Merz to present data on Xeomin clinical studies for cervical dystonia at AAPM&R

Merz Pharmaceuticals announced today that data from stability and clinical studies evaluating Xeomin® (incobotulinumtoxinA), a botulinum toxin type A free from accessory proteins, will be presented at the 71st Annual Assembly of the American Academy of Physical Medicine and Rehabilitation (AAPM&R) in Seattle, Wash. 

The U.S. Food and Drug Administration (FDA) approved XEOMIN on July 30, 2010, for the treatment of adults with cervical dystonia (CD), to decrease the severity of abnormal head position and neck pain in both botulinum toxin-naive and previously treated patients, and blepharospasm in adults who have been previously treated with Botox® (onabotulinumtoxinA). 

Stability Studies

As part of the commercial development of XEOMIN, Merz conducted studies to assess the stability of XEOMIN and the 900 kDa neurotoxin complex which is produced by Clostridium botulinum. In nature, Clostridium botulinum produces the 150 kDa neurotoxin molecule with accessory proteins, resulting in a complex with a molecular weight of 900 kDa.

Results from a study designed to assess the stability of the 900 kDa neurotoxin complex at various pH values concluded that the 150 kDa neurotoxin molecule was released in less than one minute when exposed to physiological pH values. In the study, separation conditions were qualified by Western blot and toxin activity. (Poster 108; Eisele K.H., et al.)

In a second study, the stability of three individual batches of XEOMIN was assessed in long-term and accelerated stability studies according to the ICH Q1A(R2) guideline on stability testing of drug products. The results of this study showed that the product can be safely stored without refrigeration and is not affected by short-term temperature stress between 40°C (104°F) and 60°C (140°F). (Poster 106; Grein S., et al.)

"According to these data, the speed at which accessory proteins disassociate from the neurotoxin molecule at physiological pH suggests that the necessity of these proteins in medicinal formulations of botulinum toxin type A is questionable in influencing the therapeutic effects," said Eric J. Pappert, M.D., Vice President of Medical Affairs, Merz Pharmaceuticals, LLC. "Additionally, results from the stability studies evaluating XEOMIN under various conditions suggest that accessory proteins are not required for the long-term maintenance of potency of this medicinal formulation of botulinum toxin type A."

Clinical Studies

The results of studies exploring the safety and efficacy of XEOMIN in the treatment of adults with cervical dystonia, blepharospasm and post-stroke spasticity of the upper limb will also be presented:

• Poster 49: Efficacy and safety of NT 201 (Xeomin®; Botulinum neurotoxin free from complexing proteins) in cervical dystonia (Grafe S., et al.)
• Poster 50: Efficacy and safety of NT 201 (Xeomin®; Botulinum neurotoxin type A free from complexing proteins) for the treatment of blepharospasm: Results of a double-blind, placebo-controlled, randomized, multi-center trial (Jankovic J., et al.)
• Poster 57: Overall clinical efficacy and overall tolerability of NT 201 (Botulinum neurotoxin free from complexing proteins) (Benecke R., et al.)