Companion diagnostics assay interpretation can select patients with the greatest 
targeted therapy benefits. We present the results from a prospective study 
demonstrating that pathologists can effectively learn immunohistochemical 
assay-interpretation skills from digital image-based electronic training 
(e-training). In this study, e-training was used to train board-certified 
pathologists to evaluate non-small cell lung carcinoma for eligibility for 
treatment with onartuzumab, a MET-inhibiting agent. The training program 
mimicked the live training that was previously validated in clinical trials for 
onartuzumab. A digital interface was developed for pathologists to review 
high-resolution, static images of stained slides. Sixty-four pathologists 
practicing in the United States enrolled while blinded to the type of training. 
After training, both groups completed a mandatory final test using glass slides. 
The results indicated both training modalities to be effective. Overall, 80.6% 
of e-trainees and 72.7% of live trainees achieved passing scores (at least 85%) 
on the final test. All study participants reported that their training 
experience was "good" and that they had received sufficient information to 
determine the adequacy of case slide staining to score each case. This study 
established that an e-training program conducted under highly controlled 
conditions can provide pathologists with the skills necessary to interpret a 
complex assay and that these skills can be equivalent to those achieved with 
face-to-face training using conventional microscopy. Programs of this type are 
scalable for global distribution and offer pathologists the potential for 
readily accessible and robust training in new companion diagnostic assays linked 
to novel, targeted, adjuvant therapies for cancer patients.