Phase 1 and pharmacokinetic study of intravenous irinotecan in refractory solid tumor patients with hepatic dysfunction

Mechanisms and emerging strategies for irinotecan-induced diarrhea

Irinotecan (also known as CPT-11) is a topoisomerase I inhibitor first approved for clinical use as an anticancer agent in 1996. Over the past more than two decades, it has been widely used for combination regimens to treat various malignancies, especially in gastrointestinal and lung cancers. However, severe dose-limiting toxicities, especially gastrointestinal toxicity such as late-onset diarrhea, were frequently observed in irinotecan-based therapy, thus largely limiting the clinical application of this agent. Current knowledge regarding the pathogenesis of irinotecan-induced diarrhea is characterized by the complicated metabolism of irinotecan to its active metabolite SN-38 and inactive metabolite SN-38G. A series of enzymes and transporters were involved in these metabolic processes, including UGT1A1 and CYP3A4. Genetic polymorphisms of these metabolizing enzymes were significantly associated with the occurrence of irinotecan-induced diarrhea. Recent discoveries and progress made on the detailed mechanisms enable the identification of potential biomarkers for predicting diarrhea and as such guiding the proper patient selection with a better range of tolerant dosages. In this review, we introduce the metabolic process of irinotecan and describe the pathogenic mechanisms underlying irinotecan-induced diarrhea. Based on the mechanisms, we further outline the potential biomarkers for predicting the severity of diarrhea. Finally, based on the current experimental evidence in preclinical and clinical studies, we discuss and prospect the current and emerging strategies for the prevention of irinotecan-induced diarrhea.

Clinical Outcomes of Biliary Drainage in Patients with Malignant Biliary Obstruction Caused by Colorectal Cancer Metastases

BACKGROUND AND AIM

Malignant biliary obstruction is an ominous complication of metastatic colorectal cancer (mCRC) that is challenging to solve. Biliary drainage can be performed to relieve symptoms of jaundice, treat cholangitis, or enable palliative systemic therapy. The aim of this study is to evaluate clinical outcomes of biliary drainage of malignant biliary obstruction in mCRC patients.

METHODS

Consecutive patients with malignant biliary obstruction due to mCRC who underwent endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography were included. Patient, disease, and procedural characteristics and outcomes were retrospectively collected from electronic medical records. Radiological data were prospectively reassessed. Main outcome was functional success, i.e. achievement of the intended goal of biliary drainage. Prognostic factors for functional success and survival were assessed.

RESULTS

Thirty-seven patients were included. Functional success was achieved in 18 (50%) patients. Seventeen (46%) patients experienced adverse events (suspected to be) related to the procedure. Median overall survival after biliary drainage was 61 days (IQR 31-113). No prognostic factors of functional success were identified. Performance status, presence of the primary tumor, ascites, ≥ 5 intrahepatic metastases, estimated hepatic invasion of > 50% and above-median levels of bilirubin and lactate dehydrogenase were significantly associated with poorer survival. Improved survival was seen in patients with technical, functional, or biochemical success, and with subsequent oncologic treatment.

CONCLUSIONS

Functional successful biliary drainage was achieved in half of the patients. Adverse events also occurred in nearly half of the patients. We observed a significantly longer survival in whom biliary drainage allowed palliative oncologic therapy.

Clinical outcomes of biliary drainage of malignant biliary obstruction due to colorectal cancer metastases: A systematic review

BACKGROUND AND AIMS

Malignant biliary obstruction is an ominous complication of metastatic colorectal cancer (mCRC). Biliary drainage is frequently performed to relieve symptoms of jaundice or enable palliative systemic therapy, but effective drainage can be difficult to accomplish. The aim of this study is to summarize literature on clinical outcomes of biliary drainage in mCRC patients with malignant biliary obstruction.

METHODS

We searched Medline and EMBASE for studies that included patients with malignant biliary obstruction secondary to mCRC, treated with endoscopic and/or percutaneous biliary drainage. We summarized available data on technical success, clinical success, adverse events, systemic therapy administration and survival after biliary drainage.

RESULTS

After screening 3584 references and assessing 509 full-text articles, seven cohort studies were included. In these studies, rates of technical success, clinical success and adverse events varied between 63%-94%, 42%-81%, and 19%-39%, respectively. Subsequent chemotherapy was administered in 17%-56% of patients. Overall survival varied between 40 and 122 days across studies (278-365 days in patients who received subsequent chemotherapy, 42-61 days in patients who did not).

