Receiving CD22-Directed Therapy for Hairy Cell Leukemia
Following previous lines of treatment for hairy cell leukemia, Vince Fazio enrolled in a clinical trial for CD22-targeted therapy with moxetumomab pasudotox.
PUBLISHED June 18, 2019
Robert J. Kreitman, M.D.: So, what was it like getting into the trial of an experimental drug for hairy cell leukemia after that experience with chemotherapy and rituximab?
Vince Fazio: I was actually excited to get into a trial that had promise that I would get treatment and that would take care of hairy cell. So I was very excited to get into the treatment and come to see you.
Robert J. Kreitman, M.D.: So your local doctor is the one who really found the trial and steered you toward us.
Vince Fazio: Yes. My local hematologist in Delaware found the trial. He did whatever paperwork or prep work that needed to be done to get me into the trial, and I happened to qualify. So that was wonderful news when I had that appointment with him and he told me that there was a trial and that I qualified to get into that trial.
Robert J. Kreitman, M.D.: It was probably good news also that it wasn’t too far away.
Vince Fazio: Exactly. It was only a two-hour drive from home and that was a bonus.
Robert J. Kreitman, M.D.: Of course, terrible traffic.
Vince Fazio: Yes.
Robert J. Kreitman, M.D.: And so, it only took about a month or two to get in, or did it take a lot longer?
Vince Fazio: It didn’t take very long.… I remember having the conversation with my hematologist, and I remember it being a fairly short period later where he pulled me back into the office and said he found a trial that I qualified for to deal with hairy cell leukemia.
Robert J. Kreitman, M.D.: What was it like going to NIH [National Institutes of Health] for the first time and trying to navigate getting started? In other words, trying to find your way around.
Vince Fazio: It was an experience. It’s highly secure here, so the first time coming here and having to get out of my car and having the car searched and all the security procedures at the NIH were interesting. It’s a large complex. So finding the places where I needed to go was a little tricky as well. But it was an experience.
Robert J. Kreitman, M.D.: And you found the nurses very helpful too?
Vince Fazio: Yes, they were absolutely helpful, yes.
Robert J. Kreitman, M.D.: The nurses are always great and we really appreciate their hard work. How long did it take to get started on treatment, and what was it like taking an experimental treatment? In other words, it’s not the same. You don’t just start the same day, you have to learn about the side effects and all that. Was that sort of a new experience for you?
Vince Fazio: Well, the experience that I take away from the whole thing is I was a little concerned that I was getting an experimental drug. What could this drug do? What other side effects are there with the drug? How effective it is, there was no history on it. So I was worried about those things, but also I had confidence that this drug was going to take care of the hairy cell, and that was my primary focus.And I knew I was in good hands with you.
Robert J. Kreitman, M.D.: Well, thank you. What I remember is that really your laboratory test results looked OK. You didn’t look like you had any major problems. The drug of course is called moxetumomab pasudotox. Back then we might have called it HA22 [moxetumomab pasudotox], is that right?
Vince Fazio: Exactly. I knew it by HA22 [moxetumomab pasudotox].
Robert J. Kreitman, M.D.: Right, and that HA22 actually stands for a high affinity type of agent for CD22. And the way that drug works is it has an antibody fragment on it that binds to CD22, which the hairy cells are loaded with. So hairy cell is a perfect target for this drug because it binds to the CD22 on the hairy cell, goes inside, and it has a toxin on it that kills the cell. So because these hairy cells have a median of about 40,000 sites per cell of CD22, they’re really optimal to be killed by the toxin. And, although normal B cells have CD22 on them and they may be killed as well, the cells that produce the normal B cells, the normal B lymphocytes, don’t have CD22 on them. So they can start making normal B cells, and usually within a month, the normal B cells are back up. But the hairy cells don’t recover, at least in the patients who have complete remission. And so that’s really the beauty of the targeting of hairy cell with MOXE [moxetumomab pasudotox]. By the way, we call moxetumomab pasudotox MOXE just because it’s a shorter term. So what was it like getting treated with MOXE [moxetumomab pasudotox] and what were some of the side effects that you remember back then?
Vince Fazio: I don’t remember any memorable side effects. I do remember all the water you made me drink and all of the trips to the lavatory to get rid of all that water. I was never a water drinker before that, but I drank a lot of water during that treatment. I did find a little drink enhancement helped me drink all the water that you wanted me to drink. But that’s the main thing I remember from the treatment, other than I stayed here eight days each treatment. But that was the main thing, hardly any side effects.
Robert J. Kreitman, M.D.: Not like rituximab.
Vince Fazio: No, absolutely not like rituximab.
Robert J. Kreitman, M.D.: This is very typical, what we hear from patients, that they really are surprised that it’s like getting water, with really no immediate side effects. When we use this, we tell people to drink a lot of water. This is really important, and this is something we’re trying to communicate with doctors now that the drug was approved last September and people are using it. They don’t have our experience, and we want to make sure that they know the safest way to give it. The drug can cause some kidney damage if patients are dehydrated. But if patients are well hydrated, then the drug should be well tolerated. We actually check to make sure the kidney function is good before we start, and that’s one of the reasons why we checked your kidney function and you passed. Your kidney function was OK. But if a patient’s kidney function is very poor, they probably would do better with a different drug.