AINEWS
Chondrosarcoma, a rare bone cancer with no approved drugs, gets its first FDA review filing
The FDA has accepted Inhibrx's application for ozekibart in conventional chondrosarcoma, setting an April 2027 review goal date.
The FDA has accepted Inhibrx's application for ozekibart in conventional chondrosarcoma, setting an April 2027 review goal date.
For patients with the most common form of chondrosarcoma, a cancer of cartilage-producing cells in the bone, there has never been an FDA-approved systemic therapy, meaning a drug that travels through the bloodstream to reach tumors anywhere in the body. Surgery is the only curative option, and once the disease is unresectable (cannot be removed by surgery) or has spread, the toolkit is thin.
That is the first fact of this story. The second is procedural: on June 15, 2026, the FDA accepted Inhibrx's biologics license application (BLA) for ozekibart, the company's experimental targeted biologic, in patients with unresectable or metastatic conventional chondrosarcoma, and assigned a Prescription Drug User Fee Act (PDUFA) goal date of April 14, 2027, according to the sponsor's announcement. Acceptance means the application is complete enough for the agency to start a substantive review; it is not an approval. The company says the FDA did not flag any filing review issues at acceptance.
If approved, ozekibart would be the first FDA-approved treatment for unresectable or metastatic conventional chondrosarcoma, a claim that belongs to Inhibrx and to the patients, not to a regulatory finding. The application rests on the registrational ChonDRAgon trial, in which the company reported a median progression-free survival (PFS, the length of time patients live without their disease worsening) of 5.52 months on ozekibart versus 2.66 months on placebo, with a hazard ratio (a measure of relative risk of progression or death) of 0.479, a 52% reduction in the risk of progression or death in the company's analysis. PFS is a surrogate endpoint: it shows the disease is not advancing, not that patients are living longer.
Several things are not in the release and would matter before the April 2027 decision. There is no overall survival readout in the company data summarized in the announcement, so it is not yet clear whether the PFS gain translates into lives extended. Independent verification of the trial results, by peer review, by FDA statistical review, or by a presentation at a major meeting, is still pending. Whether the FDA will convene an advisory committee to weigh the risk-benefit profile is unknown. The release does not describe how standard of care for unresectable or metastatic disease was defined in the control arm, and any eventual label could be narrower than the population studied.
What is clear is the calendar. The PDUFA goal date of April 14, 2027 is the deadline by which the FDA aims to complete its review; the agency can miss it, approve early, or issue a complete response letter (a decline that asks for more data) on or before that day. Inhibrx, headquartered in San Diego and traded on Nasdaq under the ticker INBX, is a clinical-stage biopharmaceutical company, meaning it has no products on the market, and Mark Lappe is its chief executive officer. Both descriptions come from the sponsor's release.
The audience for this story is not the stock. It is the small community of patients with conventional chondrosarcoma and the clinicians who have had nothing systemic to offer them when surgery is off the table. For them, a BLA acceptance is a procedural step, not a treatment. What to watch between now and April 2027: whether the overall survival data eventually mature and are reported, whether an advisory committee is scheduled, and whether the eventual label, if approval comes, covers the population that actually needs an option.