Targeted T cells whip up excitement for early-stage cancer immunotherapy

Cancer-fighting T cells figure prominently in the experimental immunotherapies being developed these days. And now a group of researchers says they have found a way to efficiently recruit a mass of these immune-system warriors in the fight against cancer and infectious diseases, putting a spotlight on a small study that has already produced some compelling early-stage results.

In a study published in Nature Biotechnology, investigators report that they were able to take stem cells and reprogram them to act as T cells, virtually wiping out tumors in mouse models for cancer after injecting them into the animals. These new T cells were genetically modified specifically to target certain cancers, offering a new approach that could eventually rev up the body's attack on specific types of cancer which have been elusive so far.

The potential of this type of approach was underscored in a tiny Phase I study at Memorial-Sloan Kettering Cancer Center, where scientists led by Dr. Michel Sadelain extracted and modified T cells to successfully attack lethal cases of acute lymphoblastic leukemia. This new off-the-shelf approach, reports The Scientist, could provide a far more efficient way to develop far more of these specialized T cells, which could apply to a variety of cancers.

Anywhere from 5 months to two years after the Phase I study launched, three of the 5 patients in the study were still alive as of last March. Two of the patients died--one from a blood clot--while the other relapsed. One of the sickest patients was free of the leukemia 8 days after he was treated, surprising everyone involved.

"To put these two techniques together is really groundbreaking," Ontario Cancer Institute's Pam Ohashi tells The Scientist. "The idea that you can make unlimited numbers of tumor-killing cells is very exciting."

It's important to note that all preclinical cancer drug studies generally take years in the clinic to prove their full potential. But immunotherapy has emerged as one of the hottest fields in drug R&D, and these new results are likely to be studied carefully.

- here's the study from Nature Biotechnology
- read the story from The Scientist

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