Empowers the body - protects cells and regulates the immune system

ANXV is an investigational new drug containing the human protein Annexin A5, produced by recombinant techniques in the bacteria Escherichia Coli (E.coli). Like endogenous Annexin A5, ANXV can protect cells, reduce adhesive properties and influence the actions by immune cells. Thereby has ANVX a promising potential as a therapeutic.

Mode of action

Targeting tissues affected by disease

The therapeutic effect of ANXV is proposed to be dependent on binding to its target - phosphatidylserine (PS) on cell membranes. Imaging studies with labelled Annexin A5 in animal models and in patients show it's rapid homing to PS-exposing areas and tissue affected by various diseases. By binding to, and forming a shield over membranes exposing PS, and by neutralising the overexposure of PS, ANXV is postulated to act as an immune modulator, anti-adherent, anti-inflammatory, anti-thrombotic, and cell membrane repair agent.

Protecting cells

Annexin A5 works primarily by binding to PS, a natural fat component of the cell membrane. The therapeutic potential of ANXV is broad since the presence of its target – phosphatidylserine (PS) on outer cell membranes, and its consequences, is believed to be a contributing factor to a number of human diseases.
Normally, PS is located on the inside of the cell membrane, but in various types of cell stress or damage, PS is exposed on the outside of the cell membrane. It plays a part in a signalling system that affects immune cells, making cells stickier so that they can attach to each other and form aggregates but also contributes to coagulation reactions. Annexin A5 builds a shield over PS- exposing cell membranes and neutralises the pathologic overexposure and signalling of PS.

Regulating immune cell behaviour

The ability of Annexin A5 protein to protect cells, regulate the behaviour of immune cells, and be of beneficial therapeutic effect is well-documented in scientific literature. The literature describes models of various diseases, where Annexin A5 has been shown to have cell protective, anti-adherent, anti-inflammatory properties and being focal anti-thrombotic (as opposed to a systemic anti-coagulant).

Wide range of therapeutic indications

Effects of Annexin A5 that have been demonstrated include cases of retinal vein occlusion, cancer, sickle cell anaemia, inflammatory joint disease, inflammatory bowel disease, viral diseases, blood poisoning (sepsis), myocardial infarction, traumatic brain injury, and more – in both cell systems and animal models.

Annexin Pharmaceuticals is currently investigating the therapeutic potential of ANXV as a possible First-In-Class treatment for patients recently diagnosed with retinal vein occlusion. In addition, Annexin investigates ANXV’s potential within oncology.

Therapeutic areas & clinical studies

Promising broad therapeutic coverage for ANXV

The properties of ANXV make this drug candidate potentially useful in medicine as a therapeutic agent, imaging agent, and for targeted drug delivery. The therapeutic potential of ANXV is currently being investigated in a clinical Phase 2 study in patients diagnosed with retinal vein occlusion (RVO). In addition, ANXV’s potential in the field of oncology is being investigated, while other therapeutic areas of scientific interest are currently not actively explored.

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ANXV and Retinal Vein Occlusion

Retinal Vein Occlusion (RVO) is the blockage or closing of a vein in the eye. It is the second most common sight-threatening retinal vascular disorder after diabetic retinopathy. Globally, the prevalence of RVO is reported to be over 16 million cases. RVO may present as a sudden, painless loss of vision and macular oedema.

ANXV in RVO is being investigated in an ongoing Phase 2 study in patients with recently diagnosed RVO. The multiple actions by ANXV suggest it may be beneficial for other eye diseases, such as macular degeneration and diabetic retinopathy and this may be explored following the outcomes of studies in RVO.

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ANXV and cancer

Cancer, malignant tumours and neoplasms, is a term for a heterogenous group of diseases that can affect any part of the body. The key defining feature of cancer is the rapid growth of abnormal cells that can invade parts of the body and spread to other organs; the latter process is referred to as metastasising cancer. Widespread metastases are the primary cause of death from cancer.

The potential of ANXV as a monotherapy, or in combination with other immunotherapies, and as a transporter of chemotherapy drugs is currently being investigated. The potential as monotherapy may be investigated without additional preclinical studies, while the potential as a carrier of other anti-cancer drugs warrants several pre-clinical studies before testing in patients.

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Sickle Cell Disease and ANXV

Sickle Cell Disease (SCD) is a hereditary disease that affects the red blood cells. It results in impaired blood supply, damage to organs, and severe pain, and ultimately causes premature death. SCD patients experience frequent, painful sickle cell crises when sickle cells block blood vessels in different parts of the body.

Annexin A5 has been shown to stop an ongoing sickle cell crisis in an animal model. If ANXV shows an effect in SCD patients, it would fill a major medical need. The company sees a strong scientific rationale for ANXV in SCD and is open to discussing partnerships for clinical development.

