Cancer researchers at the National Institutes of Health havebegun a new gene therapy treatment, this time combininggenetically altered cancer cells with lymphocytes activated byinterleukin-2 in an attempt to attack an otherwise untreatableskin cancer.

The team, led by Dr. Steven Rosenberg, on Tuesday injectedtumor cells altered with the gene for tumor necrosis factor(TNF) back into a 46-year-old man from whom the cells hadpreviously been taken.

Rosenberg's team expects that boosted levels of TNF willstimulate lymphocytes to infiltrate and attack the cancer.

In a second stage, the man will have lymph nodes removed fromthe region of the cancer. According to an NIH spokesman,lymphocytes from the nodes will be cultured in the lab in thepresence of interleukin-2, and returned to the patient to fightthe cancer, together with more IL-2 to keep them activated.

Experiments in mice have shown that boosting cytokineproduction by altering genes of tumor cells can immunize thebody against the tumor. TNF is a cytokine secreted by whiteblood cells. Rosenberg has used IL-2, another cytokine, toactivate lymphocytes. Now, Rosenberg has combined bothapproaches.

"We expect that they will use our vector, but I can't confirm ifit was used in this particular patient," he told BioWorld.

In January, Rosenberg attempted the first gene therapy forcancer, in which patients were injected with TNF-alteredlymphocytes.

Concerns about combined toxicities prevented Rosenberg fromobtaining immediate permission to include IL-2. Yet theprotocol allowed for eventual addition of IL-2, depending onhow toxic the TNF-altered cells proved to be by themselves.

Rosenberg's addition of IL-2 on Tuesday implies that thetoxicity seen with TNF alone was not appreciable. However, theNational Cancer Institute was unable to confirm this onTuesday.

Genetic Therapy Inc. of Gaithersburg, Md., has supplied thevector for the other three trials of gene therapy that have beenapproved so far at the NIH and at St. Jude's hospital inMemphis, Tenn. A Genetic Therapy vector will almost certainlybe part of this new attempt, said Marc Schneebaum, chieffinancial officer.

-- Roberta Friedman, Ph.D. Special to BioWorld

(c) 1997 American Health Consultants. All rights reserved.