On the morning of Aug. 19, 2011, young researcher Jonathan Gutman, MD, and the stem cell transplant team infused a patient at the University of Colorado Cancer Center with stem cells grown from donated umbilical cord blood. In this phase I clinical trial, the recently pregnant patient was fighting for her life, having delayed treatment for leukemia so that her child could develop long enough to live. Here we talk to Dr. Gutman about his work and about this fascinating new treatment.
C3: First, how is your patient?
Gutman: She’s doing great. We infused her with 2.7 billion stem cells grown from donated umbilical cord blood, and instead of the average hospital discharge at 30 or 40 days after treatment, she was able to go home to her large family and new baby 11 days after her stem cell transplant.
C3: Is this stem cell transplant the same as a bone marrow transplant?
Gutman: Yes and no. In a bone marrow transplant, for a blood cancer like leukemia, you first knock down a patient’s blood system with chemotherapy and radiation, and then use a bone marrow transplant from a matched donor to regrow it. In fact, it’s the stem cells in the marrow that regrow a patient’s blood system. But in this case we removed the stem cells from banked umbilical cord blood and grew them in the lab first before infusing them.
C3: If it’s the job of stem cells to grow more cells, why was it important to grow them in the lab first? Why couldn’t you just inject these umbilical cord stem cells into the patient and let them do their thing?
Gutman: We have in the past—doctors inject patients with umbilical cord stem cells and eventually these stem cells repopulate the blood system, as we’ve seen. But the key there is “eventually.”
In a typical unit of cord blood, there just aren’t enough cells to quickly restart the immune system, and in this time between blood systems, patients are at desperate risk of infection.
C3: Does this new treatment help close the window of danger?
Gutman: Yes, or at least it seems that way so far. I trained at the Fred Hutchinson Cancer Research Center, where this stem cell treatment was developed.
The Hutch treated 11 patients in Seattle and this was our first patient in Colorado, the 12th patient in the world to undergo this procedure. So far, it looks as if growing these stem cells before infusing them makes enough new blood to create a functioning immune system in less than half the time it takes the standard cord blood transplant.
C3: Is this an improvement even for people who can find a matched donor?
Gutman: With a matched donor, you have the opposite problem—you can infuse enough bone marrow stem cells to cut down on the time a patient spends without an immune system, but because you need such a high degree of match between the new blood and the patient’s old blood, the new blood may not recognize traces of the patient’s original, leukemic blood as foreign and so may not eradicate it entirely. Unless you use a high level of chemotherapy, patients may relapse. Then again, some patients might not be able to withstand that degree of chemo. It looks as if this trial with expanded cord blood stem cells may solve both problems—you grow enough to restart the immune system but you also leave a degree of mismatch that allows the new blood system to wipe out traces of the old.
C3: It seems strange that nobody thought of this before.
Gutman: It wasn’t that they didn’t think of it—the idea of using donated cord blood to grow more cord blood has been around for quite sometime. Only, it’s not as easy as it sounds. In the past, we’ve been able to grow more cord blood, but not more cord blood stem cells. You treat them to grow, but they mature and lose their “stemminess.” This trial uses a brand new technique, growing this cord blood in the presence of a special protein that makes the umbilical cord stem cells create more stem cells, not just more blood. Before this system, getting a 10- or 20-fold expansion of stem cells was considered a success, and now we’re getting a 500-fold expansion of these cells.
C3: That’s how you got the 2.7 billion stem cells you infused into your patient?
Gutman: Yes, exactly.
C3: Where does it go from here?
Gutman: Well, this procedure is still in a phase I clinical trial, but it definitely shows promise. We hope to see success with more patients. And then, in general, we’d like at the CU Cancer Center to use this springboard to develop more of our own science, our own trials, in addition to continuing to test promising therapies developed at Fred Hutch and elsewhere. This is an up-and-coming program with the potential to become a national leader.