On December 16, 2025 Inhibrx Biosciences, Inc. (Nasdaq: INBX) ("Inhibrx" or the "Company"), a clinical-stage biopharmaceutical company focused on developing therapeutics for oncology reported an update on the INBRX-106 Phase 2/3 clinical trial in combination with Keytruda (pembrolizumab) as a first-line treatment for patients with locally advanced unresectable or metastatic head and neck squamous cell carcinoma (HNSCC) and the Phase 1/2 trial evaluating patients with checkpoint inhibitor refractory or relapsed non-small cell lung cancer (NSCLC) in combination with Keytruda. The Company also provided a brief progress update on the expansion cohorts investigating ozekibart in combination with FOLFIRI in late-line colorectal cancer and in combination with irinotecan and temozolomide in refractory Ewing sarcoma.

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INBRX-106

Inhibrx has recruited 46 of the 60 patients in the randomized Phase 2 portion of the Phase 2/3 clinical trial evaluating INBRX-106 in combination with Keytruda versus Keytruda as a first-line treatment for patients with unresectable or metastatic HNSCC. Inhibrx expects to complete enrollment in the Phase 2 portion of the trial during the first quarter of 2026. This trial is recruiting patients who have not received prior systemic therapy for unresectable or metastatic HNSCC and have tumor PD-L1 CPS expression equal to or greater than 20. Patients are randomized one to one to either INBRX-106 in combination with Keytruda or Keytruda. The primary endpoint of the Phase 2 portion of this trial is overall response rate, supported by secondary endpoints of duration of response, progression free survival and safety.

In November 2025, Inhibrx completed enrollment of the Phase 1/2 trial evaluating 34 patients in checkpoint inhibitor refractory or relapsed NSCLC in combination with Keytruda. Primary endpoints for this cohort are objective response rate, disease control rate, duration of response and safety.

The current datasets for both HNSCC and NSCLC lack sufficient maturity to support an interpretation and conclusion on the viability of this program. Inhibrx expects that in the second half of 2026, the data should be mature enough to inform whether INBRX-106, in combination with Keytruda, demonstrates superior efficacy and sustained clinical benefit relative to the current standard of care.

KEYTRUDA is a registered trademark of Merck Sharp & Dohme Corp.

Ozekibart (INBRX-109)

In late October 2025, Inhibrx completed enrollment of 44 patients in the expansion cohort of the Phase 1/2 trial evaluating ozekibart in combination with FOLFIRI in heavily pretreated (third and fourth line) advanced or metastatic, unresectable colorectal cancer. As previously reported, ozekibart in combination with FOLFIRI was well tolerated, with durable responses and a high rate of disease control. The progression free survival data should be mature in the second quarter of 2026, and we plan to provide an update at that time.

Inhibrx expects to complete enrollment in the Phase 1/2 trial of ozekibart in combination with irinotecan and temozolomide (IRI/TMZ) for advanced or metastatic, unresectable, relapsed, or refractory Ewing sarcoma in the second quarter of 2026. If the current response and duration trends observed continue, Inhibrx plans to meet with the FDA in the second half of 2026 to discuss an accelerated approval pathway for this indication.

About INBRX-106

INBRX-106 is a precisely engineered hexavalent sdAb-based therapeutic candidate targeting OX40, designed to be an optimized agonist of this co-stimulatory receptor. It is currently being investigated in combination with Keytruda in patients with locally advanced or metastatic solid tumors, specifically HNSCC and NSCLC.

About ozekibart (INBRX-109)

Ozekibart is a precision-engineered, tetravalent death receptor 5 (DR5) agonist antibody designed to exploit the tumor-biased cell death induced by DR5 activation. Inhibrx read out a successful single agent registration study in chondrosarcoma and a BLA filing is expected in early Q2 of 2026. Additionally, Inhibrx is evaluating ozekibart in patients diagnosed with colorectal cancer and Ewing sarcoma.

(Press release, Inhibrx, DEC 16, 2025, View Source [SID1234661464])