Elizabeth A. MacLean

Real-World Treatment Patterns and Costs for Patients with Renal Cell Carcinoma Initiating Treatment with Sunitinib and Pazopanib

BACKGROUND Sunitinib and pazopanib are among the most prescribed targeted therapies for the systemic management of advanced renal cell carcinoma (RCC), but published cost comparisons between the 2 agents are few and limited by methodological and population differences. Also, sunitinib is administered on a 4-week on/2-week off cycle, and pazopanib is taken continuously. Thus, appropriate use and cost comparisons between the 2 drugs require methodological approaches to account for these differences. One way to accomplish this is to substitute expected for observed days supply. Recognizing the effects of nonrepresentative days supply values is important for assessing real-world treatment patterns and costs. OBJECTIVES To (a) characterize demographic and clinical characteristics among patients with RCC newly initiating sunitinib or pazopanib, using a large administrative claims dataset; (b) characterize treatment patterns, persistence, and costs for each treatment group; and (c) assess the effect on treatment patterns and costs for sunitinib by substituting 42 days for prescriptions with 28- or 30-day supplies to account for sunitinibs 4-week on/2-week off dosing schedule. METHODS This was a retrospective cohort study using health care claims data from the Truven MarketScan Research Databases, which include enrollment information and medical and pharmacy claims. Baseline patient demographic and clinical characteristics and treatment patterns (continuation, discontinuation, switching, or interruption; days supply; and persistence) were compared. Health care costs were calculated as mean daily index medication costs and as total, medical, and medication (all-cause and RCC-related) costs over the 12 months post-index period. Inclusion criteria were continuous health plan enrollment between 6 months pre-index and 12 months post-index; no RCC medications 6 months pre-index; ≥ 2 RCC diagnoses within ±180 days of index; and age ≥ 20 years. For demographic and clinical characteristics, treatment patterns, and costs, means (± standard deviations) for continuous data and relative frequencies for categorical data were reported. Chi-square tests or Student t-tests were used to evaluate differences other than costs. A generalized linear model with gamma distribution and log link was used for evaluating costs, controlling for patient demographic and pre-index clinical characteristics, persistence days, and index medication. All statistical tests were 2-tailed with significance set at P < 0.05 for all comparisons except for interactions with significance set at P < 0.10. The effects of substituting 42 days supply for sunitinib prescription records with 28 or 30 days supply were determined. RESULTS In total, 609 (15.1% of the sunitinib overall sample) sunitinib patients and 183 (8.3% of the pazopanib overall sample) pazopanib patients were included. Demographic and clinical characteristics were similar for each treatment cohort. The persistence periods and number of prescriptions filled were also similar. Without substitution, significant differences were observed between treatment groups in patterns of index medication use (overall P = 0.0409), with fewer patients taking sunitinib continuing treatment than patients taking pazopanib. However, with substitution, treatment patterns differed significantly (overall P = 0.0026), but with more sunitinib patients than pazopanib patients continuing treatment. Without substitution, unadjusted daily mean index medication costs were significantly different for sunitinib (

Common questions regarding clinical use of axitinib in advanced renal cell carcinoma

216) versus pazopanib (

Axitinib in metastatic renal cell carcinoma: patient characteristics and treatment patterns in US community oncology centers

177, P < 0.0001). Substitution of sunitinib days supply eliminated the significant differences in daily index medication costs between treatment groups. The 1-year RCC-related and all-cause medication, medical, and total unadjusted costs were not significantly different between treatment groups, and substitution had no effect on these costs. After adjustment for possible confounding factors, these cost results were similar to those found with unadjusted analyses. CONCLUSIONS In this study, patients with RCC who were initiating sunitinib and pazopanib had similar demographic and clinical characteristics and drug persistence patterns. The effect of substituting days supply values was demonstrated as an approach to considering differences in dosing cycles. Substitution significantly reduced sunitinib mean daily index medication costs and eliminated or reversed the direction of significant differences in costs between drugs during the persistence period. No significant differences were observed in unadjusted or adjusted 1-year costs. DISCLOSURES This study was funded and conducted fully by Pfizer. All authors are employees of Pfizer. This work was presented in part as posters at the 2015 Genitourinary Cancers Symposium, of the American Society of Clinical Oncology; Rosen Shingle Creek, Orlando, FL; February 26-28, 2015, and the 20th Annual International Meeting of the International Society for Pharmacoeconomics and Outcomes Research; Philadelphia, PA; May 16-20, 2015. All authors contributed to study concept and design and to data interpretation. Mardekian was primarily responsible for data collection, along with Harnett. MacLean and Harnett worked on the manuscript, which was revised by MacLean and Mardekian.

