Inhibrx Biosciences Inc (NASDAQ:INBX) saw its stock rise 2.6% on Monday following the U.S. Food and Drug Administration's acceptance of the company's Biologics License Application for ozekibart, a candidate therapy for patients with unresectable or metastatic conventional chondrosarcoma.
The FDA assigned a Prescription Drug User Fee Act goal date of April 14, 2027, and indicated there were no issues identified with the filing that would impede the agency's review. If ozekibart receives approval, it would represent the first FDA-approved therapy for this specific form of bone cancer and would become Inhibrx's inaugural commercial product.
The BLA is supported by data from the ChonDRAgon study, a randomized, blinded, placebo-controlled trial conducted across 67 sites worldwide that enrolled 206 patients. The trial met its primary endpoint, demonstrating a statistically significant improvement in median progression-free survival for patients treated with ozekibart compared with those who received placebo.
According to the trial results included in the filing, ozekibart reduced the risk of disease progression or death by 52% relative to placebo, with a reported stratified hazard ratio of 0.479. The disease control rate in the ozekibart arm was 54%, compared with 27.5% for placebo.
Safety findings in the study indicated that ozekibart was generally well tolerated and exhibited a manageable safety profile. The most frequently observed treatment-related adverse events were fatigue, constipation, and nausea. Hepatotoxicity was reported in 11.8% of patients receiving ozekibart versus 4.5% in the placebo group, with the majority of hepatotoxicity events characterized as Grade 1 or 2 in severity.
Chondrosarcoma is a rare malignancy that arises from cartilage-producing cells within bone and is the second most common primary bone cancer. When tumors are unresectable or have metastasized, prognosis is poor because these tumors are largely unresponsive to standard oncology therapies. The filing therefore targets a patient population with limited treatment options.
Ozekibart is described as a tetravalent death receptor 5 agonist antibody. The FDA previously granted the drug Fast Track designation in January 2021 and orphan drug designation in November 2021.
The acceptance of the BLA begins a formal regulatory review process that will continue through the assigned PDUFA date in April 2027. Investors and market participants have already reacted to the filing acceptance, reflected in the modest uptick in Inhibrx shares reported on Monday.
Key takeaways
- FDA accepted Inhibrx's BLA for ozekibart with a PDUFA date of April 14, 2027 and no filing review issues identified.
- ChonDRAgon trial (206 patients, 67 sites) met its primary endpoint, showing a 52% reduction in risk of progression or death and higher disease control rate for ozekibart versus placebo.
- Ozekibart was generally well tolerated; most common treatment-related adverse events included fatigue, constipation, and nausea, and hepatotoxicity occurred more frequently than placebo but was mostly Grade 1 or 2.