Washington Editor

While Pfizer Inc. has long been the king of the big pharmas, the company's $3.6 billion bid for King Pharmaceuticals Inc. may be the card it needs to play a larger role in the pain therapeutics space.

New York-based Pfizer not only gets King in the acquisition, but the deal brings in partnerships with other makers of pain products, including Acura Pharmaceuticals Inc. and Pain Therapeutics Inc., whose experimental pain medications currently are under review at the FDA.

News of the proposed acquisition sent shares of Bristol, Tenn.-based King (NYSE:KG) up 39.3 percent, or $3.99, to close at $14.14 Tuesday.

Shares of Pain Therapeutics (NASDAQ:PTIE) jumped 18.6 percent, or $1.16, to close at $7.41, while Acura's shares (NASDAQ:ACUR) also got a bump, rising 12.3 percent, or 28 cents, to close at $2.55.

Pfizer already has a strong foothold in the pain market with its COX-2 inhibitor Celebrex (celecoxib), which is approved to relieve the signs and symptoms of osteoarthritis, rheumatoid arthritis and ankylosing spondylitis. It also is indicated as a therapy to manage acute pain in adults.

Sales of Celebrex, however, dropped sharply after it was linked in 2004 to cardiovascular events, including heart attack and death. Indeed, Pfizer racked in $3.3 billion in 2004 for Celebrex, but the drug last year brought in nearly a billion less, at $2.38 billion.

Pfizer's pain drugs also include Lyrica (pregabalin), which is indicated to treat fibromyalgia, diabetic nerve pain and shingles-related pain. Lyrica also is approved to treat partial onset seizures in adults with epilepsy who take one or more drugs for seizures.

Pfizer reported revenues of $2.84 billion for Lyrica in 2009.

If the Pfizer bid is upheld, the big pharma gains King's long-acting opioid analgesic Embeda (morphine sulfate and naltrexone hydrochloride), which gained approval last year as a therapy to manage moderate to severe pain when a continuous, around-the-clock opioid analgesic is needed for an extended period of time.

Embeda was designed with an inner core of naltrexone hydrochloride aimed at making it difficult for drug abusers to extract the active ingredient, although regulators have said that clinical evidence of the drug's tamper resistance has not been clearly established.

King reported net sales for Embeda, which entered the market in September 2009, of $15 million during the second quarter of 2010, which was up $6 million from the first quarter.

King acquired Embeda through its $1.6 billion acquisition in 2008 of Bridgewater, N.J.-based Alpharma Inc. (See BioWorld Today, Nov. 25, 2008.)

King also is partnered with San Mateo, Calif.-based Pain Therapeutics Inc. to develop a controlled-release formulation of oxycodone, known as Remoxy, a gel capsule containing a tar-like hard liquid – a format also intended to deter abuse.

But Remoxy has had a bumpy road to approval, receiving a complete response letter in 2008 from the FDA, which called for more data. (See BioWorld Today, Dec. 12, 2008.)

King has assumed full control of all activities related to the development of Remoxy and has completed the pharmacokinetic and six-month stability studies requested by the FDA, along with a likeability study the company volunteered to conduct. King expects to resubmit Remoxy's application in the fourth quarter.

Another of King's partners in the pain medication realm is Acura, which is developing Acurox (oxycodone HCl and niacin).

The niacin and mixture of functional excipients in Acurox are aimed at reducing the potential for intranasal abuse if crushed and snorted or dissolved and injected.

While the niacin was intended to cause an unpleasant sensation of flushing when large quantities of the product are ingested, a panel of FDA experts in April raised concerns about severe flushing occurrences in patients during clinical testing. (See BioWorld Today, April 26, 2010.)

Acurox-treated patients also experienced adverse vasodilatory events.

The FDA's Anesthetic and Life Support Drugs and Drug Safety and Risk Management Advisory Committees at a joint April 22 meeting voted 19 to 1 that Palatine, Ill.-based Acura's and King's data were insufficient to show that Acurox's niacin additive and mixture of functional excipients could effectively deter potential abuse of the oxycodone drug.

Pfizer also stands to gain King's Avinza (morphine sulfate extended-release capsules), a once-daily drug approved to treat moderate to severe chronic pain in adults who need ongoing, around-the-clock pain relief for an extended period of time, and its Flector Patch (diclofenac epolamine), which is indicated to treat acute pain due to minor strains, sprains and bruises.

King's investigational pain product pipeline also includes AL-02, a combination drug that is expected to soon enter Phase III testing, and AL-04, a Phase II-stage drug.

King spokesman Jack Howarth declined to comment on Pfizer's bid. But Frank D'Amelio, Pfizer's chief financial officer, said King's assets map directly to his company's current business unit structure and provide an improved business profile and enhanced presence in the pain therapeutic area.

Bringing King's pain relief products under Pfizer's roof also would help the big pharma to fulfill one of its identified strategic areas of unmet medical need, he added.

The proposed acquisition is not only "consistent with our view of business development," but is "attractive and beneficial from a value-creation perspective for several reasons," D'Amelio told investors and analysts Tuesday during a conference call.

The deal would provide an immediate optimization of King's assets by leveraging Pfizer's scale and business unit structure, he insisted.

King's diversified business portfolio also would further diversify Pfizer's revenue, D'Amelio said.

The merger agreement would give to Pfizer King's Meridian auto-injector business for emergency drug delivery, which develops and manufactures the EpiPen and is a long-term, critical supplier to the U.S. Department of Defense.

Pfizer also will gain King's animal health business, which includes feed additive products.