Campbell, M. E.

6517 Background: In NCCTG CTs a subset of AEs are assessed at each patient (pt) evaluation based on the known safety profile of agents(s). The NCCTG routinely pre-fills the “known” AE list onto CT Case Report Forms (CRFs). Newly identified AEs may expand the AE assessment list for ongoing CTs. Our survey of NCCTG AE data (JCO 2005), demonstrated that 85% of AEs reported were pre-filled on CRFs, of which, 83% did not actually occur (Grade 0). Extending this work, we evaluated the influence of pre-filling AEs on CRFs, relative to the final AE rates reported. Methods: Our non-random sample contains 507,899 AEs collected from 1/99–6/06 on 74 NCCTG CTs, 13 of which had AEs added to the CRF pre-fill list during the CT (2,604 pts, 3 Ph I/II, 8 Ph II, 2 Ph III, 9 investigational agents). Results: An average of 2.8 AEs (range 1–6) were added to CRFs for ongoing CTs, primarily for Oxaliplatin induced AEs. 58% (21/36) of AEs added during a CT were not reported prior to the addition, 22% (8) were not reported afterwards. 5 CTs had significantly higher AE rates (p<0.01) after expanding the AE list, most notably for required blood chemistries (SGOT/alk phos/creatinine/bilirubin 14.2 vs 0.72%). Overall, the same AEs were 4-fold (range 0–25) as likely to be reported when pre-filled on the CRF. Regardless of pre-filling, only 6% of the newly required AEs were Gr 3+. Conclusions: Our data suggest a significant difference between the AE rates reported if included in the CT CRF assessment list. This may significantly influence the reported results of a CT, explaining differential AE rates reported across CTs of the same agent(s). A prospective study is planned to formally evaluate this observation. Supported by NIH Grant CA25224. No significant financial relationships to disclose.

4080 Background: Waterfall plots have been used to capture the anti-tumor efficacy of both biologic agents (Ratain JCO 2006), which mainly exhibit a cytostatic effect, but also of chemotherapeutic agents. We are not aware of an application to therapeutic studies in CRC. We conducted waterfall plot analyses on the data of N9741 which compared IFL, FOLFOX4, and IROX as first-line therapy in ACRC (Goldberg JCO 2004). Methods: 634 (IFL 215, FOLFOX 215, IROX 204) of the 795 pts presented in the published analysis had measurable disease, and are included. The percentage change in tumor measurements from baseline to 12 wks was calculated, allowing for a time window of assessment from 6 to 20 wks for those without a 12 wk measurement. Pts with progression before the 12 wk assessment were assigned a 100% increase. The average reduction in tumor burden (ARTB) was calculated as difference in waterfall AUC divided by the number of pts. ARTB captures the average percentage reduction in tumor measurements at 12 wks for a patient entering the trial. Results: Waterfall plot analysis demonstrated some tumor growth at 12 wks in 23.7% (IFL), 15.8% (FOLFOX), and 26.9% (IROX) of pts. In contrast, tumor shrinkage was observed in 67.9% (IFL), 71.6% (FOLFOX), and 61.4% (IROX) of pts. Total differential AUC was -34.4 (IFL), -61.6 (FOLFOX), and -30.4 (IROX) resulting in an ARTB of 16.0% (95% Confidence Interval (CI) (23.7%, 8.2%)) for IFL, 28.7% (35.1%, 22.2%) for FOLFOX, and 14.9% (22.5%, 7.3%) for IROX. Conclusions: Waterfall plot analyses are feasible in this and likely other CRC trials using conventional chemotherapy. Our analysis confirms the published results of N9741, but suggests a larger degree of benefit for individuals based on anti-tumor activity than captured by conventional response analysis. Waterfall plots provide a potentially useful new efficacy metric, the average reduction of tumor burden per pt, which should be validated in future trials. No significant financial relationships to disclose.

4067 Background: N9741 randomized 1691 patients (pts) to seven 5FU, Ox and Iri containing regimens for MCRC. After 20.4 months median follow-up, FOLFOX and IROX improved time to progression (TTP) and overall survival (OS) compared to IFL. Here we update OS and TTP, and report an analysis of factors prognostic of pt outcome. Methods: 5 yr OS and TTP were calculated by Kaplan-Meier per treatment (rx) arm. Pt factors [rx arm, age, gender, prior adjuvant rx, body mass index (BMI), performance status (PS), number of disease sites (#sites), neutrophil count (ANC), hemoglobin, platelets, bilirubin, alkaline phosphatase (ALK), aspartate aminotransferase (AST)] were assessed for univariate association with OS, TTP, response rate (RR), and any grade =3 toxicity. Associated factors were included in multivariate Cox and logistic regression models. Results: After a median follow-up of 4.3 yrs, FOLFOX treated pts were more likely to live 5 yrs, 9.2% versus 5.4% for IROX (p=.016) and 3.8% for IFL (p<.001). Median TTP was also significantly longer in the FOLFOX arm, 9.2 mo vs 6.5 mo for IROX (p=<.001) and 6.0 mo for IFL (p=<.001). The prognostic model found higher PS, ANC and ALK, and more disease sites were prognostic of worse OS (see table ). Age = 70 was associated with poorer survival (HR death 1.33, p=.03), but not TTP, RR, or grade =3 toxicity. FOLFOX rx was the most powerful prognostic factor for TTP and OS. The odds of grade =3 toxicity were significantly higher in FOLFOX treated pts (OR 1.65, p<.001) and lower in men (OR .63, p<.001). No significant interactions between rx arm and pt factors were present, suggesting no factor examined is predictive of rx-specific outcome. Conclusions: 9% 5 yr OS in MCRC pts treated with first-line FOLFOX sets a new benchmark. We confirmed pre-rx PS, WBC, and ALK are prognostic for OS, though FOLFOX rx was the strongest prognostic factor. No factor was associated with differential outcome or toxicity by rx arm, thus these factors cannot be used to guide rx selection. [Table: see text] [Table: see text]