Inhibrx Biosciences Provides Progress Updates on the INBRX-106 Program and the Expansion Cohorts of the ozekibart (INBRX-109) Program

Rhea-AI Summary

Inhibrx (Nasdaq: INBX) provided clinical updates on INBRX-106 and ozekibart (INBRX-109) on December 16, 2025. Key progress: INBRX-106 has enrolled 46 of 60 randomized patients in the Phase 2 portion for first-line unresectable/metastatic HNSCC and expects to finish Phase 2 enrollment in Q1 2026. A separate Phase 1/2 checkpoint inhibitor refractory/relapsed NSCLC cohort completed enrollment at 34 patients in November 2025. Current datasets lack maturity to support conclusions; maturity expected in 2H 2026 to inform efficacy versus standard of care.

Ozekibart (INBRX-109) completed enrollment of 44 patients in the FOLFIRI expansion (late-line colorectal cancer); PFS data expected to be mature in Q2 2026. Enrollment for the IRI/TMZ Ewing sarcoma cohort is expected to complete in Q2 2026; if response trends persist, Inhibrx plans an FDA meeting in 2H 2026 to discuss accelerated approval.

Positive

• INBRX-106 Phase 2 enrollment at 46 of 60 patients
• NSCLC Phase 1/2 cohort enrollment completed at 34 patients
• Ozekibart + FOLFIRI expansion enrolled 44 patients
• Ozekibart FOLFIRI PFS data expected Q2 2026

Negative

• Current INBRX-106 and NSCLC datasets lack sufficient maturity
• Phase 2 HNSCC enrollment not complete; 14 patients remaining expected Q1 2026
• Efficacy decision for INBRX-106 deferred to 2H 2026, creating near-term uncertainty

Key Figures

HNSCC Phase 2 enrollment 46 of 60 patients Randomized Phase 2 portion of INBRX-106 + Keytruda trial

HNSCC completion timing Q1 2026 Expected completion of Phase 2 enrollment for INBRX-106 HNSCC trial

PD-L1 CPS threshold CPS ≥ 20 Inclusion criterion for unresectable or metastatic HNSCC patients

NSCLC cohort size 34 patients Checkpoint inhibitor refractory or relapsed NSCLC with INBRX-106 + Keytruda

CRC expansion enrollment 44 patients Ozekibart + FOLFIRI late-line colorectal cancer cohort completed in Oct 2025

CRC PFS data timing Q2 2026 Expected maturity of progression free survival data for CRC cohort

INBRX-106 data maturity 2H 2026 Expected timing to assess INBRX-106 + Keytruda efficacy vs standard of care

Ewing sarcoma enrollment timing Q2 2026 Planned completion of ozekibart IRI/TMZ Phase 1/2 enrollment

Market Reality Check

$83.09 Last Close

Volume Volume 351,246 is about 1.53x the 20-day average of 229,460 shares ahead of this update. high

Technical Shares at $81.57 were trading above the 200-day MA of $30.66, and 13.66% below the 52-week high of $94.47 before this news.

Peers on Argus 1 Up

INBX was down 4.22% while peers showed mixed moves: SLDB up 4.81% (in momentum scanner), DMAC up 1.62%, but LXRX and PRTA down 1.64% and 2.01% respectively, indicating stock-specific trading rather than a broad sector move.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Nov 14	Earnings and pipeline	Positive	+6.0%	Q3 2025 financials plus successful ozekibart registrational endpoint and cohort updates.
Nov 04	Conference participation	Positive	+0.7%	Announcements of multiple November presentations on ozekibart and DR5 clinical data.
Oct 23	Clinical topline data	Positive	-10.0%	Positive registrational ChonDRAgon topline data and strong expansion-cohort efficacy metrics.
Oct 22	Webcast announcement	Neutral	-16.0%	Scheduling webcast for ozekibart topline results and expansion cohort updates.
Aug 13	Earnings update	Neutral	+1.6%	Q2 2025 post‑spin financials and progress of ozekibart and INBRX-106 trials.

Pattern Detected

Recent history shows several positive ozekibart clinical updates followed by mixed price reactions, including notable selloffs on good news, suggesting investor expectations and risk perceptions have been volatile around major data events.

Recent Company History

Over the last six months, INBX has focused on advancing ozekibart and INBRX-106. Positive topline registrational data in chondrosarcoma on Oct 23, 2025 and detailed follow-up via conferences were key milestones, alongside expansion cohorts in colorectal cancer and Ewing sarcoma and regular earnings/10-Q updates on cash and losses. Market reactions alternated between rallies (e.g., +6.04% on Q3 results) and sharp selloffs (e.g., -10.03% on topline data), framing today’s clinical progress update within a backdrop of volatile responses to pipeline news.

