Cardiac toxicity associated with pharmacokinetic drug-drug interaction between crizotinib and sofosbuvir/velpatasvir: A case report

This case report describes a pharmacokinetic drug-drug interaction between crizotinib, a tyrosine kinase inhibitor, and sofosbuvir/velpatasvir, a direct-acting antiviral drug, leading to cardiac toxicity. A 75-year-old man, with no cardiovascular history but a diagnosis of metastatic nonsmall cell lung cancer with mesenchymal-epithelial transition exon-14 deletion and hepatitis C virus infection genotype 1A, received both crizotinib and sofosbuvir/velpatasvir. Crizotinib was well tolerated, but 1 week after sofosbuvir/velpatasvir initiation, the patient experienced bilateral lower-limb oedema and class III New York Heart Association dyspnoea. We assumed that increased exposure to crizotinib could account for this cardiac toxicity. Drug causality was probable according to the Naranjo scale. We hypothesized a reciprocal interaction between crizotinib and velpatasvir, mediated by both cytochrome 3A4 (CYP3A4) and P-glycoprotein (P-gp). Clinicians should be aware of the risk of drug-drug interactions between direct-acting antiviral agents that inhibit CYP3A4 (glecaprevir) and/or P-gp (voxilaprevir, velpatasvir) and anticancer tyrosine kinase inhibitors that are mostly CYP3A4 and/or P-gp substrates (gefitinib, afatinib, erlotinib, crizotinib, ceritinib, lorlatinib, brigatinib, capmatinib etc.).

Predictive factors associated with pemetrexed acute toxicity

PURPOSE

Pemetrexed has shown efficacy as monotherapy or in combination with platinum salts in the treatment of non-small cell lung cancer and mesothelioma. However, severe hematological toxicities induced by pemetrexed-based chemotherapy have been observed. Some studies have suggested that drug interactions may be associated with pemetrexed toxicity. The objective of this study was to determine predictive factors, including drug interactions, associated with pemetrexed toxicity.

METHODS

This retrospective open monocentric study included patients consecutively treated with pemetrexed after a multidisciplinary risk assessment. Patients who experienced toxicity of grade 3 or 4 according to the Common Terminology Criteria for Adverse Events v5.0, or a grade 2 leading to a change in management, during the first four courses of pemetrexed, were assigned to the early limiting toxicities (ELT) group. Univariate and multivariable logistic regression models were used to test the association variables with the occurrence of ELT.

RESULTS

Seventy-four patients were included in this study (median age: 67 years, with non-small cell lung cancer adenocarcinoma (88%), mesothelioma (7%), or others (5%). Thirty-six patients (49%) were assigned to the ELT group (27 grades 3 and 4; 9 grade 2 with management modification). Three baseline factors were associated with pemetrexed ELT in univariate and multivariate analysis: cystatin clearance (p = 0.0135), albumin level (p = 0.0333), and proton pump inhibitors use (p = 0.035).

CONCLUSION

To conclude, ELT induced by pemetrexed-based treatments occur frequently in cancer patients in a real-world setting. A pretherapeutic assessment before pemetrexed initiation should include three major checkpoints: use of proton pump inhibitors, sarcopenia, and denutrition evaluation.

Relation between Plasma Trough Concentration of Pazopanib and Progression-Free Survival in Metastatic Soft Tissue Sarcoma Patients

Background: Pazopanib (PAZ) is an oral angiogenesis inhibitor approved to treat soft tissue sarcoma (STS) but associated with a large interpatient pharmacokinetic (PK) variability and narrow therapeutic index. We aimed to define the specific threshold of PAZ trough concentration (Cmin) associated with better progression-free survival (PFS) in STS patients. Methods: In this observational study, PAZ Cmin was monitored over the treatment course. For the primary endpoint, the 3-month PFS in STS was analyzed with logistic regression. Second, we performed exposure−overall survival (OS) (Cox model plus Kaplan−Meier analysis/log-rank test) and exposure−toxicity analyses. Results: Ninety-five STS patients were eligible for pharmacokinetic/pharmacodynamic (PK/PD) assessment. In the multivariable analysis, PAZ Cmin < 27 mg/L was independently associated with a risk of progression at 3 months (odds ratio (OR) 4.21, 95% confidence interval (CI) (1.47−12.12), p = 0.008). A higher average of PAZ Cmin over the first 3 months was associated with a higher risk of grade 3−4 toxicities according to the NCI-CTCAE version 5.0 (OR 1.07 per 1 mg/L increase, CI95 (1.02−1.13), p = 0.007). Conclusion: PAZ Cmin ≥ 27 mg/L was independently associated with improved 3-month PFS in STS patients. Pharmacokinetically-guided dosing could be helpful to optimize the clinical management of STS patients in daily clinical practice.