CONCLUSIONS

Successful biliary drainage in mCRC patients can be challenging to achieve and is frequently associated with adverse events. Overall survival after biliary drainage is limited, but is significantly longer in patients treated with subsequent systemic therapy. Expected benefits of biliary drainage should be carefully weighed against its risks.

Optimal Sampling Strategies for Irinotecan (CPT-11) and its Active Metabolite (SN-38) in Cancer Patients

Irinotecan (CPT-11) is an anticancer agent widely used in the treatment of a variety of adult solid tumors. The objective of this study was to develop an optimal sampling strategy model that accurately estimates pharmacokinetic parameters of CPT-11 and its active metabolite, SN-38. This study included 221 patients with advanced solid tumors or lymphoma receiving CPT-11 single or combination therapy with 5-fluorouracil (5-FU)/leucovorin (LV) (FOLFIRI) plus bevacizumab from 4 separate clinical trials. Population pharmacokinetic analysis of CPT-11 and SN-38 was performed by non-linear mixed effects modeling. The optimal sampling strategy model was developed using D-optimality with expected distribution approach. The pharmacokinetic profiles of CPT-11 and SN-38 were best described by a 3- and 2-compartment model, respectively, with first-order elimination. Body surface area and co-administration with 5-FU/LV plus bevacizumab were significant covariates (p < 0.01) for volumes of the central compartment of CPT-11 and SN-38, and clearance of CPT-11. Pre-treatment total bilirubin and co-administration with 5-FU/LV and bevacizumab were significant covariates (p < 0.01) for clearance of SN-38. Accurate and precise predictive performance (r² > 0.99, -2 < bias (%ME) < 0, precision (% RMSE) < 12) of both CPT-11 and SN-38 was achieved using: (i) 6 fixed sampling times collected at 1.5, 3.5, 4, 5.75, 22, 23.5 hours post-infusion; or (ii) 1 fixed time and 2 sampling windows collected at 1.5, [3-5.75], [22-23.5] hours post-infusion. The present study demonstrates that an optimal sampling design with three blood samples achieves accurate and precise pharmacokinetic parameter estimates for both CPT-11 and SN-38.

PLX038: a PEGylated prodrug of SN-38 independent of UGT1A1 activity

PURPOSE

The purpose of this study was to determine the importance of UGT1A1 activity on the metabolism and pharmacokinetics of a releasable PEG ~ SN-38 conjugate, PLX038A. Irinotecan (CPT-11) is converted to the topoisomerase 1 inhibitor SN-38 by first-pass hepatic metabolism and is converted to its glucuronide SN-38G by UGT1A1. With diminished UGT1A1 activity, the high liver exposure to SN-38 can cause increased toxicity of CPT-11. In contrast, releasable PEG ~ SN-38 conjugates-such as PLX038-release SN-38 in the vascular compartment, and only low levels of SN-38 are expected to enter the liver by transport through the OATP1B1 transporter.

METHODS

We measured CPT-11 and PLX038A metabolites in plasma and bile, and determined pharmacokinetics of PLX038A in UGT1A-deficient and replete rats.

RESULTS

Compared to CPT-11, treatment of rats with PLX038A results in very low levels of biliary SN-38 and SN-38G, a low flux through UGT1A, and a low SN-38G/SN-38 ratio in plasma. Further, the pharmacokinetics of plasma PLX038A and SN-38 in rats deficient in UGT1A is unchanged compared to normal rats.

CONCLUSIONS

The disposition of PEGylated SN-38 is independent of UGT1A activity in rats, and PLX038 may find utility in full-dose treatment of patients who are UGT1A1*28 homozygotes or have metastatic disease with coincidental or incidental liver dysfunction.

Population pharmacokinetic analysis of AR-67, a lactone stable camptothecin analogue, in cancer patients with solid tumors

Background AR-67 is a novel camptothecin analogue at early stages of drug development. The phase 1 clinical trial in cancer patients with solid tumors was completed and a population pharmacokinetic model (POP PK) was developed to facilitate further development of this investigational agent. Methods Pharmacokinetic data collected in the phase 1 clinical trial were utilized for the development of a population POP PK by implementing the non-linear mixed effects approach. Patient characteristics at study entry were evaluated as covariates in the model. Subjects (N = 26) were treated at nine dosage levels (1.2-12.4 mg/m²/day) on a daily × 5 schedule. Hematological toxicity data were modeled against exposure metrics. Results A two-compartment POP PK model best described the disposition of AR-67 by fitting a total of 328 PK observations from 25 subjects. Following covariate model selection, age remained as a significant covariate on central volume. The final model provided a good fit for the concentration versus time data and PK parameters were estimated with good precision. Clearance, inter-compartmental clearance, central volume and peripheral volume were estimated to be 32.2 L/h, 28.6 L/h, 6.83 L and 25.0 L, respectively. Finally, exposure-pharmacodynamic analysis using E_max models showed that plasma drug concentration versus time profiles are better predictors of AR-67-related hematologic toxicity were better predictors of leukopenia and thrombocytopenia, as compared to total dose. Conclusions A POP PK model was developed to characterize AR-67 pharmacokinetics and identified age as a significant covariate. Exposure PK metrics C_max and AUC were shown to predict hematological toxicity. Further efforts to identify clinically relevant determinants of AR-67 disposition and effects in a larger patient population are warranted.

