Juno halts clinical trial of cancer therapy after death of three patients

Juno Therapeutics, conducting a clinical trial in the use of genetically engineered cells as a treatment for cancer, has halted the tests temporarily after three patients died from swelling in the brain.

The company said yesterday that the Food and Drug Administration (FDA) had temporarily halted the study.

According to commentators, the development comes as a setback to one of the most exciting pursuits in oncology.

The deaths were ''difficult and humbling for everyone involved,'' Hans Bishop, the company's chief executive, said in a conference call with securities analysts.

Shares of Juno stock fell 27 per cent in after-hours trading.

According to Bishop and other Juno executives, they believed that the problems resulted from a combination of the particular cells being used and a chemotherapy drug. Though Juno has proposed to the FDA that the trial continue without the drug, it was not clear whether the agency would agree. It was also not clear as to when it would make a decision, though, according to Juno executives, it could be within 30 days.

Juno is working on CAR-T therapy, which involves taking blood from a patient to extract immune cells, genetically engineering them to make them kill cancer cells, and then reintroducing them into the bloodstream to go to work.

All three patients who died were in their 20s.

According to Forbes, the cancellation was blow for Juno Therapeutics, a biopharmaceutical startup valued at $4.3 billion.

Juno said the deaths occurred after the chemotherapy agent called fludarabine was added to the therapy. The company has proposed continuation of the clinical trial using cyclophosphamide as a "pre-conditioning agent."

Seattle based Juno, is in a three-way race against Kite Pharma and Novartis to bring the therapy to the market. According to Juno executives, the setback would probably mean that its initial treatment would not get to market by the end of 2017, as it had hoped.