Cancer, immune suppression and Coronavirus Disease-19 (COVID-19): Need to manage drug safety (French Society for Oncology Pharmacy [SFPO] guidelines)

The Coronavirus disease (COVID-19) pandemic is disrupting our health environment. As expected, studies highlighted the great susceptibility of cancer patients to COVID-19 and more severe complications, leading oncologists to deeply rethink patient cancer care. This review is dedicated to the optimization of care pathways and therapeutics in cancer patients during the pandemic and aims to discuss successive issues. First we focused on the international guidelines proposing adjustments and alternative options to cancer care in order to limit hospital admission and cytopenic treatment in cancer patients, most of whom are immunocompromised. In addition cancer patients are prone to polypharmacy, enhancing the risk of drug-related problems as adverse events and drug-drug interactions. Due to increased risk in case of COVID-19, we reported a comprehensive review of all the drug-related problems between COVID-19 and antineoplastics. Moreover, in the absence of approved drug against COVID-19, infected patients may be included in clinical trials evaluating new drugs with a lack of knowledge, particularly in cancer patients. Focusing on the several experimental drugs currently being evaluated, we set up an original data board helping oncologists and pharmacists to identify promptly drug-related problems between antineoplastics and experimental drugs. Finally additional and concrete recommendations are provided, supporting oncologists and pharmacists in their efforts to manage cancer patients and to optimize their treatments in this new era related to COVID-19.

Predictive Value of Soluble PD-1, PD-L1, VEGFA, CD40 Ligand and CD44 for Nivolumab Therapy in Advanced Non-Small Cell Lung Cancer: A Case-Control Study

A large interindividual variability has been observed in anti Programmed cell Death 1 (anti-PD1) therapies efficacy. The aim of this study is to assess the correlation of soluble PD-1 (sPD-1), soluble Programmed cell Death Ligand 1 (sPD-L1), Vascular Endothelial Growth Factor A (VEGFA), soluble CD40 ligand (sCD40L) and soluble CD44 (sCD44), with survival in nivolumab-treated metastatic non-small cell lung cancer (NSCLC) patients. Plasma biomarkers were assayed at baseline and after two cycles of nivolumab. A cut-off of positivity for sPD-1, sPD-L1 and sCD40L expressions was defined as a plasma level above the lower limit of quantification. Baseline sPD-1 and sPD-L1 levels were subsequently analyzed in a control group of EGFR-mutated (Epidermal Growth Factor Receptor) NSCLC patients. Association between survival and biomarkers was investigated using Cox proportional hazard regression model. Eighty-seven patients were included (51 nivolumab-treated patients, 36 in EGFR-mutated group). In nivolumab group, baseline sPD-1, sPD-L1 and sCD40L were positive for 15(29.4%), 27(52.9%) and 18(50%) patients, respectively. We defined a composite criteria (sCombo) corresponding to sPD-1 and/or sPD-L1 positivity for each patient. In nivolumab group, baseline sCombo positivity was associated with shorter median progression-free survival (PFS) (78 days 95%CI (55–109) vs. 658 days (222-not reached); HR: 4.12 (1.95–8.71), p = 0.0002) and OS (HR: 3.99(1.63–9.80), p = 0.003). In multivariate analysis, baseline sCombo independently correlated with PFS (HR: 2.66 (1.17–6.08), p = 0.02) but not OS. In EGFR-mutated group, all patients were baseline sCombo positive; therefore this factor was not associated with survival. After two cycles of nivolumab, an increased or stable sPD-1 level independently correlated with longer PFS (HR: 0.49, 95%CI (0.30–0.80), p = 0.004) and OS (HR: 0.39, 95%CI (0.21–0.71), p = 0.002). VEGFA, sCD40L and sCD44 did not correlate with survival. We propose a composite biomarker using sPD-1and sPDL-1 to predict nivolumab efficacy in NSCLC patients. A larger validation study is warranted.

The impact of body composition parameters on severe toxicity of nivolumab

BACKGROUND

The occurrence of severe, acute limiting toxicity in patients receiving anti-programmed cell death receptor-1 monoclonal antibodies, such as nivolumab, is largely unpredictable. Sarcopenia was found to be associated with anti-cytotoxic T-lymphocyte-associated protein 4 acute toxicity. We explore the clinical and pharmacological parameters influencing nivolumab toxicity, including body composition.

METHODS

From June 2015 to January 2017, all consecutive patients treated with nivolumab in our institution were prospectively included. We studied the relationship between muscle mass assessed by computed tomography, nivolumab trough level (C_min) at day 14 assessed using the enzyme-linked immunosorbent assay method, and the occurrence of immune grade III or IV toxicity or any toxicity leading to treatment discontinuation (immune-related acute limiting toxicity [irALT]).

RESULTS

In our population (n = 92) with a majority of lung cancer (72%), forty-five (51.7%) patients were sarcopenic. The median plasma nivolumab C_min at day 14 was 15.4 μg/mL (interquartile range = 11.8-21.0). In multivariate analysis, hypoalbuminaemia (<35 g/L) was independently associated with low nivolumab C_min on day 14 (odds ratio [OR] = 0.09; 95% confidence interval [CI] = 0.01-0.59, p = 0.01) and overweight/obesity with high nivolumab C_min on day 14 (OR = 5.94; 95% CI = 1.25-28.29, p = 0.03). We observed 22 irALTs in 19 patients (21%). The most frequent irALT was respiratory (6.5%) disorders and gastrointestinal (4.3%) disorders. Patients with sarcopenia were at significantly increased risk of experiencing an irALT (OR = 3.84; 95% CI = 1.02-14.46, p = 0.047). No association was found between toxicity and nivolumab plasma C_min at day 14.

