New paediatric use for Allergan's biosimilar-threatened Botox

Allergan’s Botox has another clinical use after the FDA granted approval for children with upper limb spasticity.

The drug was first approved clinically for upper limb spasticity in adults in 2010, and since then has been licensed in a range of uses including migraine, urinary incontinence, overactive bladder and lower limb spasticity.

Botox (onabotulinumtoxinA) could be threatened by biosimilars in the coming years, as Mylan has this year received confirmation from the FDA that it could develop a cheaper near-copy using the truncated biosimilars approval process.

It also faces competition in its aesthetic uses as Evolus has produced an alternative known as Jeuveau (prabotulinumtoxinA-xvfs).

But Botox remains a very important product for Allergan with therapeutic revenues of nearly $398 million in the first quarter alone, up 5.8% compared with last year’s Q1. Cosmetic revenues in Q1 were almost $230 million, up 16.7%.

The paediatric approval for Botox will help Allergan to grow its clinical revenues further, and the Dublin-based pharma is also expecting a decision from the FDA about the drug’s use in paediatric lower limb spasticity in the fourth quarter of the year.

Spasticity in children is often caused by brain or spine damage, and is often observed as muscle tightness and stiffness.

The FDA approval is based on data from two phase 3 studies evaluating the safety and efficacy of Botox in over 200 paediatric patients with upper limb spasticity.

These trials included a 12-week, double-blind study and a one-year open-label extension study.

The approved recommended dose per treatment session is three units per kilogram to six units per kilogram divided among affected muscles of the upper limb.

The total dose in paediatric patients should not exceed eight units per kilogram body weight or 300 Units, whichever is lower, in a three month interval.

Treatment is not meant to replace existing physical therapy or other rehabilitation that may have been prescribed.