A single dose of NovoBioJect increased the active form of methotrexate inside patients’ immune cells by 38%, a first step toward a potential next-generation first-line treatment for rheumatoid arthritis
- First clinical proof of principle. In an exploratory pharmacokinetic study in rheumatoid arthritis patients, a single dose of NovoBioJect led to 38% more active methotrexate inside the immune cells that drive inflammation, compared with methotrexate alone.
- Favorable single-dose safety profile. No adverse events other than mild, dose-dependent injection-site reactions were observed.
- Clear path to Phase 2a. The results de-risk the next step: a Phase 2a proof-of-concept study in the Netherlands, to be funded by a Series A financing of approximately €10 million that Amplio is now initiating.
- Large unmet need, high cost to society. Up to 60% of patients do not achieve remission on methotrexate alone and move on to second-line therapies that cost many times more. NovoBioJect is designed to raise the first-line response rate with potential cost savings for society.
AMSTERDAM, the Netherlands, October 1st, 2026 – Amplio Pharma (“Amplio”), a clinical-stage pharmaceutical company developing NovoBioJect to improve first-line treatment of rheumatoid arthritis (RA), today announced positive results from its Phase 1b study of NovoBioJect in patients with RA. NovoBioJect pairs low-dose methotrexate (MTX), the global first-line standard of care in RA for more than 40 years, with a low dose of novobiocin, which blocks the ABCG2 efflux transporter that eliminates the pro-drug MTX out of immune cells before it can become active.
In a study that enrolled 12 patients, a single dose of NovoBioJect produced a rapid and statistically significant 38% increase in accumulation of intracellular long-chain MTX polyglutamates MTX-PG4 and MTX-PG5, compared with MTX alone (P = 0.009), with a favorable safety profile. It is the first evidence in patients that the mechanism behind NovoBioJect works as designed, and it supports advancing NovoBioJect into a Phase 2a proof-of-concept study as a potential next-generation first-line RA treatment. Amplio is initiating a Series A financing of approximately €10 million to take NovoBioJect through this next phase.
Methotrexate is prescribed to roughly four out of five newly diagnosed RA patients, yet in only about 40% disease remission is achieved on methotrexate alone.[1, 2] The remaining 60% need add-on second-line biologics or targeted synthetic Disease Modifying Antirheumatic Drugs, which increase the risk of serious side effects and multiply treatment costs. Amplio’s hypothesis is that MTX fails many patients not because methotrexate does not work, but because too little of it is retained inside the cells that drive inflammation. The Phase 1b results directly support that hypothesis.
“It is rare for a Phase 1b study to give such a clear read-out on the biomarker that matters. We set out to test whether blocking the ABCG2 pump would keep more active methotrexate inside the cells that drive inflammation in RA, and in patients that is exactly what we saw, after a single dose and with a clean safety profile,” said Marguérite Mensonides-Harsema, PhD, Chief Executive Officer and Co-founder of Amplio Pharma. “These results validate the mechanism behind NovoBioJect and give us and our investors a well-founded basis to move into a Phase 2a proof-of-concept study. The question we now need to answer is whether more active methotrexate inside the cell translates into more patients reaching remission faster on first-line therapy. If it does, the impact on patients and on healthcare budgets in Europe and the United States would be substantial.”
Phase 1b study design and results
The Phase 1b study was an open-label study in 12 patients with rheumatoid arthritis on stable weekly methotrexate (15 to 25 mg), conducted in the Netherlands under an approved clinical trial application (Site: CHDR, Leiden). In a cross-over single ascending dose design, novobiocin was administered subcutaneously as a single dose of 80, 150 or 200 mg simultaneously with the patient’s regular weekly methotrexate dose. Key findings:
- NovoBioJect increased the combined intracellular accumulation of MTX-polyglutamates PG4 and PG5, the long-chain polyglutamates considered pharmacological biomarkers of methotrexate activity, in peripheral blood mononuclear cells (PBMCs) by 38% compared with methotrexate alone.
- The increase was rapid and statistically significant (P = 0.009).
- Robust plasma exposure for both methotrexate and novobiocin was achieved after subcutaneous co-administration.
- Single-dose safety assessment showed a clean profile; the only findings were mild, dose-dependent injection-site reactions. No other treatment-related adverse events were reported.
The study was designed to assess pharmacokinetics, safety and biomarker response. It was not designed or powered to establish clinical efficacy, which will be evaluated in Phase 2.
