Over the past 20 years, significant advancements in stem cell research and therapies have been one of the most promising methods of creating new insulin making cells needed to cure type 1 diabetes. Vertex Pharmaceuticals, a biotech company, recently began a clinical trial where it plans to treat 17 participants who have type 1 diabetes with new stem cell derived insulin making cells. The first patient in the trial has had positive results. Other companies around the world including ViaCyte and CRISPR, as well as Novo Nordisk, one of the biggest insulin manufacturers in the world, are also working on curing the disease. CNBC explores why finding a cure for diabetes is so hard and just how close Vertex and other companies are to solving this problem.