Value of plasma SN-38 levels and DPD activity in irinotecan-based individualized chemotherapy for advanced colorectal cancer with heterozygous type UGT1A1*6 or UGT1A1*28

Purpose

The relationship between the pharmacokinetics of irinotecan and outcomes of advanced colorectal cancer is unclear, and few studies have examined individualized irinotecan-based chemotherapy depending on plasma 7-ethyl-10-hydroxy camptothecin (SN-38) levels and dihydropyrimidine dehydrogenase (DPD) activity, particularly for the UGT1A1^*6 or UGT1A1^*28 heterozygous type.

Methods

This study retrospectively explored the relationship among plasma SN-38 level 1.5 hours after critical enzyme for irinotecan (CPT-11) administration (C_{SN-38 1.5h}), plasma SN-38 level 49 hours after CPT-11 administration (C_{SN-38 49h}), DPD activity, and clinical outcomes for the UGT1A1^*6 and UGT1A1^*28 heterozygous types.

Results

C_{SN-38 1.5h} and C_{SN-38 49h} of the UGT1A1^*6 or UGT1A1^*28 heterozygous type were close to those of UGT1A1^*6 and UGT1A1^*28 wild-types; some of those with relatively high C_{SN-38 1.5h} levels obtained better median progression-free survival (mPFS), whereas others with higher C_{SN-38 49h} concentrations showed a relatively high incidence of adverse reactions possibly because of the decreased activity of DPD.

Conclusion

Increasing the dosage of CPT-11 according to C_{SN-38 1.5h} may improve the efficacy in patients with lower C_{SN-38 1.5h} levels. For cases with comparably low DPD activity, advisable primary and subsequent dose adjustment of 5-fluorouracil based on plasma 5-fluorouracil levels may be a practical strategy for reducing the occurrence of adverse reactions for personalized treatment of the UGT1A1^*6 or UGT1A1^*28 heterozygous type.

The use of SAMe in chemotherapy-induced liver injury

Drug-induced liver injury (DILI) remains the most common cause of acute liver failure in the Western world. Chemotherapy is one of the major class of drugs most frequently associated with idiosyncratic DILI. For this reason, patients who receive chemotherapy require careful assessment of liver function prior to treatment to determine which drugs may not be appropriate and which drug doses should be modified. S-adenosylmethionine (SAMe) is an endogenous agent derived from methionine. Its supplementation is effective in the treatment of liver disease, in particular intrahepatic cholestasis (IHC). The target of this review is to analyze the mechanisms of hepatotoxicity of the principal anticancer agents and the role of SAMe in the prevention of this complication.

Clinical outcome after biliary drainage for metastatic colorectal cancer: Survival analysis and prognostic factors

INTRODUCTION

Biliary obstruction secondary to colorectal cancer liver metastases is associated with a poor prognosis especially when chemotherapy cannot be re-started. The aim of this study was to determine the survival after biliary drainage and the associated prognostic factors.

METHODS

Patients from two French centers were included retrospectively after first biliary endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography drainage for biliary obstruction secondary to liver metastases of colorectal cancer, occurring during chemotherapy.

RESULTS

The final analysis included 69 patients. Overall median survival was 115 days. In univariate analysis, a previous liver surgery, technical and functional success of drainage and restarted chemotherapy were significantly associated with an improved survival. Chemotherapy was restarted after a median of 27 days. When drainage was efficient, survival improved from 33 to 262days (p<0.001). In multivariate analysis, significant protective factors for survival included previous a hepatectomy (HR 0.41) and functional success of the drainage (HR 0.29). Predictive factors for death included increased lines of chemotherapy (HR 1.68) and fever before drainage (HR 2.97).

CONCLUSIONS

This is the first study concerning the benefits of biliary drainage for malignant biliary obstruction during the course of chemotherapy for colorectal cancer. A successful biliary drainage leads to improved survival and allows achievement of chemotherapy for 70% of patients.

