The End of “Mini-Me” Medicine

Many a proud parent has affectionately proclaimed their child to be a “mini me,” but within the field of pediatric drug development this affirmation is far from the truth. Children are not simply small adults – they need customized medicines to reflect their differing requirements. Unfortunately, the lack of tailored pediatric medicine on the market means physicians have to consider them as such, often going off-label by crushing up tablets designed for adults to create smaller dosages for someone proportionately smaller.

Compared with adult drug development, why has progress in pediatric medicine not kept pace? The unfortunate truth is that it all comes down to money. Market revenue is much lower for pediatric drugs because of the market size and the fact that fewer children fall ill compared with adults – a very unattractive investment prospect for pharma companies. Drug development is also costlier because of more complex pharmacokinetic processes caused by the size and weight differences that reflect a child’s age. Drug absorption, metabolism and elimination are just a few of the factors that need to be tweaked.

Drug delivery is also more complex and ultimately expensive for pediatric medicine. If you have ever tried to feed a child vegetables, you will know that they have notoriously fussy taste buds. The upshot? The bitter flavor associated with formulations may require masking to improve compliance. Swallowing can also be a problem in smaller children, requiring different formulations that may have a shorter shelf life but are more palatable, or alternative methods of delivery, such as sprays, with varying bioavailability.

To increase the number of pediatric medicines, some regions have introduced new regulations. One of the best examples is the European Union’s Pediatric Regulation, introduced in 2006. The regulation requires formulation companies to screen every product developed for adults for potential use in children by devising an R&D plan, known as a Pediatric Investigation Plan (PIP), with the European Medicines Agency. The Pediatric Regulation has been an invaluable driving force in helping to meet the unmet medical needs of children – 58 percent of physicians stated they are increasingly prescribing medicines according to their licensed indication for children rather than going off-label (1).

Companies who ignore the Pediatric Regulation risk the respective adult drug authorization being blocked for launch. If that wasn’t incentive enough, there are also other benefits offered for companies that comply, such as a six-month extension to the product’s supplementary protection certificate. This extension will apply, not only to the product’s pediatric indication, but to all indications of the product having the same active ingredient, free scientific advice, and two extra years of market exclusivity, if the formulation treats an orphan disease.

Over the past decade, the regulation has influenced children’s medicine formulation in a significantly positive way. Between 2007 and 2016, over 260 new medicines for use in children were authorized, and there has been a clear upward trend in the number of PIPs being completed. Though pediatric research may still be regulatory-driven rather than company driven, legislation has forced an improvement in company expertise and resources for pediatric drug development.

A particular strength of the Pediatric Regulation is tackling disease areas where the needs of adult and pediatric patients overlap. There is significantly more market revenue available for formulating adult medicines, so if there is progress in the adult pipeline then pediatrics will directly benefit. Prime case studies are rheumatology and infectious diseases, which have seen a surge in completed PIPs and available treatments. However, progress has not been exclusively in these areas – oncology, endocrinology and metabolic diseases are other research fields with a high number of PIPs registered.

But is this regulation flawless? Certainly not – while marrying adult and pediatric pipelines benefits some diseases, it also leads to many being overlooked – in particular, orphan diseases. Cancer is the leading cause of death by disease past infancy in children, but rare pediatric cancer drug development continues to advance at a glacially slow pace. The slow progress is despite the EU’s Orphan Regulation, which is having a positive affect on the development of treatments for rare cancers in adults.

An EU report evaluating the 10 years since the introduction of the Pediatric Regulation acknowledged this shortcoming, suggesting that both Regulations could be amended to work more synergistically when treating orphan diseases found in children. The report also stated a further evaluation would occur in 2019, when the Pediatric Regulation would be further finessed to ensure continued and improved advancement and acceleration.

Pediatric formulation has historically moved at a sluggish pace due to its more nuanced nature and decreased demand, but we, as an industry, should not accept this. We need medicines for children. As future pharma trends, such as personalized medicine and stratified development, make their way down the pharmaceutical value chain, it’s important that the PIP process is updated to reflect these new changes.