Gene tests: so far, so good.

Gene tests: So far, so good

The first U.S.-approved infusions of genetically engineered cells into humans have produced no significant ill effects and have begun to provide useful data, researchers told a National Cancer Institute (NCI) advisory board this week. To date, five terminally ill cancer patients have recieved the one-time doses of about 100 million gene-altered, tumor-fighting lymphocytes.

Scientists had initially obtained lymphocytes from patients' tumors, then inserted a bacterial "marker" gene into each cell in order to track the cells' survival and distribution in the body after reinfusion (SN: 5/27/89, p.324). NCI researcher Steven A. Rosenberg says tests so far indicate the cells begin to concentrate in tumors the fifth day and live and circulate in the body for at least 19 days.

Ultimately, the researchers hope to gain government permission to give patients cells engineered to secrete naturally occurring tumor-fighting compounds. At the meeting, Rosenberg revealed that he and colleagues have recently succeeded in engineering human lymphocytes to produce one such compound, tumor necrosis factor.