Identification of genetic markers associated with ibrutinib-related cardiovascular toxicity

7526

Background: Cardiovascular side effects (CVSEs: atrial fibrillation, hypertension, etc.) are common in patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib and often lead to dose reductions or discontinuation. However, the etiology of ibrutinib related CVSEs has not been elucidated. This study sought to interrogate the association between ibrutinib related CVSEs and polymorphisms in genes of the Bruton Tyrosine Kinase (BTK) signaling pathway (identified through Ingenuity Pathway Analysis) Methods: Newly diagnosed and relapsed patients with CLL who underwent treatment with ibrutinib between December 2019 and November 2020 at Levine Cancer Institute were identified. Buccal swabs were collected through an IRB approved specimen collection protocol. Data extraction included: demographics, CLL stage, cytogenetics, previous treatments, ibrutinib start dates and dose, drug related SEs, and other medications. DNA isolated from buccal swabs was genotyped for 40 single nucleotide polymorphisms (SNPs) in GATA4, SGK1, KCNQ1, KCNA4, NPPA and SCN5A genes using a custom NGS panel. Logistic regression analysis evaluated the association between SNPs and CVSEs. Results: In 50 evaluable patients, the median age was 71 years (range:48-90) and 50% received frontline ibrutinib monotherapy. CVSEs occurred in 20% of patients (n=10). In univariate analysis, 4 SNPs in 3 genes were significantly associated with CVSEs (Table). Because the genes were in the same pathway, a genetic risk score was developed which indicated that patients with at least 2 SNPs had a 12-fold increase in risk of CVSEs (Table). Conclusions: Our findings provide insights into the genetic determinants of ibrutinib related CVSEs. If replicated in a larger study, this will facilitate utility of pharmacogenetic testing (for GATA4, KCNQ1 and KCNA5 polymorphisms ) as a clinical tool to individualize ibrutinib treatment.[Table: see text]

Opioid screening and urine toxicology results in outpatient oncology palliative medicine

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Background: Opioid misuse is a major public health issue. Given widespread opioid prescribing in cancer patients (pts), screening for potential misuse is critical. There is lack of real-world data on opioid screening and urine toxicology testing in outpatient oncology palliative medicine. Methods: This is a retrospective clinical analysis of adult cancer pts previously consented for a pharmacogenomics specimen collection study between August 2019-March 2020. Pts completing ≥ 1 outpatient palliative medicine visit with at least half undergoing urine toxicology screening (UTS) per standard practice were included. Pt demographics, medication(s), UTS results, symptoms using Edmonton Symptom Assessment Scale, and opioid screening using Screener and Opioid Assessment for Patients with Pain - Short Form (SOAPP-SF) were collected at baseline and follow up visits, if available. The primary endpoint was the frequency and type(s) of non-compliant (NC) UTS. Secondarily, risk factors for NC UTS were evaluated using univariate and multivariate logistic regression. Results: Of 189 pts (632 visits), 113 underwent UTS, 125 SOAPP-SF, and 75 had both. The median age was 56, 56% were female, 58% white, 40% black, 48% had stage IV disease, and median pain score was 7. More black pts (72%) underwent UTS compared to white pts (53%) (p = 0.001). The mean age of pts with a UTS was 53 compared to 59 in those without UTS (p = 0.002). Oxycodone was the most prescribed drug (N = 125). Median SOAPP-SF was 3 (range 0-11); 38% had a score ≥ 4 (considered high risk). About half (54%; N = 61) who underwent a UTS were NC. Of these, 32 had 1 NC UTS, whereas 29 had 2 or more. The most common reason was presence of a substance not prescribed (N = 44 pts and 128 results), whereas 33 pts (53 results) were NC for substance(s) not present but prescribed. Four had presence of marijuana only and 21 with marijuana plus another NC substance; presence of cocaine and alcohol were the 2nd and 3rd most frequent aberrant result. Of those with a NC UTS and SOAPP-SF score (N = 44), 59% had a score ≥ 4. In univariate analyses, SOAPP-SF ≥ 4 (p = 0.004), nausea (p = 0.05), depression (p = 0.02), anxiety (p = 0.01), and prescriptions for antidepressants (p = 0.006), acetaminophen (p = 0.03), and/or dronabinol (p = 0.04), were associated with NC UTS. In multivariate analyses, SOAPP-SF Q4 (use of illegal drugs) (OR 2.86, 95% CI 1.64 to 5.02; p < 0.001) and prescription with muscle relaxants (OR 2.90, 95% CI 1.19 to 7.09; p = 0.019) were associated with increased odds of a NC UTS. Conclusions: About half of those undergoing UTS were NC. SOAPP-SF Q4 and prescription with muscle relaxants were associated with a NC UTS. Overall, pt demographics (e.g. younger, more female, more black patients, severe pain) varied from the typical cancer population. Screening using SOAPP-SF, UTS, pain contracts, prescription drug monitoring databases, and evaluating pt-specific risk factors is important to reduce opioid misuse risk.

