April 27, 2018 -- Scientists are harnessing the untapped power of red blood cells to help fight deadly cancers and other diseases.
Nicknamed ''superblood,'' the treatment is under study by at least three companies following similar approaches. Researchers collect red blood cells from patients, modify them so anti-cancer or other medicines can be enclosed, then inject them back into patients. The goal is improve the medicines' effectiveness while reducing harmful side effects.
Experts not involved in the research say the approach has merit, while cautioning that it is in the early stages of research. "It has broad applications -- if it's proven to be effective and safe," says Caius Radu, MD, professor of medical and molecular pharmacology at the UCLA Jonsson Comprehensive Cancer Center.
In a study presented at the American Association for Cancer Research conference in April, researchers said that adding L-asparaginase, an enzyme that’s part of a multi-drug chemotherapy treatment, to red blood cells and injecting the cells into 13 patients with acute lymphoblastic leukemia (ALL), a blood cancer, appears safe. More studies are planned.
"L-asparaginase is a very good treatment” for acute lymphoblastic leukemia," says Alison Walker, MD, an associate professor of hematology at Ohio State University’s Comprehensive Cancer Center. Walker presented the findings at the conference. But ''toxicity from (the chemo itself) can be significant and can delay further (needed) chemo," she says.
"Because the chemo is inside the red blood cell, there is less exposure,'' she says. And that should translate to less toxicity, she says.
Erytech Pharma in Lyon, France, developed the treatment and funded the study. EryDel, an Italian company, is working on a superblood treatment, EryDex, for the rare genetic disease ataxia telangiectasia (AT). AT starts in childhood and causes neurological problems such as balance issues, problems with motor skills and the immune system, and respiratory infections. Patients can lose the ability to write and talk and walk normally. Many patients die in their 20s.
EryDex loads a steroid drug into red blood cells, then gives it to patients through an IV once a month. More than 200 people have been given the treatment, says Luca Benatti, PhD, EryDel's CEO.
EryDex is a slow-release system, he says, and research has found that it ''prevents the typical steroid side effects." These can include thinning of bones, high blood sugar, cataracts, and high blood pressure.
Research has shown the treatment can delay symptoms and the course of the disease. In one study, 18 patients given monthly infusions for 6 months had a better score on a commonly used scale to assess motor skills and many other aspects of daily living. The company is conducting its final study before seeking FDA approval. Results of that study are expected by the second half of 2019.
The treatment has been granted orphan drug status by the FDA. That means the drug is designed to treat rare diseases or is unlikely to ever be profitable to a drug manufacturer. Besides ataxia telangiectasia, the company is looking at other diseases, including cancer, their system could treat.
Rubius Therapeutics in Cambridge, MA, is also studying superblood treatment for rare diseases, cancers, and immune system disorders. It has raised more than $220 million in financing for research.
Advantages of Superblood, How It Compares With Other Therapies
The less-toxic superblood approach also allows the drugs to target tumors more directly, experts say. The drugs also stay in the body longer, so superblood may be more effective in the long term.
Experts say the new technology builds on another treatment advance known as CAR T-cell therapy. CAR T-cell therapy draws on the power of the body's T cells, known as the workhorses of the immune system, due to their ability to find and kill diseased cells.
In the CAR T process, blood is drawn from a patient, T cells are separated and genetically engineered to boost their tumor-fighting ability, then returned to the patient through an IV.
Compared to CAR T, superblood has more advantages, experts say. The superblood treatment is easier to use, can be made more quickly, and is long lasting.
"The [superblood] concept is interesting," says Brian Wolpin, MD, MPH, director of the Gastrointestinal Cancer Center and the Hale Center for Pancreatic Cancer at the Dana-Farber Cancer Institute. Further testing will need to prove whether it will have a substantial impact on the diseases it treats.
Whether the new approach catches on will depend not only on how superior the treatment is, but also on costs, Radu of UCLA says.