A day after Bristol-Myers Squibb announced that the FDA approvedits semi-synthetic version of Taxol for advanced breast and ovariancancers, the regulatory agency's Oncologic Drugs AdvisoryCommittee (ODAC) rejected a similar anti-cancer drug, Taxotere,made by Rhone-Poulenc Rorer for breast and lung cancers.
According to Rhone-Poulenc's investigators, the advisory committeewas concerned about the safety of Taxotere and recommended moreclinical study to determine if the drug's toxicity can be controlled.ODAC members said they particularly were concerned about the sideeffects of fluid retention.
The committee's decision sent Collegeville, Pa.-based Rhone-Poulenc's stock (NYSE:RPR) down $3.25 Tuesday to close at $38,an 8 percent drop. The company's stock jumped more than 6 percentthe day before on speculation the drug would get a favorable nodfrom ODAC and soon enter the market in competition with Taxol.
Bristol-Myers' stock (NYSE:BMY) Tuesday was down 75 cents to$57.37.
The FDA is not bound by the advisory panel's recommendation in itsreview of Rhone-Poulenc's new drug application for Taxotere,which was submitted in July. No timetable for the FDA's ruling wasset, but Rhone-Poulenc said it has additional clinical trials under wayand expects to have those results for the FDA in about 18 months.
A Rhone-Poulenc spokesman said the advisory committee primarilywas looking at Phase II data and apparently it would have been morecomfortable with Phase III results.
Amy Langer, of the New York-based National Alliance of BreastCancer Organizations, joined Rhone-Poulenc officials Tuesday in atelephone conference briefing on ODAC's vote.
Langer said the committee's decision serves to delay the treatmentchoices available to advanced breast cancer patients, who normallylive about six to 10 months after reaching that stage of the disease.An estimated 182,000 women a year get breast cancer, she said, and46,000 will die.
Neither Taxol nor Taxotere are considered cures, but studies haveshown the drugs, which are chemically similar, can reduce tumorsize and prolong breast cancer patients' lives for as much as a year.
Rhone-Poulenc, which is 68 percent owned by France-based Rhone-Poulenc Group, is seeking approval of Taxotere for locally advancedor metastatic breast cancer and advanced non-small cell lung cancer.The drug is targeted for patients who do not respond to conventionalchemotherapies.
Taxotere, like Taxol, is a semi-synthetic form of a class of drugscalled taxoids, which are derived from the yew tree. Rhone-Poulencuses needles of the European yew tree for Taxotere, which is thebrand name for docetaxel. Bristol-Myers, of New York, makes itssemi-synthetic Taxol, whose generic name is paclitaxel, from theHimalayan yew tree.
Bristol-Myers first received FDA approval of Taxol in 1992. Thecompany developed a semi-synthetic version to avoid problemsassociated with its original source of the drug, the bark of the Pacificyew tree, which is endangered.
Bristol-Myers' product is approved for use by advanced breast andovarian cancer patients who fail to respond to conventionalchemotherapy.
Toxic Side Effects Need More Explanation
Rhone-Poulenc investigators said Tuesday the FDA's advisorycommittee members were impressed with Taxotere's anti-tumoractivity, but felt the toxic side effects may be insufficiently describedin the clinical trial data submitted by the company.
In addition to fluid retention and fatigue, side effects described in thestudies include a decrease in white blood cells, nausea,hypersensitivity and skin rash. The adverse reactions are similar tothose that occur with Taxol and other forms of chemotherapy.
ODAC voted 6-0, with two abstentions, to reject Taxotere foradvanced breast cancer and split 4-4 on recommending the drug forconditional approval. The vote against Taxotere for non-small celllung cancer, the most common form of cancer, was unanimous at 8-0.
In reporting data from the breast cancer clinical trials, Rhone-Poulenc investigators said 40 percent of the patients treated withTaxotere showed a favorable response and survival rates were 10months longer than expected for patients receiving conventionalchemotherapy.
The lung cancer studies, investigators said, revealed that the overallsurvival of patients treated with Taxotere was nine months and 38percent were still alive after a year. The median survival rate with themost common form of chemotherapy is five months. n
-- Charles Craig
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