Venous thromboembolism (VTE) incidence and risk factors in patients (pts) with non-small cell lung cancer (NSCLC) receiving front-line therapy

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Background: VTE incidence varies based on factors such as tumor type, stage, and treatment. There is limited data on VTE incidence and risk factors in NSCLC pts receiving first-line therapies, including immune checkpoint inhibitors (ICIs) and targeted therapies (TTs). Methods: This is a single institution retrospective cohort study of adult NSCLC pts who received first-line treatment between July 2003 and July 2019. Treatments included chemotherapy (chemo) (platinums, taxanes, pemetrexed, gemcitabine, etoposide, bevacizumab), ICI (pembrolizumab, nivolumab, atezolizumab, durvalumab), chemo + ICI, or TT (erlotinib, gefitinib, afatinib, osimertinib, crizotinib, alectinib, ceritinib). Diagnosis codes (ICD 9/10 codes) confirmed VTE (deep vein thrombosis and/or pulmonary embolism) and presence of risk factors which are summarized in Table. Landmark VTE incidence was estimated from cumulative incidence curves for time to VTE, death as a competing risk. Time to VTE distributions were compared between groups with Gray’s tests. Univariable and multivariable competing risk analyses identified risk factors for time to VTE. Results: In 1,618 evaluable pts, the median age was 66 years, 53% were male, 79% White, 18% Black, 58% had adenocarcinoma, 32% squamous cell carcinoma, and 47% metastatic disease. 1178 received chemo, 172 ICIs, 157 chemo + ICI, and 111 TTs. 6-month VTE rates per arm were 5.3%, 7.0%, 7.2%, and 12.0% and 12-month rates were 8.9%, 8.1%, 11.7%, and 13.3%, respectively. Cumulative incidence of VTE was not significantly different between treatment groups (p = .27). Univariable and multivariable analyses are summarized in the Table below. Conclusions: Treatment type was not associated with VTE risk in first-line NSCLC, but rates were numerically highest in pts receiving TTs. Khorana risk score was significantly associated with VTE risk and may identify those likely to benefit from thromboprophylaxis. [Table: see text]

Genetic polymorphisms associated with clostridium difficile infection in multiple myeloma patients undergoing autologous stem cell transplantation

8522

Background: CDI is the primary cause of infectious diarrhea in immunocompromised patients including those undergoing autologous stem cell transplant (SCT). Given the key role of gut microbiome and its interaction with host immune system, we investigated whether polymorphisms in innate immunity genes (identified through Ingenuity Pathway Analysis) were associated with CDI. Methods: We queried our database to identify MM patients who underwent an autologous SCT between April 2015-June 2019. Patients who had their buccal swabs collected through an IRB approved specimen collection protocol were included herein. Data were collected on age, conditioning regimen, CDI diagnosis, time from admission until CDI diagnosis, absolute neutrophil count (ANC) at time of CDI diagnosis, and antibiotic prophylaxis. Genomic DNA was extracted from buccal swabs and genotyped for 62 single nucleotide polymorphisms (SNPs) in ASPH , RLBP1L1, ATP7B, IL-8, FAK, TNFRSF14, CTH, TLR and IL-4. Univariate and multivariate logistic regression analyses were performed to assess association between CDI and presence of SNPs in these genes. Results: A total of 83 patients were identified (25 cases and 58 controls). Baseline characteristics were comparable between two groups. Median age was 67 years (range: 50-79). All patients received high dose melphalan as conditioning, and the same antibiotic prophylaxis during peri-transplant period. Median time from hospitalization until CDI diagnosis was 10 days (IQR:9 days), and median ANC was 0.7/mL (IQR:1.6/mL). Two SNPs (rs2227307 T > G in IL-8 and rs2234167 G > A in TNFRSF14) were significantly associated with CDI risk in both univariate and multivariate logistic regression analyses (Table). Conclusions: Our findings suggest that rs227307G (in IL-8) and rs2234167A (in TNFRSF14) alleles are potential risk factors for CDI after autologous SCT. Our findings, if validated in a larger cohort, would support genetic testing as a screening tool to identify patients who might benefit from prophylaxis against CDI. [Table: see text]

Pharmacogenetic (PGx) guided cancer pain management in an oncology palliative medicine (PM) clinic

117

Background: About 30% of cancer patients presenting with pain have symptomatic improvement using conventional strategies within one month. PGx may help personalize opioid selection and improve cancer pain management. Methods: This is a pragmatic pilot trial investigating the feasibility and application of PGx testing to improve pain management in adults with uncontrolled cancer pain referred to an oncology PM clinic. PM providers assessed patients using Edmonton Symptom Assessment Scale at baseline and opioid therapy was initiated or modified. A buccal swab was obtained for genotyping single nucleotide polymorphisms in: COMT, CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, and OPRM1. The first assessment occurred within one week of baseline and a second within another week if intervention was required. PGx results were available before the first assessment and utilized, if applicable, throughout the one-month study period. Pain improvement rate (≥ 2-point reduction on a 0-10 scale) from baseline to final visit, was compared to historical control data by a one-sided exact binomial test of proportions. Results: Of 75 undergoing PGx testing, 52 were evaluable for the primary endpoint (54% female, 81% white, 17% black, median age 63, 75% stage 3 or 4 disease, median personalized pain goal 3 [0-6]). 56% had pain improvement compared to 30% in historical controls (p < 0.001). At final assessment, 35% met their personalized pain goal. Of 26 (50%) requiring opioid adjustments, 18 (69%) had an actionable genotype with a 61% pain improvement rate. The two most common genes for opioid adjustment were CYP2D6 (16/18; 89%) and COMT (8/18; 44%). The most common PGx-guided modification involved switching from a CYP2D6-metabolized drug (hydrocodone, oxycodone, tramadol) to a non-CYP2D6-metabolized drug (fentanyl, hydromorphone, methadone, morphine). Conclusions: PGx implementation in an oncology PM clinic was feasible and improved pain management. Half of those requiring opioid adjustments had an actionable genotype, with the largest impact from CYP2D6 polymorphisms. Future studies should focus on preemptive PGx testing to guide initial drug selection and confirm clinical utility in a randomized trial. Clinical trial information: NCT02542397.

