Genentech Inc. shares fell Thursday after a leading medical journal said the firm's heart attack drug is only slightly more effective than a far cheaper alternative and should only be used on a limited basis.
A House subcommittee was also reported to be looking into a major 1993 study finding that the genetically engineered tPA, sold as Activase, is superior to the alternative treatment, streptokinase, which costs about one-tenth as much.
Genentech shares fell $1.125 to $45.625 in mid-morning trading on the New York Stock Exchange after tumbling as low as $44 earlier in the day.
Both drugs are known as thrombolytics, or "clot-busters," and are given to patients shortly after a heart attack occurs. Blood clots are often responsible for heart attacks and can cause strokes. They often form when blood pressure is either dangerously high or low.
TPA has long been the subject of medical controversy over its advantages and cost.
The Annals of Internal Medicine said in an editorial in its current issue that the costs of saving additional lives with tPA were prohibitive.
A 41,000 patient study, dubbed GUSTO, reported last year that the 30-day survival rate of Activase patients was one percentage point better than that of streptokinease patients. The findings helped revive sagging sales of the Genentech drug.
Using figures in the Annals editorial and comparative prices of the drugs, the cost of saving one additional life with Activase would be at least $200,000 to $240,000.
A treatment with Activase costs about $2,200 wholesale, compared with about $200 for streptokinase, which is made by Swedish drug companies AB Astra and Kabi Pharmacia AB.
The Wall Street Journal said Thursday that, prompted by the Annals articles, the House subcommittee on Oversight and Investigations is looking into the conduct of "Gusto" study.