May 23, 2017 marked the first time a tissue agnostic cancer drug was approved by the U.S. Food and Drug Administration (FDA). Traditionally, cancer drugs target specific parts of the body under the assumption that cells located close to each other have similar receptors that specific treatments can target. Rather than focusing on one specific location in the body, tissue agnostic drugs like Pembrolizumab (Keytruda) target genetic biomarkers found in various sites in the body. Created by Merck & Co., Pembrolizumab targets the programmed cell death 1 (PD-1) pathway that cancer cells may use to hide from T cells. Out of the 149 patients with microsatellite instability-high (MLH) or mismatch repair deficient (dMMR) cancers, there was an objective response rate (ORR) of 39.6% for those treated with Pembrolizumab (FDA). The significant reduction in tumor progression in the clinical trial conducted prompted the FDA to grant accelerated approval for Pembrolizumab.

Tissue agnostic drugs form a subsection of a new and growing field known as precision medicine, where medication and drugs are customized to account for different genetic, environmental, and lifestyle factors. Rather than a “one-size-fits-all” approach that is usually tailored for an average American, precision medicine aims at treating and improving survival for all people. In his 2015 State of the Union Speech, President Obama announced the launch of the Precision Medicine Initiative. The National Institute of Health followed shortly after the approval of Pembrolizumab, launching the ‘All of Us Research Program’ to collect medical data on millions of Americans for research. Just a few months ago, the FDA released document guidelines outlining a new paradigm of tissue agnostic drugs, prompting Bayer and Loxo Oncology, Inc. to create Vitrakvi.

Also known as Larotrectinib, Vitrakvi is the second tissue agnostic cancer drug to have been granted accelerated approval by the FDA on November 26, 2018. It targets adults and children with solid tumors who test positive for neurotrophic receptor tyrosine kinase (NTRK), a gene that accelerates the growth of cancerous cells by abnormally fusing with other genes. Although these fusions are rare, Vitrakvi has had a 75% overall response rate for diseases that had no alternative treatment or whose surgical removal would risk lives (FDA). “It’s amazing just how far the medical field has come in terms of improving survival rates and lengthening lives,” Alejandro Ramos ’19 said. “It won’t be long before that 75% turns closer to 100%.”

Pembrolizumab and Vitrakvi provide relief for many patients, but they have similar drawbacks to many cancer drugs on the market. Side effects such as fatigue, nausea, diarrhea, cough, and constipation are common. Prescriptions warn to limit the use of Pembrolizumab for pediatric patients because the safety of the drug for some nervous system cancers need to be further researched, and hormone levels should be monitored when using Vitrakvi to prevent liver damage in users. “With more research dedicated to medication, hopefully one day these drugs won’t have any side effects,” Elainee Chen ’19 said.

“It’s amazing just how far the medical field has come in terms of improving survival rates and lengthening lives,” Alejandro Ramos ’19 said. “It won’t be long before that 75% turns closer to 100%.”

Vitrakvi and Pembrolizumab are the first of many tissue agnostic drugs to come. Increasing efforts to personalize medication and the field of discoveries precision medicine offers is more than enough incentive for millions of dollars to be dedicated to research. With each discovery and breakthrough, humanity is one step closer to improving the quality of life all around the world.