Sickle Cell Disease: Hydroxyurea or L-Glutamine Oral Powder

Neil B. Minkoff, MD: And how does hydroxyurea in general compare to l-glutamine?

Ahmar U. Zaidi, MD: L-glutamine is a new player in the realm of sickle cell disease, and it’s also a preventive medication that has shown in the phase 3 trial that it reduces vaso-occlusive episodes by about 25%. It’s a medication that’s now just starting to make its way into clinics around America, and we are still toying with the idea of how exactly to implement it in our clinics, who should be getting it, how we should be recommending it, and what criteria we should use. We’ve had some trouble with insurance companies as far as getting the medication paid for, which has been a little bit of a barrier to us being able to use it properly.

Neil B. Minkoff, MD: Let me ask you a couple questions, then I want to bring the payers into it. Do you have a set age that you’re looking for in these patients?

Ahmar U. Zaidi, MD: In general, the phase 3 data are for patients who are 5 and older. So we are starting there, and really at this point, at least in my clinic, we’re using it in patients who are on hydroxyurea and still having issues.

Neil B. Minkoff, MD: The last question about it is you mentioned having long discussions with your patients about the potential adverse events of HU [hydroxyurea]. How does this compare to that?

Ahmar U. Zaidi, MD: Fortunately, L-glutamine has a very limited toxicity profile and a very limited adverse event list. Patients so far anecdotally seem to be doing quite well on it, and from the phase 3 data it seems like beyond minimal abdominal discomfort, there really isn’t too much to worry about.

Neil B. Minkoff, MD: I want to pull you in first, John. You had earlier mentioned some issues around the cost of these things and the use of these medications but also concerns about compliance and so on. Could you speak about the 2 products that we just have been going over, and your experience with those?

John C. Stancil, RPh: Well, I think our stance is an individual approach to this disease for the patient. Not everyone is going to respond well to hydroxyurea. We don’t prior authorize any of these drugs for our patients. The surprising thing is, and we certainly understand the value hydroxyurea has and its place in therapy, and our pediatric population is 21 years or younger, there’s only about 15% of those patients who had an actual paid claim for hydroxyurea. And then only half of those remained adherent. And in a rural state like North Carolina, it could be because of the monitoring, because that could be another 2-hour trip to a center of excellence or a physician’s office to get that monitoring or that laboratory work drawn. And then it even decreases further as the patient ages. Of the adult population, only about 5% of those patients had a paid claim for hydroxyurea and 2% were adherent.

We recognize the challenge could be met with laboratory monitoring. We don’t know. A lot of times I think there’s a lack of care management for these patients. Because a lot of times, the pharmacy knows the refill history, but the physician may not know that they’re not getting their hydroxyurea filled. And we certainly pay attention to other disease states and how important it is to be adherent, but we don’t put enough emphasis or measures around trying to ensure adherence for those patients.

Maria Lopes, MD, MS: I would love to get to that 90% adherence that you quoted in an underdeveloped country. Because that is so telling in terms of, as John stated, the underutilization of a very old drug that’s low cost and has very significant implications for symptoms and potentially even survival. I do think as we think about the barriers or the access issues around the laboratory monitoring and what comprehensive care looks like, perhaps we could facilitate the monitoring, whether it’s through services that can come into the home that can draw the labs or through case management, facilitate issues around psychosocial or transportation. But to me, this is such low-hanging fruit in terms of the opportunity to maximize the treatment. And at a center of excellence like yours, what is that adherence? Because I think as payers, we see low double digits, 12%, 15% use of hydroxyurea.

John C. Stancil, RPh: Yes, it’s not unique to North Carolina. I’m pretty sure it’s consistent.

Maria Lopes, MD, MS: The adherence is low.

Ahmar U. Zaidi, MD: Unfortunately, I would say even at a center like ours, which is one of the largest in the country, our adherence with hydroxyurea is probably in the range of 15% to 25%, which is quite unfortunate.

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