CONCLUSIONS

Our results highlight the importance of assessing body composition and suggest that sarcopenia could predict severe immune-related toxicity of nivolumab in real life.

Determinants of the interindividual variability in serum cytidine deaminase activity of patients with solid tumours

AIMS

Cytidine deaminase (CDA) activity in cancer patients' serum has been proposed as a predictive biomarker for efficacy and toxicity of nucleoside analogues. However, discrepant results about its predictive value have been reported due to the high interindividual variability in CDA activity. This study aimed at identifying determinants of this interindividual variability.

METHODS

From December 2014 to November 2015, 183 patients were prospectively included. Serum CDA activity, biological and clinical characteristics as well as five common single nucleotide polymorphisms (SNPs) in the CDA gene (c.-451C > T, c.-92A > G, c.-33_-31delC, c.79A > C, c.435 T > C) were analysed. Associations between clinical characteristics, pharmacogenetic variants and CDA activity were univariately tested. P < 0.1-candidate variables were analysed through a multivariate analysis. The association between CDA activity and toxicity was assessed for the 56 gemcitabine-treated patients. Intraindividual variability in CDA activity was explored in six pancreatic cancer patients treated with gemcitabine.

RESULTS

Median CDA activity was 3.97 U mg^-1 (range 1.53-15.49 U mg^-1 ). A univariate analysis showed that CDA activity was statistically associated with Eastern Cooperative Oncology Group performance status, mild or severe malnutrition, inflammatory syndrome, leucocyte count, neutrophil count, albumin, C-reactive protein and -c.-33_-31delC single nucleotide polymorphism. A multivariate analysis identified that only neutrophil count (P < 0.0001) and severe malnutrition (P = 0.0278) were independently associated with CDA activity. Low CDA activity (<2 U mg^-1 ) was not statistically associated with severe gemcitabine-related toxicities (P = 0.16). A decrease in CDA activity was observed during the longitudinal follow-up of six pancreatic cancer patients treated with gemcitabine (P = 0.03).

CONCLUSIONS

These results suggest that neutrophil count and malnutrition should be considered for the interpretation of pretherapeutic CDA activity.

Pharmacokinetic interaction between mitotane and etoposide in adrenal carcinoma: a pilot study

Background The combination of mitotane and platinum-etoposide chemotherapy is a front-line treatment in metastatic adrenocortical carcinoma (ACC), although this regimen shows limited efficacy. Pharmacokinetic drug-drug interaction between mitotane, a strong CYP3A4 inducer, and etoposide, which is a substrate of CYP3A4, may contribute to chemoresistance. The aim of this pilot study was to assess the pharmacokinetic interaction between mitotane and etoposide in ACC patients. Methods Five consecutive ACC patients treated with platinum etoposide (120-150 mg/m2 day 1-2-3 at cycle 1), with or without concomitant mitotane, were included. In the absence of limiting toxicity, a dose escalation of etoposide was proposed since cycle 2. Plasma etoposide concentrations were measured using liquid chromatography at 0, 4 and 24 h after each infusion. Clearance and area under the curve (AUC) of etoposide were determined at each cycle. Results Patients received two to six chemotherapy cycles, in association with mitotane (N = 4) or after mitotane discontinuation (N = 1). Etoposide clearance was two-fold higher with concomitant mitotane (4.95 L/h) than after mitotane discontinuation (2.53 L/h, P = 0.014), and 2.5-fold higher than that in reference population not treated with mitotane (1.81 L/h). Etoposide dose escalation was performed in four patients under mitotane, resulting in two minor tumor responses and one severe toxicity (febrile aplasia) at dose of 300 mg/m2/day. Tumor response was associated with higher etoposide AUC (267.3 vs 188.8 mg.h/L, P = 0.04). Conclusion A drug-drug interaction between mitotane and etoposide may contribute to the low efficacy of platinum-etoposide chemotherapy. This pilot study suggests further a potential benefit of increasing etoposide dose in ACC patients receiving mitotane.

Clinical and kinomic analysis identifies peripheral blood mononuclear cells as a potential pharmacodynamic biomarker in metastatic renal cell carcinoma patients treated with sunitinib

Background

Sunitinib is a protein tyrosine kinase (PTK) inhibitor that has immune-modulating properties. In this context, peripheral blood mononuclear cells (PBMC), mainly constituted by lymphocytes, could be a perfect surrogate tissue for identifying and assaying pharmacodynamic biomarkers of sunitinib. In this study, we investigated the changes in lymphocytes count as pharmacodynamic biomarker in metastatic renal cell carcinoma (mRCC) patients under sunitinib therapy. Thereafter, we studied the ex vivo effect of sunitinib and SU12262 (active metabolite) on PBMC from naïve mRCC patients using a high throughput kinomic profiling method.

Methods

The prognostic value of total lymphocytes count between Day 0 and Day 21 (expressed as a ratio D21/D0) was retrospectively investigated in 88 mRCC patients under sunitinib therapy. PTK PamChip^® microarrays were used to explore prospectively the ex vivo effect of sunitinib and SU12662 on PTK activity in PBMC from 21 naïve mRCC patients.

