Currently, there are an estimated 30 million people within the European Union (EU) who have a rare disease. The “Orphan Medicines” (or Orphan Drug) program was designed to facilitate the development of therapies for people living with rare conditions. To be eligible for Orphan Drug designation (or “Orphan Medicinal Product Designation”), a therapy must be intended to treat, prevent, or diagnose a life-threatening or debilitating condition that affects no more than 5 in every 10,000 people. Sponsors of these drugs also receive benefits such as lower regulatory fees, clinical protocol assistance, and 10 years of market exclusivity following drug approval. According to OncLive, INBRX-109 for chondrosarcoma earned Orphan Medicinal Product designation. 

About INBRX-109

Developed by Inhibrx, Inc., INBRX-109, a tetravalent DR5 agonistic antibody, was designed to:

Exploit tumor-biased direct cell death induction by DR5 activation in numerous cancer types. With a valency of four, it has the ability to potently agonize DR5 through efficient receptor clustering, causing cell death, but by way of our sdAb platform, also eliminates recognition by pre-existing anti-drug antibodies to lessen the potential for hyper-clustering.

Researchers hope that INBRX-109 could overcome treatment obstacles such as resistance to chemotherapy and radiation in patients whose cancer cannot be surgically removed. 

So far, INBRX-109 has been evaluated in both a Phase 1 and currently-running Phase 2 trial. Within the Phase 1 trial, 78% of patients reached disease stability, with a total disease control rate of 89%. Median progression-free survival was 7.4 months after INBRX-109 treatment. The Phase 2 ChonDRAgon study is still in the works; an estimated 201 patients will enroll. 

What is Chondrosarcoma?

Chondrosarcoma is a rare form of bone cancer that begins in cartilage cells. In many cases, chondrosarcoma affects the shoulder, pelvis, and femur, though in rarer cases, it may begin in the windpipe, knees, ribs, or skull. Doctors are unsure what causes chondrosarcoma. However, they have identified risk factors: increasing age, Li-Fraumeni syndrome, Maffuci syndrome, enchondromas, multiple hereditary exostoses, and Ollier disease. Symptoms of chondrosarcoma vary based on where the cancer develops. These can (but does not always) include:

• Large mass on the bone with pressure around it
• Localized swelling
• Progressively worsening pain
• Limited joint movement/mobility
• Bowel or bladder control issues
• Joint stiffness
• Overall weakness