Market Newsdesk

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Growing Independent Research Efforts are Expanding Evidence Base Around How PEDMARK

^®

(sodium thiosulfate injection) May Benefit Broader and More Diverse Patient Populations
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Real-World Evidence Shows Administration of PEDMARK

^®

 Approximately Six Hours After Cisplatin Can Be Safe & Easily Integrated into Patient Care and Does Not Compromise Cisplatin’s Established Antitumor Activity
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RESEARCH TRIANGLE PARK, N.C., May 21, 2026 (GLOBE NEWSWIRE) — Fennec Pharmaceuticals Inc. (NASDAQ:FENC; TSX: FRX), a specialty pharmaceutical company, today announced that new research evaluating PEDMARK^® (sodium thiosulfate injection) across multiple patient populations and tumor types will be shared as part of the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting program.

These four independently led studies build upon the established safety and efficacy of PEDMARK^®– currently approved for pediatric patients one month of age and older with localized, non-metastatic solid tumors, and recognized by the National Comprehensive Cancer Network with a 2A recommendation for use in adolescent and young adult patients – and help to expand understanding of the clinical utility of PEDMARK^® in Adolescent and Young Adult (AYA) and adult populations, where significant unmet need remains.

“Cisplatin-induced ototoxicity (CIO), or permanent hearing loss related to cisplatin chemotherapy, is increasingly recognized as a major survivorship issue in oncology,” said Koral Shah, MD, study investigator, presenter at ASCO and Hematology/Oncology Chief Fellow at City of Hope. “There is a growing interest among physicians, multidisciplinary care teams, and patients to identify strategies that may reduce long-term treatment-related toxicities and to integrate these new approaches into clinical practice. Importantly, this work reflects a broader shift in oncology — one that extends beyond tumor response alone and prioritizes survivorship and long-term quality of life. Cure is not always the end of the story. As survivorship improves, ensuring patients not only live longer but also live well is critical.”

Randomized Phase 1 Trial of Cisplatin-Based Chemotherapy With or Without Sodium Thiosulfate for Men with Metastatic Germ Cell Tumor (GCT) Abstract #:

TPS5131


Dr. Shah will present the trial design for a randomized Phase 1 study of cisplatin-based chemotherapy with or without sodium thiosulfate (PEDMARK^®) for men with metastatic germ cell tumors (GCT) that was opened to accrual by City of Hope in January of 2026. Among adult GCT survivors, approximately 75 percent develop hearing loss, with severity associated with cumulative cisplatin exposure.

Effects of Delayed Sodium Thiosulfate on Cisplatin-Induced Ototoxicity in Pediatric and Adolescent Patients with Cancer: Results from the Japanese Children’s Cancer Group STS-J01 Study Abstract #:

10052


Detailed results from the investigator-initiated Phase 2/3 STS-J01 clinical trial evaluating PEDMARK^® for the reduction of CIO in pediatric and AYA patients with non-metastatic solid tumors in Japan will be presented by Eiso Hiyama, MD, professor in the Department of Pediatric Surgery at Hiroshima University Hospital in Hiroshima, Japan. The study, which enrolled 27 patients, met its primary endpoint with a significant reduction in hearing loss in 3–18-year-old patients who received PEDMARK^® when compared with historically reported rates of hearing loss in patients receiving cisplatin alone (16-24% versus 56-63%, respectively).

Real-world Feasibility and Tolerability of PEDMARK

^®

for Otoprotection in Young Adults Receiving Cisplatin for Solid Tumors Abstract #:

e24189


Veronica Alana Vestal, MD, of the Comprehensive Cancer Center of the University of Puerto Rico will share a retrospective case series including nine patients aged 18-39 years old with localized solid tumors that demonstrate that PEDMARK^® can be feasibly incorporated into AYA and Adult oncology workflows and does not interfere with cisplatin’s antitumor activity.

