Sequus Pharmaceuticals Inc., running neck and neck withNeXstar Pharmaceuticals Inc., received an approvableletter from the FDA Friday for its liposome-based productfor AIDS-related Kaposi's sarcoma (KS).
An FDA advisory committee in February recommended"accelerated approval" of Sequus' Doxil as a second-linetherapy for KS. In June, the FDA advisory committeerecommended approval of NeXstar's DaunoXome as afirst-line therapy for KS, and the FDA sent NeXstar anapprovable letter in July.
Sequus, of Menlo Park, Calif., said Friday's letter fromthe FDA might put it back into the lead for getting aliposomal-based drug fully approved and on the market inthe U.S. Sequus still must respond to questions the FDAhad about labeling, chemistry, manufacturing and control.
"We can turn around a response in two weeks," DonaldStewart, vice president of finance for Sequus, toldBioWorld Today. "We hope to have a fourth-quarterapproval and launch."
Meanwhile, FDA officials on Friday were inspectingNeXstar's manufacturing facility. Boulder, Colo.-basedNeXstar said it hoped to have its DaunoXome approvedby the end of the year and launched in the first quarter of1996, said Joseph Alper, the company's director ofcorporate communications.
"Initially," Stewart said, "you would think they [NeXstar]would have an advantage over us given their labelingclaim [as a first-line therapy]. "The impetus is now on us.We have a Phase III study which is complete and theanalysis is done. The study will show that we have asignificantly better response rate over ABV [adriamycin,bleomycin and vincristine] and the safety profile looksvery good."
Both Stewart and Alper, while congratulating thecompetitors' efforts, agreed that physicians and patientseventually would decide which drug wins out in themarketplace.
The approvable letter for Sequus, formerly calledLiposome Technology Inc., was not unexpected. In fact itwas due by Thursday, one year after the filing of the newdrug application for Doxil. Sequus' stock(NASDAQ:SEQU) closed at $13.50 Friday, down 25cents, but still up significantly from its 52-week low of$4.50.
Doxil consists of the widely prescribed cancer drugdoxorubicin hydrochloride encapsulated in liposomes.The technology enables the liposome drug, coated withpolyethylene glycol, to remain in circulation longer.DaunoXome is a liposomal formulation of the cancerdrug daunorubicin.
The acerbated approval recommended for Doxil inFebruary came with a condition that safety and efficacymust be demonstrated in post-marketing, or Phase IV,studies.
Alex Zisson, an analyst for New York-based Hambrecht& Quist Inc., said approval of Doxil could come in two tothree months. He said getting labeling as a first-linetreatment for KS would help Sequus equalize opinions inthe marketplace. "It's true," he said, "that oncology drugsare often used off-label, but there's such a starkdifference between first-line and second-line therapy thatyou'd like to promote your drug as a first-line therapy." n
-- Jim Shrine
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