Engineering delivery beyond the blood–brain barrier

Ossianix develops VNAR-based brain shuttles designed to carry biotherapeutic payloads into the central nervous system. Its TXP1 platform targets transferrin receptor 1 to support receptor-mediated transport across the blood–brain barrier.

Explore the platform →Contact

TfR1: receptor targeted by TXP1
VNAR: deimmunised single-domain scaffold
Since 2012: operations, per the company

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The challenge

Most biotherapeutics cannot reach the brain

The blood–brain barrier protects the central nervous system but also keeps large therapeutic molecules out. Ossianix engineers shuttles that use a natural transport receptor, TfR1, to carry payloads across it.

01
VNAR engineering
A compact, deimmunised single-domain antibody scaffold derived from sharks.
02
TfR1-mediated transcytosis
Binding to transferrin receptor 1 to support receptor-mediated transport.
03
Payload transport
Fusion or conjugation formats pairing the shuttle with biotherapeutic payloads.

Interactive · 360°

The TXP1 platform, step by step

Rotate the conceptual model, or move through six stages. Every fact is in the text beside it; the 3D is illustrative only.

BloodConceptual visualizationBrain

Stage 01 / 06

The blood–brain barrier challenge

The BBB limits entry of large biotherapeutics into the brain. Delivering payloads across it is the problem Ossianix addresses.

Evidence & scope

High-level context from the company’s Science & Technology page.

Text version of all stages

01 · The blood–brain barrier challenge
The BBB limits entry of large biotherapeutics into the brain. Delivering payloads across it is the problem Ossianix addresses.
High-level context from the company’s Science & Technology page.
02 · TXP1 brain-selective shuttle
TXP1 is presented as a Brain-Selective Shuttle built on a deimmunised single-domain VNAR antibody scaffold.
Company description. Deimmunisation does not establish absence of human immunogenicity.
03 · TfR1 / receptor-mediated transcytosis
TXP1 targets transferrin receptor 1 (TfR1) to engage receptor-mediated transcytosis across the BBB.
Mechanism as described by the company. The model does not show a real receptor structure, affinity or kinetics.
04 · Biotherapeutic payload transport
The shuttle is fused or conjugated to therapeutic payloads, such as antibodies or oligonucleotides, to be carried into the brain.
Payload performance depends on cargo, dose and timepoint; no universal result is implied.
05 · Preclinical evidence
The company states TXP1 improves delivery to brain parenchyma in primates by more than 40-fold. Published mouse studies cover the related TXB2 and TXB4 variants.
Non-human primate, company-reported exposure. Not efficacy, safety or human data. A 2020 release reported >30-fold in hippocampus under specific conditions.
06 · Platform & pipeline opportunities
The published pipeline pairs TXP1 with TrkB (Parkinson’s), CD20 (multiple sclerosis), Her2 (neuro-oncology) and two undisclosed oligo programmes.
All preclinical. The chart shows IND/Phase I columns but no programme in Phase I.

Evidence, in context

What the company reports — and what it does not mean

Ossianix reports increased brain exposure in preclinical studies, including non-human primate work. Related TXB2 and TXB4 shuttles were studied in mouse models. These findings support further investigation; they do not establish clinical benefit in patients.

Science & TXP1 →

Company-reported, non-human primates

>40-fold

improved delivery to brain parenchyma in primates, per the company. Preclinical exposure — not efficacy, not human data.

Five TXP1 programmes, all preclinical

The original chart contains IND and Phase I columns; no programme enters Phase I.

Pipeline →

In vitroIn vivo miceIn vivo NHPINDPhase I

TXP1-TrkB^mAbMJFF · funded
TXP1-CD20^mAbNMSS · funded
TXP1-Her2^mAb
TXP1-oligo1
TXP1-oligo2

Phase I: not reached — Source: ossianix.co.uk Science & Technology. Arrow endpoints and funding logos do not prove IND submission or clearance, trial initiation or efficacy.

Peer-reviewed research

Four company-linked papers, 2020–2023, studying TXB2 and TXB4 in mice.

FASEB J · 2021 Feb · TXB2
Blood-brain barrier transport using a high affinity, brain-selective VNAR antibody targeting transferrin receptor 1.
FASEB J · 2020 Oct · TXB2
Brain delivery of biologics using a cross-species reactive transferrin receptor 1 VNAR shuttle.
Pharmaceutics · 2022 Jun · TXB4-TrkB
A Single Domain Shark Antibody Targeting the Transferrin Receptor 1 Delivers a TrkB Agonist Antibody to the Brain and Provides Full Neuroprotection in a Mouse Model of Parkinson's Disease.
Pharmaceutics · 2023 Feb · TXB2 / TXB4
CDR3 Variants of the TXB2 Shuttle with Increased TfR1 Association Rate and Enhanced Brain Penetration.

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Latest news

7 July 2026
Ossianix Receives Fast Forward Funding from National MS Society
US$0.8m Fast Forward support for preclinical brain-penetrant anti-CD20 work. Not clinical endorsement.
9 January 2025
Ossianix Receives Grant from The Michael J. Fox Foundation to Advance TXP1 Brain Shuttle for Delivering TrkB Agonist Antibody in Parkinson’s Disease Therapy
US$1.26m MJFF support for preclinical TXP1-TrkB development (MJFF funding year 2024). Not clinical endorsement.
17 November 2022
Attralus and Ossianix Announce an Option and License Agreement using the TXP1 Brain Shuttle for Targeted Delivery of AT-04, a Pan-Amyloid Removal Therapeutic, for Neurodegenerative Disorders
Option/licence announcement pairing AT-04 with TXP1. Current status not established.
9 November 2020
Ossianix to Present Preclinical Data Demonstrating Best-in-Class Blood Brain Barrier Delivery in Non-Human Primates by Single Domain VNAR Antibodies
Reported NHP delivery experiment (>30-fold in hippocampus under specified conditions). Not human data.