He is a Professor of Medicine, Surgery, and Molecular and Medical Pharmacology at the University of California, Los Angeles (UCLA) and Director of the Tumor Immunology Program at the Jonsson Comprehensive Cancer Center.
[3] In 2014, Ribas studied how the immune system responds and develops resistance to different immunotherapies, and how treatments might be improved by combining different regimens.
[7] During the 2017–18 academic year, Ribas and Siwen Hu-Lieskovan published a study that found that more than two-thirds of people with a rare type of melanoma responded positively to treatment with anti-PD-1 immunotherapies.
[13] He used this award to support his research into combining immunotherapy with two target therapies to extend the lives of people with advanced melanoma.
[19] In October 2020, Ribas and researcher Anusha Kalbasi found that using drugs that mimic viruses to overcome immunotherapy resistance in tumors with defective interferon signaling.