Amplio has submitted the full dataset for presentation at the ACR Convergence 2026 as a late breaking abstract.
Expert perspective
“We have known for years that the clinical effect of methotrexate depends on how much of the drug is retained and polyglutamated inside the cell, and that this varies enormously between patients. An approach that increases intracellular polyglutamate levels pharmacologically, rather than by simply raising the methotrexate dose, is scientifically compelling. These early data justify a well-designed Phase 2 study to determine whether the biomarker effect translates into better clinical outcomes for patients,” said Prof. Joel Kremer, MD, Pfaff Family Professor of Medicine, Albany Medical College; President, Corrona Research Foundation, Albany, NY.
From proof of principle to proof of concept
Amplio plans to advance NovoBioJect into a Phase 2a proof-of-concept study in newly diagnosed patients with rheumatoid arthritis, to be conducted in the Netherlands. The study is expected to compare NovoBioJect with methotrexate alone on clinical response in 100 patients over 12 weeks, with safety as primary endpoint and response rate, speed of onset of disease control and MTX-PG biomarkers as secondary endpoints. Subject to financing and regulatory approval, Amplio expects to start the study in 2027
The target product profile for NovoBioJect is a once-weekly subcutaneous autoinjector combining methotrexate and low-dose novobiocin, with the potential to increase the proportion of patients who respond to first-line therapy, to accelerate onset of action and ultimately to allow a lower methotrexate maintenance dose, while maintaining a safety profile comparable to methotrexate alone. These are development objectives that have yet to be established in a controlled Phase 2a trial.
Series A financing to fund Phase 2a
Amplio is initiating a Series A financing round of approximately €10 million to fund the Phase 2a study through read-out. The Phase 1b results materially reduce the biological risk of the program ahead of this round: the mechanism has now been demonstrated in patients, the combination has been dosed safely, and the method to track the MTX polyglutamation rates (biomarker) in Phase 2 has shown to be both robust and sufficiently sensitive.
Amplio’s Seed Round of € 1.4 million was supported by Libertatis Ergo Holding (LEH), Amsterdam UMC Ventures Holding, ROM InWest MKB-fonds and Innovatiefonds Noord-Holland. The company’s strategy is to bring NovoBioJect through clinical proof of concept and to position the asset for a strategic transaction with a partner that can take it through late-stage development and commercialization.
A growing patient population and a rising cost to healthcare systems
Rheumatoid arthritis is one of the most common chronic inflammatory diseases worldwide. An estimated 17.6 million people were living with RA in 2020, a number projected to rise to almost 32 million by 2050 as populations age.[3] In the United States, RA affects an estimated 1.8 million adults,[4, 5] and in Europe an estimated 3.3 million people live with the disease with ca. 50% of these patients in the United states and ca. 60% of the patients in Europe currently receiving treatment with methotrexate for their rheumatoid arthritis.[5] Approximately 400 000 patients are newly diagnosed and started on DMARD treatment in these regions each year.
RA typically strikes people of working age, and a large proportion of patients are women in their thirties, forties and fifties.[6]
The economic burden is substantial. In the United States, the total annual cost of RA has been estimated at more than $19 billion, with direct medical costs for patients on biologic therapy roughly three times higher than for RA patients overall.[7][8] In Europe, direct and indirect costs of RA exceed €45 billion per year.[6] Second-line biologic and targeted synthetic therapies account for a large share of these costs; in the United States, annual healthcare costs for a patient on biologic therapy exceed $40,000.[9]
By replacing metothrexate with NovoBioJect, societal impact could be twofold: more patients controlled on first-line therapy, and fewer escalations to therapies that cost tens of thousands of euros or dollars per patient per year. Amplio expects its proprietary NovoBioJect to be listed at a premium price still well below second-line biologic and targeted therapies, so that a higher first-line response rate can be achieved at a cost favorable for healthcare systems in both Europe and the United States. These expectations depend on the outcome of Phase 2 and subsequent development.
About NovoBioJect
NovoBioJect is Amplio Pharma’s proprietary combination of methotrexate (MTX) and low-dose novobiocin for the treatment of rheumatoid arthritis. MTX is a prodrug. To work, it must stay inside target cells long enough to be converted into long-chain MTX polyglutamates, its active form. The ABCG2 transporter pumps MTX out of these cells before that conversion can take place, which limits and delays the response in many patients. NovoBioJect is designed to lock MTX inside the cells that drive inflammation and increasing the formation of its active metabolites.
