NEW YORK (Reuters): Big pharmaceutical companies that make personalized blood cancer treatments are working to cut the manufacturing turnaround time by as much as half in coming years, as they try to deliver them sooner in a patient’s disease course. These treatments known as CAR-T therapies are used for the sickest patients for whom standard treatments have failed. They involve removing a patient’s T cells – a key component of the immune system – after which they are re-engineered to recognize and attack malignant cells once they are re-infused.

Gilead Sciences, Novartis, Johnson & Johnson, and Bristol Myers Squibb have made billions from their treatments, which can extend lives by months or years for patients with aggressive advanced cancers. Trimming days or weeks from the time it currently takes between removing and reintroducing the cells to a patient could open the treatment to those who otherwise would become too sick during the process, according to three doctors, the companies and analysts. Prices for the one-time treatment range from $400,000 to nearly $600,000, and analysts estimate they currently have profit margins of about 50%, so expanding the patient population is not insignificant.

Oppenheimer & Co analyst Hartaj Singh said only around 1 in 5 eligible patients receive CAR-T treatments. “It’s complex manufacturing using the patient’s own cells, but because some of the responses reported are just so long and durable, physicians will go to it,” S.