Benefits of Strensiq for rare inherited bone disorder too uncertain to justify its high cost, says NICE

The National Institute for Health and Care Excellence (NICE), the medicines cost watchdog for England and Wales, has today published draft guidance as part of its highly specialized technologies program that does not recommend US drugmaker Alexion’s (Nasdaq: ALXN) Strensiq (asfotase alfa) for treating pediatric-onset hypophosphatasia.

Strensiq was recently been approved in Europe for long-term enzyme replacement therapy in patients with pediatric-onset hypophosphatasia to treat the bone manifestations of the disease (The Pharma Letter September 1).

It is estimated that around seven people are diagnosed with pediatric-onset hypophosphatasia each year in England. The most severe forms of the condition - perinatal- and infantile-onset hypophosphatasia - tend to occur before birth and in early infancy. Infants who present with the condition in the first 6 months of life have a high mortality rate, with up to 100% of infants dying within the first year of life, mainly because of respiratory failure.

The current mainstay of treatment is supportive care, which aims to monitor and alleviate symptoms to decrease morbidity and mortality and improve quality of life. Asfotase alfa is the first therapy that specifically targets the underlying cause of hypophosphatasia. It is a targeted enzyme replacement therapy designed to restore the regulation of metabolic processes in the bones and teeth, and to reduce complications of dysregulated bone mineral metabolism.

£366,912 treatment cost

The total cost per person per year of treatment with asfotase alfa (assuming an average weight of 19.3 kg and 100% adherence) is £366,912 ($552,569).

“There is a clear clinical need for a treatment that addresses the cause of this devastating condition, and can prevent or delay its progression,” commented Meindert Boysen, Technology Appraisals Program director at the NICE, adding: “Based on the evidence presented by the company, as well as the testimony of clinical experts and patient representatives, the Committee concluded that asfotase alfa improved the probability of survival in perinatal- and infantile-onset hypophosphatasia compared with best supportive care.”

He continued: “The Committee also accepted that asfotase alfa was likely to be clinically effective across a range of outcomes, such as reducing the need for respiratory support and the severity of rickets for people with perinatal- and infantile-onset hypophosphatasia, and for outcomes such as improving growth and mobility and reducing pain compared with best supportive care for people with juvenile-onset hypophosphatasia. However, the Committee was unable to estimate from the clinical evidence the precise size of these benefits that are relevant for patients in the longer term. Furthermore, the Committee was not satisfied that the company had provided an adequate justification for the high cost per person of asfotase alfa, or for the overall cost to the NHS in terms of what could be expected to be reasonable in the context of a highly specialized service.”

Consultees, including the company, healthcare professionals, patient/carer organizations and members of the public, are now able to comment on the preliminary recommendations which are available for public consultation until January 7, 2016.