Novobiocin is a natural compound produced by soil bacteria. It was discovered in the mid-1950s and marketed for decades as an antibiotic. It blocks ABCG2 at a fraction of its former antibiotic dose. Its sodium salt is highly water soluble, which makes it suitable for injection, and existing toxicology studies support chronic dosing in combination with MTX. FDA and EMA classify products like NovoBioJect as a product with a single active pharmaceutical ingredient (MTX), supporting a well-defined path to approval in the United States and Europe.
The combination is protected by granted composition-of-matter and use patents in the United States and Europe, with protection expected to extend beyond 2040. NovoBioJect is intended as a once-weekly subcutaneous treatment, administered with an autoinjector.
About Amplio Pharma
Amplio Pharma B.V. is a clinical-stage pharmaceutical company based in Amsterdam, the Netherlands, founded in 2020 by a team with long-standing industry experience in rheumatology drug development, autoimmune disease strategy, market access and business development. The company’s approach is to amplify validated medicines: to make proven, affordable first-line treatments work better for more patients. Amplio’s lead program, NovoBioJect, aims to reinvent first-line treatment of rheumatoid arthritis. The company intends to advance NovoBioJect through clinical proof of concept and to pursue a value-maximizing strategic transaction. For more information, visit www.amplio-pharma.com.
Contacts
| Amplio Pharma B.V. Marguérite Mensonides-Harsema, PhD Chief Executive Officer marguerite@amplio-pharma.com +31 6 39 350 380 www.amplio-pharma.com |
Media contact LifeSpring Life Sciences Communication Leon Melens lmelens@lifespring.nl +31 6 53 816 427 Science Park 400, 1098 XH Amsterdam |
Forward-looking statements
This press release contains forward-looking statements regarding the development, clinical efficacy, safety, commercial potential, pricing, health-economic impact and future financing or strategic transactions relating to NovoBioJect. Such statements are based on current expectations and assumptions and are subject to substantial risks and uncertainties. In particular, the Phase 1b findings are biomarker-based and do not by themselves establish clinical efficacy or demonstrate an increased clinical responder rate. NovoBioJect’s efficacy, safety, regulatory approval, pricing, reimbursement, commercial adoption and any future financing or partnering outcomes remain subject to successful further development and regulatory review. Nothing in this press release constitutes an offer to sell or a solicitation of an offer to buy any securities of Amplio Pharma B.V.
References
[1] Myasoedova E. Predicting treatment response to methotrexate: are we closer to solving the enigma. Rheumatology 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11147535/
[2] Chen S. et al. Can methotrexate monotherapy achieve clinical remission in patients with active rheumatoid arthritis? A model-based meta-analysis. Journal of Clinical Pharmacology 2025. https://www.researchgate.net/publication/391494082_Can_Methotrexate_Monotherapy_Achieve_Clinical_Remission_in_Patients_with_Active_Rheumatoid_Arthritis_A_Model-Based_Meta-Analysis
[3] GBD 2021 Rheumatoid Arthritis Collaborators. Global, regional, and national burden of rheumatoid arthritis, 1990–2020, and projections to 2050. The Lancet Rheumatology 2023. https://www.thelancet.com/journals/lanrhe/article/PIIS2665-9913(23)00211-4/fulltext
[4] United States Bone and Joint Initiative. The Burden of Musculoskeletal Diseases in the United States, 4th edition: Rheumatoid Arthritis. https://bmus-ors.org/fourth-edition/iiib21/rheumatoid-arthritis
[5] Global Data Rheumatoid Arthritis 68-Market-Analysis and Sales Forecast. 2023
[6] Galloway J. et al. The impact of disease severity and duration on cost, early retirement and ability to work in rheumatoid arthritis in Europe: an economic modelling study. Rheumatology Advances in Practice 2020. https://pmc.ncbi.nlm.nih.gov/articles/PMC7494042/
[7] Birnbaum H. et al. Societal cost of rheumatoid arthritis patients in the US. Current Medical Research and Opinion 2010. https://pubmed.ncbi.nlm.nih.gov/19908947/
[8] Hresko A. et al. Medical care costs associated with rheumatoid arthritis in the US. Arthritis Care & Research 2018. https://pmc.ncbi.nlm.nih.gov/articles/PMC6033682/
[9] Cost of biologic treatment persistence or switching in rheumatoid arthritis. American Journal of Managed Care. https://www.ajmc.com/view/cost-of-biologic-treatment-persistence-or-switching-in-rheumatoid-arthritis
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