HEALTH NEWS

Surgeons Using Scorpion Venom to Illuminate Brain Tumors

Written by Ann Pietrangelo on May 2, 2017
scorpion

Most of us want to avoid scorpions and their venom, and with good reason.

But medical researchers have found a way to use scorpion venom to help children with brain cancer.

They’ve created a synthetic version of the venom, but without the actual poison.

They call it BLZ-100, or tumor paint.

The substance makes tumors light up and stand out from surrounding tissue during surgery.

Removing brain tumors is a particularly complex endeavor.

The objective is to remove all the cancer cells without removing healthy tissue. But it can be difficult to determine where the tumor ends and healthy tissue begins.

When you’re operating on a child with brain cancer, that’s no small matter.

Read more: Is Gleevec a wonder drug for cancer treatment? »

Why scorpion venom?

At Fred Hutchinson Cancer Research Center in Seattle, Dr. James M. Olson, pediatric oncologist and researcher, and his colleagues studied volumes of scientific literature.

They evaluated thousands of ways they might be able to light up a tumor.

The inspiration for their work was a 16-year-old patient.

In 2004, the girl underwent a 12-hour surgery to remove a brain tumor. Later, the surgeons found that some of the tumor had been left behind.

So began their mission to figure out how to illuminate tumors during surgery.

“Scorpion venom crosses the blood-brain barrier to paralyze their prey,” Olson told Healthline. “We focused on scorpion venom because the evidence suggested it would bind to brain tumor cells but not normal cells.”

They tried it first in a human brain tumor they grew in a mouse. The tumor lit up and the rest of the mouse didn’t.

They were on to something.

Since then, they’ve completed three human clinical trials involving more than 80 patients, including 20 children with brain cancer, said Olson.

The “tumor paint” can be injected into the patient’s veins on the day before or the morning of surgery. The tumor stays lit for at least several days.

Clinical trials to date haven’t resulted in many side effects, other than mild nausea and headache.

Read more: The value and cost of immunotherapy cancer treatments »

Painting other types of cancer

Tumor paint may yet prove helpful with many other types of cancer, including breast cancer.

According to Olson, it’s difficult right now for surgeons to see the difference between normal breast tissue and breast cancer during surgery.

“During breast cancer surgery, they sometimes stop with the patient under anesthesia. They send tissue to pathology and wait for the pathologist to cut, stain, and view the tissue under a microscope to assess if the margins are clear. And in a third of all cases, the patient later gets a phone call saying the pathologist found cancer cells too close to the margin. Additional surgery or other treatment is needed because of that,” he explained.

Olson hopes the new technique could ultimately eliminate those problems.

“We could allow the surgeon to see where the cancer is while they’re operating. That’s our aspiration,” he said.

Preclinical studies have found that tumor paint can light up breast, colon, prostate, lung, skin, and other types of cancer.

“In human clinical trials, we used it for three types of skin cancer and multiple types of breast cancer,” Olson said. “Nearly all the breast cancer lit up and distinguished cancer from adjacent normal tissue.”

Olson cautioned that most of the research is still in the investigational stage, but he hopes that tumor paint will drastically improve cancer surgery.

Read more: Why more women are choosing to have double mastectomies »

Project Violet

Getting from research to clinical trial to approval from the Food and Drug Administration (FDA) is no easy feat.

Olson said that even after getting encouraging data it’s difficult to get grants, especially when an idea sounds as far-fetched as scorpion venom.

But families of children with cancer took up the charge.

Olson is director of Project Violet, where a team of scientists is working to cure diseases that are considered incurable.

“Through Project Violet, our patient families have supported much of the work so far. They had chili cook-offs, golf tournaments, greeting card sales, etc. This community raised well over $20 million,” he said.

The nonprofit initiative is named after an 11-year-old who had a rare, inoperable brain stem tumor. The girl requested that her brain go to research after her death.

“These families are stepping up and working arm in arm. Kids I cared for 25 years ago and those I met just last week are working together to make it happen. This work is motivated by children with cancer,” he said. “The goal for our first FDA approval of tumor paint is for use in children with brain cancer.

Read more: A universal cancer vaccine is highly unlikely »

The road ahead

Olson said there will be additional conversations with the FDA in the coming months to discuss the design of the clinical trial that could lead to approval.

“It’s hard to say, as far as a timeline, but we’re very eager to get this over the finish line,” he said.

Olson’s lab is beginning to explore other potential uses for tumor paint, including ways to deliver treatments more effectively and with fewer side effects.

They’re working on at least a dozen other projects, similar in innovation to tumor paint, he said. These efforts are in their earliest stages.

According to the Project Violet website, the team is looking into drugs produced by potatoes, spiders, cone snails, sea slugs, horseshoe crabs, sunflowers, and violets.

“We have a lot going on right now. I liken it to “Q” in the James Bond series. We really try to do things that are high risk, but pay off, and dramatically change the way we practice medicine,” said Olson.

CMS Id: 120496