Pfizer Zoloft And Xanax XR Provide “Complete Solution” For Anxiety

Pfizer's Zoloft and recently launched Xanax XR provide the "complete solution for patients across a number of anxiety positions," Pfizer President Global Pharmaceuticals Karen Katen said during an analyst meeting in New York June 17.

"Zoloft is best in class and it can take several weeks to take effect, as you know, while Xanax XR is the benzodiazepine that works right away that may not be appropriate for long-term use. So the two products work safely and complement each other," Katen said.

Xanax XR, which Pfizer acquired in its merger with Pharmacia, was launched June 11. FDA approved the once-daily formulation of alprazolam Jan. 17 for the treatment of panic disorder. Immediate release Xanax was typically dosed three to four times a day (¹ 'The Pink Sheet' Jan. 27, 2003, In Brief).

"Now we have the number one antidepressant and the number one anxiolytic all from the same company, and they are complementary," Katen stated.

Zoloft (sertraline) had 14.5% of new prescriptions and 15.4% of total prescriptions in April in the antidepressant category, which includes GSK's Paxil CR and Wellbutrin SR , Lilly's Prozac , Wyeth's Effexor XR , and Forest's Celexa and Lexapro .

For social anxiety disorder, Zoloft had an 18.6% market share in April. "Behind the growth is solid clinical data," including a comparison of Zoloft and Paxil, Katen explained.

The study showed "that Zoloft is significantly better than the market leader Paxil in treating panic disorder with significantly more panic free patients after 12 weeks of treatment," Katen said.

After 12 weeks of treatment and a three-week taper, 60% of 79 patients on Zoloft were panic free, as compared with 41% of 72 patients on Paxil.

Pfizer held the analyst meeting to discuss its 2003 and 2004 earnings guidance following the completion of its merger with Pharmacia.

The company plans to use its newly synchronized sales force to create a unified message for Celebrex , a product promoted by Pfizer and Pharmacia separately (see ² ).

In the antihistamine market, Katen noted patients taking over-the-counter agents are beginning to return to prescription treatments.

"There are a significant number of non-responders to the OTC agents, so many people are already going back to what they had before, this is prescription medicine....They comply better with prescription medicines than they do with OTC," Katen said.

Sepracor noted an increase in prescription antihistamine market share after Claritin went OTC. Claritin patients who wished to remain on prescription medicines redistributed throughout the remaining treatments, increasing the medicines' relative market share (³ (Also see "Sepracor Estorra NDA Filing Planned By Mid-Feb.; Xopenex MDI By Year-End" - Pink Sheet, 3 Feb, 2003.), p. 28).

Pfizer does not believe the increased co-pay on prescription antihistamines will create a barrier because of Zyrtec brand loyalty.

Pfizer's Zyrtec antihistamine franchise has stabilized between April 18 and May 30. Zyrtec Tabs/Syrup declined slightly to 31% of the total weekly antihistamine prescriptions. Zyrtec-D has remained steady from March 7 to May 30 at 5%.

Obtained by Pfizer in the merger, Zyvox will be studied for the treatment of methicillin-resistant Staphylococcus aureus in diabetic foot infections.

"There is no FDA approved treatment at this time and it's a large market" Katen noted. The market includes approximately 1 mil. patients, 50%-60% of which have moderate to severe infections.

Data presented at the Infectious Disease Society of America meeting in October 2002 "showed a very high rate of success," Katen added. Zyvox had an 81% successful treatment rate compared with a 71% successful treatment rate for ampicillin/sulbactam.

Katen noted Zyvox' already strong growth: "Its growth is six times the market and six times that of its competitors."