BioSenic SA

Major Shareholding Notification • Nov 4, 2022

PRESS RELEASE - REGULATED INFORMATION 04 November 2022

Transparency notification received from S.R.I.W. SA and Sofipôle SA

Article 14 of the Law of 2 May 2007 on disclosure of major holdings

Mont-Saint-Guibert, Belgium, 04 November 2022, 7am CEST - BIOSENIC (Euronext Brussels and Paris: BIOS), the innovative company addressing unmet medical needs in in the areas of innate immunity, inflammation and organ/function repair, today announces that it has received a transparency notification from S.R.I.W. SA (Société Régionale d'Investissement de Wallonie) dated 27 October 2022. The transparency notification indicates that the combined shareholdings held by SRIW and its subsidiary, Sofipôle SA (Société Wallonne pour le Financement des Infrastructures des Pôles de Compétitivité), have passively crossed below the threshold of 5% as a result of the issuance of new shares of BioSenic to Medsenic shareholders on 24 October 2022.

The notification dated 27 October 2022 contains the following information:

• Reason for the notification:
• Downward crossing of the lowest threshold
• Passive crossing of a threshold
  • Notification by: A parent undertaking or a controlling person
  • Persons subject to the notification requirement: S.R.I.W. SA & Sofipôle SA
  • Transaction date: 24 October 2022
  • Threshold that is crossed: 5%
  • Denominator: 115,132,015

Voting rights	Previous notification	After the transaction
Holders of voting rights	# of voting rights	# of voting rights	% of voting rights
S.R.I.W SA	344,530	344,530	0.30%
SOFIPOLE SA	862,027	862,027	0.75%
Total voting rights	1,206,557	1,206,557	1.05%

• Full chain of controlled undertakings through which the holding is effectively held: The Walloon Region holds 99.43% of S.R.I.W. SA which controls 60% of the shares of Sofipôle SA. .

.The notification can be consulted on the website of BioSenic, under the heading "Shareholder Information".

About BioSenic

BioSenic is a leading biotech company specializing in the development of clinical assets issued from: (i), the allogeneic cell therapy platform ALLOB and (ii) the Arsenic TriOxide (ATO) platform. Key target indications for the platforms include Graft versus Host Disease (GvHD), Systemic lupus erythematosus (SLE), Systemic Sclerosis (SSc) and high-risk tibial fractures.

Following the merger in October 2022, BioSenic combines the strategic positionings and strengths of Medsenic and Bone Therapeutics. The merger also enables Biosenic to add to its innovative cell therapy platform and strong IP for tissue repair protection with an entirely new arsenal of various anti-inflammatory and anti-autoimmune formulations using the immunomodulatory properties of ATO/OATO.

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 BioSenic technology platforms

BioSenic's technology is based on:

• 1. The allogeneic cell and gene therapy platform, developed by Bone Therapeutics with differentiated bone marrow sourced Mesenchymal Stromal Cells (MSCs) that can be stored at the point of use in hospitals. Its current investigational medicinal product, ALLOB, represents a unique, proprietary approach to organ repair and specifically to bone regeneration, by turning undifferentiated stromal cells from healthy donors into bone-forming cells on the site of injury. These cells are produced via a proprietary BioSenic scalable manufacturing process. Following the CTA approval by regulatory authorities in Europe, the Company has initiated patient recruitment for the Phase IIb clinical trial with ALLOB in patients with difficult tibial fractures, using its optimized production process. ALLOB continues to be evaluated for other orthopedic indications including spinal fusion, osteotomy, maxillofacial and dental, and should be of value in new indications when cells will be further adapted or transformed with additional targeting properties.
• 1. The Arsenic TriOxide (ATO) platform developed by Medsenic. The immunomodulatory properties of ATO have demonstrated a double basic effect on cells of the immune system. The first effect is the increase of the cell oxidative stress in activated B, T or other cells of the innate/adaptative immune system to the point they will enter a cell death program (apoptosis) and be eliminated. The second effect is potent immunomodulatory properties on several pro-inflammatory cytokines involved in inflammatory or autoimmune cell pathways. One direct application is its use in onco-immunology to treat GvHD (Graft-versus-Host Disease) in its chronic, established stage. GvHD is one of the most common and clinically significant complications affecting long-term survival of allogeneic hematopoietic stem cell transplantation (allo-SCT). GvHD is primarily mediated by the transplanted immune system that can lead to severe multiorgan damage. Medsenic had been successful

in a Phase II trial with its intravenous formulation, allowing arsenic trioxide to be granted an orphan drug designation status by FDA and EMA and is heading towards an international Phase III confirmatory study, with a new, IP protected, oral (OATO) formulation. Moderate to Severe forms of Systemic Lupus erythematosus (SLE)° is another selected target, using the same oral formulation. ATO has shown good safety and significant clinical efficacy on several affected organs (skin, mucosae and the gastro-intestinal tract) in a phase IIa study. Systemic Sclerosis is, in addition, part of the clinical pipeline of BioSenic. Preclinical studies on pertinent animal models are positive. This gives good grounds to launch a Phase II clinical protocol for this serious disease that badly affects skin, lungs or vascularization, and with no actual current effective treatment.

For further information, please contact:

BioSenic SA François Rieger, PhD, Chief Executive Officer Tel: +33 (0)671 73 31 59 investorrelations@biosenic.com

For Belgian Media and Investor Enquiries: Bepublic Catherine Haquenne Tel: +32 (0)497 75 63 56 catherine@bepublic.be

International Media Enquiries: Image Box Communications Neil Hunter / Michelle Boxall Tel: +44 (0)20 8943 4685 neil.hunter@ibcomms.agency / michelle@ibcomms.agency

For French Media and Investor Enquiries: NewCap Investor Relations & Financial Communications Pierre Laurent, Louis-Victor Delouvrier and Arthur Rouillé Tel: +33 (0)1 44 71 94 94 bone@newcap.eu

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 of the plans and events described herein. A multitude of factors including, but not 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 contained in this press release regarding past 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 on which these forward-looking statements are based. Neither the Company nor its advisers or representatives nor any of its 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 accuracy of the forward-looking statements contained in this press release or the actual occurrence of the forecasted developments. You should not place undue reliance on forward-looking statements, which speak only as of the date of this press release.

BioSenic S.A. • Rue Granbonpré 11 - Bâtiment H (bte 24) • 1435 Mont-St-Guibert • Belgium (Europe) • Phone: +32 (0)493 09 73 66 • www.biosenic.com