Frances Johnson and her husband, Michael Schultz, are a formidable team in their field.
“He’s the Ph.D. scientist,” Johnson said one recent morning. “I’m the M.D.”
“When we pitched (to investors) together, we never lost,” Schultz said.
Their pitch: a cancer treatment that eradicates tumors without chemotherapy’s debilitating side effects.
At the University of Iowa’s BioVentures Center in Coralville, their company, Perspective Therapeutics, is directing the research needed to earn federal Food and Drug Administration approval of its technology to locate tumors, then deliver cancer-killing radiation without damaging healthy tissue.
“We’re pioneers in certain aspects of targeted radiopharmaceuticals,” Schultz said.
Conventional radiation therapy delivers high-energy gamma rays to the area of the patient’s body where a tumor is located. The delivery from outside the body can damage healthy organs and tissue as it passes through a portion of the body to the tumor.
Radiopharmaceuticals are injectable drugs containing radioisotopes, the radioactive forms of elements, that directly attack tumors. They’re designed to bind specifically to tumor cells on contact, while any residual radiation is quickly washed out of the body.
“This is a hybrid between chemo and radiation, because you’re injecting it and it’s going to the target,” Johnson said.
Isotopes & particles
Perspective Therapeutics grew out of Schultz’s work at the University of Iowa’s radiology department, which he joined in August 2006, a month after Johnson became a professor in the cardiomyopathy program.
“I was a pretty traditional grants-and-papers faculty member,” Schultz said. “I did some teaching and curriculum development. I started to recognize that we had something that could be potentially transformative for cancer patients.”
That “something” is the radiation given off by alpha particles.
Emitted by isotopes, alpha-particle radiation can be blocked by skin, a sheet of paper, or even a few inches of air. This means alpha particles only travel a few cell diameters in human tissues, concentrating injury to the tumors.
Historically, chemotherapy used another form of isotopes that emit beta-particle radiation, which has a higher probability of interacting with healthy cells because it travels much farther in human tissues.
“An alpha particle is about 7,500 times the mass of a beta particle, and it has higher energy,” Schultz said. “That delivers a lot more energy, a lot more catastrophic cell depth, which means it’s much more focused, less chance for off-target radiation.”
In 2008, the couple started Viewpoint Molecular Targeting to further investigate the properties of alpha particles.
“That limited liability company was there to interact with the University of Iowa Research Foundation, to talk about intellectual property rights, making sure we had those protected and available if something coalesced scientifically,” Johnson said.
Starting up
In 2015, Johnson left the university, and Viewpoint moved to the BioVentures Center. Johnson is now Perspective’s chief innovation officer. Schultz is chief science officer and remains an associate professor emeritus at the university.
“Mike said, ‘Hey, look at these experiments using the alpha particle therapy,’” she said. “They were amazing in some really tough-to-treat tumors like metastatic melanoma. It was like, ‘Oh, my god, this is something. This is it.’ ”
Grants from the Small Business Innovation and Research section of the National Cancer Institute funded the company’s new lab. Perspective also raised $14 million in equity funding, allowing it to step up the pace of research.
‘Nice marriage’
The work caught the attention of Isoray, a Seattle company specializing in brachytherapy, which uses injectable radioactive “seeds” to treat prostate cancer.
“That’s a pretty old technology with a flat market, so they were looking for the new thing,” Johnson said.
Isoray and Viewpoint merged in February 2023 to create Perspective Therapeutics, opening new funding for the clinical trials to prove radiopharmaceuticals are a safe, effective treatment for advanced cancers.
Perspective has since divested Isoray’s brachytherapy business.
“They needed to deploy that (capital) with some innovation they didn’t have internally,” Schultz said. “We needed capital and had lots of innovation, so that was a nice marriage.”
Perspective’s researchers settled on two isotopes of lead, identified as Pb on the periodic table. Pb-203 (Lead-203) is used as an imaging agent to locate tumors within the body, and Pb-212 delivers the high-energy radiation to attack them.
“Lead 212 has a very short half-life,” Schultz said. “You administer it, it delivers the radiation at a high dose rate for a short period of time, then it just disappears.”
“Mike and his team designed these things to be small, and to penetrate the tissues really rapidly throughout the body and stick like Velcro to the tumors,” Johnson said. “The vast majority of the radiation that’s injected is eliminated through your urine within the first three hours, a lot of it within the first 30 minutes.”
Clinical trials
About 35 of Perspective’s 120 employees work at the BioVentures Center, continuing the company’s research and manufacturing the radiopharmaceutical products supporting clinical trials at over 14 hospitals worldwide, including the University of Iowa Hospitals and Clinics and the Mayo Clinic.
“It’s kind of exciting that here in the production setting there’s a patient that’s going to be associated with every dose,” Johnson said. “They’re making a dose for that patient, they’re getting it out the door, and we have special couriers who are getting it where it needs to go.
“It’s pretty exciting, and our team needs to come in at midnight and start working on the dose that will go out the door early in the morning to the hospital.”
Clinical trials typically have three phases to test a new treatment’s safety, effectiveness and superiority compared to current standards of care. Perspective’s trials are enrolling in Phase II.
“We’re treating people with advanced metastatic melanoma, and people that have neuroendocrine tumors,” Johnson said.
Patients who might be candidates for radiopharmaceutical therapy should contact nonprofits that support cancer research.
“If you’ve had a diagnosis or you have a family member who’s had a diagnosis, look for a patient advocacy group,” Schultz said. “They generally will be very knowledgeable about what’s the latest for the type of cancer you’re talking about, and can be super helpful about directing you to the trial that makes the most sense for you.”
“Radiopharmaceuticals are still a tiny, tiny part of oncology treatment as a whole,” Johnson said. “Many cancer physicians still don’t know about what is possible. They may have heard a little bit, but there’s 20 different therapies they’re going to have to understand and know how to use, and there’s two radiopharmaceuticals out there being used today.”
What’s next?
The company is listed on the New York Stock Exchange (CATX) at $12.09 Friday.
A New Jersey production facility is planned to open this year, allowing the pace of clinical trials to double. The company has a facility in Indianapolis to produce the isotope generators needed to create lead isotopes.
“We really didn’t want to be an isotope manufacturing company,” Schultz said. “But we realized we were really plowing new ground everywhere we went. The generator was not available commercially. The Department of Energy had a generator system you could buy, but you could only get one a month, and we needed a lot more, so we invented our own.”
Perspective’s founders plan to remain close to the Iowa campus.
“We recruit nationally, but we run into some really strong people that are right here in Iowa City,” Schultz said. “The core group are people I either worked with very collaboratively, or worked for me when I was a faculty member.”
In February 2023, the Coralville City Council approved a $450,000 forgivable loan for the company, contingent on its continued operations there for at least seven years.
“There’s plans for us to build a brand-new, state-of-the-art discovery (research) center,” Schultz said. “We just get super high-quality talent and, at the same time, a relatively much less expensive footprint than Boston or San Diego, which have the biotech hubs of the nation.
“More and more, the Midwest is getting recognized as the place to be for radiopharmaceuticals.”
“Often companies will move out of the area,” Johnson said. “But we have been here for 10 years, and it all starts here. We have a pretty dedicated team, and we’re planning to stay.”