BioSenic SA

Declaration of Voting Results & Voting Rights Announcements • May 8, 2025

PRESS RELEASE – REGULATED INFORMATION 08/05/2025

Information on the total number of voting rights and shares

Mont-Saint-Guibert, Belgium, 08 May 2025 at 18:30 – BIOSENIC (Euronext Brussels and Paris: BIOS) announces an increase in the total number of voting rights and shares as a result of the issuance of new shares. The following information is published in accordance with Article 15 of the Belgian law of 2 May 2007 on the publication of major shareholdings in issuers whose shares are admitted to trading on regulated market.

Total amount of share capital on 31 March 2025	EUR 38 300 669
Total number of shares with voting rights on 31 March 2025	597 306 724
Total number of new shares issued between 31 March 2025 and 30 April 2025	55 555 555

Total amount of share capital on 30 April 2025	EUR 38 400 669
Total number of shares with voting rights on 30 April 2025	652 862 279
Total number of voting rights (denominator) on 30 April 2025	652 862 279
Total number of attributed warrants	1 161 556
Total number of convertible bonds outstanding	242
Total number of remaining convertible bonds commitments	185
Total number of shares with voting rights that can be issued following the exercise of the attributed warrants, remaining convertible bonds commitments and the conversion of the convertible bonds	2 175 250 624 (1)

(1)

• 1 161 556 shares could be issued in case all 1 161 556 attributed warrants were exercised.
• 2 174 089 068 shares could be issued in case all 242 convertible bonds outstanding as well as all 185 convertible bonds commitments of the convertible bonds programs with Global Tech Opportunities 15 were exercised and converted into shares based on the conversion price of EUR 0.001235 (95% of the Volume-Weighted-Averaged-Price of BioSenic's shares on 28 April 2025).

About BioSenic

BioSenic is a biotechnology company specialising in the clinical development of therapies for autoimmune diseases.

BioSenic is a leading biotech company specializing in the development of clinical assets issued from its Medsenic's arsenic trioxide (ATO) platform. Key target indications for the autoimmune platform include graft-versus-host-disease (GvHD), systemic lupus erythematosus (SLE), and now systemic sclerosis (SSc).

Following the merger in October 2022, BioSenic combined the strategic positionings and strengths of Medsenic and Bone Therapeutics. The merger specifically enables Medsenic/Biosenic to develop an entirely new arsenal of various anti-inflammatory and anti-autoimmune formulations using the immunomodulatory properties of ATO/oral ATO (OATO). Now that Medsenic has declared itself in cessation of payment, Biosenic will focus on new potential partnerships and the possible monetisation of its other assets (ALLOB and JTA).

BioSenic is based in the Louvain-la-Neuve Science Park in Mont-Saint-Guibert, Belgium. Further information is available at http://www.biosenic.com.

About the main Medsenic/BioSenic technology platform

PRESS RELEASE – REGULATED INFORMATION 08/05/2025

The ATO platform provides derived active products with immunomodulatory properties and fundamental effects on the activated cells of the immun e system. One direct application is its use in onco-immunology to treat GvHD (Graft-versus-Host Disease) in its chronic, established stage. cGvHD is one of the most common and clinically significant complications affecting long-term survival of allogeneic hematopoietic stem cell transplantation (allo - HSCT), a curative treatment for patients with severe blood diseases, including cancers.

Medsenic has been successful in a phase 2 trial with its intravenous formulation, Arscimed®, which has orphan drug designation status by FDA and EMA. The company was heading towards an international phase 3 confirmatory study, with its new, IP-protected, OATO formulation. Another selected target is moderate-to-severe forms of systemic lupus erythematosus (SLE), using the same oral formulation. ATO has shown good safety and significant clinical efficacy on several affected organs (skin, mucosae, and the gastrointestinal tract). Systemic sclerosis is now full part of the clinical pipeline of Medsenic/BioSenic. This serious chronic disease badly affects skin, lungs, or vascularization, and has no current effective t reatment. Preclinical studies on pertinent animal models are positive, giving good grounds to launch a phase 2 clinical protocol, using new immunomodulatory formulations of APIs recognized to be active on the immune system.

The company is currently focusing its present R&D and clinical activities on a selective, accelerated development of its autoimmune platform. However, Medsenic declared itself in cessation of payment on 18 February 2025.

For further information, please contact:

BioSenic SA

Finsys Management SRL, represented by its permanent representative Jean-Luc Vandebroek, managing director ad interim investorrelations@biosenic.com

Certain statements, beliefs and opinions in this press release are forward-looking, which reflect the company or, as appropriate, the company directors' current expectations and projections about future events. By their nature, forward-looking statements involve a number of risks, uncertainties and assumptions that could cause actual results or events to differ materially from those expressed or implied by the forward-looking statements.These risks, uncertainties and assumptions could adversely affect the outcome and financial effects ofthe plans and events described herein.A multitude of factors including, butnot limited to, changes in demand, competition and technology, can cause actual events, performance or results to differ significantly from any anticipated development.Forward looking statements containedin this press release regardingpast trends or activities should not be taken as a representation that such trends or activities will continue in the future. As a result, the company expressly disclaims any obligation or undertaking to release any update or revisions to any forward-looking statements in this press release as a result of any change in expectations or any change in events, conditions, assumptions or circumstances onwhich these forward-looking statements are based. Neitherthe company nor its advisers orrepresentatives nor anyofits subsidiary undertakings or any such person's officers or employees guarantees that the assumptions underlying such forward-looking statements are free from errors nor does either accept any responsibility for the future accuracyof the forward-looking statements containedin this press releaseorthe actual occurrenceofthe forecasteddevelopments.You should not place undue reliance on forward-looking statements, which speak only as of the date of this press release.