Results

In this retrospective study, D21/D0 lymphocytes ratio (Hazard Ratio, 1.83; CI95%, 1.24-2.71; p=0.0023) was independently associated with PFS. Interestingly, kinomic analysis showed that D21/D0 lymphocytes ratio and Heng prognostic model was statistically associated with the ex vivo sunitinib and SU12662 effect in PBMC.

Conclusion

The present study highlights that D21/D0 total lymphocytes ratio could be a promising pharmacodynamic biomarker in mRCC patients treated with sunitinib. Additionally, it paves the way to investigate the kinomic profile in PBMC as a prognostic factor in a larger cohort of mRCC patients under sunitinib therapy.

Drug monitoring of sunitinib in patients with advanced solid tumors: a monocentric observational French study

Therapeutic drug monitoring (TDM) could be helpful in oral targeted therapies. Data are sparse to evaluate its impact on treatment management. This study aimed to determine a threshold value of plasma drug exposure associated with the occurrence of grade 3-4 toxicity, then the potential impact of TDM on clinical decision. Consecutive outpatients treated with sunitinib were prospectively monitored between days 21 and 28 of the first cycle, then monthly until disease progression. At each consultation, the composite AUC_Ƭ,ss (sunitinib + active metabolite SU12662) was assayed. The decisions taken during each consultation were matched with AUC_Ƭ,ss and compared to the decisional algorithm based on TDM. A total of 105 cancer patients and 288 consultations were matched with the closest AUC_Ƭ,ss measurement. The majority (60%) of the patients had metastatic renal clear-cell carcinoma (mRCC). Fifty-five (52%) patients experienced grade 3-4 toxicity. Multivariate analysis identified composite AUC_Ƭ,ss as a parameter independently associated with grade 3-4 toxicity (P < 0.0001). Using the ROC curve, the threshold value of composite AUC_Ƭ,ss predicting grade ≥3 toxicity was 2150 ng/mL/h (CI 95%, 0.6-0.79%; P < 0.0001). At disease progression in patients with mRCC, AUC_Ƭ,ss tended to be lower than the one assayed during the first cycle (1678 vs. 2004 ng/mL/h, respectively, P = 0.072). TDM could have changed the medical decision for sunitinib dosing in 30% of patients at the first cycle of treatment, and in 46% of the patients over the whole treatment course. TDM is routinely feasible and may both contribute to improve toxicity management and to identify sunitinib underexposure at the time of disease progression.

ADAM9 expression promotes an aggressive lung adenocarcinoma phenotype

A disintegrin and metalloproteinase 9 (ADAM9) possesses potent metastasis-inducing capacities and is highly expressed in several cancer cells. Previous work has shown that ADAM9 participates in the adhesive-invasive phenotype in lung cancer cells in vitro. In this study, we evaluated whether ADAM9 expression plays a critical role in metastatic processes in vivo and in angiogenesis. We first found that high ADAM9 expression was correlated with poor lung adenocarcinoma patient prognosis on Prognoscan data base. In vivo model based on intravenous injection in nude mice showed that a stable downregulation of ADAM9 in A549 (TrA549 A9-) cells was associated with a lower number of nodules in the lung, suggesting lower potentials for extravasation and metastasis. On a subcutaneous xenograft we showed that TrA549 A9- produced significantly smaller tumours and exhibited fewer neovessels. In addition, in vitro human umbilical vein endothelial cells exposed to supernatant from TrA549 A9- could reduce the formation of more vessel-like structures. To further understand the mechanism, a human antibody array analysis confirmed that five cytokines were downregulated in TrA549 A9- cells. Interleukin 8 was the most significantly downregulated, and its interaction with CXCR2 was implicated in angiogenesis on an in vitro model. These results emphasize the critical influence of ADAM9 on lung cancer progression and aggressiveness. ADAM9 should at least be a marker of cancer aggressiveness and a potential therapeutic target for cancer treatment.

Potential drug-drug interactions with abiraterone in metastatic castration-resistant prostate cancer patients: a prevalence study in France

PURPOSE

Abiraterone acetate combined with prednisone improves survival in metastatic castration-resistant prostate cancer (mCRPC) patients. This oral anticancer agent may result in drug-drug interactions (DDI). We aimed to evaluate the prevalence of DDI with abiraterone and the possible determinants for the occurrence of these DDI.

METHODS

We performed a single centre retrospective review from electronic medical records of mCRPC patients treated with abiraterone from 2011 to 2015. Potential DDI with abiraterone were identified using Micromedex and were categorized by a 4-point scale severity.

RESULTS

Seventy-two out of ninety-five mCRPC pts (median age: 77 years [68-82]) had comorbidities. The median number of drugs used per patient was 7 [5-9]. 66 potential DDI with abiraterone were detected in 49 patients (52%): 39 and 61% were classified as major and moderate DDI, respectively. In the univariate analysis, pain (p < 0.0001), hypo-albuminemia (p = 0.032), and higher ECOG performance status (PS) (p = 0.013) were significantly associated with a higher risk of DDI with abiraterone. Pain (p < 0.0001) and PS (p = 0.018) remained significant in the multivariate analysis.

