MAY 02, 2017 5:54 PM PDT

New Imaging Tech Predicts Early Immunotherapy Response

WRITTEN BY: Kara Marker

While most traditional imaging techniques fall short for scientists looking to predict the effects of cancer immunotherapy treatments, a new method provides a unique opportunity to anticipate a person’s response and alter their medication accordingly.

Credit: Fred Hutchinson Cancer Research Center

Immunotherapy doesn’t work for everyone, and the risk of serious side effects makes the “just try it and see what happens” approach seem harsher than it needs to be. A doctor doesn’t want the patient to endure side effects if the treatment isn’t doing anything to kill cancer cells. With a new method capable of recording progress early during treatment, doctors can know when to push through and when to give up and try something else.

A new noninvasive PET imaging method is the newest beam of hope, and the subject of serious research interest at the American Association for Cancer Research. Unlike traditional techniques like CT, MRI, and FDG PET scans which can’t tell the difference between a tumor growing despite immunotherapy treatment and a tumor growing because of immunotherapy treatment, noninvasive PET imaging provides a clear distinction. While immunotherapy doesn’t cause tumor cells to proliferate - that would be counterintuitive - the treatment does bring in large populations of immune cells and increase glucose uptake, making the tumor appear on traditional images as just as large as a tumor unaffected by the treatment.

The method works by measuring granzyme B, a serine protease released by immune cells to target and kill tumor cells. Using a probe that binds granzyme B once it is released, PET scanning noninvasively provides images of where in the body immune cells are unleashing granzyme B on cancer cells.

A research team from the American Association for Cancer Research tested the probe and PET method in mice with tumors treated with an immunotherapy based on checkpoint inhibitor drugs.

"Because PET imaging is quantitative, we could measure the degree of effectiveness and put a number on it," explained Umar Mahmood, MD, PhD. The mice whose immune cells released large amounts of granzyme-B as detected by PET imaging were the same ones who responded to immunotherapy over time and showed a reduction in tumor size. The mice whose immune cells produced little granzyme-B were not as lucky.

Next, Mahmood also tested the probe technology with nine human melanoma biopsy samples and saw similar results.

“The ability to differentiate early in the course of treatment patients who are likely to benefit from immunotherapy from those who will not can greatly improve individual patient care and help accelerate the development of new therapies," Mahmood said.

The present study was published in the journal Cancer Research.

Sources: American Association for Cancer Research

About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog: ScienceKara.com.
You May Also Like
MAY 05, 2020
Immunology
Winter the Llama: An Unlikely Hero in the Fight Against COVID-19
MAY 05, 2020
Winter the Llama: An Unlikely Hero in the Fight Against COVID-19
A new hero in the fight against COVID-19 has emerged: 4-year-old Winter, a llama that currently resides in the Belgian c ...
MAY 19, 2020
Drug Discovery & Development
COVID-19 Vaccine On Track for Late 2020
MAY 19, 2020
COVID-19 Vaccine On Track for Late 2020
Moderna, a biotechnology company based in Massachusetts, has released information on its vaccine against COVID-19 from i ...
MAY 19, 2020
Drug Discovery & Development
Can Chinese Drug Cure COVID-19 Without Vaccine?
MAY 19, 2020
Can Chinese Drug Cure COVID-19 Without Vaccine?
Researchers at China’s Peking University have announced that they are developing a treatment capable of blocking C ...
JUN 15, 2020
Drug Discovery & Development
FDA Approves HPV Vaccine to Prevent Throat Cancer
JUN 15, 2020
FDA Approves HPV Vaccine to Prevent Throat Cancer
For around a decade, research has suggested that Gardasil, an HPV vaccine, could prevent throat cancer, a condition that ...
JUL 10, 2020
Drug Discovery & Development
Injection 66% Better than Daily Pill to Prevent HIV
JUL 10, 2020
Injection 66% Better than Daily Pill to Prevent HIV
Pharmaceutical company ViiV Healthcare has announced that its long-lasting, injectable drug, cabotegravir, is more effec ...
AUG 14, 2020
Microbiology
Seasonal Flu Vaccine Immunity Probably Wears Off
AUG 14, 2020
Seasonal Flu Vaccine Immunity Probably Wears Off
From year to year, the influenza virus mutates and swaps genes with other flu viruses, and we need a new vaccine. But th ...
Loading Comments...