CAR-T therapies: the future of cancer care, or an industry pipe dream?

Dendreon's prostate-cancer vaccine, Provenge, remains the only FDA-approved treatment based on T-cell therapy.

Biopharma is taking steps to personalize cancer care. Cancer immunotherapies, lauded for putting the body's own defense systems to work against cancer cells, have generated widespread excitement.

As spinoffs of cancer immunotherapies, cell therapies are gaining traction in development. “Cell therapies and immuno-oncology in general will change the face of cancer care, especially in solid tumors and high-risk hematologic malignancies,” says Dr. Andre Goy, chairman, John Theurer Cancer Center, and chief, division of lymphoma, Hackensack University Medical Center.

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Chimeric antigen receptor (CAR) T-cell therapy, in particular, is a promising contender in blood cancers. The treatments involve extracting and modifying disease-fighting T-cells in a laboratory. The CAR T-cells are then reinjected into the patient's blood with one mission: to seek and destroy cancer cells.

While analysts predict a first-in-class appearance before the FDA by 2018, many obstacles have arisen, each with a solid chance of derailing efforts. For one, Juno Therapeutics suspended a Phase-II trial for JCAR015, a CAR-T for B-cell acute lymphoblastic leukemia, when three study participants died of cerebral edema. Juno also reported one death in last year's trial for JCAR014.

Dendreon's prostate-cancer vaccine, Provenge, remains the only FDA-approved treatment based on T-cell therapy. But Provenge shouldn't be the cell-therapy poster child, because biopharma has far-more-promising approaches up its oncology sleeves.

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“We're getting better at managing CAR T-cell therapy toxicity through dose adjustment and pre-chemotherapy,” Goy says. “CAR T-cells will likely need to be used in serial cycles or in combination with checkpoint ­inhibitors.”

Novartis, Juno, and Kite Pharma nestled into the space several years ago with CD19-targeted CAR T-cell treatments in development for multiple relapsed or refractory acute lymphoblastic leukemia. Newcomer Vor BioPharma, an immuno-oncology startup with renowned cancer physician Siddhartha Mukherjee at the helm, hopes to expand the treatment's targets.

For the CAR T-cell approach to succeed, scientists will need to identify antigen targets beyond CD19 that respond with strong efficacy. They will also need to expand beyond hematology into solid tumor indications.

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Bellicum Pharmaceuticals, Theravectys, and others are working to offset an overactive immune response to some cell therapies. These companies are entrenched in preclinical development of CAR T-cell control switches.

But Goy predicts that Cellectis, Adaptimmune, Celyad, and other firms may maintain a competitive edge given their allogenic CAR T-cell technology. The next generation of T-cell therapies is expected to expand beyond the patient-specific limitations with an off-the-shelf option available for use with any patient.