Smoking, Headaches And Allergies: Rx Pipeline Drugs May Impact OTCs

Pfizer and Schering-Plough are developing a number of new prescription drugs and line extensions that could make inroads into large OTC categories.

For example, Schering has several new formulations pending in its allergy drug pipeline.

A Claritin/Singulair joint venture with Merck, described as a non-sedating antihistamine leukotriene inhibitor and indicated for dual-action treatment of seasonal allergic rhinitis, currently is in Phase III development.

Schering also is developing 12- and 24-hour formulations of Clarinex (desloratadine), a brand that has lost market share and seen flat sales in recent quarters (¹ (Also see "Claritin Growth Plateaus As Schering Moves Ahead With Consent Decree" - Pink Sheet, 25 Oct, 2004.), p. 8).

Clarinex-D 12 Hour currently is in Phase III trials; Schering filed an NDA for Clarinex-D 24 Hour in May.

Separately, Pfizer is working on an Rx smoking cessation drug. The firm's nicotinic partial agonist varenicline currently is in Phase III clinicals. The nicotine replacement therapy pill is purported to reduce cravings, ease withdrawal symptoms and diminish the physical rewards of smoking, according to the company.

Pfizer Worldwide Development President Joe Feczko delivered the results of a Phase II study showing a continuous quit rate in more than half of patients taking varenicline at a Nov. 30 analyst conference in Groton, Conn.

The placebo-controlled trial demonstrated a 51% quit rate in 1 mg varenicline users over a four-week period, compared to 12% for placebo. The drug also showed comparable quit rates to GlaxoSmithKline's Zyban (bupropion).

Pfizer says the drug appears to be well-tolerated, and ongoing Phase III studies will explore varenicline's ability to improve quit rates on a long-term basis. Although the NRT drug is in late-stage development, Pfizer has not yet set a timeline for filing an NDA.

In the headache medicine category, Pfizer is touting the recent success of its Relpax (eletriptan) migraine drug, which has steadily increased its market share over the past 20 months.

While competing medications such as GSK's market-leading Imitrex (sumatriptan) and Merck's Maxalt have remained relatively flat, Pfizer says Relpax has grown 28% from Feb. 2003 through Oct. 2004 to become the number three triptan in the U.S.

Pfizer has been targeting nonprescription migraine medications including Bristol-Myers Squibb's Excedrin Migraine as part of a strategy to carve out a niche for the product from OTC users (² (Also see "Pfizer Touts Relpax Efficacy Versus Excedrin Migraine In Study" - Pink Sheet, 22 Mar, 2004.), p. 11).

Earlier this year, the firm sponsored an open-label clinical study demonstrating Excedrin non-responders preferred the Rx remedy due to greater efficacy and a comparable adverse event profile.

Pfizer also significantly increased its share of the Rx arthritis market since the withdrawal of Merck's Vioxx (rofecoxib), Global Pharmaceuticals President Karen Katen reported at the analyst meeting.

Since Vioxx was pulled Sept. 30, Pfizer's COX-2 inhibitors Celebrex (celecoxib) and Bextra (valdecoxib) have gained approximately eight points to occupy 41% of the total market.

Pfizer has worked to fend off pressure from OTC analgesic manufacturers with a television ad campaign questioning their safety (³ (Also see "Pfizer Ad Says OTCs “Aren’t As Safe As You Might Think”" - Pink Sheet, 25 Oct, 2004.), p. 5).

"It's a sad fact that more Americans die from nonsteroidal-induced GI bleeds than die from AIDS," said CEO Hank McKinnell, estimating the former at 16,500 and the latter at 15,000.

"We tend to think that because these are older, well-known agents, we've all taken them, that they are safe. Wrong."

McKinnell further expressed his desire to keep the COX-2 safety debate out of the mainstream press. "Let's debate this in the appropriate forum, which are the advisory committees of the FDA, and the FDA's own experts."