Inhibrx Announces Updated Efficacy and Safety Data from the Expansion Cohorts in the Phase 1 Trial of INBRX-109 for the Treatment of Chondrosarcoma

SAN DIEGO, Nov. 16, 2022 /PRNewswire/ -- Inhibrx, Inc. (Nasdaq: INBX), a clinical-stage biopharmaceutical company dedicated to the development of therapeutics for oncology and rare diseases, today announced updated efficacy and safety data from the ongoing Phase 1 INBRX-109 expansion cohorts for the treatment of chondrosarcoma. Inhibrx presented this dataset as of May 2022 at the Annual Connective Tissue Oncology Society (CTOS) Conference today, which included matured data on the original chondrosarcoma cohort and initial data from an additional cohort of chondrosarcoma patients with the isocitrate dehydrogenase (IDH) mutation. Additionally, Inhibrx announced further updated results from this dataset as of November 2022.

Among the 33 patients evaluable as of November 8, 2022, the observed disease control rate was 87.9%, or 29 out of 33 patients as measured by RECISTv1.1, with two patients achieving partial responses (6.1%) and 27 patients achieving stable disease (81.8%). Disease control was observed in patients with and without IDH1/IDH2 mutations. Of those achieving stable disease 55.6% had decreases from baseline in tumor size. Clinical benefit was durable, 14 of 33 patients (42.4%) who achieved disease control had a clinical benefit lasting greater than 6 months, and the longest duration of stable disease is 20 months. To date, the median progression-free survival (PFS) is 7.6 months, and five patients remain on study.

Treatment-related adverse events (AEs) were reported in less than 5% of the patients with the most common being increased alanine aminotransferase (ALT), increased aspartate aminotransferase (AST), and increased blood bilirubin and fatigue. There were no grade 4 or 5 events reported among patients with treatment-related AEs.About Chondrosarcoma

Chondrosarcoma is a rare malignant bone tumor of cartilage-producing cells and usually arises in the pelvis or long bones. Although chondrosarcoma is considered rare with an estimated annual incidence of 1 in 200,000, it is the most common primary bone cancer found in adults. Surgical resection is the only curative treatment and patients with unresectable or metastatic disease have a poor prognosis. There are currently no approved therapies for unresectable or metastatic chondrosarcoma.About INBRX-109