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Vote for STAT Madness

It’s a three-peat! Children’s National again competes in STAT Madness

Vote for STAT Madness

Children’s National Hospital collects patients’ blood, extracts T-cells and replicates them in the presence of specific proteins found on cancer cells which, in essence, teaches the T-cells to target specific tumor markers. Training the T-cells, growing them to sufficient quantities and ensuring they are safe for administration takes weeks. But when patients return to the outpatient clinic, their T-cell infusion lasts just a few minutes.

For the third consecutive year, Children’s National was selected to compete in STAT Madness, an annual bracket-style competition that chooses the year’s most impactful biomedical innovation by popular vote. Children’s entry, “Immunotherapy of relapsed and refractory solid tumors with ex vivo expanded multi-tumor associated antigen specific cytotoxic T lymphocytes,” uses the body’s own immune system to attack and eliminate cancer cells in pediatric and adult patients with solid tumor malignancies.

In 2018, Children’s first-ever STAT Madness entry advanced through five brackets in the national competition and, in the championship round, finished second. That innovation, which enables more timely diagnoses of rare diseases and common genetic disorders, helping to improve kids’ health outcomes around the world, also was among four “Editor’s Pick” finalists, entries that spanned a diverse range of scientific disciplines.

An estimated 11,000 new cases of pediatric cancer were diagnosed in children 14 and younger in the U.S. in 2019. And, when it comes to disease, cancer remains the leading cause of death among children, according to the National Institutes of Health. An enterprising research team led by Children’s National faculty leveraged T-cells – essential players in the body’s immune system – to treat pediatric and adult patients with relapsed or refractory solid tumors who had exhausted all other therapeutic options.

“We’re using the patient’s own immune system to fight their cancer, rather than more traditional chemotherapy drugs,” says Catherine M. Bollard, M.D., director of the Center for Cancer & Immunology Research at Children’s National and co-senior author of the study. “It’s more targeted and less toxic to the patient. These T-cells home in on any cancer cells that might be in the body, allowing healthy cells to continue to grow,” Dr. Bollard adds.

That means patients treated in the Phase I, first-in-human trial didn’t lose their hair and weren’t hospitalized for the treatment. After a quick clinical visit for their treatment, they returned to normal activities, like school, with good energy levels.

“With our specially trained T-cell therapy, many patients who previously had rapidly progressing disease experienced prolonged disease stabilization,” says Holly J. Meany, M.D., a Children’s National oncologist and the study’s co-senior author. “Patients treated at the highest dose level showed the best clinical outcomes, with a six-month, progression-free survival of 73% after tumor-associated antigen cytotoxic T-cell (TAA-T) infusion, compared with 38% with their immediate prior therapy.”

The multi-institutional team published their findings from the study online July 29, 2019, in the Journal of Clinical Oncology.

“Our research team and our parents are delighted that some patients treated in our study continue to do well following T-cell therapy without additional treatment. In some cases, two years after treatment, patients do not appear to have active disease and are maintaining an excellent quality of life,” says Amy B. Hont, M.D., the study’s lead author. “One of these was a patient whose parents were told his only other option was palliative care. Our innovation gives these families new hope,” Dr. Hont adds.

The 2020 STAT Madness #Core64 bracket opened March 2, and the champion will be announced April 6.

In addition to Drs. Hont, Meany and Bollard, Children’s National co-authors include C. Russell Cruz, M.D., Ph.D., Robert Ulrey, MS, Barbara O’Brien, BS, Maja Stanojevic, M.D., Anushree Datar, MS, Shuroug Albihani, MS, Devin Saunders, BA, Ryo Hanajiri, M.D., Ph.D., Karuna Panchapakesan, MS, Payal Banerjee, MS, Maria Fernanda Fortiz, BS, Fahmida Hoq, MBBS, MS, Haili Lang, M.D., Yunfei Wang, DrPH, Patrick J. Hanley, Ph.D., and Jeffrey S. Dome, M.D., Ph.D.; and Sam Darko, MS, National Institute of Allergy and Infectious Diseases.

Financial support for the research described in this post was provided by the Children’s National Hospital Heroes Gala, Alex’s Army Foundation, the Children’s National Board of Visitors and Hyundai Hope on Wheels Young Investigator Grant to Support Pediatric Cancer Research, the Children’s National Research Institute Bioinformatics Unit, the Clinical and Translational Science Institute and the National Institutes of Health under award No. UL1-TR001876.

ID-KD vaccine induced T-cell cytotoxicity

Fighting lethal cancer with a one-two punch

The immune system is the ultimate yin and yang, explains Anthony D. Sandler, M.D., senior vice president and surgeon-in-chief of the Joseph E. Robert Jr. Center for Surgical Care at Children’s National in Washington, D.C. With an ineffective immune system, infections such as the flu or diarrheal illness can run unchecked, causing devastating destruction. But on the other hand, excess immune activity leads to autoimmune diseases, such as lupus or multiple sclerosis. Thus, the immune system has “checks and balances” to stay controlled.

