At the University of Florida, Rally Researchers Dr. Elias Sayour MD, PhD and Dr. Brian Stover MD are busy studying the most common form of bone cancer in children and adolescents: osteosarcoma. Through support from the Rally Foundation for Childhood Cancer Research, they secured federal funding from the U.S. Department of Defense, which led to the development of a new cancer vaccine technology.
This new vaccine is currently testing in clinical trials for canine patients with osteosarcoma, with first-in-human trials happening in the near future. With these exciting new developments on the horizon, we reached out to Dr. Sayour and Dr. Stover to learn more about their field, their research, and how your donations help make an impact.
What is Osteosarcoma?
Osteosarcoma is the most common form of bone cancer in children and adolescents. We most often see it start in bones near the knee, pelvis or shoulder area. Although this cancer starts in the bones, it can spread throughout the body, including to the lungs and other bony sites. The grade of the cancer cells determines how quickly the cancer might spread. For example, low grade osteosarcoma is less likely to spread, while high grade cancer cells tend to grow and spread much faster.
Osteosarcoma in Children & Adolescents
Osteosarcoma can affect children of all ages, but we most commonly see it in teenagers. The cancer has been linked to adolescent growth spurts as bones are growing and developing.
The treatment of osteosarcoma consists of very aggressive chemotherapy, which continues for over six months. After the first two and a half months of chemotherapy, surgery is needed to remove the tumor, which may involve amputation of an extremity.
If treatment is started before the cancer has spread to other parts of the body, we are able to cure most individuals. However, if the cancer has already spread to other locations, the prognosis tends to be significantly worse. If a patient with osteosarcoma relapses, it can be very difficult to treat and cure. We will often try new combinations of chemotherapeutic agents or consider alternative surgical approaches for this disease. Patients may be offered the opportunity for surgical resection, or removal, of individual lung nodules, but depending on the amount and/or location, this can prove challenging.
New Developments in Treatment
Essentially, surgery and chemotherapy have been the mainstays of osteosarcoma treatment over the last 30 years without significant breakthroughs in the standard of care treatment approach. We have discovered that both chemotherapy and surgery are crucial for curing this disease. If surgery is used alone, the cancer often returns. Chemotherapy is needed both before and after surgery to help prevent cancer spread. Despite these treatments, the overall prognosis of someone with osteosarcoma has not significantly changed in the last 30 years.
While the prognosis for many forms of childhood cancer has significantly improved over the last several decades, outcomes for patients with treatment-resistant osteosarcomas, otherwise known as refractory osteosarcomas, have not appreciably changed. These poor outcomes necessitate development of novel targeted therapeutics. Unlike traditional chemotherapy that acts on both normal and cancerous cells, targeted therapies block the growth and spread of cancer cells alone. We believe in harnessing the immune system to recognize and reject osteosarcoma in an exquisitely targeted fashion without the deleterious side effects we commonly see with surgery and chemotherapy. Rally funding has allowed us to research and develop a new treatment using immunotherapy.
Immunotherapy is a new targeted therapy that tries to “wake up” or reprogram the immune system to reject cancer. There are several trials attempting to reprogram the immune system against cancer. Many of these trials involve T cells. T cells are specialized immune cells in all of us designed to “search and destroy” foreign targets. Sometimes, drugs are used to activate a patient’s T cells against their cancer. Alternatively, T cells can be harvested from patients and reprogramed against their cancer in a laboratory before reintroduction into the bloodstream.
We have created a personalized vaccine that takes genetic material from a patient’s tumor, which we load into a nanoparticle for delivery to the immune system. A nanoparticle is a microscopic particle that can be used to deliver drugs, heat, light or other substances directly to cancer cells. In our case, these nanoparticles communicate with a patient’s immune system, which activates their T cells against osteosarcoma. We have shown in mouse models that this nanoparticle vaccine can treat and cure the spread of osteosarcoma.
Funding for a Better Future
Rally’s funding has allowed us to witness the promise of this new therapy in mice and facilitated translation of this technology in a clinical trial for pet dogs diagnosed with osteosarcoma. Based on these promising data, we anticipate being in first-in-human trials for patients with osteosarcoma in the very near future, possibly within the next three years! We are extremely excited about this prospect and what it could mean for osteosarcoma patients.
From the Patient’s Perspective
We have learned that children and teenagers just starting their lives can have their worlds forever changed after an osteosarcoma diagnosis—but we have also learned about their resiliency. Current treatments can really take a toll physically, mentally and emotionally on both the patients and their families. From the harsh side effects of chemo to the endless hospital visits, surgeries and tests, these kids face it all. Their physical strength is inspiring, but even more so is their courage and determination to beat osteosarcoma and live a full life.
There was one patient in particular that we’ll never forget. A little girl with osteosarcoma having spread throughout multiple bones in her body always had the brightest smile, one that would light up a room. She was acutely aware of her diagnosis, and yet, she always looked outward to make others happy. Although we were her treating physicians, she went out of her way to give us gifts and comfort us. Individuals like her are our heroes and they teach us every day. We can only hope to give back to our patients what they have given us.