CONCLUSIONS

Polypharmacy is an issue among mCRPC patients. In our study, half of the patients have potential DDI with abiraterone. Patients with pain and poor PS are at higher risk of DDI with abiraterone. A medication review by a pharmacist is of crucial importance to prevent DDI with abiraterone.

Vemurafenib pharmacokinetics and its correlation with efficacy and safety in outpatients with advanced BRAF-mutated melanoma

Vemurafenib is a BRAF kinase inhibitor approved for first-line treatment of metastatic BRAF (V600) -mutant melanoma. However, data on the pharmacokinetic/pharmacodynamic (PK/PD) relationship are lacking. The aim of this prospective, multicenter study was to explore the PK/PD relationship for vemurafenib in outpatients with advanced BRAF-mutated melanoma. Fifty-nine patients treated with single-agent vemurafenib were prospectively analyzed. Vemurafenib plasma concentration (n = 159) was measured at days 15, 30, 60, and 90 after treatment initiation. Clinical and biological determinants (including plasma vemurafenib concentration) for efficacy and safety were assessed using Cox's model and multivariate stepwise logistic regression. Median progression-free survival (PFS) and overall survival were 5.0 (95 % confidence interval [95 % CI] 2.0-6.0) and 11.0 (95% CI 7.0-16.0) months, respectively. Twenty-nine patients (49 %) experienced any grade ≥3 toxicity and the most frequent grade ≥2 toxicity was skin rash (37 %). Severe toxicities led to definitive discontinuation in seven patients (12 %). Grade ≥2 skin rash was not statistically associated with better objective response at day 60 (p = 0.06) and longer PFS (hazard ratio 0.47; 95 % CI 0.21-1.08; p = 0.075). Grade ≥2 skin rash was statistically increased in patients with ECOG  ≥ 1 (odds ratio 4.67; 95 % CI 1.39-15.70; p = 0.012). Vemurafenib concentration below 40.4 mg/L at day 15 was significantly associated with a shorter PFS (1.5 [0.5-5.5] vs. 4.5 [2-undetermined] months, p = 0.029). Finally, vemurafenib concentration was significantly greater in patients developing grade ≥2 rash (61.7 ± 25.0 vs. 36.3 ± 17.9 mg/L, p < 0.0001). These results suggest that early plasma drug monitoring may help identify outpatients at high risk of non-response or grade ≥ 2 skin rash.

Erlotinib pharmacokinetics: a critical parameter influencing acute toxicity in elderly patients over 75 years-old

Background Older non-small cell lung cancer (NSCLC) patients under erlotinib are reported to experience more acute toxicity. We hypothesized that modifications in erlotinib pharmacokinetics might explain this observation. Methods A monocentric prospective clinico-pharmacological study included stage IIIb/IV NSCLC consecutive pts. treated with erlotinib. The plasma concentration of erlotinib (Ce) was measured at steady state on day 15. We studied the relationship between age > 75 years, and Ce, using the Mann-Whitney U test and with the occurrence of acute toxicity, using a Fisher's test. Results A total of 53 pts. were analyzed. Median age was 68 years (31-83), 56 % were female. All pts. > 75 years experienced toxicity: all grade acute adverse events were 1.6 fold more frequent (100 % vs 61 %; OR 95 % CI [1.9-INF]; p = 0.003). At day 15, Ce increased with age. Over 75 years old, the mean Ce was 1.5 fold higher: 2091 ng/mL (95 % CI [1476; 2706]) vs 1359 (95 % CI [1029; 1689]; p = 0.024). In pts. over 80 years old, the mean Ce was doubled: 2729 (95 % CI [1961; 3497]) vs 1358 ng/mL (95 % CI [1070; 1646]; p = 0.0019). Reduced lean body mass over 75 years (median 36.6 kg versus 49.1 kg) might account for these differences. Finally, the risk of early erlotinib discontinuation was increased by 11 in older pts. (33 % vs 3 % OR 17.2; 95 % CI [1.7; 892.5] p = .005). Conclusion The risk of overexposure to erlotinib increases with age. Reduced lean body mass may explain erlotinib pharmacokinetics and excessive acute toxicity in the elderly.

Clinical pharmacology, drug-drug interactions and safety of pazopanib: a review

INTRODUCTION

In the past decade, treatment options for metastatic renal cell carcinoma and soft-tissue sarcoma have expanded. Pazopanib was discovered during the screening of compounds that suppressed vascular endothelial growth factor receptor-2 (VEGFR-2). As other tyrosine kinase inhibitors (TKI), pazopanib is not totally specific for one target since it also inhibits stem-cell factor receptor (cKIT), platelet-derived growth factor receptors (PDGFRα, β), VEGFR-1 and -3. Areas covered: Clinical pharmacology, drug-drug interactions and safety data published on pazopanib, between January 2006 and April 2016, are reviewed. Expert opinion: This new therapy has been shown to improve progression-free survival compared with previous approaches, in renal cell cancer and soft-tissue sarcoma. However, some specific sub-populations, such as elderly patients, patients with brain metastases or with Eastern Cooperative Oncology Group Performance Status (ECOG PS) 2 or comorbidities, are poorly represented in pivotal pazopanib phase III studies. Pazopanib meets criteria defining therapies as candidates for therapeutic drug monitoring: large intra- and inter-patient pharmacokinetic variability, potential pharmacokinetic drug-drug interactions, pharmacokinetic/pharmacodynamic relationship and narrow therapeutic index. Knowledge of predictors that can be used to guide dosing regimens in the target population and in special populations needs to be improved.