Impact of Electronically Accessible Pathways (EAPathways) on clinical trial enrollment at a large multisite cancer center

6517

Background: Clinical pathways streamline evidence-based treatment decisions and provide consistent, high-quality, value-based care. A high-quality clinical pathway should enhance screening and access to clinical trials. Our healthcare system utilizes EAPathways to allow providers to select treatment regimens vetted by section experts, inquire about clinical trials, and refer to relevant programs (e.g. palliative medicine) or testing (e.g. genomics) at a main cancer center and 22 regional sites. With over 400 clinical trials, our goal is to provide access regardless of where a patient lives or receives treatment. We aim to explore the impact of EAPathways on clinical trial enrollment at our healthcare system. Methods: This study is a retrospective review to compare clinical trial inquiries through EAPathways and clinical trial enrollment using Oncore between 1/1/2017 and 7/31/2018. The primary outcome is the success rate reported as the total number of inquiries that resulted in clinical trial enrollment. Other outcomes include a comparison of inquiries and enrollments for hematology and solid tumor oncology, cancer treatment and non-treatment (e.g. specimen collection), and our main cancer center and regional sites. The number of and reason for opting out of treatments or trials was also analyzed. Results: A total of 29.1% (740/2539) of clinical trial inquiries through EAPathways resulted in clinical trial enrollment. Success rates for the following settings were reported: 39.5% (223/564) in hematology, 26.2% (517/1975) in solid tumor oncology, 27.0% (594/2203) in treatment trials, and 43.5% (146/336) in non-treatment clinical trials. Sixty-three percent of enrollments were at our main cancer center compared to regional sites. A total of 39.7% (3356/8453) of patients were enrolled into an opt-out pathway due to reasons such as performance status, organ dysfunction, or hospice. Conclusions: Clinical pathways can provide access to clinical trial enrollment in multiple settings. These baseline metrics will help assess process improvement needs to increase clinical trial enrollment success rates and address reasons for opt-out.

Supportive care medications (SCMs) and pharmacogenomics (PGx) relevance in 6,985 cancer patients (pts) undergoing distress screening

11592

Background: SCMs are prescribed based on symptom burden, but response is variable, possibly due to PGx. We investigated the association between symptom burden, SCM prescribing, and frequency of SCMs with PGx evidence. Methods: Cancer pts ≥ 18 years old and completing electronic distress screening within 90 days of intake between 1/1/2017-12/31/2017 were included. Anxiety was measured using Generalized Anxiety Disorder 2-item (0-6) and depression using Patient Health Questionnaire-2 (0-6). Fatigue, nausea, neuropathy, pain and sleep were measured on a 0-10 scale. SCM prescribing within 90 days of intake was documented. Logistic regression compared symptom scores and SCM prescribing. Receiver Operating Characteristics analysis estimated sensitivity/specificity. Optimal symptom thresholds were selected according to Youden’s J statistic. SCMs with PGx evidence level A or B (according to Clinical Pharmacogenetics Implementation Consortium) were summarized. Results: Of 6985 pts, 65% were female, 75% Caucasian, 20% African American and median age was 60. 49% reported ≥ 1 severe symptom, which correlated with SCM prescribing (p < 0.001). 3208 (46%) were prescribed SCM(s), mainly for pain (69%) or nausea (46%). Of these, 2759 (86%) received ≥ 1 SCM with PGx evidence and 2695 (84%) received a SCM metabolized by CYP2D6 - hydrocodone (47%), ondansetron (41%), and oxycodone (28%). Based on reported CYP2D6 allele frequencies conferring altered metabolism (~20%), 539 of the 2695 pts may have altered drug response. Threshold scores for each symptom are summarized in the table. Fatigue and nausea were not associated with SCM prescribing. Conclusions: Symptom burden is high in cancer pts and correlates with SCM prescribing. Many SCMs have PGx evidence, suggesting preemptive testing, particularly for CYP2D6, may have broad applicability in this population.[Table: see text]

Examination of the Screener and Opioid Assessment for Patients with Pain-Short Form (SOAPP-SF) in an oncology palliative medicine clinic

