ASCO: No Survival Benefit for Shark Cartilage in NSCLC

CHICAGO, June 3 -- Adding shark cartilage extract to chemoradiation failed to improve survival in non-small cell lung cancer (NSCLC) patients, results of a government-mandated clinical study show.

Patients who received the extract, known as AE-941, along with chemoradiation actually had slightly worse survival times compared with those who received just the standard therapy, although the difference was not statistically significant, said Charles Lu, M.D., of the University of Texas M.D. Anderson Cancer Center in Houston.

"This study represents the first large phase III trial of a shark cartilage-derived pharmaceutical compound," said Dr. Lu at the American Society of Clinical Oncology meeting here.

"Therefore," he said, "current clinical data do not support the routine use of shark cartilage-derived products as anticancer therapies."

For years cancer patients have used over-the-counter shark cartilage compounds, with or without the knowledge of their physicians. Congress responded to the consumer demand with a funded mandate to study shark cartilage's therapeutic potential in cancer.

According to the National Cancer Institute, preclinical studies showed that shark cartilage has antiangiogenic activity and that it shrank or slowed the growth of NSCLC cells. Dr. Lu said results of phase I and II clinical trials suggested that the substance had activity at higher doses in some NSCLC patients.

The NCI-sponsored multicenter trial initially had an enrollment target of 756 patients, but the trial was stopped early because of slow patient accrual. Dr. Lu reported findings on 379 patients with unresectable stage III NSCLC.

He and his colleagues randomized the patients to 120 ml of AE-941 BID or placebo. The AE-941, a water extract of dogfish shark cartilage, was delivered frozen in 120-ml vials that patients thawed and then self-administered.

All patients received induction chemotherapy and concomitant chemoradiation therapy. The primary outcome was survival. When the trial ended, patients who had received AE-941 had a median survival of 14.4 months, compared with 15.6 months for the placebo group (P=0.73). There was also no benefit from AE-941 in any of the sub-group analyses that stratified subjects by gender, stage (IIIA versus IIIB) or chemotherapy regimen.

The study will likely bring down the curtain on a product that entered large-scale clinical evaluation riding the tide of generally favorable data from experimental and small clinical studies. In a move portending the negative outcome of the trial, AEterna Zentaris, the Canadian manufacturer of AE-941, announced in March that it would cease production of the shark cartilage extract.