Abstract 2038: Sunitinib impact on kinome profiles of peripheral blood mononuclear cells from renal cell carcinoma patients: Do molecular effects correlate with clinical data

Introduction: Sunitinib, a potent multi-tyrosine kinase (TK) inhibitor, is a standard first-line treatment for metastatic renal cell carcinoma (mRCC). In addition to its antiangiogenic activity, sunitinib is known to have immune-modulating properties especially on regulatory T-cells and tumor-infiltrating lymphocytes. However, data is sparse about sunitinib impact on peripheral lymphocytes and new data is needed to gain insights into the angiogenesis and immunity bidirectional link. This study aims to fill such a gap by investigating the clinical and intracellular modifications of sunitinib on peripheral blood mononuclear cells (PBMC) from naïve mRCC patients.

Methods: Initially, a retrospective study was conducted in 88 mRCC patients treated with first-line sunitinib therapy to assess the evolution of lymphocyte count (expressed as a ratio between Day 21 and Day 0 i.e. D21/D0) during the first cycle of treatment. A new prospective study was carried out to determine kinomic profiles in PBMC from 21 naïve mRCC patients and 12 healthy volunteers. TK activity profiles of PBMC lysates were generated on TK PamChip® microarrays. The ex vivo effect of sunitinib and its active metabolite SU12662 were also determined in PBMCs. All data were analyzed using BioNavigator software.

Results: The retrospective preliminary study showed that an increased D21/D0 lymphocytes ratio was significantly associated with a shorter Progression Free Survival (PFS) in multivariate analysis (p = 0.0023). In the prospective study, the phosphorylation level in PBMCs from mRCC patients was significantly lower than in healthy volunteers for 74 peptides (p&lt;0.05). Ex vivo exposure to sunitinib or SU12662 led to a decreased phosphorylation level for majority of peptides in PBMCs from mRCC patients. Moreover, sunitinib had a stronger inhibitory profile than SU12662 for 80 peptides (p&lt;0.05). The ex vivo sunitinib effect was statistically correlated with the IMDC (“Heng”) prognostic model and D21/D0 lymphocytes ratio and 53 and 16 peptides, respectively were found to be significant. Less ex vivo inhibition was associated with both a poor prognosis according to Heng and an increased D21/D0 lymphocytes ratio.

Conclusions: Our retrospective study shows a decreased lymphocyte count on D21 after sunitinib initiation is a favorable prognostic factor in mRCC patients. The kinomic analysis of TKs in PBMCs after ex vivo exposure to sunitinib correlates with both Heng prognostic score and lymphocyte D21/D0 ratio, suggesting that PBMCs could be an interesting biological matrix to seek future biomarkers regarding clinical efficacy of sunitinib. Further investigations are underway to determine the involvement of signaling pathways contributing to the inter-individual variability in kinomic profiles of PBMCs from mRCC patients treated with sunitinib.

Citation Format: Audrey Bellesoeur, Gaelle Noe, Audrey Thomas-Schoemann, Olivier Huillard, Faris Naji, Savithri Rangarajan, Alicja Puszkiel, Jerome Alexandre, François Goldwasser, Benoit Blanchet, Michel Vidal. Sunitinib impact on kinome profiles of peripheral blood mononuclear cells from renal cell carcinoma patients: Do molecular effects correlate with clinical data. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2038.

[Tyrosine kinase inhibiting the VEGF pathway and elderly people: Tolerance, pre-treatment assessment and side effects management]

Angiogenesis inhibition is a major antitumor strategy that has emerged during the last decade. Oral tyrosine kinase inhibitors (TKI) targeting the VEGF receptor, including sunitinib, sorafenib, axitinib, regorafenib, pazopanib, and vandetanib reduce tumor growth and metastasis. These agents are approved for the treatment of metastatic diseases in first or second-line. They display a narrow therapeutic index. However, data in the elderly and/or in patients with multiple illnesses remain scarce. This population is classically excluded from clinical trials. The aim of this review is to provide an overview of existing literature regarding antiangiogenic TKI tolerance in the elderly (>70 years old). We also highlight key points of the pre-therapeutic evaluation and summarize the management of common toxicities.

Effect of glucuronidation on transport and tissue accumulation of tyrosine kinase inhibitors: consequences for the clinical management of sorafenib and regorafenib

INTRODUCTION

UDP-glucuronosyltransferases (UGTs) are a multigenic family of enzymes responsible for the glucuronidation reaction. Many therapeutic classes of drugs used in solid tumors are UGT substrates, including cancer therapies.

AREAS COVERED

This article describes the tyrosine kinase inhibitors (TKIs) undergoing hepatic glucuronidation; its effect on transport and tissue accumulation and the clinical consequences of this particular metabolism. A PubMed search concerning the pharmacokinetics of the TKIs was performed. All are extensively metabolized by CYP450. Two TKIs, sorafenib and regorafenib, also have a major UGT-mediated metabolism and were therefore studied.

