Pfizer is taking over the 89% of Icagen it doesn’t already own for $49.8 million. The company agreed to pay $6 per share. Icagen lost about 23% of its value in early morning trading today, dropping from $7.75 at yesterday’s close to open today at $5.96. Icagen was last trading at $6 on July 13.
Pfizer and Icagen have been working together since 2007 on small molecule treatments for pain and related disorders. The focus has been on compounds that modify three specific sodium ion channels, which are important in the generation of electrical signals in nerve fibers that mediate the initiation, transmission, and sensation of pain. In November 2010, the companies chose to move Nav1.7 into clinical advancement.
“Icagen’s capabilities and core ion channel technology will help to further expand Pfizer’s position in the pain relief disease area and our ability to develop potential first-in-industry drugs for the treatment of pain and related disorders,” remarks Ruth McKernan, svp, Pfizer’s pain and sensory disorders and regenerative medicine unit known as Neusentis.
Icagen’s lead ion-channel targeting drug, however, is currently on clinical hold. In September 2010, the firm stopped enrolling patients into a study evaluating up to 600 mg doses of ICA-105665 in participants with photosensitive epilepsy due to a serious adverse event. The molecule also generated negative results in a Phase Ib pain study.
ICA-105665 is designed to selectively open certain subtypes of KCNQ potassium channels that the firm says have been validated as playing important roles in certain conditions characterized by abnormal neuroexcitability, such as seizures, and potentially also chronic pain disorders.
Besides ICA-105665 and the small molecules against pain and related disorders developed along with Pfizer, Icagen has additional research-stage programs in pain and inflammatory disorders.
Pfizer has been investing in the area of pain therapeutics for a while. It has two best-selling pain medications on the market: Lyrica for seizures, fibromyalgia, diabetic neuropathy, and herpes zoster; and Celebrex, a nonsteroidal anti-inflammatory.
In October 2010, Pfizer shelled out $3.6 billion to buy King Pharmaceuticals, which has three marketed pain drugs: Avinza, the Flector Patch, and Embeda, reportedly the first approved opioid pain product with design features intended to discourage misuse and abuse. King's portfolio includes a prescription pharmaceutical business focused on delivering new formulations of pain treatments designed to discourage common methods of misuse and abuse.
In its own pipeline Pfizer is covering various targets and types of therapeutics from small molecules to mAbs to stem cells. Most recently, in May of this year, Neusentis inked a deal with Cellzome to characterize epigenetic factors involved in stem cell differentiation.
Between June and July of last year, however, Pfizer had to halt three trials with its lead candidate, an antinerve growth factor mAb, tanezumab: a Phase III trial in osteoarthritis patients to treat chronic pain; a Phase II study in chronic low back pain; and a Phase II study in painful diabetic peripheral neuropathy.
Pfizer’s small molecule JAK inhibitor has had better luck in treating arthritis pain. The company reported that tasocitinib significantly reduced the signs and symptoms of moderate-to-severe RA, a primary endpoint. The drug, administered as monotherapy, also improved physical function versus placebo at three months. The drug did not meet a third primary endpoint of disease remission.