Background: The new SARS-CoV-2 Omicron variant XBB.1.5 has shown extraordinary immune escape even for fully vaccinated individuals. There are currently no approved antibodies that neutralize this variant, and antiviral drug escape mutations have been identified. COVID-19 has risen to the third leading cause of death in the U.S, and the continued emergence of new variants puts immunocompromised and elderly patients at high risk. A rapid and cost-effective method to develop novel effective neutralizing antibodies is urgently needed. Methods: An antibody panel that broadly neutralizes currently circulating Omicron variants was obtained by in vitro affinity maturation using phage display. Starting from a single parent clone, antibody engineering was performed in iterative stages in real time as variants emerged using a proprietary technology called STage-Enhanced Maturation (STEM). Results: Humanized from a rabbit neutralizing antibody against the original Wuhan-Hu-1 strain, the parent clone showed undetectable neutralization of later Omicron variants, while an early-stage clone possessing only an engineered light chain potently neutralizes some BA.2 but not BA.4/BA.5 lineage variants. However, the final heavy and light chain engineered antibodies show potent neutralization of BQ.1.1 and XBB.1.5 by surrogate virus neutralization test (sVNT) and pM KD affinity for all variants by biolayer interferometry. Conclusions: Our work not only details novel therapeutic candidates but also validates a unique general strategy to create broadly neutralizing antibodies to current and future SARS-CoV-2 variants. Statement of Significance: We report engineering and characterization of SARS-CoV-2 therapeutic antibodies that neutralize all Omicron variants to date. Surrogate virus neutralization assay shows low ng/mL IC50 values and biolayer interferometry shows pM affinity. The use of a proprietary platform technology, STage Enhanced Maturation (STEM), is detailed.