Background: Systemic agents in cancer treatment were often associated with possible infusion reactions (IRs). This study estimated the incidence of IRs requiring medical intervention and assessed the clinical and economic impacts of IRs in patients with colorectal cancer (CRC) treated with cetuximab.Patients and methods: Details on patients with CRC receiving cetuximab in 2004–2006 were extracted from a large USA administrative claims database. IRs were identified based on the occurrence of outpatient treatment, emergency room (ER) visit, and/or hospitalization for hypersensitivity and allergic reactions. Multivariate regressions were used to examine potential risk factors and quantify the economic impact of IRs.Results: A total of 1122 CRC patients receiving cetuximab were identified. The incidence of IRs requiring medical intervention was 8.4%. Sixty-eight percent of the patients had treatment disruptions and 34% discontinued cetuximab treatment. Mean adjusted costs were $13 863 for cetuximab administrations with an IR requiring ER visit or hospitalization and $6280 for those with an IR requiring outpatient treatment, compared with $4555 for those without an IR.Conclusions: The incidence rate of cetuximab-related IRs requiring medical intervention in clinical practice was found to be higher than rates reported in the product label and clinical trials. The clinical and economic impacts of these IRs are substantial.

4120 Background: New systemic chemotherapies, particularly the MoAbs, bevacizumab (BMab), cetuximab (CMab), and panitumumab (PMab) have advanced therapy for mCRC. However, the optimal combination and sequencing of these and other chemotherapies are not established, and little is known about their patterns of use in clinical practice. We examined the frequency, patterns of use, and dosing changes of MoAbs across lines of therapy. Methods: The dataset consists of Varian and Impac electronic medical records for 304,654 cancer patients from 91 practice sites across 19 states. Inclusion/exclusion criteria were applied: ≥18 years old, newly diagnosed with mCRC or developed metastases during 1/1/2004 - 1/31/2008, and could be observed ≥3 months beyond their dates of metastases. Patients on a clinical trial at any time during the analysis were excluded. Results: The study sample included 1,655 patients (52% male, mean age 61.9 years). 11% received all five therapeutic classes: fluoropyrimidines, irinotecan, oxaliplatin, EGFR MoAbs (PMab and CMab), and VEGF MoAb (BMab). 19% received at least 3 treatment classes. BMab, fluorouracil, leucovorin, oxaliplatin (BMab+FOLFOX) was the most frequently observed 1st line regimen in 26% of patients. Across the study period more patients received BMab than PMab or CMab (69%, 7%, and 22%, respectively, for any exposure); 55% received BMab for 1st-line therapy. A BMab dose increase within a line of therapy was recorded in 22% of patients for 1st-line, 21% for 2nd-line, and 15% for 3rd-line. Among patients who continued BMab from 1st to 2nd line (N=239) and 2nd to 3rd line (N=88), 44% and 39%, respectively had a dose increase (mean/month 890mg to 1078mg, and 844mg to 1053mg). Conclusions: The most frequent 1st-line chemo regimen was FOLFOX. BMab was the most commonly administrated MoAb. Trends toward dose-escalation of BMab were observed both within lines of therapy and across lines of therapy. [Table: see text]

6553 Background: Several long-standing chemotherapy regimens are available to treat metastatic colorectal cancer (mCRC) including: oxaliplatin plus 5-fluorouracil (5-FU) and leucovorin (FOLFOX); and Irinotecan plus 5-FU and leucovorin (FOLFIRI). More recently, new biologic therapies were approved for use in mCRC. This cohort study examines trends in first-line chemotherapy treatments for newly diagnosed mCRC patients after the introduction of capecitabine (CAP) in 2001 and the biologic therapies in 2004. Methods: Using a large, US-based administrative medical claims database of a national commercially insured population, patients with newly diagnosed mCRC were identified from 2001 to 2005. At least 6-months of patient history prior to mCRC diagnosis were required to confirm patients were newly diagnosed. Patients were followed from initial mCRC diagnosis to death, disenrollment, or 12/31/2006. Results: Total of 3,781 newly diagnosed mCRC patients were identified between 2001–2005. On average over the 5 years, 58% of patients (with annual variation ± 4% points) received chemotherapy/biologic treatment in the year following their mCRC diagnosis; mean days to initiation of chemotherapy treatment decreased from 135 to 62 between 2001–2005. In 2001, FOLFIRI (40%), 5-FU (30%), and CAP (20%) were the most prevalent first-line treatments. In 2005, first-line treatment regimens were more diverse: FOLFOX plus bevacizumab (35%), FOLFOX alone (15%), 5-FU (15%), and CAP (15%) were the most prevalent, while 33% of patients used other treatment combinations. Among mCRC patients diagnosed in 2005, 63% were treated with at least one biologic therapy in the first year after diagnosis (57% received bevacizumab; 26% received cetuximab). Conclusions: While rates of chemotherapy use remained relatively constant between 2001–2005, patients initiated chemotherapy treatment sooner after their initial diagnosis and the standard course of therapy shifted from being FOLFIRI-based to FOLFOX-based. A rapid uptake in biologic therapies occurred. The majority of newly diagnosed mCRC patients were users of biologic therapy within one year following their introduction. [Table: see text]