SCD: Unmet Needs, Prevalence, and Burden of Disease

Biree Andemariam, MD: I wanted to then now ask Mattthew Heeney. That’s a bit of an unmet need, right, in sickle cell disease? Now, let’s talk about unmet needs. But also, talk about the prevalence and the burden of sickle cell disease. What do we know about that? Both in the US and globally.

Matthew M. Heeney, MD: [Concerning] the prevalence in the United States, there’s estimated to be about 100,000 to 120,000 affected Americans, which makes sickle cell disease considered by the FDA [U.S. Food and Drug Administration] to be an orphan disease. However, the global burden of disease is massive, millions of affected patients. And thus, we’re just a one small component of the burden of this disease to our species globally. And that’s an important thing to think about when we’re trying to develop potential therapies or improvements in a raw outcome. And the unmet needs are different in different parts of the world. But I think they’re great. I think [that] maybe I’m a socialist or something, but I think that there’s so much that this particular disease, and chronic disease in general, is affected by one’s overall stability of job, home, insurance, etc, that play such an important role on your outcome of a chronic disease. But then, much more specific to sickle cell disease unmet needs, we’ve talked a bit about vaso-occlusive pain. And we really don’t have great management tools for that. We basically have heat and hydration. And then, there are no more pathophysiologically directed tools. At that point, we give you a bunch of medications to help you forget your pain until it passes. And subsequently, that’s a huge still unmet need. Because most of the disease-modifying medications that we have talked about, and will talk about, are really related to reducing vaso-occlusive painful events or other complications, but not eliminating.

Thus, there will still be a need for optimal treatment of those vaso-occlusive painful events. I think that’s really still one of the big ones that we often forget about when we are thinking about disease-modifying medications. But there is still a need for more medications. Concerning the ones that we have, I think we have some successes. Unfortunately, there is a long period between the approval of hydroxyurea and the subsequent approval of Endari. But although they have had successful clinical trials, none of them have really made a massive impact, in terms of the overall wellbeing of our patients. Thus, these are small incremental changes. And I think that, ultimately the big unmet need as an investigator in this field is to combine some of these medications that work on the pathophysiology of sickle cell at different parts of its cascade. And therefore, hopefully have additive or, dare to dream, synergistic benefits to the patients overall. Hence, I don’t think there is a great appetite for industry to do those studies. Why would there be? And that’s why I think the federal government will have to step in to try to really support the good clinical trials looking at these medications that we now have potentially multiple. Those are just some. I’m sure my colleagues have other great news. There are a lot of unmet needs.

Biree Andemariam, MD: Yes, I agree with you. I think with combination therapy, we need to do those studies in one way or another to understand as we develop newer therapies how do they work in combination? Is there any synergy? Is there any overlapping toxicity we need to know?

Transcript edited for clarity