Researchers at McMaster say they’ve found an effective treatment for lung cancer, which is considered the most deadly form of cancer.
The treatment, known as “checkpoint blockade therapy”, was established by combining two forms of immunotherapy. Essentially, one kills a significant number of lung tumour cells while triggering changes to the tumour that enable the second therapy to finish the job.
“We’ve found that re-arming lung cancer patients’ natural killer immune cells acts as a triple threat against lung cancer,” explains Sophie Poznanski, the McMaster PhD student and CIHR Vanier Scholar who is lead author of a paper to be published Friday, Jan 22 in the Journal for ImmunoTherapy of Cancer.
“First, these highly activated cells are able to kill tumour cells efficiently. Second, in doing so, they also reactivate tumour killing by exhausted immune cells within the patients’ tumours. And third, they release factors that sensitize patients’ tumours to another immunotherapy called immune checkpoint blockade therapy. As a result, we’ve found that the combination of these two therapies induces robust tumour destruction against patient tumours that are initially non-responsive to therapy.”
Previous breakthroughs using similar therapy had earned Japanese researcher Tasuku Honjo and American immunologist James Allison the 2018 Nobel Prize for Medicine or Physiology.
Checkpoint blockade therapy works by unlocking cancer’s defence against the body’s natural immune response. The therapy can be highly effective in resolving even advanced cases of lung cancer. However, it only works in about 10 per cent of patients who receive it.
The research team, featuring 10 authors in total, has shown that the supercharged immune cells, when deployed, release an agent that breaks down tumours’ resistance to checkpoint blockade therapy, allowing it to work on the vast majority of lung-cancer patients whose tumours would otherwise resist the treatment.
“We needed to find a one-two punch to dismantle the hostile lung tumour environment,” says Ali Ashkar, a professor of Pathology and Molecular Medicine and a Canada Research Chair who is Poznanski’s research supervisor and the corresponding author on the paper.
“Not only is this providing a new treatment for hard-to-treat lung cancer tumours with the natural killer cells, but that treatment also converts the patients who are not responsive to PD1-blockade therapy into highly responsive candidates for this effective treatment”.
The researchers are now working to organize a human clinical trial of the combined therapies.