Our first drug —
and the idea behind it.
OBX34 is the first of a family of drugs that copy the microbiome's immune signals. It starts in the clinic where the human evidence is strongest — lung-cancer patients on immunotherapy — then broadens to more patients whose gut is working against their treatment, and, over time, to other immunotherapies and other cancers.
Pipeline overview
| Program | Indication | Modality | Stage |
|---|---|---|---|
OBX34Lead program |
2L NSCLC, post-ICI progressionlung cancer after immunotherapy relapse · + anti-PD-1 |
Oral tablet | |
OBX34Expansion |
ICI-refractory solid tumorsunfavorable gut microbiome, identified by a simple test |
Oral tablet |
Progresses from the OBX34 Phase 1/2a
|
OBX200Immunology |
Autoimmune diseaseundisclosed indication |
Oral tablet | |
OBX300Next generation |
Solid tumorsundisclosed indication |
Oral tablet |
Stages are indicative of current development status and are subject to regulatory progress.
Proposed first-in-human study: NSCLC with acquired resistance to checkpoint blockade.
Proposed design · not yet initiated
The first clinical study of OBX34 is designed to read out quickly in a setting where the biology is unambiguous: advanced non-small cell lung cancer in patients who derived clinical benefit from anti-PD-1 therapy and subsequently progressed — acquired, rather than primary, resistance. It is a defined, previously-responding population, and it is the setting in which the human evidence that changing the microbiome can restore checkpoint response is strongest.
The proposed Phase 1/2a would escalate oral OBX34 alongside anti-PD-1 therapy to establish a recommended Phase 2 dose, then expand at that dose in patients undergoing checkpoint rechallenge.
- Design. Open-label, multicenter dose escalation followed by single-arm expansion at the selected dose. OBX34 is given orally as an add-on; anti-PD-1 therapy continues per label.
- Primary endpoints. Safety and tolerability, dose-limiting toxicities, and selection of the recommended Phase 2 dose.
- Secondary and exploratory. Objective response rate and progression-free survival by RECIST 1.1, duration of response, pharmacokinetics, and target engagement — Gasdermin D / IL-1β pathway readouts with paired stool and tumor sampling.
- Key eligibility. Documented prior benefit on checkpoint therapy followed by radiographic progression, with enrichment for patients with recent antibiotic exposure.
Design is pre-IND and subject to change following regulatory feedback. IND/CTA filing targeted for H2 2027 — no study is open and no patients have been dosed.
A clear path from the lab to results in patients.
Entering IND-enabling
The first IND/CTA-enabling activities are underway — toxicology, manufacturing, and regulatory preparation.
Clearance to begin trials
Regulatory clearance to begin the first study in people.
First trial in patients
Lung cancer, after immunotherapy relapse — testing safety, the right dose, and early signs of activity.
Broadening out
More disrupted-gut patients first — then other immunotherapies and cancers the same biology reaches.
One drug today — a whole approach the same biology can carry.
OBX34 is the first test of the model. But a drug designed to reset the tumor's environment isn't limited to one medicine or one cancer — the approach should help wherever a hostile environment is holding immunotherapy back.
The first drug
OBX34 with immunotherapy in relapsed lung cancer — where the evidence is strongest today, and the fastest way to test it in people.
More patients
The wider group whose gut is unfavorable for reasons beyond recent antibiotics, found with a simple microbiome test.
Beyond lung cancer
Other immunotherapies and cancer types where resetting the environment could help more patients respond — pursued as the data supports it.
The full data package and development plan.
Available to partners under confidentiality, on request.