Abstract B102: NSCLC observations combining medical charts and administrative claims data

PURPOSE An overview of the responses to some of the most frequently asked questions regarding axitinib administration and dosage modifications used in clinical practice are presented. SUMMARY Axitinib was approved for second-line treatment of advanced renal cell carcinoma by the Food and Drug Administration on January 27, 2012. Inquiries received over the first six months after the approval date were reviewed. A large number of questions were related to administration of axitinib in different patient populations or in patients with various comorbidities, such as its (1) use in patients unable to swallow oral medication or administration of axitinib via a nasogastric tube, (2) use in patients with renal or hepatic impairment, (3) central nervous system penetration and use in patients with brain metastases, (4) drug interactions, particularly with anticoagulants, and (5) dosage modifications. Responses to these inquiries were provided based on the published literature or from data on file from the manufacturer. The dosage of axitinib can be adjusted for use in patients with hepatic impairment or in patients who cannot otherwise tolerate the usual regimen. Patients taking concomitant warfarin can also take axitinib, and patients who cannot swallow oral medications can receive a liquid formulation of the drug, though its efficacy and comparability to the tablet formulation has not been tested. CONCLUSION Based on the published literature and company data on file, the axitinib dosage may be modified to accommodate patients with renal or hepatic impairment, who cannot swallow oral medication, are receiving concomitant warfarin, or who cannot otherwise tolerate the standard dosage regimen. For patients who cannot swallow, an oral suspension can be prepared because crushing axitinib is not recommended.

Real-World Axitinib Use in the United States: A Retrospective Study Using Linked Datasets

AIM To study patient characteristics and treatment patterns in real-world axitinib use for metastatic renal cell carcinoma. PATIENTS & METHODS We conducted a retrospective analysis of second- or third-line axitinib use between 1 January 2012 and 31 October 2014 in 135 metastatic renal cell carcinoma patients using the US Oncology Network database. RESULTS Overall, 86.7% had clear cell histology, 57.8% had stage III/IV disease at diagnosis and 55.6% were poor risk by Heng criteria. Median treatment duration was 4.6 months (range: 0.03-35.49); 80.7% initiated axitinib at 5 mg/day twice daily, and 67.4% maintained this dose. Overall, 77.8% discontinued treatment, mainly due to disease progression (50.5%) and toxicity (21.9%). CONCLUSION Axitinib usage patterns were consistent with the National Comprehensive Cancer Network Guidelines®. Ease of use among community oncologists and patient tolerance are key features of axitinib.

Axitinib treatment among patients with mRCC in a U.S. community oncology setting: A retrospective study of 135 patients.

Background: We previously examined diagnostic testing and treatment patterns for NSCLC using administrative claims data which relied on ICD-9-CM diagnosis codes. With no specific code for NSCLC, an algorithm was developed to exclude cases with SCLC. Subsequently, medical record data were added to verify the claims-based NSCLC algorithm and to supplement observations of NSCLC diagnostic testing and treatment patterns. Objective: To evaluate a claims-based algorithm for identifying NSCLC based on diagnosis in the medical record and to re-examine diagnostic testing and treatment patterns after combining claims data with medical chart data. Methods: The previous study attempted to identify patients with metastatic NSCLC by requiring a diagnosis for lung cancer (162.xx) and diagnosis of metastatic disease (196.xx, 197.xx,198.xx), with no other malignancy. Patients were excluded if a medication typically used to treat SCLC was dispensed. In total, 2,623 patients with suspected NSCLC met these criteria. For the follow-up study, medical chart records were requested from providers who were identified from claims where metastatic disease was first listed. From the chart data, abstractors identified data for 356 patients that could be matched to claims data from the prior study. Results: Of the 356 suspected NSCLC patients with charts and claims data, 204 did not specify type. Of the other 132, 79% had NSCLC and 21% had SCLC. Patients with NSCLC were 85% white, 10% black, 5% other, mostly male (62%), mean age 71 years, residing across 31 states. Stage at diagnosis was noted for all patients (n = 120) with 34% Stage 1 or 2, 17% Stage 3, and 47% Stage 4. Fewer than half (44%) had molecular testing within 45 days of the date of metastasis in the claims data. Most (93%) had evidence of histological testing via claims data with charts indicating 37% with adenocarcinoma, 21% squamous cell, Conclusions: Based on analysis of chart data, the NSCLC algorithm for claims data did not effectively exclude SCLC. NSCLC would be expected in 85% of cases and SCLC in 10-15% of all lung cancers, yet the algorithm developed to select NSCLC yielded a sample with about 21% SCLC. Claims data allow for a fairly comprehensive view of a large number of patients, but important information is not available, such as a distinction between NSCLC and SCLC. Medical record data enable greater depth of patient and tumor characteristics, but missing data may be common due to less restrictive reporting standards and because reporting is not tied to reimbursements as is the case with coding and claims. Combining medical record data with claims data for an observational study facilitates more detailed and comprehensive views of diagnostic testing and treatments, but researchers must compromise on sample size. Citation Format: Phil Schwab, Elizabeth MacLean, Marc Chioda, Keran Moll, Margaret Pasquale, Jack Mardekian, Tracy Futch. NSCLC observations combining medical charts and administrative claims data. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B102.