Targeted Therapy May Yield Fewer Adverse Events for Patients with Pancreatic Cancer

Researchers at Osaka University and the University of Heidelberg are exploring a new method of targeted radiation therapy that sends alpha-emitting particles directly to stroma cells in pancreatic cancer tissue. This method may offer an effective treatment for pancreatic cancer with fewer adverse events in surrounding organs compared with the current standard of care, chemotherapy and radiation therapy.

According to lead author Tadashi Watabe, MD, PhD, there is often a tradeoff between efficacy against cancer cells and off-target events in non-cancerous cells with traditional anti-cancer therapies.

“We're focused on finding ways to re-balance this tradeoff in radiotherapy, by increasing the dose of radiation delivered to cancer cells while keeping it localized to those cells as much as possible," Watabe said.

In the study, published in The Journal of Nuclear Medicine, researchers examined radioactive “homing” molecules that, when injected into a patient, travel straight to the site of a tumor to deliver cancer-killing outcomes. In the study, researchers used a molecule with an isotope that emits alpha particles, which travel shorter distances than the beta particles emitted by traditional isotopes. This means that their “off-target effect” is more limited than traditional therapy.

The molecule binds to a protein called FAP found exclusively on stroma cells that surround pancreatic tumors and various types of cancers. Stroma cells encase solid tumors and act as a barrier. Treatments for pancreatic cancer are often stymied by stoma cells. However, this process also researchers to target a high energy dose of radiation directly to the tumor site.

"We are very encouraged by these initial results," Watabe concluded. "We think the approach has enormous therapeutic potential, particularly for patients with pancreatic cancer who've exhausted their other treatment options. What's especially exciting is that our method of targeting the stroma can in principle work against many other types of cancer. We think this could represent a new path forward in radiation therapy."

Reference

• Breaking the Stroma Barrier: Study Shows a New Way to Hit Cancer with Radiation [press release]. Published October 4, 2019. https://resou.osaka-u.ac.jp/en/research/2019/20191004_2. Accessed October 22, 2019.