Ask the Expert Blog Series: Cystic Fibrosis

Ask the Expert Blog Series: Cystic Fibrosis

BY Bertrand Sohier, MD, Global Therapeutic Area Head for Pulmonology, Critical Care, Cardiovascular and Endocrinology - 5.15.19 -

Bertrand Sohier, MD, is the Global Therapeutic Area Head for Pulmonology, Critical Care, Cardiovascular and Endocrinology within Parexel’s Global Medical Services division.

A board-certified respiratory physician, Bertrand began his career practicing pulmonology and oversaw a hospital unit that treated numerous adult Cystic Fibrosis (CF) patients. During this time he had the opportunity to see the progress made in the management of those patients’ disease, and the limits of the available treatments. One particular experience that inspired Bertrand’s passion for CF research was when he treated two sisters both afflicted by CF and bright university students who told Bertrand they did not know whether they would have any future, but that they wanted to use their limited lifespan to show their value. This had a significant impact on Bertrand and was one of the defining moments that led him to a career in clinical research. Through this work, Bertrand has been involved in the development of several compounds and CF projects. In recognition of CF Awareness Month, Bertrand shared his personal perspective on the disease today, the current treatment landscape and how Parexel can improve the outlook for patients facing CF.

Parexel Insights: How widespread is Cystic Fibrosis (CF) today?

Bertrand Sohier: CF is a genetic disease and its prevalence differs according to study populations. It is most frequent in the Caucasian population (1 case out of 3,000 births) and far less frequent in Asiatic (1 out of 50,000) or African populations (1 out of 10,000). For instance, in the USA, 93.6 percent of cases occur in Caucasian patients.

More patients have CF today, but that is only because those that have CF are living longer. There were 22,976 cases in 2002 and 29,887 cases in 2017 in the USA and the figures are similar in the EU. The graph below illustrates that patients with CF are living longer today and there are now more adults than children with CF.Graph illustrating that patients with Cystic Fibrosis are living longer today and there are now more adults than children with CF.Source : 2015 US Patient registry; annual data report. CF Foundation

Parexel Insights: What is Parexel’s experience and expertise working in CF?

Bertrand Sohier: It is an encouraging time in CF. Thirty years of hard work on the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene and the functioning of chloride channels  — which are the primary defect in this condition  — has finally paid off.  Several drugs now are available that profoundly improve both patients’ quality of life and life expectancy. Parexel was involved in 39 projects in CF in the past five years and was clinically involved in 16 of them, supporting Phase II, III and IV studies for drugs that had a significant impact and really change the life of a patient. We also implemented a fully expanded access program that allowed young patients to access a breakthrough drug before it was made available to the market. This was critical for these patients as the treatment prevents irreversible deterioration of the respiratory function.

Parexel Insights: What are the main challenges for patients with CF?

Bertrand Sohier: These advancements are so encouraging when you look at the impact of CF on patients and their families. As an adult pulmonologist I remember the adult cases coming in my department. At the time, most patients passed away during childhood and adolescence, so the adults living with the disease knew that their time left could be limited. This has markedly changed now, and life expectancy for CF patients today is more than 60 years. Treatment is still a challenge, requiring two hours per day on average and specific diet and lifestyle restrictions. Fortunately, it has become less burdensome with the availability of recent CFTR corrector therapy.

Parexel Insights: Tell us a little about the current treatment landscape for CF.

Bertrand Sohier: The below scheme illustrates the two main types of treatments that are used in CF: one to treat consequences of the disease, and the other to target the underlying mechanism. As discussed, the advent of CFTR was really a game-changer for therapy for CF patients in need.

CF: Two Classes of Treatment

Treatment of CF disease consequences CFTR correctors and potentiators
  • Inhaled antibiotics to prevent exacerbation
  • Support to clear thick mucus from airways
    • Drugs
    • Physiotherapy
  • Target underlying defects to correct chloride channel dysfunction
  • Correctors are specific of certain mutation or types of mutation (example: F508del mutation)
  • Potentiators are not specific of a mutation and aim at restoring the chloride channel function
Parexel Insights: What is the most exciting thing happening today in CF research?

Bertrand Sohier: There are more than 1,900 known CFTR mutations, which explains why it is so difficult to discover new treatments that can work on all mutations and patients. However, the ability to directly act on the consequences of the most frequent mutations has resulted in some exciting advancements that would have been unheard of even 15 years ago. As shown in the following figure, there are now oral treatments (CFTR correctors) that target the misfold proteins and reshape them to restore their function — an incredibly impactful treatment for patients.Figure displaying oral treatments (CFTR correctors) that target the misfold proteins and reshape them to restore their function.Mechanism of action of a CFTR corrector which “opens” a close chloride channel
Source: British Medical Journal 2018; doi:

Parexel Insights: What stakeholders need to get involved to improve the outlook for CF patients?

Bertrand Sohier: CFTR correctors are life-changing but also expensive: $379,780 (per patient per year for a fixed combination[i]). This price challenges what patients and their families can afford and poses a societal dilemma. Drug discovery and development is costly and the number of patients with CF is limited, which clearly explains the high costs of the drug per patient. As an industry, we need to have an even greater sense of urgency with CF trials. Innovation will help us in this regard. For instance, bringing the trial to a patient’s home rather than putting the burden of the procedures on parents and patients with long and repeated site visits could foster trial participation and be more cost-efficient.

Parexel Insights: What is an unknown or misunderstood aspect of CF that you think people should know?

Bertrand Sohier: I am surprised that the breakthrough advances in CF treatments over the last five years have barely reached the newspaper headlines. Cystic Fibrosis is no longer as devastating a disease as it once was for thousands of patients across the globe. Today, patients are living longer with better quality of life. Moreover, the industry can learn a lot from this treatment model, which shows great potential for application in other genetic diseases lacking treatments. Parexel is part of this effort and we are proud of how far we as an industry have come in helping patients with this difficult disease.

[i] Pratyusha Vadagam et al J Manag Care Spec Pharm, 2018 Oct;24(10):987-997)

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