Genetic Treatment Offers Hope to Leukemia Patients

I'm excited about the prospect of restarting the Biomedical Engineering blog on CR4! So much of what happens in the world of research and biotechnology affects our lives on a daily basis that I would be hard pressed to find someone who doesn't interact with a device or technology designed by a biomedical engineer every day. Plus, the work is cool and could someday save your life!

As a recent college graduate with a degree in Biomedical Engineering, there are many areas that I'm interested in learning about and sharing with you. I usually tend to prefer news and information about medical devices, mostly because I like the physicality of the device. You can pick it up, look at it, and directly see the impact it has on the patient. But I also appreciate breakthroughs in research and advances in tissue engineering and genetic engineering. The two areas work hand-in-hand; a new hip implant won't be successful if research on the material interaction within the body wasn't done. So, I'm going to do my best to talk about all things Biomedical, Biotechnical, and even Biology related.

The Discovery

This month, a new gene therapy technique was being identified to treat leukemia. According to the Leukemia and Lymphoma Society, one person in the US is diagnosed with a blood cancer approximately every four minutes, which equates to 137,260 people being diagnosed with leukemia, lymphoma or myeloma in 2010. Current treatment for Leukemia is a bone marrow transplant from a close relative or bone marrow match donation. This procedure is dangerous, painful, and holds only a 50% chance of a cure at best. So a breakthrough in the treatment or cure can make a major difference in the lives of hundreds of thousands of patients.

The new treatment was developed at the University of Pennsylvania's Abramson Cancer Center. The protocol for the therapy is to remove the patients' T cells, modify them, and infuse the new cells back into the patient's body following chemotherapy. The therapy provides a "tumor-attack" roadmap for the treatment of other cancers including those of the lung and ovaries and myeloma and melanoma.

How It Works

A small group of patients with advanced chronic lymphocytic leukemia (CLL) have shown sustained remissions of up to a year after being treated with genetically engineered versions of their own T cells. Each of the three patients in the study had T cells removed, and the team of researchers reprogrammed the T cells to attack tumor cells by genetically modifying them. Once the cells were modified, they focused all of their killing activity on cells which expressed a protein expressed specifically to CLL tumor cells and normal B cells. Cells which do not express the protein are ignored. The modification also includes the addition of a signaling molecule that tells the cell to produce cytokines that trigger other T cells to multiply in order to grow a bigger army until all the target cells in the tumor are destroyed. On average, each modified T Cell can kill thousands of tumor cells and overall, destroying at least two pounds of tumor in each patient!

Of the three patients in the study, two appear cancer-free after a year and one is improved but still has some cancer. The patients may become ill with chills, nausea, and fever. This is a condition that occurs when a larger number of cancer cells die at the same time. It's a sign that the therapy is working! The main complication seems to be that the treatment also kills some other infection-fighting blood cells, which is treatable.

The Next Step

The patients in the study are thrilled with the success of the treatment and the modification therapy can be potentially used to treat other forms of cancer! Final approval is still a long way away. Larger clinical trials need to be completed, current patients in the study need to be monitored for long-term side effects, and further studies need to be done to test the success on other forms of cancer - but it's a leap in the right direction.

My interest in these subjects is also personal. After several close family members passed away from cancer, I wanted a way that I could help. So I became a volunteer with the American Cancer Society's Relay For Life Events. It's an amazing experience and a lot of fun. If you haven't been to an event yet, check it out!

References

Leukemia and Lymphoma Society: Facts and Statistics

Penn Medicine: Genetically Modified "Serial Killer" T Cells Obliterate Tumors in Patients with Chronic Lymphocytic Leukemia, Penn Researchers Report

Full scientific study can be found at The New England Journal of Medicine and Science Translational Medicine Aug 2011