex as a covariate to explore possible sex-based differences in pharmacokinetics and drug–drug interactions (DDI) to attempt a relationship with published clinical outputs. We observed that covariate sex is lacking in most clinical outcome reports and suggest a series of ethic-based proposals to improve research activities and identify relevant different sex outcomes. We propose a deeper integration of preclinical, clinical, and translational research addressing statistical and clinical significance jointly; to embed specific sex-divergent endpoints to evaluate possible gender differences objectively during all stages of research; to pay greater attention to sex-divergent outcomes in polypharmacy scenarios, DDI and bioequivalence studies; the clear reporting of preclinical and clinical findings regarding sex-divergent outcomes; as well as to encourage the active role of scientists and the pharmaceutical industry to foster a new scientific culture through their research programs, practice, and participation in editorial boards and Institutional Ethics Review Boards (IRBs) and Research Ethics Committees (RECs). We establish the IRB/REC as the centerpiece for the implementation of these proposals. We suggest the expansion of its competence to follow up clinical trials to ensure that sex differences are addressed and recognized; to engage in data monitoring committees to improve clinical research cooperation and ethically address those potential clinical outcome differences between male and female patients to analyze their social and clinical implications in research and healthcare policies.

Highly fluorescent nitrogen-doped graphene quantum dots as a green, economical and facile sensor for the determination of sunitinib in real samples

The preparation of nitrogen-doped graphene quantum dots (N-GQDs), by a simple and inexpensive synthetic procedure, is reported with blue emission and a high quantum yield of 78%.

Sunitinib Possible Sex-Divergent Therapeutic Outcomes

Sunitinib is a tyrosine kinase inhibitor used for the treatment of renal cell carcinoma and metastatic brain tumors. Preclinical pharmacokinetic studies have shown higher sunitinib hepatic and brain exposure in female mice and higher sunitinib kidney concentrations in male mice. We explored whether sex-divergent tissue pharmacokinetics may anticipate sex-divergent therapeutic and toxicology responses in male and female patients. The review of the available scientific literature identified case reports, case series reports, clinical trials, and other studies associating sex with sunitinib outcomes. The results suggest male patients may respond better to renal cell carcinoma treatment and female patients may have better brain tumor treatment outcomes but a higher incidence of adverse events. Although more high-quality evidence is needed, these results, as anticipated by the preclinical data, may indicate possible sunitinib sex-divergent therapeutic outcomes in patients. In addition, we propose the systematic analysis of sex-based outcomes in clinical trial reports and their inclusion and review in the ethics committees and review boards to prevent, amongst others, patient burden in upcoming clinical trials.

Seizures and cancer: drug interactions of anticonvulsants with chemotherapeutic agents, tyrosine kinase inhibitors and glucocorticoids

Patients with cancer commonly experience seizures. Combined therapy with anticonvulsant drugs (AEDs) and chemotherapeutic drugs or tyrosine kinase inhibitors carries inherent risks on drug-drug interactions (DDIs). In this review, pharmacokinetic studies of AEDs with chemotherapeutic drugs, tyrosine kinase inhibitors, and glucocorticoids are discussed, including data on maximum tolerated dose, drug clearance, elimination half-life, and organ exposure. Enzyme-inducing AEDs (EIAEDs) cause about a 2-fold to 3-fold faster clearance of concurrent chemotherapeutic drugs metabolized along the same pathway, including cyclophosphamide, irinotecan, paclitaxel, and teniposide, and up to 4-fold faster clearance with the tyrosine kinase inhibitors crizotinib, dasatinib, imatinib, and lapatinib. The use of tyrosine kinase inhibitors, particularly imatinib and crizotinib, may lead to enzyme inhibition of concurrent therapy. Many of the newer generation AEDs do not induce or inhibit drug metabolism, but they can alter enzyme activity by other drugs including AEDs, chemotherapeutics and tyrosine kinase inhibitors. Glucocorticoids can both induce and undergo metabolic change. Quantitative data on changes in drug metabolism help to apply the appropriate dose regimens. Because the large individual variability in metabolic activity increases the risks for undertreatment and/or toxicity, we advocate routine plasma drug monitoring. There are insufficient data available on the effects of tyrosine kinase inhibitors on AED metabolism.