Audiometric Outcomes for Intravenous Sodium Thiosulfate for Cisplatin-Induced Ototoxicity Prevention in Adults with Head and Neck Cancer Abstract 3:

e18110


Real world data supporting potential use of PEDMARK^® (sodium thiosulfate injection) in adults with head and neck cancers will be published by Leslie Worona, FNP-BC, OCN, oncology nurse practitioner and James Johns, MD at Mount Sinai Hospital. Findings from the multi-institutional retrospective review of 15 adults with head and neck cancers (HNC) showed that PEDMARK^® could be safely given ≥six hours after cisplatin dosing, was easy to incorporate into the real-world care plan for adults with HNC and was associated with preservation of clinically significant hearing.

“Collectively, these studies represent an important step forward in addressing a critical unmet need and highlight the potential for PEDMARK^® to meaningfully impact patient care more broadly. At the same time, significant gaps and opportunities remain. Adolescent and young adult as well as adult patients continue to face a similar burden, yet prospective data in these populations are still emerging,” said Pierre S. Sayad, PhD, M.S., chief medical officer of Fennec Pharmaceuticals. “The research being shared at the American Society of Clinical Oncology Annual Meeting reflects Fennec’s ongoing commitment to expanding the evidence base supporting use and integration of PEDMARK^® to prevent cisplatin induced ototoxicity in additional patient populations and tumor types.”

The full abstracts are also available on the ASCO® website. 

About Cisplatin-Induced Ototoxicity

Cisplatin and other platinum-based chemotherapies are widely used to treat solid tumors and have been vital in improving survival rates. Unfortunately, these life-saving treatments often result in permanent, irreversible hearing loss, also known as ototoxicity.¹

Hearing loss from cisplatin treatment is not rare. Studies show that between 60-90% of patients treated with cisplatin may develop hearing loss, depending upon the dose and duration of chemotherapy². Many of those treated with cisplatin will require lifelong hearing aids or cochlear implants, which can be helpful for some, but do not reverse the hearing loss and can be costly over time.³ Treatment-induced hearing loss can reduce quality of survivorship as it impacts many aspects of life, such as speech and language skills, academic performance, social-emotional development, career potential and the ability to live independently.^4,5 While audiologic monitoring is recommended to help manage ototoxicity, it is currently underutilized in certain cancer patient populations.

PEDMARK

^®

 (sodium thiosulfate injection)

PEDMARK^® is the first and only U.S. Food and Drug Administration (FDA) approved therapy indicated to reduce the risk of ototoxicity associated with cisplatin treatment in pediatric patients 1 month of age and older with localized, non-metastatic, solid tumors. It is a unique formulation of sodium thiosulfate in single-dose, ready-to-use vials for intravenous use in pediatric patients. PEDMARK is also the first and only therapeutic agent with proven efficacy and safety data with an established dosing regimen, across two open-label, randomized Phase 3 clinical studies, the Children’s Oncology Group (COG) Protocol ACCL0431 and SIOPEL 6.

Additionally, PEDMARK is recommended for the adolescent and young adult (AYA) population by the National Comprehensive Cancer Network, or NCCN, with a 2A endorsement.

Approximately 500,000 patients in the U.S. are diagnosed annually with cancers that could be treated with a platinum-based chemotherapy.⁶,⁷ The incidence of ototoxicity depends upon the dose and duration of chemotherapy, and many of those treated will require lifelong hearing aids. Until the FDA approval of PEDMARK, there were no preventative agents for this hearing loss. Patients with hearing loss resulting from cancer treatment have a statistically significant worse quality of life compared with peers who have no hearing loss.⁸⁹

PEDMARK has been studied by co-operative groups in two Phase 3 clinical studies of survival and reduction of ototoxicity, COG ACCL0431 and SIOPEL 6. Both studies have been completed. The COG ACCL0431 protocol enrolled childhood cancers typically treated with intensive cisplatin therapy for localized and disseminated disease, including newly diagnosed hepatoblastoma, germ cell tumor, osteosarcoma, neuroblastoma, medulloblastoma, and other solid tumors. SIOPEL 6 enrolled only hepatoblastoma patients with localized tumors.

