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# Inhibrx's Cancer Drug Hits 80% Response Rate In HPV-Positive Head And Neck Tumors, More Than Double Pembrolizumab Alone
- URL: https://www.bullished.co/inhibrxs-cancer-drug-hits-80-response-rate-in-hpv-positive-head-and-neck-tumors-more-than-c422dd13/
- Published: 2026-10-02T16:41:15.000Z
- Updated: 2026-10-06T14:00:16.000Z
- Description: An investor presentation filed Monday shows INBRX-106 combined with pembrolizumab achieved an 80% confirmed response rate versus 33% for the checkpoint inhibitor alone.
- Author: Matteo Parrino
- Tags: SEC Filings, INBX, Industry: Healthcare

Inhibrx Biosciences disclosed mid-stage trial data Monday showing its lead oncology candidate, INBRX-106, produced an [80% confirmed response rate](https://www.sec.gov/Archives/edgar/data/0002007919/000200791926000050/inhibrxpresentation%5Fsept.htm?ref=bullished.co) in HPV-positive head and neck cancer patients when paired with pembrolizumab — more than double the 33% rate seen with pembrolizumab alone. The figures came from a corporate investor presentation attached to an 8-K filed with the SEC on Monday, September 28\. Inhibrx first reported the HPV-positive result in a Sept. 8 press release; the Sept. 28 presentation restates it alongside updated milestones.

## What The HexAgon Data Shows

In the HPV-positive subset of the mid-stage HexAgon trial, INBRX-106 plus pembrolizumab delivered a complete response rate of 30% versus 0% for pembrolizumab alone. The six-month progression-free survival rate in that subset reached 90% for the combination arm, compared with 33% for the control arm, with median progression-free survival not yet reached in the combination group versus 4.6 months for pembrolizumab alone. 

Across all patients enrolled in the mid-stage portion of HexAgon — a seamless mid-stage-to-late-stage study in first-line recurrent or metastatic head and neck squamous cell carcinoma with a PD-L1 combined positive score of 20 or higher — the combination achieved a 48.3% confirmed objective response rate versus 26.5% for pembrolizumab alone. The complete response rate across all patients was 13.8% versus 0%, and median progression-free survival was 9.6 months for the combination compared with 4.9 months for the control arm. The company also reported that INBRX-106 drove up to a 15-fold increase in T-cell proliferation and up to a 4-fold increase in T-cell activation relative to pembrolizumab alone.

INBRX-106 is designed as a hexavalent OX40 agonist, meaning it simultaneously engages multiple OX40 receptors to drive stronger clustering and signaling than earlier bivalent formats were able to achieve. The company describes the mechanism as complementing checkpoint inhibitors: pembrolizumab removes a brake on T-cell activity, while INBRX-106 acts as an accelerator by enhancing T-cell proliferation, survival, and memory formation.

## The Accelerated Approval Path And What Comes Next

Inhibrx said in the [presentation](https://www.sec.gov/Archives/edgar/data/0002007919/000200791926000050/inhibrxpresentation%5Fsept.htm?ref=bullished.co) that it plans to add 50 additional HPV-positive patients to the mid-stage portion of HexAgon. The company said that expansion could support an accelerated FDA approval pathway, with a potential decision by the end of 2028 or early 2029\. The company characterizes the HPV-positive head and neck cancer market as worth more than $4 billion.

Beyond that subset, Inhibrx sees a broader commercial opportunity across tumor types it describes as highly immunogenic — including bladder cancer, non-small cell lung cancer, melanoma, microsatellite instability-high and tumor mutational burden-high cancers, and triple-negative breast cancer — which it estimates represent a combined market of more than $50 billion. An ongoing mid-stage lung cancer study is intended to serve as proof of concept for expanding INBRX-106 with pembrolizumab across those tumor types.

The company expects to begin the late-stage portion of the HexAgon study in the second half of 2027.

## The Second Pipeline Asset: Ozekibart In Chondrosarcoma

Inhibrx's other lead candidate, ozekibart (also called INBRX-109), is a DR5 agonist that has already met its primary endpoint in a registrational trial for chondrosarcoma, a rare bone cancer. That trial enrolled 137 patients on the drug versus 69 on placebo and produced a 52% reduction in the risk of disease progression or death. Median progression-free survival more than doubled to 5.52 months from 2.66 months for the placebo group.

The company is targeting a potential ozekibart approval and first commercial launch for metastatic or unresectable chondrosarcoma in the first half of 2027\. Inhibrx also plans to meet with the FDA to discuss a registrational trial design for ozekibart in first-line colorectal cancer and a potential accelerated regulatory pathway for fourth-line colorectal cancer, with interim data from combination cohorts in colorectal cancer expected in the first half of 2027.

## Financial Position And Share Activity

As of August 6, 2026, Inhibrx reported $219.5 million in cash and cash equivalents, with 14.7 million common shares outstanding and 19.7 million fully diluted shares outstanding — the latter figure includes approximately 4.0 million employee and board option reserves, roughly 1 million pre-funded warrants, and approximately 0.2 million warrants.

INBX shares were essentially flat in Friday trading, up about 0.01% at $97.94 versus the prior close, according to market data.

The next concrete dates on the calendar are the late-stage HexAgon initiation, expected in the second half of 2027, and the potential ozekibart commercial launch for chondrosarcoma, targeted for the first half of 2027.

*Editor's Note: An earlier version misplaced three milestones from Inhibrx's Sept. 28 presentation. The potential ozekibart approval and launch and the colorectal cancer interim data are expected in the first half of 2027, and the Phase 3 HexAgon initiation in the second half of 2027\. The 80% HPV-positive response rate was first disclosed Sept. 8\. Thanks to a reader for the catch!*

### Sources

- [8-K Filing — Inhibrx Biosciences, Inc. (INBX)](https://www.sec.gov/Archives/edgar/data/0002007919/000200791926000050/inhibrx-20260928.htm?ref=bullished.co) — SEC EDGAR
- [Exhibit inhibrxpresentation\_sept.htm — Inhibrx Biosciences, Inc. 8-K exhibit](https://www.sec.gov/Archives/edgar/data/0002007919/000200791926000050/inhibrxpresentation%5Fsept.htm?ref=bullished.co) — SEC EDGAR