One step closer to making ‘off-the-shelf’ immune cell therapy for cancer a reality 

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Immunotherapy is a type of cancer treatment that uses a person’s own immune system to fight cancer. It comes in a variety of forms including targeted antibodies, cancer vaccines, and adoptive cell therapies. While immunotherapies have revolutionized the treatment of aggressive cancers in recent decades, they must be created on a patient-specific basis and as a result can be time consuming to manufacture/process and incredibly costly to patients already bearing the incalculable human cost of suffering from the cruelest disease.

Fortunately, the rapid progress that has led to the present era of cancer immunotherapy is expected to continue as scientists look for ways to improve efficacy and reduce cost. Just this week, a CIRM-funded study published in Cell Reports Medicine revealed a critical step forward in the development of an “off-the-shelf” cancer immunotherapy by researchers at UCLA. “We want cell therapies that can be mass-produced, frozen and shipped to hospitals around the world,” explains Lili Yang, the study’s senior author. 

Lili Yang, the study’s senior author and a member of UCLA’s Broad Stem Cell Research Center

In order to fulfil this ambitious goal, Yang and her colleagues developed a new method for producing large numbers of a specialized T cell known as invariant natural killer T (iNKT) cells. iNKT cells are rare but powerful immune cells that don’t carry the risk of graft-versus-host disease, which occurs when transplanted cells attack a recipient’s body, making them better suited to treat a wide range of patients with various cancers.

Using stem cells from donor cord-blood and peripheral blood samples, the team of researchers discovered that one cord blood donation could produce up to 5,000 doses of the therapy and one peripheral blood donation could produce up to 300,000 doses. The high yield of the resulting cells, called hematopoietic stem cell-engineered iNKT (HSC–iNKT) cells,could dramatically reduce the cost of producing immune cell products in the future. 

In order to test the efficacy of the HSC–iNKT cells, researchers conducted two very important tests. First, they compared its cancer fighting abilities to another set of immune cells called natural killer cells. The results were promising. The HSC–iNKT cells were significantly better at killing several types of tumor cells such as leukemia, melanoma, and lung cancer. Then, the HSC–iNKT cells were frozen and thawed, just as they would be if they were to one day become an off-the-shelf cell therapy. Researchers were once again delighted when they discovered that the HSC–iNKT cells sustained their tumor-killing efficacy.

Next, Yang and her team added a chimeric antigen receptor (CAR) to the HSC–iNKT cells. CAR is a specialized molecule that can enable immune cells to recognize and kill a specific type of cancer. When tested in the lab, researchers found that CAR-equipped HSC–iNKT cells eliminated the specific cancerous tumors they were programmed to destroy. 

This study was made possible in part by three grants from CIRM.

Latest CIRM TRAN1 awards focus on CAR-based cell therapy to treat cancer

Earlier this week the CIRM ICOC Board awarded $14.5 million to fund three translational stage research projects (TRAN1), whose goal is to support early development activities necessary for advancement to a clinical study or broad end use of a potential therapy. Although all three projects have their distinct area of focus, they all utilize CAR-based cell therapy to treat a certain type of cancer. This approach involves obtaining T cells, which are an immune system cell that can destroy foreign or abnormal cells, and modifying them with a chimeric antigen receptor (CAR). This enables the newly created CAR-engineered cells to identify specific tumor signals and destroy the cancer. In the sections below we will take a deeper look at each one of these recently approved projects.

TRAN1-12245

Image Description: Hideho Okada, M.D., Ph.D.

$2,663,144 was awarded to the University of California, San Francisco (UCSF) to develop specialized CAR-T cells that are able to recognize and destroy tumor cells in glioblastoma, an aggressive type of cancer that occurs in the brain and spinal cord. The specialized CAR-T cells have been created such that they are able to detect two specific signals expressed in glioblastoma. Hideho Okada, M.D., Ph.D. and his team at UCSF will test the therapy in mice with human glioblastoma grafts. They will be looking at preclinical safety and if the CAR-T cell therapy is able to produce a desired or intended result.

TRAN1-12250

Image Description: Lili Yang, Ph.D.

$5,949,651 was awarded to the University of California, Los Angeles (UCLA) to develop specialized CAR-engineered cells from human blood stem cells to treat multiple myeloma, a type of blood cancer. Lili Yang, Ph.D. and her team have developed a method using human blood stem cells to create invariant natural killer T (iNKT) cells, a special kind of T cell with unique features that can more effectively attack tumor cells using multiple mechanisms and migrate to and infiltrate tumor sites. After being modified with CAR, the newly created CAR-iNKT cells are able to target a specific signal present in multiple myeloma. The team will test the therapy in mice with human multiple myeloma. They will be looking at preclinical safety and if the CAR-iNKT cells are able to produce a desired or intended result.

TRAN1-12258

Image Description: Cristina Puig-Saus, Ph.D.

Another $5,904,462 was awarded to UCLA to develop specialized CAR-T cells to treat melanoma, a form of skin cancer. Cristina Puig-Saus, Ph.D. and her team will use naïve/memory progenitor T cells (TNM), a subset of T cells enriched with stem cells and memory T cells, an immune cell that remains long after an infection has been eliminated. After modification with CAR, the newly created CAR-TNM cells will target a specific signal present in melanoma. The team will test the therapy in mice with human melanoma. They will be looking at preclinical safety and if the CAR-TNM cells are able to produce a desired or intended result.

Engineered T cells made from stem cells could provide immunity against multiple cancers

Dr. Lily Yang

Within all of our bodies there is a special type of “super” immune cell that holds enormous potential. Unlike regular immune cells that can only attack one cancer at a time, these “super” immune cells have the ability to target many types of cancers at once. These specialized cells are known as invariant natural killer T cells or iNKT cells for short. Unfortunately, there are relatively few of these cells normally present in the body.

However, in a CIRM-funded study, Dr. Lily Yang and her team of researchers at UCLA have found a way to produce iNKT cells from human blood stem cells. They were then able to test these iNKT cells on mice with both human bone marrow and human cancers. These mice either had multiple melanoma, a type of blood cancer, or melanoma, a solid tumor cancer. The researchers then studied what happened to mice’s immune system, cancers, and engineered iNKT cells after they had integrated into the bone marrow.

The results were remarkable. The team found that the blood stem cells now differentiated normally into iNKT cells, producing iNKT cells for the rest of the animal’s life, which was generally about a year. Mice without the engineered stem cell transplants had undetectable levels of iNKT cells while those that received the engineered cells had iNKT cells make up as much as 60% of the total immune system cells. The team also found that the engineered iNKT cells were able to suppress tumor growth in both multiple myeloma and melanoma.

Dr. Yang, in a press release by UCLA health, discussed the significance of the results in this animal model and the enormous potential this could have for cancer patients.

“What’s really exciting is that we can give this treatment just once and it increases the number of iNKT cells to levels that can fight cancer for the lifetime of the animals.” said Yang.

In the same press release, Dr. Yang continued to highlight the study’s importance by saying that,

“One advantage of this approach is that it’s a one-time cell therapy that can provide patients with a lifelong supply of iNKT cells.”

Researchers mentioned that they could control total iNKT cell make up in the immune system depending on how they engineered the blood stem cells. However, more research is needed to determine how these engineered iNKT cells might be useful for treating cancer in humans and evaluating any long-term side effects associated with an increased number of these cells.

The full results of this study were published in the journal Cell Stem Cell.