Historically, both osteosarcoma and neuroblastoma have been difficult to treat. Therefore, new treatment options are needed for these cancers, which predominantly affect children and teenagers. According to Medical XPress, a research team from the Stanford University School of Medicine sought to evaluate anti-GD2 and anti-CD47 antibodies as potential therapeutic options. While the antibodies were relatively ineffective on their own, the researchers found that the combined therapy was powerful.

Learn more about the study findings in Nature Medicine.

Antibody Combination: Anti-GD2 and Anti-CD47

So why did the researchers choose anti-GD2 and anti-CD47 antibodies? Well, CD47 is often expressed on cancer cells. It helps the cells evade immune response by setting off a “don’t eat me” signal. Typically, these signals are found on healthy cells and help the immune system only remove unsafe or harmful cells from the body. Researchers also found that GD2, which is found on neuroblastoma and osteosarcoma cells, functioned with a “don’t eat me” signal.

However, in mice models of these cancers, anti-GD2 antibodies or anti-CD47 antibodies on their own did little in terms of treatment. So researchers decided to try a combination of the antibodies. After treating mice models of neuroblastoma with the combination therapy, the mice were effectively cured. The tumors shrank and disappeared. Those who did not receive the combination therapy unfortunately died. While the combination treatment did not cure osteosarcoma, it did stop the cancer from metastasizing.

The combination treatment works by preventing “don’t eat me” signals and stopping GD2 and CD47 from hiding. Additionally, it prompted macrophages (a type of white blood cell) to more quickly and effectively consume the cancer cells. In fact, instead of the “don’t eat me” signals, the treatment caused more calreticulin (an “eat me” signal) to form on the cells’ surface.

More research is needed to determine whether this treatment could be beneficial for humans. Currently, a clinical trial is underway to learn more.

About Neuroblastoma and Osteosarcoma

Neuroblastoma

Genetic mutations in neuroblasts, or immature nerve cells made during fetal development, cause the formation of neuroblastoma, a rare cancer that forms in nerve tissue. Normally, neuroblasts mature or disappear by birth. However, in some cases, these cells form a tumor. In many cases, neuroblastoma tumors form on the adrenal glands. The cancer may also develop in the chest, neck, abdomen, or near the spine. Neuroblastoma is most common in young children (aged 5 or younger). Potential symptoms include:

• Bone pain
• Bulging eyes and/or dark circles around the eyes
• Unintended weight loss
• Pale skin
• An abdominal, neck, or chest lump
• Difficulty breathing (in infants)
• Abdominal distention (in infants)
• Painless, bluish lumps under the skin (in infants)

Osteosarcoma

Also called osteogenic sarcoma, osteosarcoma is a cancer which forms in the bones, particularly in areas where the bone is growing quickly (such as the shinbone or femur near the knee). Although osteosarcoma is rare, it is also the most common form of bone cancer in children. Typically, this cancer affects males more than females. Symptoms vary based on the location of the tumor, but may include:

• Bone pain or tenderness
• Limited joint motion
• Limping
• Redness or swelling at the tumor location
• Bone fractures
• Unintended weight loss
• Anemia (low red blood cell count)