Recruiting
Phase 2
Phase 3

INBRX-106 & Pembrolizumab

Sponsor:

Inhibrx Biosciences, Inc

Code:

NCT06295731

Conditions

Head and Neck Squamous Cell Carcinoma (HNSCC)

HPV-associated Oropharyngeal Squamous Cell Carcinoma (HPV+ OPSCC)

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

INBRX-106

Pembrolizumab

Study Details

Brief summary:

This seamless phase 2/3 randomized controlled study will evaluate the efficacy and safety of the hexavalent OX40 agonist antibody ordastobart (INBRX-106) combined with the anti-PD-1 antibody pembrolizumab versus pembrolizumab (+ placebo in phase 3) as first-line treatment for patients with recurrent or metastatic (R/M) HPV-positive Oropharyngeal Squamous Cell Carcinoma (HPV+ OPSCC) expressing PD-L1.

Conditions

Head and Neck Squamous Cell Carcinoma (HNSCC)

HPV-associated Oropharyngeal Squamous Cell Carcinoma (HPV+ OPSCC)

Study ID

NCT06295731

Start date

May 14, 2024

Status verified date

Oct, 2026

Completion date

May, 2031

Anticipated

Primary completion date

Dec, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

  • Has histologically or cytologically confirmed diagnosis of recurrent/metastatic oropharyngeal squamous cell carcinoma (OPSCC) considered incurable by local therapies.
  • Has tumor PD-L1 expression with a combined proportion score (CPS) ≥1 by central testing.
  • HPV-positive tumor status as assessed locally by p16 immunohistochemistry (IHC).
  • Has measurable disease per RECIST 1.1 guidelines.
  • Has an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.

Exclusion Criteria:

  • Has primary tumor site (any histology) of any other location than oropharynx.
  • Has received prior systemic therapy (eg, prior chemo-, immune-, or biologic therapy) for R/M HNSCC.

  • Prior systemic therapy completed >6 months prior to signing informed consent is allowed if given as part of multimodal treatment for locoregionally advanced disease with curative intent, and no PD/recurrence occurred within 6 months of its completion. Prior systemic immunotherapy with curative intent, including but not limited to anti-PD-(L)1 agents, is allowed if PD/recurrence occurred ≥12 months after its completion.
  • Has clinically active central nervous system metastases and/or carcinomatous meningitis.
  • Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of study treatment.
  • Rapidly progressing disease.
  • Active or high risk of tumor-associated bleeding.
  • Current or history of immune-related disease that required systemic treatment in past 2 years, except for replacement therapy.

Study Design

Enrollment

450 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: ordastobart (INBRX-106) plus pembrolizumab

Participants will receive INBRX-106 plus pembrolizumab, both given by intravenous (IV) infusion every 3 weeks (QW3)

active comparator: pembrolizumab monotherapy (+ placebo in phase 3 part)

Participants will receive pembrolizumab (plus placebo in Phase 3), given by intravenous (IV) infusion every 3 weeks (QW3)

Interventions

INBRX-106

INBRX-106 0.1 mg/kg by intravenous (IV) infusion, given every 3 weeks (QW3)

Pembrolizumab

Pembrolizumab 200 mg by intravenous (IV) infusion, given every 3 weeks (QW3)

Primary outcome measure

  • Phase 2: Objective Response Rate by investigator (ORRinv) [ Time Frame: From randomization to progressive disease (PD) or death (up to 1 year) ]
  • Phase 3: Progression-Free Survival by Investigator (PFSinv) [ Time Frame: From randomization to PD or death (up to 4 years) ]
  • Phase 3: Overall Survival (OS) [ Time Frame: From randomization until death from any cause (up to 4 years) ]

Central Contacts and Locations

Central contacts

Study Director - Inhibrx

858-500-7833clinicaltrials@inhibrx.com

Locations

City of Hope Medical Center

Recruiting

Duarte, California, United States, 91010

Contacts

800-826-4673

Principal Investigator:

Victoria M Villaflor, MD

Los Angeles Cancer Network (LACN)

Recruiting

Los Angeles, California, United States, 91204

Contacts

213-977-1214

Principal Investigator:

Sungwon Rachel Kyung, MD

Medical Oncology Associates of San Diego

Recruiting

San Diego, California, United States, 92123

Contacts

Amanda Somo

858-637-7860asomo@oncologysandiego.com

Principal Investigator:

