cytomegalovirus

A look back: CIRM funded trial aims to help patients suffering from chronic viral infections

/ Yimy Villa / 1 Comment
Dr. Michael Pulsipher

All this month we are using our blog and social media to highlight a new chapter in CIRM’s life, thanks to the voters approving Proposition 14. We are looking back at what we have done since we were created in 2004, and also looking forward to the future. Today we look at a way of making blood stem cell transplants safer and more readily available

Blood stem cell transplants have provided lifechanging treatments to individuals.  This statement is observed firsthand in several patients in CIRM funded trials for X-linked Chronic Granulomatous Disease (X-CGD), Sickle Cell Disease (SCD), and Severe Combined Immunodeficiency (SCID).  The personal journeys of Evangelina Padilla-Vaccaro, Evie Junior, and Brenden Whittaker speak volumes for the potential this treatment holds.  In these trials, defective blood stem cells from the patient are corrected outside the body and then returned to the patient in a transplant procedure.

Unfortunately, there is still a certain degree of risk that accompanies this procedure.  Before a blood stem cell transplant can be performed,  diseased or defective blood stem cells in the patient’s bone marrow need to be removed using chemotherapy or radiation to make room for the transplant.  This leaves the patient temporarily without an immune system and at risk for a life-threatening viral infection.  Additionally, viral infections pose a serious risk to patients with immune deficiency disorders, with viruses accounting upwards of 40% of deaths in these patients.

That’s why in October 2017, the CIRM ICOC Board awarded $4.8M to fund a clinical trial conducted by Dr. Michael Pulsipher at the Children’s Hospital of Los Angeles.  Dr. Pulsipher and his team are using virus-specific T cells (VSTs), a special type of cell that plays an important role in the immune response, to treat immunosuppressed or immune deficient patients battling life-threatening viral infections.  This trial includes patients with persistent viral infections after having received a blood stem cell transplant as well as those with immune deficiency disorders that have not yet received a blood stem cell transplant.  The VSTs used in this trial specifically treat cytomegalovirus (CMV), Epstein-Barr virus (EBV), and adenovirus infections.  They are manufactured using cells from healthy donors and are banked so as to be readily available when needed. 

One challenge of receiving a stem cell transplant can be finding a patient and donor that are a close or identical match.  This is done by looking at specific human leukocyte antigens (HLA), which are protein molecules we inherit from our parents.  To give you an idea of how challenging this can be, you only have a 25% chance of being an HLA identical match with your sibling. 

Because VSTs are temporary soldiers that are administered to fight the viral infection and then disappear, Dr. Pulsipher and his team are using partially HLA-matched VSTs to treat patients in their trial.  Previous studies have indicated that partially HLA-matched T-cells can be effective in treating patients.  The availability of partially HLA-matched VST banks that can be used “off the shelf” improves accessibility and shortens the time for patients to receive VST therapy, which will save lives.

To learn more about Dr. Pulsipher’s work, please view the video below:

CIRM Board invests in three new stem cell clinical trials targeting arthritis, cancer and deadly infections

/ Kevin McCormack / 8 Comments

knee

Arthritis of the knee

Every day at CIRM we get calls from people looking for a stem cell therapy to help them fight a life-threatening or life-altering disease or condition. One of the most common calls is about osteoarthritis, a painful condition where the cartilage that helps cushion our joints is worn away, leaving bone to rub on bone. People call asking if we have something, anything, that might be able to help them. Now we do.

At yesterday’s CIRM Board meeting the Independent Citizens’ Oversight Committee or ICOC (the formal title of the Board) awarded almost $8.5 million to the California Institute for Biomedical Research (CALIBR) to test a drug that appears to help the body regenerate cartilage. In preclinical tests the drug, KA34, stimulated mesenchymal stem cells to turn into chondrocytes, the kind of cell found in healthy cartilage. It’s hoped these new cells will replace those killed off by osteoarthritis and repair the damage.

This is a Phase 1 clinical trial where the goal is primarily to make sure this approach is safe in patients. If the treatment also shows hints it’s working – and of course we hope it will – that’s a bonus which will need to be confirmed in later stage, and larger, clinical trials.

From a purely selfish perspective, it will be nice for us to be able to tell callers that we do have a clinical trial underway and are hopeful it could lead to an effective treatment. Right now the only alternatives for many patients are powerful opioids and pain killers, surgery, or turning to clinics that offer unproven stem cell therapies.

Targeting immune system cancer

The CIRM Board also awarded Poseida Therapeutics $19.8 million to target multiple myeloma, using the patient’s own genetically re-engineered stem cells. Multiple myeloma is caused when plasma cells, which are a type of white blood cell found in the bone marrow and are a key part of our immune system, turn cancerous and grow out of control.

As Dr. Maria Millan, CIRM’s President & CEO, said in a news release:

“Multiple myeloma disproportionately affects people over the age of 65 and African Americans, and it leads to progressive bone destruction, severe anemia, infectious complications and kidney and heart damage from abnormal proteins produced by the malignant plasma cells.  Less than half of patients with multiple myeloma live beyond 5 years. Poseida’s technology is seeking to destroy these cancerous myeloma cells with an immunotherapy approach that uses the patient’s own engineered immune system T cells to seek and destroy the myeloma cells.”

In a news release from Poseida, CEO Dr. Eric Ostertag, said the therapy – called P-BCMA-101 – holds a lot of promise:

“P-BCMA-101 is elegantly designed with several key characteristics, including an exceptionally high concentration of stem cell memory T cells which has the potential to significantly improve durability of response to treatment.”

Deadly infections

The third clinical trial funded by the Board yesterday also uses T cells. Researchers at Children’s Hospital of Los Angeles were awarded $4.8 million for a Phase 1 clinical trial targeting potentially deadly infections in people who have a weakened immune system.

Viruses such as cytomegalovirus, Epstein-Barr, and adenovirus are commonly found in all of us, but our bodies are usually able to easily fight them off. However, patients with weakened immune systems resulting from chemotherapy, bone marrow or cord blood transplant often lack that ability to combat these viruses and it can prove fatal.

The researchers are taking T cells from healthy donors that have been genetically matched to the patient’s immune system and engineered to fight these viruses. The cells are then transplanted into the patient and will hopefully help boost their immune system’s ability to fight the virus and provide long-term protection.

Whenever you can tell someone who calls you, desperately looking for help, that you have something that might be able to help them, you can hear the relief on the other end of the line. Of course, we explain that these are only early-stage clinical trials and that we don’t know if they’ll work. But for someone who up until that point felt they had no options and, often, no hope, it’s welcome and encouraging news that progress is being made.