Luis A. Diaz

Luis A. Diaz, Jr. MD, associate professor of Oncology, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, discusses the efficacy of PD-1 inhibitor pembrolizumab (Keytruda) in heavily pretreated colorectal cancer patients with mismatch repair (MMR). Luis A. Diaz, Jr. MD, associate professor of Oncology, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, discusses the efficacy of PD-1 inhibitor pembrolizumab (Keytruda) in heavily pretreated colorectal cancer patients with mismatch repair (MMR). Previously, MMR deficiency was primarily seen as a prognosis marker, and in late stage colorectal cancer it was typically linked to worse prognosis, said Diaz. His team hypothesized that MMR deficient tumors may have immunogenic properties and could response positively to anti-PD1 therapies. Many of the patients in the study treated with anti-PD1 therapy had advanced stage cancer, had failed several lines of previously therapy, and were in hospice care at the time of the trial, said Diaz. Patients with advanced disease responded dramatically, said Diaz. Tumor markers came down, tumors shrank, and overall clinical response improved. Anti-PD1 therapy could be beneficial not only for colon cancer patients, but patients with multiple tumors types that have mismatched repair deficiency, said Diaz. Dr. Luis Diaz is a leading authority in oncology who has pioneered several genomic diagnostic and therapeutic approaches for cancer. He is head of the Division of Solid Tumor Oncology at the Memorial Sloan Kettering Cancer Center where he specializes in the treatment of advanced pancreatic and colorectal cancers. Prior to his role at MSKCC, he was a member of the Ludwig Center for Cancer Genetics and Therapeutics at Johns Hopkins and also directed the Swim Across America Lab. He is also founder of several entities that focus on genomic analyses of cancers including Inostics, PapGene and Personal Genome Diagnostics (PGDx). Dr. Diaz has undergraduate and medical degrees from the University of Michigan, and completed residency training at the Osler Medical Service at Johns Hopkins and medical oncology training at the Sidney Kimmel Cancer Center at Johns Hopkins. Dr. Diaz is involved in near-patient translational studies with the goal of bringing diagnostic and therapeutic studies to patients. His work has involved the clinical development of tumor-derived DNA as a biomarker for cancer screening, early detection, monitoring and measurement of early residual disease. The preliminary studies served as the basis for his most recent invention, the ‘molecular pap smear,’ which is a promising approach for the early detection of ovarian and endometrial cancers. He has also harnessed the power of cancer mutations as potent antigens and championed the use of checkpoint inhibitors in the treatment of patients with tumors with high mutational burden. His landmark proof-of this principle study used PD-1 blockade in patients with mismatch repair deficiency and showing dramatic and potentially curative responses in 90% of metastatic patients, which resulted in the first historic FDA approval of a cancer treatment for any solid tumor in adults and children with a specific genetic feature.