Market Pulse Summary

This announcement detailed enrollment progress and timelines for INBRX-106 and ozekibart across multiple oncology indications, noting that key datasets for HNSCC, NSCLC, colorectal cancer, and Ewing sarcoma should mature between Q2 2026 and 2H 2026. Investors may track whether trials complete enrollment as planned, how response rates and progression free survival evolve, and any future regulatory interactions. Prior news flow shows markets reacting strongly to major data updates, underscoring the importance of upcoming readouts.

Key Terms

pembrolizumab medical

"in combination with Keytruda® (pembrolizumab) as a first-line treatment"

A cancer immunotherapy drug that helps the body’s immune system recognize and attack tumor cells by blocking a molecular “brake” that tumors use to hide. Investors watch it because regulatory approvals, clinical trial results, dosing rules, and competition directly affect potential sales, profit forecasts, and the valuation of companies that sell or license the drug—think of trial outcomes as checkpoint signs that can open or close a revenue road.

head and neck squamous cell carcinoma medical

"for patients with locally advanced unresectable or metastatic head and neck squamous cell carcinoma"

A type of cancer that starts in the thin, flat cells that line the mouth, throat, voice box and upper airway; imagine the lining like roof shingles that, when damaged, can grow into a harmful lump. It matters to investors because its diagnosis, treatment options and regulatory approvals drive demand for drugs, tests and therapies—affecting clinical trial outcomes, market size, company valuations and the financial risk/reward of healthcare investments.

non-small cell lung cancer medical

"refractory or relapsed non-small cell lung cancer (NSCLC) in combination"

A broad category of lung tumors that grow from the cells lining the airways and make up the majority of lung cancer cases; it includes several subtypes that behave and respond to treatment differently, like different models of the same car family. It matters to investors because its large patient population and variety of treatment options — surgery, traditional chemo, targeted drugs and immunotherapies — create major markets where clinical trial results, drug approvals or changing treatment guidelines can quickly affect a company’s revenue and stock value.

FOLFIRI medical

"ozekibart in combination with FOLFIRI in late-line colorectal cancer"

FOLFIRI is a chemotherapy combination used to treat certain cancers, made from the drugs fluorouracil (5-FU), leucovorin, and irinotecan — think of it as a three‑ingredient recipe designed to attack cancer cells in different ways. Investors care because its use affects demand for related drugs, influences clinical trial and approval outcomes, and can drive revenue or cost pressures for companies involved in manufacturing, supplying supportive care, or developing competing therapies.

irinotecan medical

"in combination with irinotecan and temozolomide in refractory Ewing sarcoma"

Irinotecan is a chemotherapy medicine that interferes with cancer cells’ ability to copy their genetic instructions, causing them to stop dividing and die; think of it as a wrench thrown into a cell’s copying machine. It matters to investors because regulatory approvals, clinical trial results, patent status, manufacturing supply and pricing affect a drugmaker’s revenue prospects and can drive stock moves when new data or decisions change the drug’s market potential.

temozolomide medical

"in combination with irinotecan and temozolomide in refractory Ewing sarcoma"

An oral chemotherapy drug that works by damaging the DNA of cancer cells so they can no longer grow and divide, most commonly used to treat certain brain tumors. For investors, temozolomide matters because clinical trial results, approvals, patent status, manufacturing supply and safety data can reshape a company’s drug revenue prospects and valuation—think of it as a key product in a biotech’s toolbox whose success or failure directly affects the business outlook.

overall response rate medical

"primary endpoint of the Phase 2 portion of this trial is overall response rate"

Overall response rate is the percentage of patients in a clinical study whose measurable disease shrinks or disappears after receiving a treatment. Investors watch it like a product’s “hit rate” because higher response rates can signal a drug’s effectiveness, boost chances of regulatory approval and market demand, and affect a company’s future revenue prospects, similar to how a higher batting average suggests a more reliable player.

progression free survival medical

"secondary endpoints of duration of response, progression free survival and safety"

Progression free survival is the length of time during and after a treatment when a disease, such as cancer, does not get worse or spread. It is an important measure because longer periods of stability can indicate that a treatment is effectively controlling the condition. For investors, it provides insight into the potential durability and success of a therapy or medication.

AI-generated analysis. Not financial advice.

SAN DIEGO, Dec. 16, 2025 /PRNewswire/ -- Inhibrx Biosciences, Inc. (Nasdaq: INBX) ("Inhibrx" or the "Company"), a clinical-stage biopharmaceutical company focused on developing therapeutics for oncology today announced 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.

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.

About Inhibrx Biosciences, Inc.

