Opexa Tries a Personalized Cell Therapy Against Last, Worst Stage of MS

5/2/13Follow @tanseyverse

Pharmaceutical companies have been fielding a slate of new drugs for multiple sclerosis in the past few years—most recently the new oral pill diethyl fumarate (Tecfidera) that analysts see as a potential multibillion-dollar revenue source for Weston, MA-based Biogen Idec (NASDAQ: BIIB).

For the most part, however, the new MS drugs treat the progressive disease in its early stage, called relapsing-remitting MS, in which patients have periodic attacks of brain inflammation but then recover some of their lost muscle strength and other abilities. Unfortunately, doctors have little to offer patients who move into a later stage, secondary progressive MS, which causes a gradual and lasting decline in physical functioning.

It’s that later phase of the disabling neurodegenerative disease that the small Texas biotechnology company Opexa Therapeutics (NASDAQ: OPXA) decided to tackle. Opexa’s cell-based immunotherapy imilecleucel-T (Tcelna), if successful in clinical trials, could become the first “personalized” treatment for multiple sclerosis, says CEO Neil Warma (pictured above). The company uses a blood sample from each patient to generate cells designed to activate the immune system against the individual traits of that person’s disease. The cells are then re-injected into the patient.

Opexa is hoping its cell therapy will provide a much safer alternative to the currently approved drug for secondary progressive MS (SPMS), a repurposed cancer drug called mitoxantrone (Novantrone.) Side effects are often a significant drawback of MS drugs, but doctors have to be particularly careful with mitoxantrone, which comes with an FDA “black box” warning because it can have toxic effects on the heart.

“It’s rarely used, or it’s used with caution,” Warma says. Doctors may try keeping patients with SPMS on drugs approved for the relapsing form of MS, but often there’s little clinical evidence of efficacy in SPMS and a risk of side effects, Warma says. “An awful lot of patients are not taking anything,” he says.

Opexa, based in The Woodlands, TX, north of Houston, was once among the competitors in the crowded field of drug companies developing treatments for relapsing-remitting MS (RRMS). The Texas company saw encouraging efficacy trends and a reassuring safety record in a mid-stage trial of imilecleucel-T in both RRMS and SPMS patients that ended in late 2008, Warma says. Opexa received the FDA’s approval for a Phase 3 trial in RRMS.

But Opexa took a pause to regroup and plan its best path forward, says Warma, who became CEO in 2008. The company modernized processes at its manufacturing plant to prepare for the scale-up needed for a large clinical trial and the possible commercial launch of imilecleucel-T. Opexa also rearranged its priorities after listening to pharmaceutical industry advisors who said the company should pursue approval first in secondary progressive MS, an area of significant unmet need.

Multiple sclerosis is an unpredictable disorder whose effects vary among individuals from mild flare-ups to paralyzing disabilities. About 2.1 million people worldwide suffer from the disease, including at least 400,000 in the United States, according to the National Multiple Sclerosis Society. The relapsing form of MS accounts for about 85 percent of cases. But many early stage MS patients develop secondary progressive MS after 10 to 20 years, Warma says. A successful treatment for SPMS could compete for a 40 percent share of a U.S. market in MS drugs now worth as much as $12 billion a year, he says.

Opexa has emerged from its rebuilding phase over the past year, growing to more than 30 employees and adding experts in clinical research, manufacturing, and regulatory issues. In September, the company began … Next Page »

Bernadette Tansey is a freelance journalist based in Berkeley, CA. Follow @tanseyverse

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