Please describe your current practice. How many patients with lysosomal storage diseases do you currently treat?

Can you please give a short description of MPSI, MPSII and MPSII(a+b) phenotypes and describe the similarities and differences.

How many patients of MPS 1/2/3 there are in US? Which proportion would be considered moderate vs. severe patients? Are these hard populations to identify, and would you consider them  “under-diagnosed” populations?

What types of physicians are treating patients with MPS 1/2/3? How many centers/specialists are in the US? Do you find the parents/patient advocacy groups to be well-organized?

What is the standard of care for each one of the diseases? What % of patients are treated? What would be the reason for patients not to be on the treatment?

What are the unmet needs in those diseases? What would be the top 2-3 things you would like to change with regard to the current standard of care?

How effective is Hematopoietic stem cell transplantation (HSCT) and Enzyme Replacement in each one of those diseases (MPS1/MPS2/MPS3)? What proportion of patients undergo a successful HSCT?

Do you use Enzyme Replacement in patients who were treated with HSCT? If “Yes”, do you experience any "pushback" from payors?

What is the average annual cost of treatment for each one of the diseases? How much does ER and HSCT cost? Do you encounter any problems with payors when prescribing off-label treatment for those patients?

What is your view on the current gene therapy in development from (Abeona) / gene editing (Sangamo) to deal with MPS? What are you most excited about and concerned about for those programs?

How important in your view is the penetration of the enzyme into the CNS?

What is your view on the presented clinical data by Abeona? Is there anything that concerns you in the data? Is it reasonable to expect a higher clinical benefit with constant levels of enzyme in the blood (gene therapy) vs. once a week enzyme replacement with a short T1/2 in the blood?

How problematic is ADA (anti-drug antibodies) in those patients? Which proportion of patients develop ADA?

• Does it have a negative effect on the effectiveness of the treatment?
• What application in your view will it have on the gene therapy?
  
• Can immune-tolerance be induced in patients with ADA?
  

If approved and safe in which proportion and what types of patients will the gene therapy be used?  Will it be used before or after the currently approved enzyme replacement/ hematopoietic stem cell transplantation? What is the general view of your colleagues about using gene therapy in those patients?  

Does a $200K-$400K annual price range for a safe and effective treatment (let’s assume more effective than current standard of care) sound reasonable to you?  

Do you anticipate problems with enrollment for those studies? For example, will it be hard to find MPS1 patients which are >18 years old?

Should we anticipate to see therapeutic effect (not only enzyme levels in blood) in adults’ population pre-treated with enzyme replacement therapy (the population which is first to be enrolled into the clinical trials)? Can we potentially anticipate seeing improvement in CNS related symptoms?