Liposomal Irinotecan: A Review in Metastatic Pancreatic Adenocarcinoma

Intravenous liposomal irinotecan injection (Onivyde®) is approved for use in combination with 5-fluorouracil and leucovorin (5-FU/LV) in patients with metastatic pancreatic adenocarcinoma that has progressed following gemcitabine-based therapy. Liposomal irinotecan is a liposome-encapsulated formulation of the topoisomerase-1 inhibitor irinotecan, developed to overcome the pharmacological and clinical limitations of non-liposomal irinotecan. In the pivotal multinational, phase III NAPOLI-1 trial in patients with metastatic pancreatic adenocarcinoma that had progressed following gemcitabine-based therapy, liposomal irinotecan in combination with 5-FU/LV significantly prolonged median overall survival (OS; primary endpoint) and median progression-free survival (PFS) at the time of the primary analysis (after 313 events) and final analysis (after 382 events) compared with 5-FU/LV control therapy. The objective response rate was also significantly higher in the liposomal irinotecan plus 5-FU/LV group than in the control group. Liposomal irinotecan-based combination therapy had a manageable safety profile; the most common treatment-emergent adverse events (TEAEs) of grade ≥3 severity were haematological or gastrointestinal in nature. The incidence of neutropenic sepsis was low. In a setting where there is a paucity of second-line treatment options, liposomal irinotecan in combination with 5-FU/LV is an important emerging treatment option for metastatic adenocarcinoma of the pancreas that has progressed following gemcitabine-based therapy.

Chemotherapy in patients with hepatobiliary cancers and abnormal hepatic function

Sorafenib and cisplatin plus gemcitabine currently represent first-line treatment standards in advanced hepatocellular carcinoma and biliary cancer, respectively. Conventional cytotoxic agents (monotherapy or combination therapy) have demonstrated activity in the second-line setting or in those in which first-line agents are contraindicated. A strategy for safe yet effective administration of such systemic therapies in patients with advanced hepatobiliary cancer and abnormal liver function needs to be strongly considered. Here, we highlight the safety and tolerability of systemic therapies routinely used for the treatment of advanced hepatobiliary cancer in patients with hepatic dysfunction. Based on data from available clinical studies, we review dosing strategies recommended for chemotherapy and targeted therapy in those with liver dysfunction. Dose modifications for many agents in this population remain empiric due to limited clinical evidence. Future dedicated phase I studies are needed to provide further dosing considerations for combination therapy in those with abnormal liver function in which data is lacking.

Patients with Metastatic Colorectal Cancer and Hyperbilirubinemia Treated with FOLFIRI plus Bevacizumab as First-Line Treatment

Metastatic colorectal cancer (mCRC) combined with hyperbilirubinemia is typically considered a contraindication to irinotecan-based therapy, a proven first-line treatment of mCRC. Herein, we present 6 consecutive patients with mCRC combined with hyperbilirubinemia who underwent UGT1A1 genotyping before receiving FOLFIRI plus bevacizumab. Dose escalation of irinotecan was performed according to the results of UGT1A1 genotyping in all patients. Improvement in the serum total bilirubin level to a normal range was noted in all 6 patients. Disease control was 100%. The median progression-free survival was 7.5 months and the median overall survival was 8.5 months. FOLFIRI plus bevacizumab as a first-line chemotherapy may achieve effective disease control and be safe in patients with mCRC and hyperbilirubinemia based on UGT1A1 genotyping. More prospective clinical studies are necessary to evaluate the clinical benefits and safety of this treatment approach.

Drug-induced hepatotoxicity in cancer patients - implication for treatment

INTRODUCTION

All anticancer drugs can cause idiosyncratic liver injury. Therefore, hepatoprotective agents assume particular importance to preserve liver function. Hepatic injury represents 10% of cases of acute hepatitis in adults; drug-related damage is still misjudged because of relative clinical underestimation and difficult differential diagnosis. Chemotherapeutic agents can produce liver toxicity through different pathways, resulting in different categories of liver injuries, but these drugs are not homogeneously hepatotoxic. Frequently, anticancer-induced hepatotoxicity is idiosyncratic and influenced by multiple factors.

AREAS COVERED

The aim of this paper is to perform a review of the literature regarding anticancer-induced liver toxicity. We described hepatotoxicity mechanisms of principal anticancer agents and respective dose reductions. Furthermore, we reviewed studies on hepatoprotectors and their optimal use. Tiopronin, magnesium isoglycyrrhizinate and S-Adenosylmethionine (AdoMet) demonstrated, in some small studies, a potential hepatoprotective activity.

