Trial Outcomes & Findings for Biodistribution Study of CMD-193 in Patients With Advanced Tumours Expressing the Lewis-Y Antigen (NCT NCT00293215)

Biodistribution Study of CMD-193 in Patients With Advanced Tumours Expressing the Lewis-Y Antigen

Biodistribution data were collected after subjects received a single infusion of 111-In-CMD-193 over 1 hour on Day 1 of Cycle 1. Gamma camera imaging with anterior and posterior whole body scans using conjugate view methodology were performed on Days 1, 2, 3 or 4, 5 or 6, and 7 or 8 following the 111-In-CMD-193 infusion. A standard was included in the field of view at each imaging time point. Single-photon emission computerized tomography (SPECT) imaging of relevant areas of disease were performed on at least one occasion following the 111-In-CMD-193 infusion. Biodistribution analysis was performed by examination of whole body and SPECT images by experienced nuclear medicine physicians.

Gamma camera imaging with anterior and posterior whole body scans using conjugate view methodology were performed on Days 1, 2, 3 or 4, 5 or 6, and 7 or 8 following the 111-In-CMD-193 infusion. Whole body clearance, or biological half-time, was calculated from the whole body anterior and posterior planar images. A region of interest (ROI) was calculated to encompass the whole body, and for each ROI at each time point, the mean counts per pixel per minute was normalized to imaging time point Day 1. From this time-activity curve, an exponential clearance expression was fitted to obtain effective half-time. This was then corrected for the physical half-life of 111-In (67.45 hours) to account for physical decay to obtain the biological half-time.

During Cycle 1 (111-In-CMD-193 infusion) serum samples for pharmacokinetics were collected on Days 1 (pre-infusion and 1 and 4 hours after the start of the infusion), 3, 8 and 15. Serum obtained from subjects following infusion of 111-In-CMD-193 was aliquoted and counted in a gamma scintillation counter. Duplicate standards prepared from the injected material were counted at each time point with serum samples to enable calculations to be corrected for the isotope physical decay. A 2-compartment IV bolus model with macro-parameters, no lag time and first order elimination (WNL Model 8) was fitted to individual labelled infusions for each subject using un-weighted nonlinear, least squares with WinNonLin version 5.2. T½α and T½β represent half lives of the initial and terminal phases of disposition.

During Cycle 1 (111-In-CMD-193 infusion) serum samples for pharmacokinetics were collected on Days 1 (pre-infusion and 1 and 4 hours after the start of the infusion), 3, 8 and 15. Serum obtained from subjects following infusion of 111-In-CMD-193 was aliquoted and counted in a gamma scintillation counter. Duplicate standards prepared from the injected material were counted at each time point with serum samples to enable calculations to be corrected for the isotope physical decay. A 2-compartment IV bolus model with macro-parameters, no lag time and first order elimination (WNL Model 8) was fitted to individual labelled infusions for each subject using un-weighted nonlinear, least squares with WinNonLin version 5.2.

During Cycle 1 (111-In-CMD-193 infusion) serum samples for pharmacokinetics were collected on Days 1 (pre-infusion and 1 and 4 hours after the start of the infusion), 3, 8 and 15. Serum obtained from subjects following infusion of 111-In-CMD-193 was aliquoted and counted in a gamma scintillation counter. Duplicate standards prepared from the injected material were counted at each time point with serum samples to enable calculations to be corrected for the isotope physical decay. A 2-compartment IV bolus model with macro-parameters, no lag time and first order elimination (WNL Model 8) was fitted to individual labelled infusions for each subject using un-weighted nonlinear, least squares with WinNonLin version 5.2.

During Cycle 1 (111-In-CMD-193 infusion) serum samples for pharmacokinetics were collected on Days 1 (pre-infusion and 1 and 4 hours after the start of the infusion), 3, 8 and 15. Serum obtained from subjects following infusion of 111-In-CMD-193 was aliquoted and counted in a gamma scintillation counter. Duplicate standards prepared from the injected material were counted at each time point with serum samples to enable calculations to be corrected for the isotope physical decay. A 2-compartment IV bolus model with macro-parameters, no lag time and first order elimination (WNL Model 8) was fitted to individual labelled infusions for each subject using un-weighted nonlinear, least squares with WinNonLin version 5.2.

Computed tomography (CT) scans were performed at screening, between Days 15 and 21 of Cycles 2 and 4, and at study completion. Response was assessed using RECIST version 1.0 (Therasse et al, J Natl Cancer Inst 2000; 92:205-16), and all response assessment was performed by a single experienced radiologist. Per RECIST, target lesions are categorized as follows: complete response (CR): disappearance of all target lesions (no evaluable disease); partial response (PR): ≥ 30% decrease in the sum of the longest diameter of target lesions; progressive disease (PD): ≥ 20% increase in the sum of the longest diameter of target lesions; stable disease (SD): small changes that do not meet above criteria.

Positron emission tomography with 18F-labeled fluorodeoxyglucose (18F-FDG-PET) was done at screening and between Days 15-21 of Cycles 2 and 4 or at study completion. Metabolic response was calculated using the target lesion with the greatest baseline standardized uptake value (SUV) and categorized per EORTC guidelines (Young et al. Eur J Cancer 1999;35:1773-82): progressive metabolic disease was an increase in 18F-FDG tumor maximum SUV (SUVmax) of \> 25% within the tumor ROI determined on baseline scans, visible increase in 18F-FDG tumor uptake (\>20% in the longest dimension) or new 18F-FDG uptake in metastatic lesions. Stable metabolic disease was an increase in tumor 18F-FDG SUVmax of \< 25% or decrease of \< 15% and no visible increase in 18F-FDG tumor uptake (\>20% in the longest dimension). Partial metabolic response was a reduction of 15-25% in tumor 18F-FDG SUVmax after 1 cycle and \> 25% after \> 1 cycle (reduced tumor 18F-FDG uptake was not required).