196

Background: The National Comprehensive Cancer Network states opioids can be used to treat cancer pain and prescribers should identify patients at risk for opioid misuse; research in this area is limited. In the non-cancer population, SOAPP-SF is a validated tool to predict aberrant drug behavior; a score of ≥ 4 (out of 20) is considered high risk. We performed a retrospective observational study to determine the utility of the SOAPP in identifying opioid misuse in the oncology population as measured by a non-compliant toxicology screen. Methods: Consecutive consults seen during a 6-month period completed the 5-question SOAPP-SF and Edmonton Symptom Assessment System (ESAS) form. Toxicology screens assessed non-compliance (i.e., absence of prescribed medications and/or presence of non-prescribed or illegal substances). Logistic regression models estimated the associations of composite and individual SOAPP-SF scores and ESAS symptom scores with non-compliant screens. Threshold analysis were conducted to identify an optimal SOAPP-SF cutoff. Results: Of 192 consults, 64 patients providing SOAPP-SF score and toxicology screen were evaluable. Mean age was 59 ± 9.8 years: 56% were female, 34% and 62% were African American and Caucasian respectively. Median SOAPP-SF score was 2 (range: [0, 12]). Non-compliant screens were observed in 31% of patients. The area under the curve (AUC) was 0.65. The validated SOAPP-SF cutoff score of ≥ 4 was associated with a sensitivity and specificity of 0.43 and 0.79, respectively (p = 0.082). Sensitivity (0.76) and specificity (0.72) were maximized at a cutoff score of ≥ 3 (p < 0.001). When evaluated individually, the SOAPP-SF question about smoking habit was associated with a non-compliant screen (p = 0.020). Increased ESAS pain scores were associated with SOAPP-SF score ≥ 3 (p = 0.013). Conclusions: SOAPP-SF can identify oncology patients at risk for opioid misuse. Preliminary analyses suggest a more appropriate threshold of identification is a score of ≥ 3 not ≥ 4. Future work will increase numbers of evaluable patients and examine other factors associated with opioid misuse.

Level of burden of supportive care-relevant pharmacogenetic markers in general population

221

Background: Precision medicine has become part of oncology, with implications for therapy selection, treatment avoidance, dosing, and risk prediction. The presence of clinically predictive germline variants has also opened the hope that objective predictors of patient toxicity will be in the future. This is an opportunity for oncology, where selection from amongst apparently equal supportive care treatment options can be subjective. Methods: The incidence of genetic risk for untoward drug effect was characterized in 1193 consecutive patients submitted for clinical pharmacogenetics testing using a 50 gene panel. Not all were cancer patients, so this reflects a potential patient population. For each patient, the need to stop/avoid, adjust dose, and select an alternate medication was determined for the treatment of pain (CYP2D6, CYP1A2, OPRM1), nausea/vomiting (CYP2D6), antifungal prophylaxis (CYP2C19) or depression (CYP2D6, CYP2C`9). It is recognized that there are many sources of variation in the response and toxicity to these classes of medications. Results: Of the 1193 patients, 173 (14.5%) would have a recommendation to avoid oxycodone, codeine, or tramadol therapy and a non-standard dosage for 893 patients (75%). A change in antiemetic would be suggested for 35 patients (3%). If voriconazole antifungal prophylaxis was clinical required, 289 (24%) would need a dose increase, while 45 (3.8%) should be switched to a different regimen. The majority (759 patients; 64%) should avoid some of the commonly used agents for depression because of lack of efficacy or heightened risk of toxicity, while 195 patients would need a dose adjustment. Conclusions: Pharmacogenetics markers that put patients at risk for lack of efficacy or toxicity to supportive care medications was commonly observed. Thankfully there are many options for most supportive care areas, allowing genetic information to help focus treatment selection. In addition, for number of supportive care medications we do not know the sources of variable response, genetic or otherwise. There are opportunities to apply precision oncology principles to patient management now, while research helps toward the goal of objective medication selection.

Impact of pharmacy interventions on pain management in an oncology palliative medicine (PM) outpatient clinic

119

Background: PM can improve the quality of life and survival for cancer patients (pts); however, the demand for PM challenges providers with delayed follow ups resulting in less than one-third of pts achieving significant pain improvement between clinic visits. Engaging pharmacists in the provision of PM may help improve pain management in cancer pts. Methods: Adult cancer pts starting a new pain regimen or requiring changes to an existing regimen at baseline were referred for pharmacy follow up in 3-7 days (assessment #1). The pharmacist evaluated each pt using the Edmonton Symptom Assessment Scale and recommended changes to the referring PM provider, prompting a 2nd follow up in 3-7 days (assessment #2). If no changes were required, pts continued therapy and returned for the final clinic visit (day 28 +/- 7). The primary endpoint was the proportion of pts achieving significant pain improvement (≥ 2-point decrease in pain score on a scale of 0-10) from baseline to final visit, which was compared to historical controls using Fisher’s Exact test. Changes in pain severity from baseline to final visit were compared using Generalized McNemar’s test, and descriptive statistics were used to describe characteristics at assessment #1. Results: Of 102 pts evaluable for the primary endpoint, 76% had stage IV disease, 58% were female, and median age was 57 yrs. Significantly more pts achieved pain improvement from baseline to final visit compared to historical controls (49% v 30%; P < 0.001). Changes in pain severity from baseline to final visit are described in the table. At assessment #1, 70% of pts required an intervention, primarily due to uncontrolled pain (72%), side effects (26%), and/or lack of response to non-pain medications (22%). The most common types of interventions were dose adjustments (62%), education (36%), and/or adding a new medication (30%). Over 90% of recommendations were accepted by the referring PM provider. The median time of assessment was 15 mins. Conclusions: Routine inclusion of pharmacists in the outpatient PM interdisciplinary team improves the effectiveness of pain management. [Table: see text]

The impact of sarcopenia on toxicity and pharmacokinetics of 5-fluorouracil (5FU) in colorectal cancer