EXPERT OPINION

The prescription of the same dose of sorafenib and regorafenib for all patients may be inappropriate since at each enzymatic step of this multistep metabolism inter-individual fluctuations exist. Having a non-exclusive CYP-mediated route of metabolism may reduce the risk of variability in drug exposure when CYP3A4 substrates are concomitantly given. Several clinical consequences derive from this pharmacokinetic particularity of sorafenib and regorafenib. Since no clear difference distinguishes TKIs in efficacy in large randomized trials, the differences for the clinical management of their toxicity is a critical aspect.

Investigational therapies up to Phase II which target PDGF receptors: potential anti-cancer therapeutics

INTRODUCTION

The platelet-derived growth factor receptor (PDGFR) pathway has important functions in cell growth and, by overexpression or mutation, could also be a driver for tumor development. Moreover, PDGFR is expressed in a tumoral microenvironment and could promote tumorigenesis. With these biological considerations, the PDGFR pathway could be an interesting target for therapeutics. Currently, there are many molecules under development that target the PDGFR pathway in different types of cancer.

AREAS COVERED

In this review, the authors report the different molecules under development, as well as those approved albeit briefly, which inhibit the PDGFR pathway. Furthermore, the authors summarize their specificities, their toxicities, and their development.

EXPERT OPINION

Currently, most PDGFR kinase inhibitors are multikinase inhibitors and therefore do not simply target the PDGFR pathway. The development of more specific PDGFR inhibitors could improve drug efficacy. Moreover, selecting tumors harboring mutations or amplifications of PDGFR could improve outcomes associated with the use of these molecules. The authors believe that new technologies, such as kinome arrays or pharmacologic assays, could be of benefit to understanding resistance mechanisms and develop more selective PDGFR inhibitors.

Multidisciplinary risk assessment to reveal cancer treatments in complex cancer patients

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Background: Older age is a cause of disparity in cancer treatment decision and treatment guidelines for patients with comorbidities, polypharmacy, denutrition or psycho-social frailty are needed. A pre-therapeutic multidimensional assessment might improve the complex patient management. We developed an experimental program of integrated medicine called ARIANE. We report 18 months activity of this outpatient setting evaluation, its feasibility and impact on treatment decision-making. Methods: Complex patients with predefined cancer treatment strategy entered into the program. A one-day evaluation combined consultations of cardiologist, geriatrician, diabetologist, anesthetist, pharmacist, pain specialist, dietician, psychologist and social worker. Evaluation of performance status, EKG, ejection fraction, ASA score, diabetes, social vulnerability and malnutrition was performed including a geriatric assessment, which focused on items like comorbidity (CIRS-G), dependance (ADL, IADL), fails (Up and Go Test), cognitive impairment (MMSE, Clock Drawing Test) and depression (GDS scale). A pharmacist assessed the risk of drug-drug interactions. Results: Eighty-seven pts, median age 81 years (range 25-94), 76% male, 51% PS 0-1, 77% grade 3 or 4 comorbidity were included. Genito-urinary, lung cancers and sarcoma represented 77% of pts. Eighty-two percent of pts were assessed by at least ≥ 7 participants. Identified factors of vulnerability were polypharmacy (n=65; 75%; >3 drugs), social distress or severe malnutrition (both n=21; 24%), depression (n=17; 19.5%) and cognitive impairment (n=13; 15%). We identified drug interaction in 18 pts (27%). The risk assessment resulted in anticancer treatment changes in 47/87 patients (54%): protocol adaptation (n=19/87; 22%), less aggressive treatment (n=15/87; 17.2%), or more intensive therapy (n=13/87; 15%). Conclusions: A one-day multidisciplinary risk assessment is an answer to the complexity of unfit cancer patients and improves the safety of anticancer treatments.

A new strategy to target regulatory T cells in solid tumors

The depletion of regulatory T cells (Tregs) is a promising therapeutic strategy to enhance antitumor immune responses. Our recent findings indicate that low doses of arsenic trioxide can delay tumor growth in murine models of colon and breast cancer by depleting Tregs through oxidative and nitrosative bursts.

Drug safety evaluation of sorafenib for treatment of solid tumors: consequences for the risk assessment and management of cancer patients

INTRODUCTION

Sorafenib is a multi-tyrosine kinase inhibitor (TKI). Considerable clinical experience has been accumulated since its first Phase III clinical trial in metastatic renal cancer patients in 2007. The management of its early acute toxicity in fit patients is well known. The management of prolonged treatment becomes the new challenge.

AREAS COVERED

Using sorafenib as a key word for PubMed search, we review preclinical and clinical data and discuss the pharmacokinetics and pharmacodynamics of sorafenib, its acute and cumulative toxicities and their consequences for patient management.

EXPERT OPINION

The systematic multi-disciplinary risk assessment of cancer patients prior to TKI initiation reduces the risks of acute and late toxicity, especially drug-drug interactions and arterial risks. Sarcopenia is now identified as a major risk of severe toxicity. The very diverse clinical pictures of cumulative toxicity must be known. The monitoring of sorafenib systemic exposure is helpful especially in elderly patients. Moreover, at disease progression, it allows distinguishing between underexposure to sorafenib and truly acquired resistance to the drug. The optimal use of sorafenib should allow improving the reported results of flat-dose. Finally, most of this knowledge could be used for the development and optimal use of the other TKIs.