EXPERT OPINION

Actually, in the literature only small experiences are reported. Even though hepatoprotective agents seem to be useful in the oncologic setting, the lack of well-designed prospective Phase III randomized controlled trials is a major limit in the introduction of hepatoprotectors in cancer patients and these kind of studies are warranted to support their use and to give further recommendations for the clinical practice.

Cancer and liver cirrhosis: implications on prognosis and management

Liver cirrhosis, the end-stage of every chronic liver disease, is not only the major risk factor for the development of hepatocellular carcinoma but also a limiting factor for anticancer therapy of liver and non-hepatic malignancies. Liver cirrhosis may limit surgical and interventional approaches to cancer treatment, influence pharmacokinetics of anticancer drugs, increase side effects of chemotherapy, render patients susceptible for hepatotoxicity, and ultimately result in a competitive risk for morbidity and mortality. In this review, we provide a concise overview about the impact of liver cirrhosis on the management and prognosis of patients with primary liver cancer or non-hepatic malignancies.

Irinotecan, a key chemotherapeutic drug for metastatic colorectal cancer

Irinotecan hydrochloride is a camptothecin derivative that exerts antitumor activity against a variety of tumors. SN-38 produced in the body by carboxylesterase is the active metabolite of irinotecan. After irinotecan was introduced for the treatment of metastatic colorectal cancer (CRC) at the end of the last century, survival has improved dramatically. Irinotecan is now combined with 5-fluorouracil, oxaliplatin and several molecularly-targeted anticancer drugs, resulting in the extension of overall survival to longer than 30 mo. Severe, occasionally life-threatening toxicity occurs sporadically, even in patients in relatively good condition who have a low risk of chemotherapy-induced toxicity, often causing the failure of irinotecan-based chemotherapy. Clinical pharmacological studies have revealed that such severe toxicity is related to exposure to SN-38 and genetic polymorphisms in UDP-glucuronosyltransferase 1A1 gene. The large inter- and intra-patient variability in systemic exposure to SN-38 is determined not only by genetic factors but also by physiological and environmental factors. This review first summarizes the roles of irinotecan in chemotherapy for metastatic CRC and then discusses the optimal dosing of irinotecan based on the aforementioned factors affecting systemic exposure to SN-38, with the ultimate goal of achieving personalized irinotecan-based chemotherapy.

Compartmentalized accumulation of cAMP near complexes of multidrug resistance protein 4 (MRP4) and cystic fibrosis transmembrane conductance regulator (CFTR) contributes to drug-induced diarrhea

Diarrhea is one of the most common adverse side effects observed in ∼7% of individuals consuming Food and Drug Administration (FDA)-approved drugs. The mechanism of how these drugs alter fluid secretion in the gut and induce diarrhea is not clearly understood. Several drugs are either substrates or inhibitors of multidrug resistance protein 4 (MRP4), such as the anti-colon cancer drug irinotecan and an anti-retroviral used to treat HIV infection, 3'-azido-3'-deoxythymidine (AZT). These drugs activate cystic fibrosis transmembrane conductance regulator (CFTR)-mediated fluid secretion by inhibiting MRP4-mediated cAMP efflux. Binding of drugs to MRP4 augments the formation of MRP4-CFTR-containing macromolecular complexes that is mediated via scaffolding protein PDZK1. Importantly, HIV patients on AZT treatment demonstrate augmented MRP4-CFTR complex formation in the colon, which defines a novel paradigm of drug-induced diarrhea.

Pre-treatment serum total bilirubin level as an indicator of optimal CPT-11 dosage

BACKGROUND

Irinotecan (CPT-11), a highly effective chemotherapeutic agent, can cause severe neutropenia and diarrhea. The area under the curve of plasma levels over time of SN-38, an active metabolite of CPT-11, was previously reported to correlate with the pre-treatment serum total bilirubin level (PTB). However, there are no established criteria for selecting CPT-11 dose on the basis of PTB. Therefore, we evaluated PTB as an indicator for the optimal CPT-11 dose.

METHODS

Retrospective analyses were conducted in patients administered CPT-11 as a single agent at the Osaka National Hospital from June 2006 to July 2013. Data obtained during the first 28 days following CPT-11 administration were analyzed to compare PTB between patients with and without grade 3-4 neutropenia and grade 3-4 diarrhea. Receiver operating characteristics (ROC) curve analysis was performed to determine the optimal PTB cutoff value for PTB-associated toxicity. Subgroup analysis was performed comparing the incidence of toxicity in patients with PTB values below or above the cutoff value.