ANXV and cardiovascular diseases

Cardiovascular disease is a collective term for diseases that affect the heart and/or the blood vessels. It is the most common cause of death, both in Sweden and in most industrialised countries. Common examples are myocardial infarction, peripheral occlusive arterial disease (PAOD), and stroke, often caused by atherosclerosis. Atherosclerosis is a chronic inflammatory disease of the blood vessels. There is still no anti-inflammatory medication available to treat such conditions.

Annexin A5 has demonstrated desirable effect in preclinical models but clinical development activities are currently not explored.


The ANXV pipeline

ANXV is currently evaluated for use in two diseases - RVO and cancer.

Route to market

Manufacturing of ANXV

ANXV contains Annexin A5 protein, and as such is produced with help of a bacteria. The ANXV manufacturing process has been developed and performed according to well-established procedures, regulations and guidelines. This work, Chemistry, Manufacturing and Control (CMC), is a major part of the development of a pharmaceutical product.

The ANXV product

ANXV is a biologic pharmaceutical investigational product that contains human protein Annexin A5. ANXV is produced via a recombinant technique using gene expression in the microorganism Escherichia Coli (E.coli), by incorporating the sequence of human Annexin A5 DNA into E.coli genome. The Annexin A5 protein is expressed in large quantities during fermentation of E.coli and is subsequently purified to remove all but the Annexin A5 protein.

ANXV Drug Substance (DS) is the pure ANXV protein dissolved in a buffer solution at a concentration that is appropriate for long term storage. To have a concentration and amount appropriate for administration to a patient, the ANXV DS is diluted and sterilised to become the ANXV Drug Product (DP), before it is transferred to vials for storage until use.

The CMC process

Chemistry, Manufacturing and Control (CMC), is the “heart” of drug product manufacture, both during development and when the drug is on the market. CMC includes a number of steps, such as:

  • Development and testing of the manufacturing process
  • Testing that the drug is the same on each manufacturing occasion
  • Testing that the formulation is optimal and that the drug does not contain any impurities
  • Testing that the drug is stable over time, at different temperatures and humidity situations
  • Testing how the drug reacts when exposed to light, during transportation, and if it adheres to different materials
  • Scaling up the production to a commercial size
  • Characterising the manufacturing process; for instance, in detail tests of each step during production
  • Validating the manufacturing process by producing at least three batches on a commercial size and confirming that they are consistent

The Phase 1 study with ANXV

During a Phase 1 study, the investigational new drug is for the first time being evaluated in humans. The results are expected to show if the drug is well-tolerated and safe to use, and provide guidance to the design of future studies.

Safety and tolerability of a new drug candidate are the key priorities – this is true both during development and when the product is on the market. Once the product has undergone pre-clinical animal studies demonstrating an acceptable toxicity profile, the next step is to perform human Phase 1 studies.

Phase 1 studies in general

The regulatory path for evaluation of safety and efficacy in humans is described in detail in both national legislation and in globally recognised guidelines, such as the International Conference of Harmonisation (ICH) guidelines. Phase 1 studies are the first step of a drug´s evaluation in humans.

Phase 1 studies evaluate the safety of the product. First, very low single doses are tested, followed by higher single doses, and thereafter multiple doses in the event the product is intended to be dosed during several days when on the market. The single dose level is called Single Ascending Dose, or SAD. The level containing multiple doses is called Multiple Ascending Doses, or MAD.

Participants in Phase 1 studies

Participants in Phase 1 studies
Normally, the participants in Phase 1 studies are healthy volunteers, as it is important to evaluate what the drug is doing to the body, without any interference from diseases. For very toxic drugs, such as cytostatic cancer treatments, Phase 1 studies are performed with cancer patients, as it would be unethical to expose healthy people to toxic treatments with the risk of resulting in severe adverse events. Potentially, cancer patients may also benefit from the drug.

Evaluation of safety

Safety during a clinical study is mainly evaluated via the collection of data relating to adverse events. An adverse event is any unexpected medical occurrence associated with the use of a drug in humans, whether or not considered drug-related. This means that during a clinical trial, information about all medical events that occur, such as colds, fractures or allergies, will be collected and summarised. Physicians will consider if the adverse events are related to the drug under investigation. It may also be the case that events not considered related to the drug are occurring to a greater extent than usual, and therefore may have been caused by the drug.

Thorough monitoring

Monitoring of those participating in a Phase 1 study is done continuously by measuring blood pressure, pulse, ECG and taking blood samples. As it may be the first time the drug is administered to a person, he or she is often required to stay in the clinic overnight, sometimes for several nights, for observation.

Pharmacokinetics and pharmacodynamics

Measurement of concentration of the drug in the blood is a main focus during a Phase 1 study. Therefore, blood sampling will take place on a number of occasions during the study to be able to investigate at what time after drug administration the highest concentration is obtained, and also how long it takes for the drug to be removed from the blood. This is Pharmacokinetics – what the body does with the drug – and consists of four parts: absorption, distribution, metabolism, and excretion.

