Discrepancies of assessments in a RECIST 1.1 phase II clinical trial – association between adjudication rate and variability in images and tumors selection

Abstract Background In imaging-based clinical trials, it is common practice to perform double reads for each image, discrepant interpretations can result from these two different evaluations. In this study we analyzed discrepancies that occurred between local investigators (LI) and blinded independent central review (BICR) by comparing reader-selected imaging scans and lesions. Our goal was to identify the causes of discrepant declarations of progressive disease (PD) between LI and BICR in a clinical trial. Methods We retrospectively analyzed imaging data from a RECIST 1.1-based, multi-sites, phase II clinical trial of 179 patients with adult small cell lung cancer, treated with Cabazitaxel compared to Topotecan. Any discrepancies in the determination of PD between LI and BICR readers were reviewed by a third-party adjudicator. For each imaging time point and reader, we recorded the selected target lesions, non-target lesions, and new lesions. Odds ratios were calculated to measure the association between discrepant declarations of PD and the differences in reviewed imaging scans (e.g. same imaging modality but with different reconstruction parameters) and selected lesions. Reasons for discrepancies were analyzed. Results The average number of target lesions found by LI and BICR was respectively 2.9 and 3.4 per patient (p < 0.05), 18.4% of these target lesions were actually non-measurable. LI and BICR performed their evaluations based on different baseline imaging scans for 59% of the patients, they selected at least one different target lesion in 85% of patients. A total of 36.7% of patients required adjudication. Reasons of adjudication included differences in 1) reporting new lesions (53.7%), 2) the measured change of the tumor burden (18.5%), and 3) the progression of non-target lesions (11.2%). The rate of discrepancy was not associated with the selection of non-measurable target lesions or with the readers’ assessment of different images. Paradoxically, more discrepancies occurred when LI and BICR selected exactly the same target lesions at baseline compared to when readers selected not exactly the same lesions. Conclusions For a large proportion of evaluations, LI and BICR did not select the same imaging scans and target lesions but with a limited impact on the rate of discrepancy. The majority of discrepancies were explained by the difference in detecting new lesions. Trial Registration ARD12166 (https://clinicaltrials.gov/ct2/show/NCT01500720)

Cabazitaxel Versus Topotecan in Patients with Small-Cell Lung Cancer with Progressive Disease During or After First-Line Platinum-Based Chemotherapy

Introduction: Patients with small-cell lung cancer (SCLC) typically respond well to initial chemotherapy. However, relapse invariably occurs, and topotecan, the only approved second-line treatment option, has limited efficacy. Taxanes have activity in SCLC, and cabazitaxel is a second-generation taxane with potential for enhanced activity in chemorefractory malignancies. Methods: Patients with SCLC who relapsed after initial platinum-based chemotherapy were randomly assigned to receive cabazitaxel 25 mg/m(2) every 21 days or topotecan 1.5 mg/m(2) on days 1-5 every 21 days. Two patient subgroups, defined by chemosensitive and chemo-resistant/refractory disease, were assessed in combination and separately. Results: The safety profile of cabazitaxel and topotecan was consistent with previous studies, and despite considerable toxicity in both arms, no new safety concerns were identified. Patients receiving cabazitaxel had inferior progression-free survival compared with topotecan (1.4 versus 3.0 months, respectively; two-sided p &lt; 0.0001; hazard ratio = 2.17, 95% confidence interval = 1.563-3.010), and results were similar in both the chemosensitive and chemorefractory subgroups. No complete responses were observed in either arm, and no partial responses were observed in the cabazitaxel group. The partial response rate in the topotecan arm was 10%. Median overall survival was 5.2 months in the cabazitaxel arm and 6.8 months in the topotecan arm (two-sided p = 0.0125; hazard ratio = 1.57, 95% confidence interval = 1.10-2.25). Conclusion: Cabazitaxel, a next-generation taxane, had inferior efficacy when compared with standard-dose topotecan in the treatment of relapsed SCLC. Topotecan remains a suboptimal therapy, and continued efforts to develop improved second-line treatments are warranted

An open-label study to investigate the cardiac safety profile of cabazitaxel in patients with advanced solid tumors

PURPOSE: This study assessed the cardiovascular safety of cabazitaxel, based on thorough evaluation of QT and non-QT variables, and the relationship between pharmacokinetic and pharmacodynamic electrocardiographic (ECG) profiles and the occurrence of Grade ≥3 cardiovascular adverse events. METHODS: Patients with advanced solid tumors were treated with cabazitaxel 25 mg/m(2) every 3 weeks. Digital ECG recordings were obtained during Cycle 1 over 24 h after dosing. The primary end point was effect of cabazitaxel on QT interval corrected by the Fridericia formula (QTcF). Secondary end points were additional ECG parameters (QT, PR and QRS intervals, and heart rate), plasma pharmacokinetics of cabazitaxel and overall clinical safety. RESULTS: The pharmacodynamic (ECG) population included 94 patients. In 63 patients with a full 24-h ECG evaluation, the maximum upper bound of 90 % confidence interval (CI) for mean QTcF change from baseline was 7.46 ms (mean 4.8 ms), occurring at 1 h 30 min post-infusion. The slope of QTcF change from baseline versus cabazitaxel concentration was slightly negative (-0.012 [95 % CI -0.017; -0.008], equivalent to a 1.2 ms decrease per 100 ng/mL increase in cabazitaxel concentration). For non-QT variables, no effect was noted. No Grade ≥3 cardiac adverse events were observed; Grade ≥3 hypotension and lymphocele occurred in two patients and one patient, respectively. CONCLUSION: These results suggest that cabazitaxel has no clinically significant cardiovascular adverse effects in patients with advanced solid tumors