From Malaria to Demodex Blepharitis: A Chief Medical Officer's Global Health Mission
The career of Dr. José Trevejo, Chief Medical Officer of Tarsus Pharmaceuticals, began with his childhood experience of running to seek medical help for his mother who had malaria. Today, he is leading his team to advance TP-03 as the first FDA-approved treatment for Demodex blepharitis, a condition affecting approximately 25 million patients in the United States.
When Dr. José Trevejo recalls the day his mother fell ill, the image that comes to mind most is running.
He was only four or five years old, living in Ghana. His mother had a fever from malaria—a disease both common and feared in many tropical parts of the world—and she was too weak to get out of bed.
"She asked me to go get the doctor, so I literally ran out into the street—there were no phones—and I ran all the way to bring the doctor back," he says. "In West Africa in the 1970s, there was hardly any way to communicate other than showing up in person."
So he ran along unpaved roads in the humid, hot Ghanaian weather until he reached the doctor's clinic. He doesn't remember other details—like how he got home, or even if he was scared—but the doctor came, and his mother eventually recovered.
"All I remember is being in motion. Maybe that's where I am now," he says. "If something needs to be done to help people avoid suffering? Then I think, okay, let's do it. Let's get moving."
Trevejo has remained in motion ever since as a physician-scientist, and today he is Chief Medical Officer at Tarsus Pharmaceuticals, a biopharmaceutical company based in California. The company's lead candidate, TP-03, could become the first FDA-approved treatment for Demodex blepharitis, an inflammatory eyelid condition affecting about 25 million patients in the U.S., caused by an infestation of Demodex mites, tiny external parasites common in humans. TP-03 works by killing the Demodex mites themselves.
"This is definitely a highly unmet medical need. It would be a first-in-class treatment for the disease," Trevejo says.
With Phase 3 studies complete, the FDA has accepted the drug's New Drug Application (NDA) and set aPDUFA target date of August 25。
"Joining the company at this exciting time of transition from a clinical-stage to a potential commercial-stage company," says Trevejo, who joined Tarsus in February 2022.
Beyond the high unmet treatment need, Demodex blepharitis is also highly underrecognized. But it has a hallmark sign—cylindrical waxy debris at the base of the eyelashes. As Tarsus prepares for potential FDA approval, it is currently running a disease awareness campaign for eye care professionals called "Look at the Lids."
"Once eye care providers start looking for these signs, they'll realize how common this condition is," Trevejo says. "It makes sense, because the mites that cause it are present in 100% of people. Everyone has these mites on their face, and most of the time they coexist with us on the face, but when they get into the lash area, that's when you can get problems like Demodex blepharitis."
Where science and medicine meet
At its root, Demodex blepharitis is an infectious disease—an area that has been Trevejo's clinical interest for years.
"In infectious disease practice, you basically encounter a lot of medical mysteries that you have to solve," he says.
After completing his undergraduate studies in applied mathematics at UCLA, Trevejo earned a Ph.D. in molecular and cell biology from Cornell University and an M.D. through the Cornell-Rockefeller-Sloan Kettering Tri-Institutional program. He then headed to Boston, where he completed his residency in internal medicine at Brigham and Women's Hospital and a fellowship in infectious diseases at Beth Israel Deaconess Medical Center, both teaching affiliates of Harvard Medical School, where he also served as an instructor.
"In infectious disease practice, you basically encounter a lot of medical mysteries that you have to solve."
Dr. José Trevejo
Chief Medical Officer at Tarsus Pharmaceuticals
His later move to industry was a logical choice, driven both by his scientific interests and his medical degree—which was specifically designed to train physician-scientists.
"I wanted to do something translational, bridging the gap between technology and medicine," he says. "Industry is actually an ideal career path for M.D.-Ph.D. graduates, because that's exactly what you're doing. You have to understand the science, and you have to understand the clinical application."
He found that bridge at Draper Laboratory, a nonprofit research lab spun out of MIT, where he worked on a project using new technology to rapidly diagnose tuberculosis. Since then, he has held roles in clinical development at companies including Genentech, Ironwood Pharmaceuticals, and Vertex Pharmaceuticals.
"My passion has always been in tackling diseases with high unmet need," he says.
Diseases affecting the world
Trevejo was born in California, but when he was a baby, his mother took him to Ghana. She was following her own father—Trevejo's grandfather—who went there to try to start businesses. Those ventures ultimately failed, and after a brief stay in neighboring Togo, Trevejo and his mother moved back to the U.S.
"We started from scratch," he says. "It was just the two of us."
His mother's dedication and work ethic deeply influenced him—he remembers her taking three buses each way to work as she climbed from secretary to office manager—and so did his international upbringing.
"I'm American, but I also consider myself a global citizen. I care about what happens around the world," he says. "I also learned to be adaptable and flexible, and to appreciate different ways of life and perspectives."
He applies that worldview to his work as a leader and drug developer.
"When you're developing a drug... you have to be able to really connect with and empower your team. My appreciation for different perspectives has led to a philosophy: we try to bring together people from diverse backgrounds to find the best answers to these tough problems," he says. "Other people think differently, and sometimes the right answer can come from somewhere else, so you have to be open to that."
His experience living abroad and witnessing a family member suffer from malaria was also formative.
"I've been fascinated by diseases that affect the world since I was a child," he says. "I think that interest has stayed with me since childhood, and I've always wanted to find ways to help people suffering from devastating diseases."
Today, he is coming full circle in that sense: Tarsus is studying whether its pipeline product TP-05—being developed for Lyme disease—could also be used as a preventive for malaria. In a way, he is still that boy running to solve a problem.
"Maybe that's a parable," he says. "I'm always looking for solutions."