633

Background: Great heterogeneity exists in the ability of adults with cancer to tolerate treatment. Variability in body composition may affect rates of metabolism of cytotoxic agents and contribute to the variable chemotherapy toxicity observed. The goal of this study was to explore the impact of body composition, in particular sarcopenia, on the pharmacokinetics of 5-fluorouracil (5FU) in a cohort of patients receiving FOLFOX +/- bevacizumab for colorectal cancer. Methods: We performed a secondary analysis of a completed multicenter trial that investigated pharmacokinetic-guided 5FU in patients receiving mFOLFOX6 +/- bevacizumab [Patel et al. The Oncologist 2014]. Computed Tomography (CT) images that were performed as part of routine care were used to for body composition analysis. Skeletal muscle area (SMA) and density (SMD) were analyzed from CT scan L3 lumbar segments using radiological software. SMA and height (m2) were used to calculate skeletal muscle index (SMI = SMA/m2). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD. Differences were compared using two group t-tests and fisher’s exact tests. Results: Of the 70 patients from the original study, 25 had available CT imaging. The mean age was 59, 52% female, 80% Caucasian, and 92% with either stage III or IV disease. Eleven patients (44%) had grade 3/4 toxicity, and 12 patients were identified as sarcopenic (48%) [per Martin et al. JCO 2013]. Sarcopenic patients had numerically higher first cycle 5FU AUCs compared to non-sarcopenic patients (19.3 vs. 17.3 AUC, p= 0.43) and higher grade 3/4 toxicities (50 vs 38.5%, p= 0.70). Patients with low SMG ( < 1475 AU) had higher grade 3/4 toxicities (62 vs 25%, p= 0.11) and higher hematologic toxicities (46 v 8%, p= 0.07). Conclusions: CRC patients with sarcopenia had numerically higher first cycle AUCs of 5FU and a higher incidence of severe toxicities; however, this was not statistically significant, possibly due to limited sample size. SMG, an integrated muscle measure, was more highly correlated with toxicity outcomes than either SMI or SMD alone. Further research exploring the role of body composition in pharmacokinetics is needed with a focus on alternative dosing strategies in sarcopenic patients.

Efficacy of acupuncture (ACU) therapy for cancer-related pain management in oncology patients (pts)

196

Background: Cancer-related pain negatively affects symptom burden, morbidity, and mortality. Evidence suggests the use of ACU to relieve cancer-related pain. We investigated ACU efficacy and patient-specific factors associated with pain improvement. Methods: Medical charts were reviewed from oncology pts receiving ACU and concurrent palliative medicine management. Pre- and post-ACU pain scores, as assessed by the Edmonton Symptom Assessment Scale (ESAS), were measured at each session. Univariate logistic regression models, including an over-dispersion parameter to account for multiple observations per pt, were used to investigate the association between patient-specific variables (Table) and significant pain improvement, defined as a ≥ 2-point reduction in ESAS pain score, at each session. Results: A total of 122 ACU sessions from 53 pts were included in the analysis. Significant pain improvement was observed in 47% of all sessions (mean reduction 1.8). Baseline non-neuropathic pain was significantly associated with a higher odds of achieving pain reduction (OR 2.351; P = 0.047). Conversely, an opposite association was identified for baseline neuropathic pain (OR 0.421; P = 0.048). Age, stage, number of sessions and tumor type were not significantly associated with pain improvement, although several trends were noted (Table 1). Conclusions: ACU is an appropriate adjunct therapy for cancer-related pain, particularly for non-neuropathic pain. Larger studies to confirm patient-specific variables and further investigation into therapy related side effects will assist in determining a personalized approach to ACU therapy in the oncology population. [Table: see text]

A genome-wide association study (GWAS) of docetaxel-induced peripheral neuropathy in CALGB 90401 (Alliance)

11053

Background: There are currently no effective methods for predicting, preventing, or treating chemotherapy-induced peripheral neuropathy. We performed a genome-wide association study in a clinical trial of castration-resistant prostate cancer (CRPC) to discover variants that may be useful for identifying patients at high risk of neuropathy during docetaxel treatment. Methods: Treatment and toxicity data were collected prospectively on the Cancer and Leukemia Group B (CALGB) 90401 trial of chemotherapy naïve CRPC patients treated with docetaxel and prednisone ± bevacizumab. Genotyping was performed by the RIKEN Institute using the Illumina HumanHap610-Quad platform. Genetically defined European subjects were included in the discovery analysis of all single nucleotide polymorphisms (SNPs) that passed quality control. The primary endpoint was the cumulative dose level triggering a grade 3+ sensory neuropathy. The inference was conducted within the framework of a competing risk model accounting for early treatment termination induced by death or progression, or other toxicities. SNPs that were highly associated with neuropathy were assessed for a broader taxane effect in a cohort of paclitaxel-treated patients from a breast cancer clinical trial, CALGB 40101. Results: 623 Caucasian patients and 498,022 SNPs were included in the discovery analysis. The incidence of grade 3 neuropathy was 8%. One intergenic SNP (rs11017056) was associated with increased risk of neuropathy (HR=2.83, p=4.7x10-7). This association surpassed the genome-wide significance threshold after covariate adjustment (p=7.2x10-8). However, none of the 7 SNPs selected for replication were associated with neuropathy in the paclitaxel-treated breast cancer cohort. Conclusions: Using a prospectively enrolled prostate cancer patient cohort we identified multiple SNPs that may identify risk of docetaxel-induced peripheral neuropathy, but not paclitaxel-induced neuropathy. However, since it is unknown whether the genetic factors that affect taxane neuropathy are drug-specific, further replication studies in docetaxel-treated cohorts are of great interest.