Cancer takes advantage of “the checks and balances,” harnessing the natural brakes that the immune system puts in place to avoid overactivity. As the cancer advances, molecular signals from tumor cells themselves turn on these natural checkpoints, allowing cancers to evade immune attack.

Several years ago, a breakthrough in pharmaceutical science led to a new class of drugs called checkpoint inhibitors. These medicines take those proverbial brakes off the immune system, allowing it to vigorously attack malignancies. However, Dr. Sandler says, these drugs have not worked uniformly and in some cancers, they barely work at all against the cancer.

One of these non-responders is high risk neuroblastoma, a common solid tumor found outside the skull in children. About 800 U.S. children are diagnosed with this cancer every year. And kids who have the high-risk form of neuroblastoma have poor prognoses, regardless of which treatments doctors use.

However, new research could lead to promising ways to fight high-risk neuroblastoma by enabling the immune system to recognize these tumors and spark an immune response. Dr. Sandler and colleagues recently reported on these results in the Jan. 29, 2018, PLOS Medicine using an experimental model of the disease.

The researchers created this model by injecting the preclinical models with cancer cells from an experimental version of neuroblastoma. The researchers then waited several days for the tumors to grow. Samples of these tumors showed that they expressed a protein on their cell surfaces known as PD-L1, a protein that is also expressed in many other types of human cancers to evade immune system detection.

To thwart this protective feature, the researchers made a cancer vaccine by removing cells from the experimental model’s tumors and selectively turning off a gene known as Id2. Then, they irradiated them, a treatment that made these cells visible to the immune system but blocked the cells from dividing to avoid new tumors from developing.

They delivered these cells back to the experimental models, along with two different checkpoint inhibitor drugs – antibodies for proteins known as CLTA-4 and PD-L1 – over the course of three treatments, delivered every three days. Although most checkpoint inhibitors are administered over months to years, this treatment was short-term for the experimental models, Dr. Sandler explains. The preclinical models were completely finished with cancer treatment after just three doses.

Over the next few weeks, the researchers witnessed an astounding turnaround: While experimental models that hadn’t received any treatment uniformly died within 20 days, those that received the combined vaccine and checkpoint inhibitors were all cured of their disease. Furthermore, when the researchers challenged these preclinical models with new cancer cells six months later, no new tumors developed. In essence, Dr. Sandler says, the preclinical models had become immune to neuroblastoma.

Further studies on human patient tumors suggest that this could prove to be a promising treatment for children with high-risk neuroblastoma. The patient samples examined show that while tumors with a low risk profile are typically infiltrated with numerous immune cells, tumors that are high-risk are generally barren of immune cells. That means they’re unlikely to respond to checkpoint inhibiting drugs alone, which require a significant immune presence in the tumor microenvironment. However, Dr. Sandler says, activating an immune response with a custom-made vaccine from tumor cells could spur the immune response necessary to make these stubborn cancers respond to checkpoint inhibitors.

Dr. Sandler cautions that the exact vaccine treatment used in the study won’t be feasible for people. The protocol to make the tumor cells immunogenic is cumbersome and may not be applicable to gene targeting in human patients. However, he and his team are currently working on developing more feasible methods for crafting cancer vaccines for kids. They also have discovered a new immune checkpoint molecule that could make this approach even more effective.

“By letting immune cells do all the work we may eventually be able to provide hope for patients where there was little before,” Dr. Sandler says.

In addition to Dr. Sandler, study co-authors include Priya Srinivasan, Xiaofang Wu, Mousumi Basu and Christopher Rossi, all of the Joseph E. Robert Jr. Center for Surgical Care and The Sheikh Zayed Institute for Pediatric Surgical Innovation (SZI), at Children’s National in Washington, D.C.

Financial support for research described in this post was provided by the EVAN Foundation, the Catherine Blair foundation, the Michael Sandler Research Fund and SZI.

ID-KD vaccine induced T-cell cytotoxicity

Mechanism of Id2kd Neuro2a vaccination combined with α-CTLA-4 and α-PD-L1 immunotherapy in a neuroblastoma model. During a vaccine priming phase, CTLA-4 blockade enhances activation and proliferation of T-cells that express programmed cell death 1 (PD1) and migrate to the tumor. Programmed cell death-ligand 1 (PD-L1) is up-regulated on the tumor cells, inducing adaptive resistance. Blocking PD-L1 allows for enhanced cytotoxic effector function of the CD8+ tumor-infiltrating lymphocytes. Artist: Olivia Abbate