RESULTS

Although PTB incidence was significantly higher in patients who developed grade 3-4 neutropenia than in those who did not, PTB was not associated with grade 3-4 diarrhea. The PTB cutoff value for association with grade 3-4 neutropenia occurrence was set at 0.8 mg/dL. The incidence of febrile neutropenia (FN) significantly elevated to 21% in patients with PTB ≥0.8 mg/dL, whereas that of patients with PTB <0.8 mg/dL was 4%. In the subgroup analysis, no difference was found in the neutropenia incidence between patients treated with a dose below 80 mg/m(2) and those treated on a weekly schedule.

CONCLUSIONS

PTB can be used as a predictive marker of CPT-11-induced severe neutropenia and FN. In patients with PTB ≥0.8 mg/dL, the CPT-11 dose should be reduced to less than 80 mg/m(2) with weekly dosing.

Clinical outcome of biliary drainage for obstructive jaundice caused by colorectal and gastric cancers

OBJECTIVE

To clarify the prognostic factors for patients with obstructive jaundice due to advanced colorectal and gastric cancers who had undergone percutaneous transhepatic biliary drainage.

METHODS

Baseline variables and clinical outcomes were evaluated for 92 consecutive patients treated with percutaneous transhepatic biliary drainage.

RESULTS

Of the 92 patients, 32 (35%) had colorectal cancer and the remaining 60 (65%) had gastric cancer. Percutaneous transhepatic biliary drainage was successfully achieved in 74 (80%) patients, and 39 of them could receive subsequent chemotherapy. The median survival after percutaneous transhepatic biliary drainage was 273 days in the 39 patients who had undergone successful percutaneous transhepatic biliary drainage and subsequent chemotherapy, 65 days in 35 patients who had undergone successful percutaneous transhepatic biliary drainage but who had not received subsequent chemotherapy and 34 days in the remaining 18 patients who had undergone unsuccessful percutaneous transhepatic biliary drainage (P < 0.001). Multiple liver metastases and hepatic hilar bile duct stricture were independently associated with unsuccessful percutaneous transhepatic biliary drainage. Poor performance status, multiple liver metastases, presence of ascites, multiple prior chemotherapy administrations, undifferentiated type histology and high serum CA19-9 level were independently associated with a poor prognosis. A prognostic index calculated based on the number of these six factors was used to classify the patients into a good-risk group (index ≤2) (n = 56) and a poor-risk group (index ≥3) (n = 36). The median survival time and 2-month survival rate for the two groups were 163 and 44 days, respectively, and 85.7 and 33.3%, respectively (P < 0.001).

CONCLUSIONS

As regards the introduction of percutaneous transhepatic biliary drainage in patients with obstructive jaundice due to colorectal and gastric cancers, careful patient selection might be necessary. A prognostic model seems to be useful for making decisions as to whether percutaneous transhepatic biliary drainage is indicated for particular patients.

Colorectal cancer patients with liver metastases and severe hyperbilirubinemia: A consecutive series that explores the benefits and risks of chemotherapy

Background:

Do colorectal cancer patients with hyperbilirubinemia and liver metastases benefit from chemotherapy?

Methods/Results:

This study entailed a review of 3,019 consecutive patients with colorectal cancer. Within this cohort, 20 met the study’s a priori selection criteria, which included a new diagnosis of colorectal cancer, no prior therapy, and a total bilirubin of ≥3.0 mg/dL. All 20 patients had liver metastases, and as a whole the group had a median serum bilirubin of 6.4 mg/dL (range 3.1, 28 mg/dL). Six patients received chemotherapy with an oxaliplatin-containing regimen, and four subsequently sustained a drop in their bilirubin. In one instance, a drop from 27.2 to 2.5 mg/dL occurred. These six patients lived a median of 71 days (range 23+, 283 days), but one treatment-related death occurred. In contrast, patients who received only supportive care lived a median of 28 days.

Conclusion:

Chemotherapy appears to provide modest benefit to newly diagnosed colorectal cancer patients with severe hyperbilirubinemia.