Application of pharmacokinetic (PK)-guided 5-fluorouracil (FU) in clinical practice

2595

Background: Body surface area (BSA)-based dosing of FU results in up to 100-fold inter-individual PK variability. PK-guided FU compared to BSA-based dosing resulted in higher response rates and decreased rate of toxicities in two randomized clinical trials. A paucity of data exists on PK-guided FU dosing in the clinical setting. Methods: A total of 70 colorectal cancer (CRC) patients (pts) from 6 academic and community sites received mFOLFOX6 (FU 2,400 mg/m2over 46 h every 2 wks) +/- bevacizumab. Peripheral blood was obtained 2-44 h after start of FU infusion and AUCs were estimated using an immunoassay at Myriad Genetics. FU doses for cycles 2-4 (C2-4) were adjusted algorithmically to target an area under the concentration-time curve (AUC) of 20-25 mg*h/L. The primary outcome was the % of pts within target AUC by C4, with a secondary outcome of toxicity rates compared to historical data. Comparisons between cycles were made using generalized linear models, accounting for repeated observations within pt. Results: The % of pts within target AUC post C1 and C4 was 30% (17/57, 95%CI: 18-43%) and 46% (24/52, 95%CI: 32-61%), respectively (OR=2.16, p=0.05). For each subsequent cycle, the odds of a pt being within range increases by 28% (p=0.04) (Table). The median dose needed to achieve target AUC at C4 was 2,580 (range 1,920-3,484) mg/m2. The median AUC post C1 and C4 was 19 and 21 mg*h/L, respectively. Less grade 3/4 mucositis and diarrhea were seen compared to historical data (3 v 15% and 6 v 12%, respectively); however, no difference in grade 3/4 neutropenia was noted (27 v 33%). Nine pts were non-evaluable by protocol for PK analysis, largely due to sampling/processing errors. Conclusions: PK-guided FU resulted in a greater number of pts achieving the targeted AUC and fewer pts under-dosed at C4 compared to C1. Individualization of FU dosing in the front-line, community and academic, setting is achievable for the treatment of CRC; however, larger clinical trials are needed to define the clinical utility of PK-guided FU. Clinical trial information: NCT01164215. [Table: see text]

Evaluating variability in fluorouracil (FU) exposure in obese and non-obese patients with colorectal cancer using full weight-based dosing

409

Background: Approximately 30% of cancer patients are obese. Controversy exists on how to best use body weight to safely and effectively dose chemotherapy. Additionally, body surface area (BSA)-based dosing is associated with high pharmacokinetic (PK) variability and is a poor indicator of optimal drug exposure. Methods: We estimated FU exposure post cycle 1, as indicated by area under the curve (AUC), in 58 colorectal cancer patients receiving mFOLFOX6 (FU 2400 mg/m2 [BSA calculated using actual body weight (ABW)] over 46 hours) +/- bevacizumab. AUCs were determined using an immunoassay at Myriad Laboratories. The primary objective was to identify variability in FU exposure in obese and non-obese patients using body mass index (BMI), BSA, and ABW. Groups were compared using two group t-tests. Results: No significant difference in AUC was observed between obese (BMI ≥ 30 kg/m2) and non-obese (< 30 kg/m2) patients. A significantly lower AUC was observed in patients with a BSA ≥ 2.0 m2 compared to those < 2.0 m2 (p=0.02). The AUC for obese and non-obese patients ranged from 7-34 and 12-38 mg*hr/L, respectively. Only 32% and 28% of obese and non-obese patients, respectively, were within the previously reported therapeutic target AUC 20-25 mg*hr/L. Males had significantly lower AUCs compared to females (mean 18.7 v 22.4, p=0.03). FU AUC was not strongly correlated with BMI, BSA, or ABW (Pearson correlation of -0.03, -0.26, and -0.15, respectively). Conclusions: BSA-based dosing is associated with variable FU exposure. Lower AUCs in patients with a BSA ≥ 2.0 m2 supports both ASCO recommendations for full-weight-based dosing in obese patients and the value of dosing assessment across patient populations. Further study of AUC-based dosing is warranted as our data do not support a reduction in variable exposure based on BMI, BSA, or ABW dosing. [Table: see text]

Investigating the utilization of pharmacokinetic-guided fluorouracil in colorectal cancer

e13109

Background: Fluorouracil (FU) has remained the cornerstone of colorectal cancer (CRC) therapy for > 40 years; however, recent evidence suggests inter-individual pharmacokinetic (PK) variability in response. Methods: A total of 58 CRC patients from 6 academic and community sites received mFOLFOX6 (FU 2400 mg/m2 over 46 hours every 2 weeks) +/- bevacizumab. FU doses for cycles 2-4 were adjusted based on an algorithm to target an AUC of 20-25 mg*h/L. Peripheral blood was obtained 2-46 hours post beginning of infusion (BOI) and AUCs were determined using an immune-based assay (OnDose). The primary objective of this study is to describe the feasibility of PK-guided FU in clinical practice using descriptive statistics with a secondary objective of toxicity assessment. Results: Mean AUC post cycle 1 in evaluable patients (n=39) was 19.8 +/- 6.3 mg*h/L (range 7-38) with 31% within, 51% under, and 18% over the AUC target. Based on cycle 1 results, the mean dose estimated to achieve AUC 20-25 mg*h/L would be 2,505 +/- 304 mg/m2 (range 2,040-3,600). For cycle 1, the mean AUC at 2 and 18-24 hours post BOI was 17.5 +/- 6.9 and 21.6 +/- 6.3, respectively. Of 58 patients, 19 were not evaluable due to logistical issues such as sampling errors, dosage deviation from protocol, no stabilizing agent added to sample, or the patient was unable to return to clinic for sampling. Three hospitalizations due to serious adverse events occurred, with 2 at AUCs > 30. See the table for toxicities. Conclusions: Significant heterogeneity is noted in FU AUC with BSA-based dosing, with the majority of patients below the protocol-specified AUC threshold. Although FU should be at steady-state 2 hours post BOI until the end of infusion, a difference in AUC was seen between samples taken at 2 and 18-24 hours. With little study withdrawal observed after initial patient enrollment, appropriate logistical training can allow for individualization of FU in the front-line, community setting for the treatment of CRC; however, larger clinical trials are needed to define the clinical utility of PK-guided FU. [Table: see text]

