WinRho SD became the first biotechnology drug approved this yearas the FDA granted a marketing license to sell the polyclonalantibody for prevention of Rh isoimmunization in pregnant womenand for treatment of immune thrombocytopenic purpura (ITP), aplatelet disorder that can cause uncontrolled bleeding.
WinRho was developed by Rh Pharmaceuticals, of Winnipeg,Canada. Univax Biologics Inc., of Rockville, Md., acquired U.S.marketing rights in 1992 and filed a product license application withthe FDA in June 1993.
Univax said Monday the FDA approval came exactly one year afterthe agency's Office of Blood Research and Review advisorycommittee reported that it had no significant objections to the drug.WinRho, Univax's first marketable product, already is sold in Canadaby Rh Pharmaceuticals.
Univax's stock (NASDAQ:UNVX) closed Monday at $7.50 pershare, up 13 cents. WinRho is the 21st biotechnology drug to reachthe market since the industry's inception more than a decade ago.
Matthew Geller, an analyst with Oppenheimer & Co. in New York,said the FDA's approval of WinRho was quicker than anticipated andindicates the agency can be aggressive in reviewing products fordisorders, such as ITP, with few treatment alternatives.
"The FDA gave [Univax] a formal approval with an approvable lettermeaning they expedited this a bit," said Ed Hurwitz, an analyst withRobertson Stephens & Co. in San Francisco. "That indicates there isa compelling need for virally inactivated plasma products."
WinRho will be the only virally inactivated Rh immune globulin drugon the market. Last year, responding to a potential problem withhepatitis C contamination of plasma products, the FDA asked allpharmaceutical companies making antibody drugs to submit a planfor viral inactivation.
Although most of WinRho's sales are projected for ITP, where thedrug has little competition, analysts said WinRho could grab more ofthe competitive Rh isoimmunization market than expected because ofthe contamination concerns.
Judith Hautala, Univax's vice president for corporatecommunications and planning, said the company expects to beginselling WinRho in six to eight weeks and has projected sales for thefirst 12 months of $10 million to $12 million.
Hurwitz estimated sales would reach between $7 million to $10million this year and could jump to between $30 million to $35million for 1996. Peak sales, he added, are estimated at about $90million annually.
ITP is a blood disorder in which the immune system destroysplatelets, leading to uncontrolled bleeding. WinRho was approved forchronic and acute ITP and for treatment of ITP as a secondarycondition to HIV infection.
Rh isoimmunization involves Rh incompatibility in a pregnantwoman who is Rh negative while her fetus is Rh positive. At birth thefetus' Rh positive blood cells can enter the mother's blood, triggeringan immune system reaction that can endanger the baby andsubsequent pregnancies where the fetus is Rh positive.
WinRho SD contains high levels of antibodies to the Rh (D) antigen.It is produced by stimulating plasma donors with Rh-positive bloodcells. The SD signifies solvent-detergent, which is used to ensureviral inactivation of the blood-derived drug.
Hautala said Univax's price per treatment for ITP would be about$650 to $700. For Rh isoimmunization, which requires a lesseramount of the drug, Univax's price would be about $65 to $70 pertreatment.
ITP, Hautala said, is treated when uncontrolled bleeding occurs andpatients usually suffer about four to five episodes a year. Univax, sheadded, believes if patients were to receive the drug 10 times annually,WinRho could prevent the excessive bleeding.
Under Univax's agreement with Rh Pharmaceuticals, the latter willmanufacture the drug and will receive 60 percent of profits up to $50million in sales, after which the two companies will split profits, 50-50.
Hautala said Univax is hiring 13 sales people and they willcoordinate with a group of biologics specialty distributors, who havea network of 40 to 50 sales representatives.
Univax reported a net loss for 1994 of $21.8 million and analysts saidWinRho won't make the company profitable. Hautala said Univaxhas another product, StaphVAX, in Phase II clinical development forkidney dialysis patients and a third drug, HyperGAM+CF, is about toenter Phase II trials for cystic fibrosis. n
-- Charles Craig
(c) 1997 American Health Consultants. All rights reserved.