Endpoint comparison for bone mineral density measurements in North Central Cancer Treatment Group cancer clinical trials N02C1 and N03CC (Alliance)

Bone mineral density (BMD) measurement can vary depending upon anatomical site, machine, and normative values used. This analysis compared different BMD endpoints in two clinical trials. Trial results differed across endpoints. Future clinical trials should consider inclusion of multiple endpoints in sensitivity analysis to ensure sound overall study conclusions.

INTRODUCTION

Methodological issues hamper efficacy assessment of osteoporosis prevention agents in cancer survivors. Osteoporosis diagnosis can vary depending upon which bone mineral density (BMD) anatomical site and machine is used and which set of normative values are applied. This analysis compared different endpoints for osteoporosis treatment efficacy assessment in two clinical studies.

METHODS

Data from North Central Cancer Treatment Group phase III clinical trials N02C1 and N03CC (Alliance) were employed involving 774 patients each comparing two treatments for osteoporosis prevention. Endpoints for three anatomical sites included raw BMD score (RawBMD); raw machine-based, sample-standardized, and reference population-standardized T scores (RawT, TSamp, TRef); and standard normal percentile corresponding to the reference population-standardized T score (TPerc). For each, treatment arm comparison was carried out using three statistical tests using change and percentage change from baseline (CB, %CB) at 1 year.

RESULTS

Baseline correlations among endpoints ranged from 0.79 to 1.00. RawBMD and TPerc produced more statistically significant results (14 and 19 each out of 36 tests) compared to RawT (11/36), TSamp (8/36), and TRef (7/36). Spine produced the most statistically significant results (26/60) relative to femoral neck (20/60) and total hip (13/60). Lastly, CB resulted in 44 statistically significant results out of 90 tests, whereas %CB resulted in only 15 significant results.

CONCLUSIONS

Treatment comparisons and interpretations were different across endpoints and anatomical sites. Transforming via sample statistics provided similar results as transforming via reference or machine-based norms. However, RawBMD and TPerc may be more sensitive to change as clinical trial endpoints.

Cardiac Safety of Lapatinib Given Concurrently with Paclitaxel and Trastuzumab as Part of Adjuvant Therapy for Patients with HER2+ Breast Cancer: Pilot Data from the Mayo Clinic Cancer Research Consortium Trial RC0639

Background: Despite the impressive results of the trastuzumab adjuvant therapy trials, 15% of patients (pts) with HER2 overexpressing or amplified breast cancer developed tumor relapse at 4 years. Lapatinib is a reversible tyrosine kinase inhibitor against ErbB1 and ErbB2. The current study was developed to assess the cardiac safety and feasibility of adding lapatinib to paclitaxel and trastuzumab following doxorubicin and cyclophosphamide as part of adjuvant therapy.Methods: A single-arm phase II study of doxorubicin (A, 60 mg/m2 day 1) and cyclophosphamide (C, 600 mg/m2 day 1) [q2w or q3w for 4 cycles]; followed by PTL: paclitaxel (P, 80 mg/m2 weekly), trastuzumab (T, 4 mg/kg loading dose then 2 mg/kg weekly), and lapatinib (L, 1000 mg PO daily which was later amended to 750 mg) [total of 12 weeks of treatment]; followed by T (6 mg/kg day 1, every 3 weeks) and L (1000 mg PO daily) [total of 40 weeks of treatment] was conducted. The primary endpoint was severe symptomatic congestive heart failure (CHF: New York Heart Association Class III or IV with a drop in left ventricular ejection fraction [LVEF] of at least 10 percentage points to below 50% confirmed by cardiologist) with secondary endpoints of cardiac death and grade 3+ cardiac adverse events (AEs).Results: From April 2007 to October 2008, 109 evaluable pts were enrolled and initiated study treatment. Median age was 51 (range 28-72). Median follow-up is 10.2 months. No pts experienced CHF or cardiac death while on active treatment. One pt had CHF and 1 pt died due to myocardial infarction (MI) after they went off study treatment. The pt with CHF refused further treatment after completing 2 cycles of PTL and had CHF 1.8 months post PTL discontinuation with LVEF of 45% and dyspnea on exertion. The pt with MI went off study treatment due to non-cardiac AEs after completing 2 cycles of PTL and died 2.9 months post PTL discontinuation. Mean LVEF at baseline was 63.6% (N=109, SD=5.7); end of AC was 63.3% (N=104, SD=6.4); end of PTL was 59.9% (N=89, SD=8.3); and cycle 12 was 59.7% (N=66, SD=7.1). Grade 3+ non-hematologic AEs with incidence >5% include diarrhea (N=42, 39% & included both 1000mg & later amended 750mg dosing), fatigue (N=15, 14%), nausea (N=7, 6%), vomiting (N=7, 6%), acne (N=6, 6%), and hypokalemia (N=6, 6%). Pre-treatment cardiac marker data (troponin-T, troponin-I, brain natriuretic peptide, creatine kinase MB isoenzyme) will also be presented.Conclusions: Preliminary data suggest that the inclusion of L does not add to the cardiac profile of T. Data from ALTTO and long-term follow data are needed to confirm the cardiac safety of this regimen. Cardiac marker data are being analyzed in the context of changes in LVEF. We gratefully acknowledge support from the Breast Cancer Research Foundation and GlaxoSmthKline for this study.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3086.

Geological record and reconstruction of the late Pliocene impact of the Eltanin asteroid in the Southern Ocean

In 1995, an expedition on board the research vessel FS Polarstern explored the impact site of the Eltanin asteroid in the Southern Ocean, the only known asteroid impact into a deep ocean basin. Analyses of the geological record of the impact region place the event in the late Pliocene (approximately 2.15 Myr) and constrain the size of the asteroid to be >1 km. The explosive force inferred for this event places it at the threshold of impacts believed to have global consequences, and its study should therefore provide a baseline for the reconstruction and modelling of similar events, which are common on geological timescales.