Solaris Health looks at the gene therapy revolution

Gene therapies are bringing new hope for many people with diseases caused by genetic disorders and for their families. In the last few years, we have seen treatment possibilities expand and, looking at the current pipeline of drugs heading in the direction of the regulatory bodies in the coming months (for instance to treat haemophilia, rare ophthalmic disorders and for Duchenne muscular dystrophy/DMD), genetic therapies are likely to represent a revolution in medicine over the coming years.

While there is an understandable excitement among pharma and patient communities in currently targeted therapeutic areas, there’s also a need to scope out how these new therapies will fit into a real-life scenario and how patient access will be managed. It feels like a whole new world is almost within our grasp (most of us can only begin to imagine the desperate hope of a family affected by DMD or other rare conditions, as they see potentially life-changing drugs almost within reach). Yet there are the practical realities to consider such as specialist clinic set up, follow-up protocols and long-term implications to name but a few issues which will need attention as these new drugs become available.

These fascinating new offerings will need a new environment in which to operate. How will patients with long-term conditions be selected for treatment, what counselling will be needed before and after treatment? And of course, as with all healthcare provision, each country’s requirements will need to be shaped individually. Pharma companies hoping to introduce a new treatment will have been considering their launch plans for some time and will undoubtedly have proposals for support services and treatment registries that can be provided either as an added value service or in conjunction with existing healthcare provision. And every new therapy will have its own specific challenges depending on the disease it is targeting.

As an example, in the case of Strimvelis (autologous CD34⁺ cells transduced to express adenosine deaminase [ADA]), the first ex vivo stem cell gene therapy approved by the EMA (European Medicines Agency), licensed in 2016 and approved by NICE (National Institute for Health and Care Excellence) earlier this year, the patients are young children, suffering from a severe dysfunction of the immune system leading to recurrent severe and opportunistic infections and failure to thrive. If not diagnosed and treated promptly, adenosine deaminase severe combined immunodeficiency (usually known as ADA-SCID) often proves fatal within the child’s first years of life.¹ The ground-breaking treatment uses a virus to insert functional copies of the ADA gene into stem cells extracted from the patient’s bone marrow. The gene-corrected cells are then reintroduced to the patient, who can then expect to start making previously missing ADA enzyme, helping to rebuild their immune system.

The only approved manufacturing centre for Strimvelis is in Milan, Italy, and due to the 6‑hour shelf life of Strimvelis, the treatment is only available at Hospital San Raffaele Telethon Institute for Gene Therapy in Milan. As a result, patients and their families will need to travel to this hospital for treatment and to stay for many weeks. However, for families seeking the promise of a ‘one-time only’ cure, this may be considered an acceptable requirement. The limited availability and need to travel to Milan means that the Italian price tag will be the same for everyone in Europe at 594,000 Euros.² But to put this into context, ADA-SCID is an ultra-rare condition, which affects only around 12 patients per year in Europe (<1 patient per 100,000 live births) and the Italian Medicines Agency, known as AIFA, struck a deal with the manufacturer, GSK, so that if the treatment doesn’t work, they have negotiated a money back guarantee.³

Cost is, of course, often the stumbling block for any new medicine and a crucial consideration for both healthcare systems and for the manufacturers themselves. Most gene therapies are being developed for rare conditions where patient numbers are very small and development costs high, so new approaches to payment (as in the Strimvelis model) may help alleviate pressure on healthcare systems to some degree as well as compensating pharma companies for the long research and development cycle. However, in most areas where genetic treatments are being developed, for instance haemophilia and DMD, there will be far more than 12 patients per year seeking treatment.

But, of course, low patient numbers can also result in huge risk for manufacturers. There has already been one notable disappointment. In 2017 uniQure pulled its gene therapy, Glybera (alipogene tiparvovec) for the rare inherited disorder lipoprotein lipase deficiency (LPLD) from Europe after 5 years, having treated just one patient. The drug had gained a reputation as the world’s most expensive medicine (at $1million per patient) and the company could not see how patient numbers would increase, as the administrative burden of gaining reimbursement was a major hurdle for potential prescribers.

There are many, many complex rare disorders and so while scientists welcome the intellectual challenge of finding successful new treatments and even cures, commercialization certainly could prove to be problematic. Genetic treatment developments to date mainly involve the use of a viral vector to introduce an intact gene, either directly into the patient (in vivo) or indirectly via transduction of cells before reinfusion into the patient (ex vivo), to reconstitute or modify a harmful gene variant. Either approach is highly complicated and requires vision to create the service provision required and for manufacturers there may also be a question over how they can upscale these processes to meet likely demand – even given the relatively small patient numbers.

There’s also the moral danger of being seen to be ‘playing God’. How should patients be selected for treatment, who comes first, and who makes these decisions? Current therapies in development look likely to be suitable only for small, specific groups of patients initially, so we are most likely to see a slow start overall. And maybe this is the best way, enabling clinicians and pharma to find ways to work together over a period of time and to build the services needed around these new treatments.  There are certainly difficulties to be faced and hard decisions to be made, but on the other hand genetic medicine offers hope to so many patients and their families that would have been unimaginable only a few years ago.

It’s fascinating to be working in an industry that is demonstrating such a wonderful commitment to top class innovation, investing in leading edge science and demonstrating real empathy for those facing life limiting illness and disability. Of course there will be hurdles, but there’s a real excitement around these developments and a feeling that despite the cost and other potential limitations, gene therapy is now here to stay and will find its path through the healthcare maze.

References

1.Hershfield M. Adenosine deaminase deficiency. GeneReviews, NCBI Bookshelf; last updated March 2017. https://www.ncbi.nlm.nih.gov/books/NBK1483/ (accessed September 2018).

2.Evaluation consultation document – Strimvelis for treating adenosine deaminase deficiency–severe combined immunodeficiency. Issue date: October 2017.

3.MIT Technology Review of 09.08.16. Last accessed 19.09.18. https://www.technologyreview.com/s/602113/gene-therapy-cure-has-money-back-guarantee/ (accessed September 2018).

Marian Byrt
Client Partnership Director