Inhibrx Biosciences is a clinical-stage biopharmaceutical company focused on developing a broad pipeline of novel biologic therapeutic candidates. Inhibrx Biosciences utilizes diverse methods of protein engineering to address the specific requirements of complex target and disease biology, including its proprietary protein engineering platforms. Inhibrx Biosciences was incorporated in January 2024 as a direct, wholly-owned subsidiary of Inhibrx, Inc. Prior to the sale of Inhibrx, Inc. and the INBRX-101 program to Sanofi S.A., Inhibrx Biosciences acquired certain corporate infrastructure and other assets and liabilities through a series of internal restructuring transactions effected by Inhibrx, Inc. Inhibrx, Inc. also completed a distribution to holders of its shares of common stock of 92% of the issued and outstanding shares of Inhibrx Biosciences. Following such transactions, Inhibrx Biosciences' current clinical pipeline of therapeutic candidates includes ozekibart and INBRX-106, both of which utilize multivalent formats where the precise valency can be optimized in a target-centric way to mediate what we believe to be the most appropriate agonist function. For more information, please visit www.inhibrx.com.

Forward-Looking Statements

Inhibrx cautions you that statements contained in this press release regarding matters that are not historical facts are forward-looking statements. These statements are based on Inhibrx's current beliefs and expectations. These forward-looking statements include, but are not limited to, statements regarding: Inhibrx's judgments and beliefs regarding the strength of Inhibrx's pipeline; statements regarding the safety and efficacy of its therapeutic candidatesbased on topline and interim results; the potential for its therapeutic candidates to be used for certain indications; the clinical development of its therapeutic candidates, including expected enrollment, data readouts, regulatory submissions and interactions, and the timing thereof; and any presumption that topline, interim or preliminary data will be representative of final data or data in later clinical trials. Actual results may differ from those set forth in this press release due to the risks and uncertainties inherent in Inhibrx's business, including, without limitation, risks and uncertainties regarding: topline data may not accurately reflect the complete results of a particular study or trial and remain subject to audit, and final data may differ materially from topline data; the initiation, timing, progress and results of its preclinical studies and clinical trials, and its research and development programs; its ability to advance therapeutic candidates into, and successfully complete, clinical trials; its interpretation of topline, interim or preliminary data from its clinical trials, including interpretations regarding disease control and disease response; results from preclinical studies or early clinical trials not necessarily being predictive of future results; unexpected adverse side effects or inadequate efficacy of its therapeutic candidates that may limit their development, regulatory approval and/or commercialization; the potential for its programs and prospects to be negatively impacted by developments relating to its competitors, including the results of studies or regulatory determinations relating to its competitors; the timing or likelihood of regulatory filings and approvals and regulatory developments in the U.S. and foreign countries; the successful commercialization of its therapeutic candidates, if approved; an accelerated development or approval pathway may not be available for its therapeutic candidates and any such pathway may not lead to a faster development process; it may not realize the benefits associated with orphan drug designation, including that orphan drug exclusivity may not effectively protect a product from competition and that such exclusivity may not be maintained; the pricing, coverage and reimbursement of its therapeutic candidates, if approved; its ability to utilize its technology platform to generate and advance additional therapeutic candidates; and other risks described from time to time in the "Risk Factors" section of its filings with the U.S. Securities and Exchange Commission, including those described in its Annual Report on Form 10-K, its Quarterly Reports on Form 10-Q, and supplemented from time to time by its Current Reports on Form 8-K as filed from time to time. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof, and Inhibrx undertakes no obligation to update these statements to reflect events that occur or circumstances that exist after the date hereof. All forward-looking statements are qualified in their entirety by this cautionary statement, which is made under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.

Investor and Media Contact:

Kelly Deck, CFO
ir@inhibrx.com
858-795-4260

 

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SOURCE Inhibrx Biosciences, Inc.

FAQ

How many patients has Inhibrx enrolled in the INBRX-106 Phase 2 (HNSCC) trial as of Dec 16, 2025?

The company has enrolled 46 of 60 randomized patients in the Phase 2 portion for HNSCC.

When does Inhibrx expect to complete enrollment for the INBRX-106 Phase 2 HNSCC trial (INBX)?

Inhibrx expects to complete Phase 2 enrollment in Q1 2026.

What is the enrollment status of the INBRX-106 NSCLC checkpoint refractory cohort (INBX)?

Enrollment for the NSCLC checkpoint inhibitor refractory/relapsed cohort completed at 34 patients in November 2025.

How many patients were enrolled in the ozekibart (INBRX-109) FOLFIRI expansion cohort and when is PFS data expected?

The FOLFIRI expansion enrolled 44 patients, and PFS data are expected to be mature in Q2 2026.

When might Inhibrx meet the FDA to discuss accelerated approval for ozekibart in Ewing sarcoma (INBX)?

If current response and duration trends continue, Inhibrx plans to meet with the FDA in 2H 2026 to discuss an accelerated approval pathway.

Will current INBRX-106 and NSCLC data support regulatory or clinical conclusions now?

No; the company states the current datasets lack sufficient maturity and expects interpretive data in 2H 2026.