Phase I and pharmacokinetic study of trabectedin 3-hour infusion every three weeks in patients with advanced cancer and alteration of hepatic function

Maximum tolerated dose (MTD), recommended dose (RD), and pharmacokinetics (PK) were evaluated for trabectedin 3-h every-3-weeks schedule in 33 cancer patients stratified according to liver dysfunction degree as per baseline alkaline phosphatase (AP). Stratification was as follows: stratum I [upper limit of normal (ULN) < AP ≤ 1.5 × ULN; n = 16], stratum II [1.5 × ULN < AP ≤ 2.5 × ULN; n = 12], and stratum III [AP >2.5 × ULN; n = 5] (bilirubin <2.5 × ULN for all 3 strata). In each stratum, patients were treated in sequential cohorts at escalating doses. Dose-limiting toxicities (DLTs) were grade 3 transaminase increases not recovering baseline values on day 21, febrile neutropenia/grade 4 neutropenia lasting >5 days and AP increase more than twice over baseline. The MTD and RD for stratum I (mild baseline AP) was 1.3 mg/m(2). Recruitment was stopped early in strata II/III (moderate/severe baseline AP) without reaching the MTD due to slow accrual and difficulty in finding patients. Biochemical parameters other than AP (bilirubin, AST or ALT) were similar between strata. No relevant PK differences were found between strata. In conclusion, the MTD and RD (1.3 mg/m(2)) were confirmed only for stratum I. Stratification criteria based on baseline AP apparently did not segregate the patients according to their liver dysfunction degree. Antitumor activity was found in patients with pretreated ovarian cancer.

Impaired irinotecan biotransformation in hepatic microsomal fractions from patients with chronic liver disease

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

The anticancer agent irinotecan is a prodrug that is hydrolyzed by hepatic carboxylesterase to its active and toxic metabolite SN-38 and oxidized by CYP3A4 to its inactive metabolite APC. Irinotecan therapy is complicated by co-administered drugs that inhibit CYP3A4 and decrease APC formation and that indirectly increase SN-38 formation. Dose adjustment in cancer patients with liver disease has been recommended.

WHAT THIS STUDY ADDS

In microsomal fractions from patients with severe hepatic dysfunction both APC and SN-38 formation were decreased due to down-regulation of CYP3A4 and carboxylesterase enzymes. Thus relative SN-38 : APC formation was preserved. In some fractions the SN-38:APC ratio was increased, thus providing a possible explanation for clinical reports of increased SN-38 exposure in some patients with liver dysfunction. Close monitoring of SN-38 formation in patients with severe liver disease is warranted.

AIMS

Dose modification with the anticancer agent irinotecan is recommended in patients with severe liver dysfunction. This study evaluated the impact of liver disease on the relative formation of phase I products of irinotecan biotransformation in human microsomes in vitro.

METHODS

Microsomes from subjects with normal liver function and liver dysfunction (n=20) were assessed for irinotecan biotransformation and the expression of cytochrome P450 (CYP) 3A4 and carboxylesterase (CES) enzymes.

RESULTS

Liver disease down-regulated CYP3A4 expression (median 33% of control, range 0-126%, P<0.05) and impaired CYP3A4-dependent oxidation of irinotecan to the inactive 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]carbonyloxycamptothecin (APC) (median 0.2, range 0-1.21 pmol mg protein(-1) min(-1) compared with median 0.66, range 0-2.35 in control, P<0.01). CES-mediated hydrolysis of irinotecan to 7-ethyl-10-hydroxycamptothecin (SN-38) was also impaired in liver disease (median 8.38, range 0-20.7 pmol mg protein(-1) min(-1) compared with median 13.3, range 0-28.9 in control, P<0.05). In seven of 20 liver disease microsomes neither metabolite was detected but in three the SN-38:APC ratio was high (41-68) compared with the remaining 10 samples (ratio 11-36).

CONCLUSIONS

Down-regulation of CYP3A4 in liver disease decreased APC formation from irinotecan. SN-38 production was decreased and CES1 and 2 were down-regulated in most samples. However, in a subset of disease samples SN-38 production was relatively high because CYP3A4 activity was markedly impaired. This may account for clinical reports of increased SN-38 exposure in some patients with liver disease. Dose adjustments in cancer patients with liver disease who receive irinotecan are important and circulating SN-38 concentrations should be monitored closely.

Part II: Liver function in oncology: towards safer chemotherapy use

The liver is fundamentally important in drug metabolism. In oncology, the astute clinician must not only understand the meaning and limitations of commonly ordered liver biochemical tests, but also be aware of which anticancer agents might induce liver dysfunction, and of the strategies for appropriate dosing of patients with pre-existing liver dysfunction. In part I of our Review, we highlighted both the importance and inadequacies of identifying serum biochemical liver abnormalities in oncology; we also discussed a lack of routine formal investigation of liver function. We summarised chemotherapy-related hepatotoxicity and other causes of liver toxic effects in patients with cancer. Here in part II, we discuss trials that have specifically assessed chemotherapy dosing strategies in the setting of overt biochemical liver dysfunction and we note their recommendations. Furthermore, we review other assessments of liver metabolic and excretory function, particularly in the setting of chemotherapy drug handling. We discuss the potential use of these metabolic probes in practice.

