PFIZER’s ZOLOFT U.S. SALES NEAR $175 MIL. IN FIRST YEAR ON MARKET; PRICE REDUCTION COULD BE RESPONSE TO PAXIL LAUNCH; NORVASC OFF TO "GREAT START"

Pfizer's antidepressant Zoloft (sertraline) generated nearly $175 mil. in U.S. sales in its first year on the market, materials distributed by Pfizer at a Feb. 26 securities analysts meeting in New York City indicate. New prescriptions for Zoloft continue to track ahead of launch numbers for the first serotonin reuptake inhibitor, Lilly's Prozac, Pfizer said. At 35 weeks post-launch, Zoloft was generating 46,400 new prescriptions compared to 39,000 for Prozac in 1988. Worldwide sales of Zoloft were $195 mil. in 1992, up from $3 mil. in 1991. Zoloft was approved by FDA Dec. 30, 1991 and launched in the U.S. in the first quarter of 1992 ("The Pink Sheet" Jan. 6, 1992, p. 6). Pfizer Chairman William Steere indicated that the firm will consider reducing Zoloft's price in response to the launch of SmithKline Beecham's Paxil. Paxil was approved by FDA at the end of 1992 and is being launched at a discount to both Prozac and Zoloft ("The Pink Sheet" Jan. 4, p. 6). "We haven't really enumerated what our pricing strategy is going to be," Steere said. "Obviously, we'll have to look at pricing." Pfizer, however, believes that the launch of Paxil will continue the expansion of the serotonin reuptake inhibitor market. Chief Financial Officer Henry McKinnell noted that 70% of depressed patients still receive older classes of medication. Pfizer is not ruling out a price reduction for another 1992 launch, the azalide antibiotic Zithromax (azithromycin). McKinnell presented data showing that monthly new prescriptions of Zithromax through January are running ahead of other recent antibiotic launches, including Bristol-Myers Squibb's Cefzil, Lilly's Lorabid, Searle's Maxaquin and Upjohn's Vantin. However, at 120,000 new scripts per month, Zithromax has just over a quarter of the volume of Abbott's azalide antibiotic Biaxin. Biaxin and Zithromax were approved at the same time, although Biaxin was launched four months ahead of the Pfizer entry. Pfizer's initial detailing efforts "have had to focus on educating physicians about Zithromax' unique pharmacokinetic profile and dosing schedule," McKinnell said. "We will now be able to focus on comparative advantages" of Zithromax versus other therapies. Pfizer has data to show "that patients feel better quicker on Zithromax," McKinnell maintained. Steere was asked if the respective costs of Zithromax and Biaxin are affecting the market. The "cost of cure with Zithromax is very competitive," Steere answered. "As a matter of fact, it is lower than a lot of the more recent drugs that have come on the market, including Biaxin," he maintained. "It's certainly not our intention at this time to look at a price reduction of Zithromax," Steere told the analysts, adding, "We have a number of interesting strategies under way" to increase sales. "I'm sanguine that Zithromax will do extremely well." However, Steere added, "at some point in time, I guess we would have to re-evaluate our pricing." Sales of Pfizer's new calcium channel blocker Norvasc (amlodipine) more than doubled in 1992 to $190 mil., Pfizer said. U.S. sales contributed about $20 mil. following launch in September. Norvasc is "off to a great start," McKinnell said. Weekly new prescription data show that "Norvasc has managed to separate itself" from a "pack" of newer cardiovascular drugs including Sandoz' DynaCirc, Warner-Lambert's Accupril, Ciba-Geigy's Lotensin, Rhone-Poulenc Rorer's Dilacor XR and Merck's Plendil, McKinnell claimed. An NDA for treatment of congestive heart failure is slated for a fourth quarter filing. Pfizer's older Procardia (nifedipine) calcium channel blocker line posted sales of $1.12 bil. in 1992, a 25% increase over 1991. Procardia XL sales accounted for over $1 bil. of that total, McKinnell said. Immediate-release Procardia capsule sales declined to $56 mil. "We expect 1993 to be another year of good growth [for Procardia XL] even in an increasingly competitive cost-conscious market," McKinnell said. He presented "preliminary results" from an "independent study" rating the "total cost of drug in management of patients with mild to moderate hypertension." Taking into account drug price, supplemental medications, laboratory costs, clinical visits and side effect costs, the study showed that Procardia XL had the lowest total cost among calcium channel blockers, McKinnell said. McKinnell called the data "the type of study increasingly necessary to demonstrate the cost effectiveness of products." During the Feb. 26 meeting, Pfizer emphasized its ability to compete no matter what shape the Clinton Administration's health care reform effort takes (see preceding story). Pfizer's Waxman/Hatch marketing exclusivity for once-a-day nifedipine expired in September. At a July analysts meeting, the firm maintained that generic versions would have difficulty showing "functional equivalence" to the Alza-developed XL delivery system, which has patent protection through 2002 ("The Pink Sheet" Aug. 3, 1992, p. 12). Pfizer met with FDA's Office of Generic Drugs in late January or early February. The firm may have been discussing bioequivalence standards for Procardia XL. K-V Pharmaceuticals has an approved ANDA suitability petition for extended-release nifedipine tabs. The antifungal Diflucan (fluconazole) topped the $500 mil. mark in sales in 1992, reaching $532 mil. Sales were up 36% over 1991. U.S. sales contributed about $200 mil. of the worldwide total. An NDA for vaginal candidiasis was filed in December, McKinnell noted. A pediatric NDA is slated for the third quarter. Sales of the alpha blocker Cardura (doxazosin) jumped 90% in 1992 to $177 mil., with U.S. sales contributing approximately $50 mil. Pfizer expects worldwide filings for a benign prostatic hyperplasia indication for the drug in the second quarter. The nonsedating antihistamine Reactine (cetirizine) is performing well in Canada and "could surprise us all" once approved in the U.S., McKinnell maintained. Since its launch in Canada in June 1991, Reactine has captured 12% of the total antihistamine market as a prescription-only product despite nonprescription availability of other nonsedating antihistamines. "We hope to see approval [of Reactine] in the U.S. this year," McKinnell said. Approval of both Reactine and Schering-Plough's Claritin has been delayed due to carcinogenicity concerns which resulted in a June 1991 advisory committee discussion of the issue. Schering-Plough said Feb. 11 that it believes Claritin will be approved "shortly" ("The Pink Sheet" Feb. 15, In Brief). McKinnell added that Reactine could be "an interesting candidate" for an Rx-to-OTC switch. A pediatric NDA was filed in January, he said. Pfizer's NDA filing target for the anti-arthritic drug tenidap has been pushed back to late third quarter or early fourth quarter of this year. International filings are still slated to begin in April. "In most foreign markets, we plan a sequential filing, with the first submission to cover rheumatoid arthritis and a supplemental filing for osteoarthritis," McKinnell said. "The U.S. NDA filing, which will be for both rheumatoid and osteoarthritis, will occur later than the European filings because we have been interacting with the FDA concerning new standards for statistical analyses and data presentations for new anti-arthritic agents." FDA's Arthritis Drugs Advisory Committee discussed tenidap and the statistical issues during a closed meeting Jan. 5 ("The Pink Sheet" Feb. 1, In Brief). After that meeting, Pfizer "began preparing the NDA, the largest in Pfizer history," McKinnell said. Pfizer's database for the combined cytokine/prostaglandin inhibitor includes over 10,000 patients, and the firm has said it will seek a disease-modifying claim for rheumatoid arthritis ("The Pink Sheet" Aug. 3, 1992, p. 10).