Rare diseases and orphan drugs have recently been in the spotlight as an area of growth and increasing investment from pharmaceutical companies and healthcare providers. Inevitably, rare diseases have attracted interest for the development and use of drug delivery devices.
A disease is classified as rare if it affects fewer than 254 000 Europeans or 200 000 Americans. There are over 7000 rare diseases and 1 in 17 people will be affected by a rare disease at some point in their life. Whilst 75% of rare diseases affect children, only 45% of drugs in the EU and 70% in the US, that available for rare diseases, are approved for children.
Since 30% of patients with rare diseases die before their 30th birthday, it’s important that paediatrics are not excluded from access to these medications.
Recent regulatory change has made it more commercially viable to develop a rare disease drug, particularly for paediatrics, with the FDA granting the developer a ‘priority review’ voucher entitling the holder to a faster review of a drug. This can be sold on for as much as $350 million. In Europe, adding a paediatric label extends the drug’s exclusivity period by two years for adults in addition to children.
Market drivers including a fertile regulatory landscape are not enough to guarantee the commercial success of an orphan drug. Users have to be able to achieve the correct dosage, which has to be reliably taken. Adherence is critical to achieving results and the drug needs to be taken in a manner that maximises its efficacy. For a drug to fail because of one of these factors will not only deprive users of its benefits, but have major impact on its commercial success.
Drug delivery devices can have a significant impact on all these factors but many rare disease products are provided in standard syringes and vials and are not provided with patient needs in mind. Below, I list four key reasons why devices will shape the treatments of paediatric rare diseases.
A paediatric patient usually requires smaller doses than an adult. Pen devices allow for more accurate and better compliance than a syringe and this is particularly useful for children who would otherwise require help receiving a dose. Administration of BMN111 for the treatment of Achondroplasia requires dose adjustment depending on the child’s size. The use of injection pens and autoinjectors may allow a more accurate dose control in comparison to vial and syringe drug delivery systems. This has already been applied in diabetes management – products like the JuniorSTAR insulin pen help children administer smaller doses than an adult pen.
For medications that have to be taken regularly, frequent trips to a hospital are often not practical for a child and carer. Many drugs are therefore administered by the child’s carer, but this can be very limiting when the child goes to school or seeks independence. In diabetes management, pumps are perceived as an appropriate option for the youngest users – NICE recommends the use of pump therapy for children under 12 years old in routine diabetes care. Such devices require no input from the user to deliver a dose and so do not require extensive parental or guardian intervention to ensure the dose is taken – allowing children more independence as well as giving the parents much-needed flexibility.
Use of pumps may have a place in rare diseases and particularly treatments that require daily dose regimes. Examples include Reata Pharmaceuticals’ Bardoxolone Methyl for the treatment of Alport syndrome and Atlantic Pharmaceuticals’ Alicaforsen for the treatment of Antibiotic Refractory Pouchitis. The former is being tested for daily injections with patients aged 12 years and older.
Adherence to treatment is more than just a case of remembering – self-treatment can be intimidating for both adults and children. Ensuring a patient is confident enough to follow their medication instructions is critical to a drug’s success. Interestingly, adherence in children with growth hormone deficiency can be improved with automated injection devices such as the easypod®). easypod® is a fully automated injection device, the user doesn’t see the needle and it is able to track the time, date and dose administered. This makes it easier to self-medicate and also gives clinicians and parents reassurance that the medication is being taken correctly. A current study into the MOD-4023 compound by Opko Biologics for treatment of paediatric growth hormone deficiency requires weekly subcutaneous injections with children aged between 3 and 11 years.
A drug’s efficacy can be affected by the delivery method. A drug delivery method often cannot be simply ‘scaled down’ to suit use in paediatrics. For example, spacers are an established technology to aid children to use inhalers as they reduce the velocity of the aerosol and allow more time for the drug to be inhaled, increasing the drug’s efficacy. A smaller dose from a standard inhaler is not enough to make the drug as effective as it could be. Similarly to spacers, nebulisers can control drug delivery at specific sites as shown in a clinical study into inhaled Prolastin using the AKITA® nebuliser by Vectura for Cystic Fibrosis patients aged 8 years and older.
Developing drug delivery devices for orphan drugs may not seem as an obvious commercial decision – small target population, little competition and need to differentiate on top of the cost of development. However, the clinical performance of drugs often relies on the use of an appropriate device and, hence, we anticipate devices to play an ever increasing role in this space.