Sensorion (FR0012596468 – ALSEN) a pioneering clinical-stage biotechnology company which specializes in the development of novel therapies to restore, treat and prevent hearing loss disorders, today announces it has met the primary endpoint for its Proof of Concept (POC) Phase 2a clinical trial of SENS-401 for residual hearing preservation following cochlear implantation.

The Phase 2a trial is a multicentric, randomized, controlled, open-label trial aimed at evaluating the presence of SENS-401 in the cochlea (perilymph) at therapeutic concentrations after 7 days of twice-daily oral administration prior to cochlear implantation due to moderately severe to profound hearing impairment (“primary endpoint”). Patients started treatment with SENS-401 seven days before implantation and continued to receive SENS-401 for a further forty-two days. The study also assesses a number of secondary endpoints, including the change of hearing threshold from baseline to the end of the study in the implanted ear at several frequencies. The study has been developed in collaboration with Cochlear Limited (Cochlear), the global leader in implantable hearing devices.

On February 1, 2024, Sensorion announced the completion of patient inclusion in the Phase 2a clinical trial of SENS- 401 for the residual hearing preservation after cochlear implantation. A total of 28 patients have been randomized and 25 patients have been implanted with a cochlear implant; 16 in the treated arm and 9 in the control non- treated arm.

The presence of SENS-401 in the perilymph at a level compatible with potential therapeutic e cacy has been

con rmed in 100% of the patients sampled, 7 days after the start of the treatment, con rming that the primary endpoint was met. These results con rm that SENS-401 administered orally crosses the labyrinth barrier. The study is now completed, the follow-up of the last patients is still ongoing and the secondary endpoints including results on the preservation of the residual hearing will be available and analyzed later this year. The Company plans to publish the complete readout of the study in Q3 2024.

Nawal Ouzren, Chief Executive O cer of Sensorion, said: "We are delighted to announce we met the primary endpoint for the Phase 2a clinical trial of SENS-401 for residual hearing preservation. We are looking forward to the publication of the full dataset of this study, including secondary endpoints, that is expected later this year. We would like to thank the patients and physicians involved in the study, as well as our industrial partner Cochlear Limited, with whom we designed this study, for their con dence and commitment. Those positive results are a key milestone in our development plan for SENS-401, a promising drug-candidate, for which we have the ambition to demonstrate the e cacy in hearing loss protection in several strategic indications."

In 2017, Sensorion and Cochlear signed a research collaboration agreement on SENS-401, under which Cochlear has an option, exercisable once the data of the complete readout of this study is available, to negotiate with Sensorion the rights for a global license to distribute SENS-401 for applications and uses related to certain implantable devices.

About SENS-401

SENS-401 (Arazasetron), Sensorion’s clinical stage lead drug candidate, is an orally available small molecule that aims to protect and preserve inner ear tissue from damage responsible of progressive or sequelae hearing impairment. Sensorion currently develops SENS-401 in a Phase 2a for the prevention of residual hearing loss in patients scheduled for cochlear implantation and in a Phase 2 clinical trial for the prevention of Cisplatin-Induced Ototoxicity. SENS-401 has been granted Orphan Drug Designation by the EMA in Europe for the treatment of sudden sensorineural hearing loss, and by the FDA in the U.S. for the prevention of platinum-induced ototoxicity in pediatric population.

About Sensorion

Sensorion is a pioneering clinical-stage biotech company, which specializes in the development of novel therapies to restore, treat and prevent hearing loss disorders, a signi cant global unmet medical need. Sensorion has built a unique R&D technology platform to expand its understanding of the pathophysiology and etiology of inner ear related diseases, enabling it to select the best targets and mechanisms of action for drug candidates. It has two gene therapy programs aimed at correcting hereditary monogenic forms of deafness, developed in the framework of its broad strategic collaboration focused on the genetics of hearing with the Institut Pasteur. SENS-501 (OTOF-GT)

targets deafness caused by mutations of the gene encoding for otoferlin and is currently developed in a Phase 1/2 clinical study and GJB2-GT targets hearing loss related to mutations in GJB2 gene to potentially address important hearing loss segments in adults and children. The Company is also working on the identi cation of biomarkers to improve diagnosis of these underserved illnesses. Sensorion’s portfolio also comprises clinical-stage small molecule programs for the treatment and prevention of hearing loss disorders. Sensorion’s clinical-stage portfolio includes one Phase 2 product: SENS-401 (Arazasetron) progressing in a Phase 2 proof of concept clinical study of SENS-401 in Cisplatin-Induced Ototoxicity (CIO) and, with partner Cochlear Limited, in a study of SENS-401 in patients scheduled for cochlear implantation. A Phase 2 study of SENS-401 was also completed in Sudden Sensorineural Hearing Loss (SSNHL) in January 2022.

www.sensorion.com Label: SENSORION

ISIN: FR0012596468

Mnemonic: ALSEN Disclaimer

This press release contains certain forward-looking statements concerning Sensorion and its business. Such forward looking statements are based on assumptions that Sensorion considers to be reasonable. However, there can be no assurance that such forward-looking statements will be veri ed, which statements are subject to numerous risks, including the risks set forth in the 2022 full year nancial report published on March 30, 2023, and available on our website and to the development of economic conditions, nancial markets and the markets in which Sensorion operates. The forward-looking statements contained in this press release are also subject to risks not yet known to Sensorion or not currently considered material by Sensorion. The occurrence of all or part of such risks could cause actual results, nancial conditions, performance or achievements of Sensorion to be materially

di erent from such forward-looking statements. This press release and the information that it contains do not constitute an o er to sell or subscribe for, or a solicitation of an o er to purchase or subscribe for, Sensorion shares in any country. The communication of this press release in certain countries may constitute a violation of local laws and regulations. Any recipient of this press release must inform oneself of any such local restrictions and comply therewith.

Investor Relations

Noemie Djokovic, Investor Relations and Communications Associate

ir.contact@sensorion-pharma.com International Media Relations

Ulysse Communication

Pierre-Louis Germain / 00 33 (0)6 64 79 97 51 plgermain@ulysse-communication.com Nicolas Entz / 00 33 (0)6 33 67 31 54 nentz@ulysse-communication.com

Bruno Arabian / 00 (0)6 87 88 47 26

barabian@ulysse-communication.com

Source: Sensorion