Utility of prostaglandin in the identification of discontinuous pulmonary arteries by echocardiography

We describe two distinct cases in which discontinuous pulmonary arteries were identified by echocardiography and color Doppler imaging. In both cases, perfusion of one or both pulmonary arteries was dependent on a patent ductus arteriosus. Establishment of the source of perfusion and the anatomy of the discontinuous pulmonary arteries were evident only after an infusion of prostaglandin had been initiated, thus demonstrating that its use was a key component in the identification of this disease entity.

McLafferty-type rearrangement in the collision-induced dissociation of Li+, Na+ and Ag+ cationized esters of N-acetylated peptides

In this study we investigated the multi-stage collision-induced dissociation (CID) of N-terminally acetylated di-, tri- and tetrapeptides in the form of C-terminal ethyl, n-propyl, isopropyl, n-butyl and tert-butyl esters and cationized by the attachment of Li(+), Na(+) and Ag(+). While methyl ester versions of the metal cationized peptides primarily eliminate H(2)O following collisional activation and dissociation, the ethyl, propyl and butyl ester versions of the peptides exhibit a dissociation pathway consistent with gamma-hydrogen transfer to the C-terminal carbonyl group, with associated elimination of an alkene, in a McLafferty-type rearrangement. The rearrangement leaves a metal cationized, free-acid form of the peptide, as confirmed by comparing the multi-stage CID of rearrangement products generated from peptide esters with the CID of corresponding metal cationized free-acid peptides. The transfer of a gamma-hydrogen in the rearrangement reaction was confirmed by investigating the CID of ethyl esters for which the terminal methyl group was labeled with deuterium. We found that the rearrangement product was significantly more abundant, relative to other product ions, when derived from isopropyl and tert-butyl esters than from ethyl, n-propyl or n-butyl ester analogues.

Effects of tumour necrosis factor-α in the human forearm: blood flow and endothelin-1 release

Increased circulating concentrations of tumour necrosis factor-α (TNF-α) are seen in several pathological conditions associated with vascular disease. TNF-α induces the synthesis of endothelin-1 (ET-1), a potent vasoconstictor, by the endothelium. However, there is profound vasodilatation in sepsis, where circulating levels of both ET-1 and TNF-α are elevated. The details of the interaction between ET-1 and TNF-α and the predominant resulting haemodynamic effect in healthy humans are unclear. The aim of the present study was to determine the effects of intra-arterial TNF-α on ET-1 spillover, vascular tone and endothelial function in the healthy human forearm. Brachial arterial and deep venous blood samples, forearm plasma flow measurements and blood flow responses to acetylcholine and sodium nitroprusside were obtained in six healthy subjects before and during a 6h infusion of TNF-α into the brachial artery. Forearm blood flow was significantly greater than baseline during exposure to TNF-α [median (lower quartile, upper quartile): baseline, 2.6 (2.1,2.8) ml·min-1·100ml-1; TNF-α, 4.6 (4.5,5.1) ml·min-1·100ml-1; P<0.05]. The rate of release of ET-1 was significantly greater than baseline after 30 and 260min of TNF-α infusion [median (lower quartile, upper quartile): baseline, 0.8 (0.6,1.1)pg·min-1·100ml-1; 30min, 2.4 (1.9,3.2)pg·min-1·100ml-1; 260min, 4.1 (3.1,4.2)pg·min-1·100ml-1; P<0.05]. The vasodilatory response to acetylcholine was diminished during TNF-α infusion, whereas the response to sodium nitroprusside remained unchanged. We thus demonstrate for the first time that local TNF-α increases ET-1 spillover from the human forearm and impairs endothelium-dependent vasodilatation. In spite of this action, TNF-α has a vasodilatory effect, resulting in an increase in forearm blood flow.

