Peptide-HLA (pHLA) targeting therapeutics like TCR-based adoptive cell therapy or bispecific T cell engaging receptor molecules hold great promise for the treatment of cancer. Comprehensive pre-clinical screening of therapeutic candidates is important to ensure patient safety but is challenging because of the size of the potential off-target space. By combining stabilized peptide-receptive HLA molecules with microarray printing and screening, we have developed an ultra-high-throughput screening platform named ValidaTe that enables large scale evaluation of pHLA-binder interactions. We demonstrate its potential by measuring and analyzing over 30.000 binding curves for a high-affinity T cell Engaging Receptor (TCER) towards a large pHLA library. Compared to a dataset obtained by conventional bio-layer interferometry (BLI) measurements, we illustrate that a massively increased throughput is obtained by our microarray screening without compromises in data quality, paving the way for use in pre-clinical safety screening of pHLA-targeting drugs.