Steven Kossman, MD

Sarcoma Oncology Center

Recruiting

Santa Monica, California, United States, 90403

Contacts

310-499-8851

Principal Investigator:

Neal Chawla, MD

The Oncology Institute of Hope & Innovation

Recruiting

Miami, Florida, United States, 33169

Contacts

562-693-4477

Principal Investigator:

Edgardo Santos, MD

Mid Florida Hematology and Oncology Center

Recruiting

Orange City, Florida, United States, 32763

Contacts

866-977-6322

Principal Investigator:

Santosh Nair, MD

University of Illinois Cancer Center

Recruiting

Chicago, Illinois, United States, 60612

Contacts

Annette Kinsella

312-996-6275annettek@uic.edu

Principal Investigator:

Ameen Salahudeen, MD, PhD

Norton Cancer Institute

Recruiting

Louisville, Kentucky, United States, 40202

Contacts

502-629-3569

Principal Investigator:

Jaspreet Grewal, MD

Karmanos Cancer Institute

Recruiting

Detroit, Michigan, United States, 48201

Contacts

313-576-9811

Principal Investigator:

Ammar Sukari, MD

Washington University St. Louis

Recruiting

St Louis, Missouri, United States, 63110

Contacts

314-747-6475

Principal Investigator:

Jesse Zaretsky, MD

Intermountain Health, St. Vincent Regional Hospital, Cancer Centers of Montana

Recruiting

Billings, Montana, United States, 59102

Contacts

406-238-6963

Principal Investigator:

Patrick Cobb, MD

Oncology Hematology West, PC dba Nebraska Cancer Specialists

Recruiting

Omaha, Nebraska, United States, 68130

Contacts

402-334-4773

Principal Investigator:

Yungpo B. Su, MD

Comprehensive Cancer Centers of Nevada

Recruiting

Las Vegas, Nevada, United States, 89169

Contacts

Ann Lovelace

ann.lovelace@usoncology.com

Lindsay Kondo

7029523406lindsay.kondo@usoncology.com

Principal Investigator:

Kyaw Thein, MD

Christus St. Vincent Regional Cancer Center

Recruiting

Santa Fe, New Mexico, United States, 87505

Contacts

505-913-8900

Principal Investigator:

Andrea Teague, MD

UNC Lineberger Comprehensive Cancer Center

Recruiting

Chapel Hill, North Carolina, United States, 27599-7305

Contacts

Jonathan Jackson

919-966-4432jtjacks@email.unc.edu

Helan Mathai

919-966-4432helan@email.unc.edu

Principal Investigator:

Siddharth Sheth, DO

Oklahoma University Stephenson Cancer Center

Recruiting

Oklahoma City, Oklahoma, United States, 73104

Contacts

Shae Pfenning, RN

405-271-8001Shae-Pfenning@ouhsc.edu

Principal Investigator:

Minh Phan, md

UPMC Hillman Cancer Center

Recruiting

Pittsburgh, Pennsylvania, United States, 15232

Contacts

Jennifer Ruth

412-623-4522Ruthj2@upmc.edu

Justin Siegel

412-623-4522siegeljt@upmc.edu

Principal Investigator:

Dan Zandberg, MD

CHRISTUS Spohn Cancer Center

Recruiting

Corpus Christi, Texas, United States, 78404

Contacts

361-861-9721

Principal Investigator:

Swetha Panati, MD

VCU Massey Comprehensive Cancer Center

Recruiting

Richmond, Virginia, United States, 23298

Contacts

Elisabeth Holmes

804-628-2622masseyirb@vcu.edu

Principal Investigator:

Erin Alesi, MD

More Information

Sponsor

Inhibrx Biosciences, Inc

Last update posted

Oct 27, 2026

Last verified

Oct, 2026

Keywords

  • OX40 receptor agonist
  • PD-L1 positive
  • Pembrolizumab
  • Immunotherapy
  • Chemotherapy-free
  • HNSCC
  • Head and Neck Cancer
  • Keytruda
  • Oropharyngeal cancer
  • INBRX-106
  • HPV positive
  • squamous cell carcinoma
  • OPSCC
  • ordastobart

Trial information was received from ClinicalTrials.gov and was last updated on 2026-10-28. This information was provided to ClinicalTrials.gov by Inhibrx Biosciences, Inc on 2026-10-27. Recruitment status is synced daily from ClinicalTrials.gov and may not reflect the sponsor's current status. Confirm during your call.