Treatment of sunitinib-induced hypertension in solid tumor by nitric oxide donors

Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) are overexpressed in the majority of renal cell carcinomas. This characteristic has supported the rationale of targeting VEGF-driven tumour vascularization, especially in clear cell RCC. VEGF-inhibiting strategies include the use of tyrosine kinase inhibitors (sunitinib, axitinib, pazopanib, and sorafenib) and neutralizing antibodies such as bevacizumab.

Hypertension (HTN) is one of the most common adverse effects of angiogenesis inhibitors. HTN observed in clinical trials appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2: agents with higher potency are associated with a higher incidence of HTN. Although the exact mechanism by tyrosine kinase inhibitors induce HTN has not yet been completely clarified, two key hypotheses have been postulated. First, some studies have pointed to a VEGF inhibitors-induced decrease in nitric oxide synthase (NOS) and nitric oxide (NO) production, that can result in vasoconstriction and increased blood pressure. VEGF, mediated by PI3K/Akt and MAPK pathway, upregulates the endothelial nitric oxide synthase enzyme leading to up-regulation of NO production. So inhibition of signaling through the VEGF pathway would lead to a decrease in NO production, resulting in an increase in vascular resistance and blood pressure. Secondly a decrease in the number of microvascular endothelial cells and subsequent depletion of normal microvessel density (rarefaction) occurs upon VEGF signaling inhibition.

NO donors could be successfully used not only for the treatment of developed angiogenesis-inhibitor-induced hypertension but also for preventive effects.

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Hypertension appears to correlate with the potency of VEGF kinase inhibitor against VEGFR-2.

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Sunitinib is associated with several side effects, with hypertension being the most common one.

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VEGF inhibitors induce decrease in nitric oxide synthase and nitric oxide production, that can result in vasoconstriction and increased blood pressure.

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NO donors could be successfully used for the treatment of angiogenesis-inhibitor-induced hypertension and also for preventive effects.

Converting potent indeno[1,2-b]indole inhibitors of protein kinase CK2 into selective inhibitors of the breast cancer resistance protein ABCG2

A series of indeno[1,2-b]indole-9,10-dione derivatives were synthesized as human casein kinase II (CK2) inhibitors. The most potent inhibitors contained a N(5)-isopropyl substituent on the C-ring. The same series of compounds was found to also inhibit the breast cancer resistance protein ABCG2 but with totally different structure-activity relationships: a N(5)-phenethyl substituent was critical, and additional hydrophobic substituents at position 7 or 8 of the D-ring or a methoxy at phenethyl position ortho or meta also contributed to inhibition. The best ABCG2 inhibitors, such as 4c, 4h, 4i, 4j, and 4k, behaved as very weak inhibitors of CK2, whereas the most potent CK2 inhibitors, such as 4a, 4p, and 4e, displayed limited interaction with ABCG2. It was therefore possible to convert, through suitable substitutions of the indeno[1,2-b]indole-9,10-dione scaffold, potent CK2 inhibitors into selective ABCG2 inhibitors and vice versa. In addition, some of the best ABCG2 inhibitors, which displayed a very low cytotoxicity, thus giving a high therapeutic ratio, and appeared not to be transported, constitute promising candidates for further investigations.

Tyrosine kinase inhibitors enhance ciprofloxacin-induced phototoxicity by inhibiting ABCG2

The tyrosine kinase inhibitor (TKI) class of anticancer agents inhibits ABCG2-mediated drug efflux. ABCG2 is an important component of the blood-retinal barrier, where it limits retinal exposure to phototoxic compounds such as fluoroquinolone antibiotics. Patients treated with TKIs would be expected to be at greater risk for retinal phototoxicity. Using an in vitro system, our results indicate that the TKIs gefitinib and imatinib abrogate the ability of ABCG2 to protect cells against ciprofloxacin-induced phototoxicity. We conclude that the concurrent administration of ABCG2 inhibitors with photoreactive fluoroquinolone antibiotics may result in retinal damage.