Chemotherapy in elderly patients with colorectal cancer

Significant advancements in chemotherapy for metastatic colorectal cancer (mCRC) have been achieved over the past decade, and the median overall survival duration is now close to 24 months with appropriate treatment. The most widely recommended chemotherapy regimens are based on the use of irinotecan or oxaliplatin in combination with 5-fluorouracil and leucovorin; some data suggest further benefit with the addition of the targeted agents bevacizumab or cetuximab. Colorectal cancer primarily affects the elderly; however, much of the defining clinical research in this field has excluded subjects of advanced age or with a poor performance status, making it difficult for clinicians to interpret current treatment paradigms for their older patients. Most clinical trials that have included elderly patients document similar survival rates and toxicity profiles to those seen in younger patients. Moreover, survey data suggest that >70% of elderly patients with cancer are willing to undergo strong, palliative chemotherapy. While these findings suggest that age itself should not determine candidacy for chemotherapy, it is important to note the great heterogeneity of the elderly population with regard to overall health, independence, and performance status. The use of a comprehensive geriatric assessment is recommended to evaluate chemotherapy appropriateness. The management of frail elderly patients and those with a short life expectancy should be focused on palliation, while fit elderly patients can receive aggressive therapy in a similar fashion to younger patients.

Irinotecan toxicity

PURPOSE OF REVIEW

The toxicity of irinotecan is predictable, manageable and nonadditive in the majority of patients; however, with its increasing use alone and in combination with other agents and modalities, the recognition and control of these adverse effects remain a clinical challenge. Major efforts over the last several years have focused not only on adding fluoropyrimidines and epidermal growth factor receptor inhibitors to irinotecan, but also investigating factors that account for interindividual differences in toxicities.

RECENT FINDINGS

The association of uridine diphosphoglucuronosyl transferase 1A polymorphisms with increased irinotecan-induced diarrhea and neutropenia, the dose adjustment of irinotecan in the setting of hepatic dysfunction and the observation that 'chemo' liver can develop in the neoadjuvant colorectal cancer setting are recently reported. Also, data from the Sandostatin LAR Depot Trial for the Optimum Prevention of chemotherapy-induced diarrhea support the 30 mg dose of octreotide LAR to manage the condition.

SUMMARY

Recent evidence demonstrates that patients with hepatic insufficiency, uridine diphosphoglucuronosyl transferase 1A polymorphisms (e.g. 1A128 homozygotes and heterozygotes), are at greater risk for irinotecan-induced toxicity. Adjusting irinotecan's dose to the degree of hepatic insufficiency is now established. While 'chemo' liver is not specific to irinotecan, its occurrence influences strategies for treating advanced colorectal cancer. Finally, controlling chemotherapy-induced diarrhea with 30 mg of octreotide LAR is adequate for most patients.

Serum Total Bilirubin as a Predictive Factor for Severe Neutropenia in Lung Cancer Patients Treated with Cisplatin and Irinotecan

OBJECTIVE

To clarify the association between pre-treatment total bilirubin (PTB) level and severe toxicity in patients receiving cisplatin and irinotecan.

METHODS

We analyzed retrospectively the relationships of grade 4 neutropenia or grade 3-4 diarrhea and clinical variables including PTB and pre-treatment neutrophil counts (PNC) using a logistic regression model.

RESULTS

One hundred and twenty-seven patients (93 men, 34 women; median age: 61 years; range: 24-74 years) received cisplatin (60 or 80 mg/m2) on day 1 and irinotecan (60 mg/m2) on days 1 and 8 every 3 weeks or on days 1, 8 and 15 every 4 weeks. Grade 4 neutropenia occurred in 29 patients (23%) and grade 3-4 diarrhea occurred in 13 patients (10%). Grade 4 neutropenia was associated with a higher PTB level (odds ratio: 4.9; 95% confidence interval: 1.4-17.7), a higher cisplatin dose (2.8, 1.0-7.8) and a lower PNC (1.5, 1.0-2.3). Grade 3-4 diarrhea was associated with liver metastasis (11.2, 2.2-57.4), a higher cisplatin dose (5.0, 1.2-21.3) and a lower PNC (2.0, 1.1-3.6).

CONCLUSIONS

PTB level was associated with the severity of neutropenia caused by cisplatin and irinotecan.