Another important aspect of Phase 1 studies is pharmacodynamics – what the drug does to the body. Phase 1 studies are not designed to evaluate effect or efficacy of the drug. However, via measurements of so called biomarkers it is possible to attain a good understanding of the potential effect. Specifically, the relationship between pharmacokinetics and pharmacodynamics, which is the relationship between concentration of the drug and the biomarkers.

ANXV Phase 1 study

The ANXV Phase 1 study was a First in Human study, meaning it was the first time the drug was administered to humans. During year 2020 to 2021, 46 healthy volunteers participated in the ANXV phase 1 study at a dedicated Phase 1 CRO in the Netherlands. The study consisted of a Single Ascending Dose (SAD) level, with one ANXV treatment, and a Multiple Ascending Dose (MAD) level, including five days of treatment. ANXV was tested in doses from 0.25 mg to 2 mg.
The study provided a solid basis for the future development of ANXV, and demonstrated a favourable safety and tolerability profile of ANXV in healthy volunteers at all dose levels tested. Data from the ANXV Phase 1 study is intended to support Phase 2 studies in several indications. ID: NCT04850339

Phase 2 study in Retinal Vein Occlusion

The aim in a Phase 2 study is to investigate if the drug has an effect and to identify the optimal dose, while evaluating the efficacy and safety at different doses. The participants are patients with the disease intended to be treated when the product is on the market. The ANXV Phase 2a study in Retinal Vein Occlusion is ongoing, with the aim to show proof of concept.

ANXV Phase 2a study in Retinal Vein Occlusion (RVO)

The ANXV Phase 2a study in RVO is currently ongoing at several clinical sites in the USA. The goal is to obtain proof of concept that ANXV is safe to use and has an effect in patients with RVO. As the study is the first investigation of ANXV in patients, the eligibility criteria are narrow. This is to assure the results show a true ANXV effect, but also to minimise the risk for patients with concomitant diseases, as it is not yet well-known how ANXV will affect other diseases or concomitant use of other pharmaceutical products.

The main purpose of the ANXV Phase 2a study is to measure safety and tolerability in patients with RVO. This is assessed via:

  • Adverse events (any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related)
  • Vital signs (e.g. blood pressure, pulse, ECG and respiratory rate)
  • Haematology and safety blood samples

Anti-drug antibodies are also measured. This is a specific need when administering proteins (or other types of biologic drugs) as they are similar to the body’s own proteins. If the body reacts to the study drug and produces antibodies, there is a risk that the anti-drug antibodies react with the body’s own endogenous proteins.


The first evaluation of data from the study was reported in August 2023. An expert evaluation committee recommended unmasking of the treatment and it was shown that 2 out of 4 patients on ANXV had signals of effect during the study, and more were stable in their disease after having received a single dose of anti-VEGF treatment. Anti-VEGF treatment was given 3-4 weeks after the ANXV treatment, with the aim to decrease some remaining macular oedema. Patients with RVO normally receive anti-VEGF treatments every 1-2 months over several years, it is therefore unexpected that these patients did not need more than one anti-VEGF treatment during at least a six-month period. ID: NCT05532735

Vision evaluations

The most common, and regulatory accepted, assessment to evaluate effect of ophthalmological drugs is Best Corrected Visual Acuity (BCVA). This is a test most people have probably done in school or at an optometrist, performed when standing a few metres from a board showing letters in different sizes. How good or bad your vision is can be estimated based on the size of the letters you are able to read.

Except for BCVA, the ANXV Phase 2a study is assessing the potential efficacy of ANXV, for example by the following evaluations/tests:

  • Swelling of the macula (oedema)
    RVO often causes swelling in the eye as the blood outflow in the vein is impaired, which in turn often affects the optic nerve and vision. Macular swelling is measured by Spectral Domain Optical Coherence Tomography (SD-OCT) / Spectral Domain Optical Coherence Tomography Angiography (OCTA).
  • Retinal sensitivity
    Measurement of retinal sensitivity and abnormal functionality in the retina is performed with Mesopic Microperimetry.
  • Retinal area of non-perfusion
    An image is taken after fluorescein is administered to the patient, and areas which are highlighted/non-highlighted show areas where blood flow has been affected or where the blood cannot pass. This is obtained with the help of Ultra-Wide Field Fluorescein Angiography (UWF-FA).
  • Ischemic or non-ischemic RVO
    Patients with milder types of RVO have leaky retinal vessels, but if the blood vessels are closed-off, the RVO is more severe and considered Ischemic RVO. This can be assessed with Ultra-Wide Field Fluorescein Angiography (UWF-FA).