Targeting lingering brain cancer with radiation immediately after surgery
CEO: Matthew Likens
Based: Phoenix, Arizona
The scoop: Removing a tumor from a person’s brain is a delicate, complicated balance. A surgeon must judge each action and whether it does more good than harm: Take out too much tissue, and you may take away too much function; move too quickly against a growing threat, and wounds may not heal.
But GT Medical looks to put its thumb on the scale. Typically, standard clinical practice involves surgery to excise the bulk of the tumor, followed by daily treatments of beam radiation to kill any malignant cells left behind, or at least hinder their growth and eventual return.
However, that phase of therapy can’t begin until weeks after the operation, as the body needs to recover before being subjected to strong, directed doses of radiation. That time is, instead, ceded to the cancer.
GT Medical, founded by a group of five neurosurgeons, radiation oncologists and brain tumor specialists, aims to change the standard of care to deliver radiation therapy at minute one. The company’s bioresorbable GammaTile implant is placed within the brain during the final steps of surgery, just before closing up, to line the walls of the fresh tumor cavity with radioactive seeds.
Over the following months, the tile’s structure slowly melts away into the body as it evenly bathes the immediate area with constant, low-dose radiation—enough to kill cancer cells without harming healthy tissue—leaving behind only small, inert capsules of cesium and titanium.
“We call it an elegantly simple design,” says GT Medical CEO Matthew Likens. “But the cool thing is, you're getting most of the radiation upfront, right after it's placed.”
As the cesium-131 isotope decays, it delivers half of its total radioactive dose within the first nine or 10 days, with about 95% being spent within six weeks.
“It’s when those cells have already been disrupted, and they're most vulnerable to the assault of radiation,” Likens says. “As opposed to waiting three weeks, and allowing residual tumor cells to possibly re-establish themselves and make the challenge for adjuvant radiation therapy that much greater.”
Additionally—by delivering lower doses of radiation from within, versus weeks of external beam treatments—patients do not lose their hair.
“Sometimes that sounds trivial when you have a patient facing a brain tumor, but there are published articles saying this is a huge emotional issue for many patients,” he says. “They view themselves as being changed by their disease, and it's very difficult to deal with emotionally. It’s a big deal.”
What makes GT Medical fierce: In a clinical trial of people with brain tumors, including high-grade gliomas, meningiomas and metastases, the GammaTile implant increased overall survival and delayed the median time to cancer recurrence by nearly 10 additional months, compared to the patients’ previous therapies.
The company picked up its first FDA clearance for GammaTile in July 2018, for treating recurrent brain tumors, including aggressive glioblastomas. Earlier this year, GT Medical received a new green light from the agency to expand its use to newly diagnosed cancers—roughly tripling its potential patient population to the estimated 200,000 people diagnosed annually with operable brain tumors.
That nod, in turn, sets the stage for a wider commercial rollout planned for later this month. Previously, the company had been operating with a limited release in a select number of U.S. cancer treatment centers.
“We wanted to make sure that as we began adoption at various hospitals around the country, that not only do we have our manufacturing act together, but we could produce the product in a very reliable, timely way each time it's delivered—because these surgeries are scheduled very precisely and we're producing a product specifically for that patient,” Likens said.
The company also had people on the ground at each new institution to guide them in the first few procedures, as well as through the safety requirements for handling and transporting the material.
“It's been very deliberate, but that’s really paid off,” he said. “We've understood a lot about how this is going to be utilized, and we've been able to ramp up the capacity that’s required.”
And nearly wherever they’ve gone, the clinicians they’ve worked with have had their own ideas of where the technology can be used next—including with different shapes, sizes or isotopes.
“They're all coming up with their favorite part of the anatomy,” Likens said. “Be it tumors of the breast, pancreas, liver or head and neck or spine—there are a lot of ideas where this could provide real benefits for patients. So we have our eyes on that.”