Cord blood transplants help children fighting deadly diseases

Dr. Paul Szabolcs: Photo courtesy of UPMC

A simple blood stem cell transplant is showing tremendous promise in treating a wide range of metabolic, blood and immune disorders such as thalassemia and some leukodystrophies.

These are considered rare diseases – meaning there are fewer than 200,000 people with them in the US – so there is often little funding available to develop new therapies to help people suffering from them. So, researchers at UPMC Children’s Hospital of Pittsburgh set out to develop a therapy that could help several different disorders without having to craft individual approaches for each condition.

The team used blood stem cells from donated umbilical cords and placentas. In a news article, study senior author Dr. Paul Szabolcs, said they then used a combination of chemotherapy and immunotherapy to prepare the patients for the transplant and increase the chance of success.

“We approached the topic with the mindset to design a regimen that carefully balances low-intensity chemo (bringing safety) with sufficiently effective immunotherapy to blast away the patients’ immune system, therefore preventing rejection. Rejection has been a common failure when other centers explored the reduced-intensity conditioning (RIC) approach with cord blood. We are the first to prove the RIC is able to give reliable results in long-term engraftment.”

Szabolcs says another advantage to their approach was that it meant there didn’t need to be a perfect immune system match of donor and recipient.

“That’s huge for ethnic minorities. The probability of a perfect match is very low, but with a cord blood graft, we have a chance to overcome this discrepancy over the course of a couple months and then taper immunosuppressants away.”

Altogether 44 children were treated this way. After undergoing the preparation, they had the blood stem cells transfused into them and, once those cells had integrated into the body they got a second, smaller, transfusion a few weeks later to help kick start their immune system.

Most of the complications from the infusions were mild, and while around 5 percent of children died from viral infection due to the immune suppression this was much lower than in earlier studies. Another encouraging sign was that none of the children suffered severe Graft vs Host disease which can be fatal.

Thirty of the children in the trial suffered from metabolic disorders, meaning their bodies were unable to remove dangerous toxins, and this led to developmental delays in their brains. One year after the treatment all 30 children had normal enzyme levels and their neurological decline had stopped. Some of the children even showed improvements and gained new skills.

Most of the children with metabolic disorders had leukodystrophies. These are usually fatal within a few years of diagnosis. Even with a cord blood transplant the three-year survival rate is only 60 percent. In this trial more than 90 percent of children with leukodystrophies were alive after three years.

Dr. Szabolcs says this approach has a lot of advantages over existing approaches, including cost.

“There has been a lot of emphasis placed on cool new technologies that might address these diseases, but — even if they prove effective — those aren’t available to most centers. The regimen we developed is more robust, readily applicable and will remain significantly less expensive.”

The study was published in the journal Blood Advances.

CIRM-supported study shows promise in fighting acute myeloid leukemia

Chemotherapy

Chemotherapy

For years chemotherapy has been a mainstay in the war against cancer. While it can be very effective it can also come with some nasty side effects. Since chemo works by killing rapidly growing cells, it not only hits the cancer cells, but can also hit other rapidly growing cells too, including those in our hair roots, which is why many people undergoing chemo lose their hair.

So, the key to a truly effective anti-cancer therapy is one that does as much damage as possible to the cancer cells, and as little as possible to all the healthy cells in the body. A therapy being developed by Cellerant Therapeutics seems to have found that sweet spot in a new therapy targeting acute myeloid leukemia (AML).

AML starts in the bone marrow and quickly moves into the blood, where it can spread to other parts of the body. It is the second most common form of leukemia and claims around 10,000 lives in the US every year. Chemotherapy is the main weapon used against AML but it can also cause nausea, hair loss and other complications and in most cases has limited effectiveness because, over time, the leukemia cells get used to it.

Cellerant 2013In a study published in the journal Blood Advances, Cellerant researchers explain the limitations of existing treatments.

“The current standard of care for acute myeloid leukemia (AML) is largely ineffective with very high relapse rates and low survival rates, mostly due to the inability to eliminate a rare population of leukemic stem cells (LSCs) that initiate tumor growth and are resistant to standard chemotherapy.”

Cellerant has developed a therapy called CLT030 which targets CLL1, a marker found on the surface of leukemia cells but not on normal blood stem cells. Preclinical studies in mice show CLT030 is able to zero in on this surface marker and attack the leukemia but do little damage to blood or other surrounding cells.

In a news release, Ram Mandalam, President and CEO of Cellerant, said this is encouraging news:

“AML remains a significant unmet medical need, and our therapy, CLT030, that can target leukemic stem cells precisely while minimally affecting normal hematopoietic stem cells could improve outcomes while avoiding much of the toxicities associated with conventional chemotherapy and other targeted therapeutics.”

Mandalam says they are now doing the late-stage preclinical testing to be able to apply to the Food and Drug Administration for permission to start a clinical trial. CIRM is funding this stage of the research.