Drug interactions with solid tumour-targeted therapies

Drug interactions are an on-going concern in the treatment of cancer, especially when targeted therapies, such as tyrosine kinase inhibitors (TKI) or mammalian target of rapamycin (mTOR) inhibitors, are being used. The emergence of elderly patients and/or patients with both cancer and other chronic co-morbidities leads to polypharmacy. Therefore, the risk of drug-drug interactions (DDI) becomes a clinically relevant issue, all the more so as TKIs and mTOR inhibitors are essentially metabolised by cytochrome P450 enzymes. These DDIs can result in variability in anticancer drug exposure, thus favouring the selection of resistant cellular clones or the occurrence of toxicity. This review provides a comprehensive overview of DDIs that involve targeted therapies approved by the FDA for the treatment of solid tumours for more than 3 years (sorafenib, sunitinib, erlotinib, gefitinib, imatinib, lapatinib, everolimus, temsirolimus) and medicinal herb or drugs. This review also provides some guidelines to help oncologists and pharmacists in their clinical practice.

How to predict sunitinib exposure and toxicity: A pharmacokinetic-pharmacodynamic study

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Background: Su (su), a tyrosine kinase VEGFR inhibitor, is subject to large inter-individual variability in drug exposure (AUC) and toxicity. We investigated the variability factors influencing AUC as well as the relationship between acute severe toxicity, AUC and genetic polymorphisms in adult cancer patients under su. Methods: The plasma concentrations of su and SU12662 (active metabolite) were assessed on day 7 and 21 of the first cycle. For variability investigation, su, SU 12662 and composite AUC (su+SU12662) were estimated from a population approach, then normalized to 50mg daily dose of su. Genetic polymorphisms for CYP3A4, CYP3A5, CYP1A2, NR1I2, NR1I3, P-gP and BCRP1 were analyzed. Clinical acute toxicity was graded using the NCI 4.0 scale on days 7 and 21. Baseline clinical and biologic characteristics including the lean body mass (LBM), absolute AUC and pharmacogenetic variants were tested univariately for association with toxicities. LBM was simply estimated from gender, height and weight. Candidate variables with p<0.1 were analyzed in a multivariate analysis. Results: Ninety-two pts were evaluable whose 66 for genetic analysis. Sixty-three percent of pts were male, 71% were PS 0-1, 60% had renal carcinoma. A large interindividual variability in normalized composite AUC was observed (CV=40%); LBM and ABCG2polymorphism (421C>A) were identified as major variability factors (p<0.0001 and p=0.014, respectively). Grade³2 hypertension, thrombocytopenia and hand-foot skin reaction were observed in 50, 11 and 10% respectively. Age (OR=1.47 [1.01-2.15], p=0.048) and su AUC (OR=1.16 [1.05-1.28], p=0.005) were independently associated with grade³3 toxicity within the first month, and SU12662 AUC with grade 3 thrombocytopenia (OR=1.27 [1.03-1.57], p=0.028). A formula was built from LBM to define the initial su dose to reach a target composite AUC of 1500ng/mL.h. Conclusions: Monitoring sunitinib and SU12662 exposure may be helpful to prevent severe toxicities. The estimation of LBM, based on gender and anthropometric characteristics, is useful to determine the initial daily dosing of sunitinib.

Early sorafenib-induced toxicity is associated with drug exposure and UGTIA9 genetic polymorphism in patients with solid tumors: a preliminary study

Background

Identifying predictive biomarkers of drug response is of key importance to improve therapy management and drug selection in cancer therapy. To date, the influence of drug exposure and pharmacogenetic variants on sorafenib-induced toxicity remains poorly documented. The aim of this pharmacokinetic/pharmacodynamic (PK/PD) study was to investigate the relationship between early toxicity and drug exposure or pharmacogenetic variants in unselected adult outpatients treated with single-agent sorafenib for advanced solid tumors.

Methods

Toxicity was recorded in 54 patients on days 15 and 30 after treatment initiation and sorafenib exposure was assessed in 51 patients. The influence of polymorphisms in CYP3A5, UGT1A9, ABCB1 and ABCG2 was examined in relation to sorafenib exposure and toxicity. Clinical characteristics, drug exposure and pharmacogenetic variants were tested univariately for association with toxicities. Candidate variables with p<0.1 were analyzed in a multivariate analysis.

Results

Gender was the sole parameter independently associated with sorafenib exposure (p = 0.0008). Multivariate analysis showed that increased cumulated sorafenib (AUC_cum) was independently associated with any grade ≥3 toxicity (p = 0.037); UGT1A9 polymorphism (rs17868320) with grade ≥2 diarrhea (p = 0.015) and female gender with grade ≥2 hand-foot skin reaction (p = 0.018). Using ROC curve, the threshold AUC_cum value of 3,161 mg/L.h was associated with the highest risk to develop any grade ≥3 toxicity (p = 0.018).

Conclusion

In this preliminary study, increased cumulated drug exposure and UGT1A9 polymorphism (rs17868320) identified patients at high risk for early sorafenib-induced severe toxicity. Further PK/PD studies on larger population are warranted to confirm these preliminary results.