For the first time ever, a 13-year-old boy has been cured of a deadly brain cancer

( This article originally appeared on 6.25.24)

Few things strike fear in the heart of parents and doctors more than a cancer called diffuse intrinsic pontine glioma, or DIPG. Primarily found in children, DIPG is a highly aggressive brain tumor that is uniformly fatal, with less than 10 percent of children surviving longer than two years after diagnosis.

But for the first time ever, a 13-year-old boy from Belgium named Lucas Jemeljanova has beaten the odds .

Diagnosed with DIPG at age six, Lucas’ doctor Jacques Grill told Lucas’ parents, Cedric and Olesja, that he was unlikely to live very long. Instead of giving up hope, Cedric and Olesja flew Lucas to France to participate in a clinical trial called BIOMEDE, which tested new potential drugs against DIPG.

Lucas was randomly assigned everolimus in the clinical trial, a chemotherapy drug that works by blocking a protein called mTOR. mTOR helps cancer cells divide and grow new blood vessels, while everolimus decreases blood supply to the tumor cells and stops cancer cells from reproducing. Everolimus , a tablet that’s taken once per day, has been approved in the UK and the US to treat cancers in the breast, kidneys, stomach, pancreas, and others—but until the BIOMEDE clinical trial, it had never before been used to treat DIPG.

Lucas Jemeljanova poses with his mother (lesja Jemeljanova / Facebook)

Though doctors weren’t sure how Lucas would react to the medication, it quickly became clear that the results were good.

“Over a series of MRI scans, I watched as the tumor completely disappeared,” Grill said in an interview . Even more remarkably, the tumor has not returned since. Lucas, who is now thirteen, is considered officially cured of DIPG.

Even after the tumor was gone, Grill, who is the head of the Brain Tumor Program in the Department of Child and Teenage Oncology at Gustave Roussy cancer research hospital in Paris, was reluctant to stop Lucas’ treatments. Until about a year and a half ago, Lucas was still taking everolimus once every day.

“I didn’t know when to stop, or how, because there was no other reference in the world,” Grill said.

While Lucas is the only one in the clinical trial whose tumor has completely disappeared, seven other children have been considered “long responders” to everolimus, meaning their tumors have not progressed for more than three years after starting treatment.

Lucas Jemeljanova with his mother (Facebook) (lesja Jemeljanova / Facebook)

So why did everolimus work so well for Lucas? Doctors think that an extremely rare genetic mutation in Lucas’ tumor “made its cells far more sensitive to the drug,” Grill said, while the drug worked well in other children because of the “biological peculiarities” of their tumors.

While everolimus is by no means a cure, the trial has provided real hope for parents and families of children diagnosed with DIPG. Doctors must now work to better understand why Lucas’ tumor responded so well to the drug and how they can replicate those results in tumor “organoids”—artificially-grown cells that resemble an organ. After that, said Marie-Anne Debily, a researcher in the BIOMEDE trial, “the next step will be to find a drug that works as well on tumor cells.”

In the meantime, however, Lucas’ doctors are thrilled.

“Lucas’ case offers real hope,” said Debily.

Lucas Jemeljanova with his parents and sister (lesja Jemeljanova / Facebook)