ImmunityBio (IBRX) Starts Phase 1b/2 Sepsis Trial of NAI — What's Verified, What's Unknown

The event

ImmunityBio (IBRX) has a Phase 1b/2 clinical trial start dated September 15, 2026 — today — with an "exact" date confidence rating in BioSniper's tracker, meaning the date derives from a primary-source record rather than a projected window. The registered trial is an open-label study evaluating the safety and efficacy of nogapendekin alfa inbakicept (NAI) plus standard of care in critically ill adults with sepsis.

This briefing lays out what our tracked data can verify about the event, the company, and the platform behind it — and, just as important, what remains unknown.

What's verified

The trial. The tracked title reads: "Phase 1b/2, Open-Label Clinical Trial Evaluating the Safety and Efficacy of Nogapendekin Alfa Inbakicept (NAI) Plus Standard of Care in Critically Ill Adults With Sepsis." That is the full scope of what the record carries — the design is open-label, the population is critically ill sepsis adults, and the intervention is NAI added to standard of care.

The company. ImmunityBio, Inc. is an active-listed biotechnology company with a tracked market capitalization of approximately $8.8 billion.

Institutional positions as tracked. The most recent 13F data in BioSniper (quarter-end March 31, 2026) records 4 institutional filers holding IBRX, with a combined tracked value of roughly $49.1 million. The two largest tracked positions: Woodline Partners LP ($26.4 million in tracked value) and UBS Group AG ($22.6 million). A boundary note: 13F filings capture long US-equity positions above disclosure thresholds from filing institutions only — this tracked figure is a floor for institutional exposure, not a census of all ownership.

The platform cadence. NAI (also known as N-803, and commercially as ANKTIVA) anchors one of the most aggressive trial-start rhythms we track. Over the past 24 months, BioSniper has recorded 22 catalyst events for ImmunityBio, of which 20 are trial starts across phases 1–3. Sepsis is not new territory for the program — today's event is the fourth tracked trial this year whose registered title names sepsis, after:

• July 6, 2026 — Phase 2 start: NAI plus standard of care in critically ill sepsis adults with persistent lymphopenia
• April 15, 2026 — two starts on the same date (a Phase 2 and a Phase 3): NAI and iNKT cells in severe community-acquired pneumonia with or without sepsis/ARDS

The critical-care push runs alongside Phase 3 starts earlier in 2026 in first-line advanced non-small cell lung cancer (May 29) and BCG-naïve/BCG-exposed high-grade non-muscle-invasive bladder cancer (May 15). A pancreatic-cancer combination study (NAI with sotevtamab and zabadinostat plus chemotherapy) also entered Phase 1 at the start of this month, on September 1, 2026.

Taken together, today's start extends a sepsis and critical-care franchise that ImmunityBio has built across four tracked studies in 2026 — two in pneumonia/ARDS and two in sepsis proper — all layered on the same IL-15 superagonist backbone.

The wider docket

Beyond critical care, the same 24-month window shows how broadly the IL-15 platform and its cell-therapy combinations are being pushed:

• Oncology Phase 3s: besides the NSCLC and bladder-cancer starts above, an October 2025 Phase 3 pairs N-803 with tislelizumab or a prior failed checkpoint inhibitor plus docetaxel in checkpoint-resistant advanced NSCLC.
• Brain and blood cancers: a July 2026 Phase 2 in recurrent glioblastoma combines NAI, PD-L1 t-haNK, bevacizumab, and tumor-treating fields; Phase 1 and Phase 2 studies through 2025–2026 test CD19 t-haNK with N-803 and rituximab in relapsed/refractory B-cell lymphomas and leukemia.
• Earlier-stage spread: Phase 2 studies in long COVID (two starts, September and November 2025), high-risk prostate cancer around surgery and around radiation (December 2025), platinum-resistant ovarian cancer with M-CENK plus N-803 (November 2024), and a Phase 1/2 of intravesical recombinant mycobacterium rMBCG in bladder cancer (October 2025).
• Regulatory track record: an AdCom event for ANKTIVA is recorded on May 5, 2025 — the only regulatory-committee event in the window — and a patent expiry tied to NDA021660 is tracked for January 2034.

The pattern our data shows: one cytokine platform, many combination anchors (t-haNK, M-CENK, iNKT cells, rituximab, bevacizumab, BCG), and indication breadth that few companies of this size attempt.

What remains unknown

• Trial scope beyond the title. Enrollment targets, primary endpoints, and study duration are not carried in this record. We leave them UNKNOWN rather than estimating.
• Bound drug entity. This catalyst record does not carry a bound drug entity in our graph, so aggregated trial statistics are not attached to the event itself; NAI appears by name across the trial titles above.
• Outcomes. No outcome is recorded for any of the recent trial starts — recent starts are, by definition, unevaluated.
• 13F freshness. Tracked institutional positions are as of Q1 2026; later filings are not yet reflected in the figures above.

How to watch it

• ImmunityBio company profile — verified pipeline, financials, and tracked catalysts in one place
• Catalyst event record — the tracked entry for this Phase 1b/2 start

Data as tracked by BioSniper on September 15, 2026. Fields we cannot verify are marked UNKNOWN rather than estimated. This briefing is informational and is not investment advice.