Norepinephrine spillover from human adipose tissue before and after a 72-hour fast

Adipose tissue lipolysis is at least in part stimulated by the sympathetic nervous system (SNS). Although there is a generalized decrease in SNS activity with fasting, the rate of lipolysis during fasting increases. The aim of this study was to determine whether there is an association between activation of sympathetic nerves innervating adipose tissue and the increase in lipolysis seen during fasting in humans. We used the isotope dilution technique to measure regional norepinephrine spillover from abdominal sc adipose tissue from seven healthy subjects before and after a 72-h fast. Our results showed a significant increase in adipose tissue spillover of norepinephrine (mean +/- SEM, 0.40 +/- 0.09 vs. 1.08 +/- 0.18 pmol.100 g(-1).min(-1), P < 0.05) and arterial norepinephrine concentrations (0.92 +/- 0.10 vs. 1.23 +/- 0.08 nmol.liter(-1), P < 0.05) after the fast with no significant change in total body norepinephrine spillover, forearm norepinephrine spillover, epinephrine concentrations, or energy expenditure. We show for the first time, in humans, a selective regional increase in adipose tissue norepinephrine spillover in response to a 72-h fast and suggest that the SNS may play a greater role in the regulation of lipid metabolism during fasting than previously thought.

Nutritional regulation of lipid metabolism in human adipose tissue

Pfeiffer and colleagues years ago pointed out that different distributions and amounts of adipose tissue are associated with abnormalities of lipolysis and lipoprotein metabolism. Adipose tissue has several crucial roles including (i) mobilization from stores of fatty acids as an energy source, (ii) catabolism of lipoproteins such as very-low-density lipoprotein and (iii) synthesis and release of hormonal signals such as leptin and interleukin-6. These adipose tissue actions are crucially regulated by nutrition. The review considers the existence of metabolic pathways and modes of regulation within adipose tissue, and how such metabolic activity can be quantitated in humans. Nutrition can influence adipose tissue at several 'levels'. Firstly the level of obesity or malnutrition has important effects on many aspects of adipose tissue metabolism. Secondly short-term overfeeding, underfeeding and exercise have major impacts on adipose tissue behaviour. Lastly, specific nutrients are capable of regulating adipose tissue metabolism. Recently there have been considerable advances in understanding adipose tissue metabolism and in particular its regulation. This review discusses the behaviour of adipose tissue under various nutritional conditions. There is then a review of recent work examining the ways in which nutritional influences act via intra-cellular mechanisms, insulin and the sympathetic innervation of adipose tissue.

Acupuncture for episodic tension-type headache: a multicentre randomized controlled trial

A multicentre, randomized clinical trial was undertaken to test the hypothesis that acupuncture is more efficacious than sham control procedure in the prevention of episodic tension-type headache. Fifty subjects were randomized to receive a course of treatment with either brief acupuncture or a sham procedure. Subjects were followed up for 3 months. Changes in headache were assessed by daily diary, the primary outcome measure being the number of days with headache. No significant differences were found between the changes in the two groups for any measure at any time point. Results also show that patient blinding was successful. In conclusion, this study does not provide evidence that this form of acupuncture is effective in the prevention of episodic tension-type headache.

Norepinephrine spillover in forearm and subcutaneous adipose tissue before and after eating

The sympathetic nervous system regulates lipolysis. There are regional differences in the sensitivity of lipolysis to adrenergic regulation. Little is known about regional sympathetic activity in response to eating in humans. We studied the effect of feeding on systemic and local sympathetic nervous system activity and lipolysis in lean healthy subjects (three women and five men; age, 27.0+/-2.0; body mass index, 23.4+/-1.2 kg/m(-2)) using isotope dilution methodology and arterio-venous sampling. Feeding increased arterial norepinephrine (NE) concentration (mean premeal, 0.96+/-0.12 nmol/L x L; mean postmeal, 1.28+/-0.14 nmol/L x L; P < 0.02) and total body NE spillover (mean premeal, 2.11+/-0.30 nmol/min x L; mean postmeal, 2.76+/-0.31 nmol/min x L; P < 0.02), whereas the arterial epinephrine concentration decreased (mean premeal, 289+/-61 pmol/L; mean postmeal, 170+/-5 pmol/L; P < 0.02). Palmitate concentration and total body systemic rate of appearance of palmitate declined postprandially (mean premeal, 117 +/- 15 micromol/min; mean postmeal, 38+/-4 micromol/min; P < 0.01). NE spillover increased by the same proportion in both forearm and adipose tissue [in forearm, mean premeal and postmeal, 1.02+/-0.11 and 2.41+/-0.44. nmol/100 mL x min, respectively (P < 0.02); in adipose tissue, mean premeal and postmeal, 0.41+/-0.12 and 0.73+/-0.17 nmol/100 g x min, respectively (P < 0.02)]. The results show that a meal caused differential changes in systemic sympatho-adrenal activity and an increase in sympathetic activity in adipose tissue postprandially, However, this increase in postprandial sympathetic activity was not enough to overcome the inhibition of lipolysis by insulin.

Coupling of poly(ethylene glycol) to albumin under very mild conditions by activation with tresyl chloride: characterization of the conjugate by partitioning in aqueous two-phase systems

Poly(ethylene glycol) activated with tresyl chloride has been covalently linked to albumin as a result of a 2-h incubation in 0.05 M sodium phosphate buffer, pH 7.5, containing 0.125 M sodium chloride (0.344 OSM). The coupling of poly(ethylene glycol) to albumin was demonstrated by the increase in the partition coefficient of the protein in poly(ethylene glycol)-dextran aqueous two-phase systems. A linear relationship between the log of the partition coefficient of the poly(ethylene glycol)-albumin conjugate and the degree of modification (measured as the amino groups consumed during the coupling step) has been demonstrated. Countercurrent distribution in the two-phase system showed that poly(ethylene glycol)-albumin was heterogeneous with respect to its partitioning behavior, indicating that the albumin was not uniformly modified with poly(ethylene glycol).