Indications and Usage

PEDMARK^® (sodium thiosulfate injection) is indicated to reduce the risk of ototoxicity associated with cisplatin in pediatric patients 1 month of age and older with localized, non-metastatic solid tumors.

Limitations of Use

The safety and efficacy of PEDMARK have not been established when administered following cisplatin infusions longer than 6 hours. PEDMARK may not reduce the risk of ototoxicity when administered following longer cisplatin infusions, because irreversible ototoxicity may have already occurred.

Important Safety Information

PEDMARK is contraindicated in patients with history of a severe hypersensitivity to sodium thiosulfate or any of its components.

Hypersensitivity reactions occurred in 8% to 13% of patients in clinical trials. Monitor patients for hypersensitivity reactions. Immediately discontinue PEDMARK and institute appropriate care if a hypersensitivity reaction occurs. Administer antihistamines or glucocorticoids (if appropriate) before each subsequent administration of PEDMARK. PEDMARK may contain sodium sulfite; patients with sulfite sensitivity may have hypersensitivity reactions, including anaphylactic symptoms and life-threatening or severe asthma episodes. Sulfite sensitivity is seen more frequently in people with asthma.

PEDMARK is not indicated for use in pediatric patients less than 1 month of age due to the increased risk of hypernatremia or in pediatric patients with metastatic cancers.

Hypernatremia occurred in 12% to 26% of patients in clinical trials, including a single Grade 3 case. Hypokalemia occurred in 15% to 27% of patients in clinical trials, with Grade 3 or 4 occurring in 9% to 27% of patients. Monitor serum sodium and potassium levels at baseline and as clinically indicated. Withhold PEDMARK in patients with baseline serum sodium greater than 145 mmol/L.

Monitor for signs and symptoms of hypernatremia and hypokalemia more closely if the glomerular filtration rate (GFR) falls below 60 mL/min/1.73m².

Administer antiemetics prior to each PEDMARK administration. Provide additional antiemetics and supportive care as appropriate.

The most common adverse reactions (≥25% with difference between arms of >5% compared to cisplatin alone) in SIOPEL 6 were vomiting, nausea, decreased hemoglobin, and hypernatremia. The most common adverse reaction (≥25% with difference between arms of >5% compared to cisplatin alone) in COG ACCL0431 was hypokalemia.

Please see full Prescribing Information for PEDMARK^® at: www.PEDMARK.com.

About Fennec Pharmaceuticals

Fennec Pharmaceuticals Inc. is a specialty pharmaceutical company committed to the fight against ototoxicity in cancer patients who receive cisplatin-based chemotherapy. Fennec is focused on the commercialization of PEDMARK^® to reduce the risk of platinum-induced ototoxicity in cancer patients. PEDMARK received FDA approval in September 2022 and European Commission approval in June 2023 and United Kingdom (U.K.) approval in October 2023 under the brand name PEDMARQSI^Ò.

In March 2024, Fennec entered into an exclusive licensing agreement under which Norgine Pharmaceuticals Ltd., a leading European specialist pharmaceutical company, with rights to commercialize PEDMARQSI^® in Europe, U.K., Australia and New Zealand. PEDMARQSI is now commercially available in multiple countries.

PEDMARK has received Orphan Drug Exclusivity in the U.S. and PEDMARQSI has received Pediatric Use Marketing Authorization in Europe which includes eight years plus two years of data and market protection.

For more information, please visit www.fennecpharma.com and follow on LinkedIn.

Forward Looking Statements


Except for historical information described in this press release, all other statements are forward-looking. Words such as “believe,” “anticipate,” “plan,” “expect,” “estimate,” “intend,” “may,” “will,” or the negative of those terms, and similar expressions, are intended to identify forward-looking statements. These forward-looking statements include statements about our business strategy, timeline and other goals, plans and prospects, including our commercialization plans respecting PEDMARK
^®
/
PEDMARQSI

^®

, the market opportunity and demand for and market impact of PEDMARK
^®
/
PEDMARQSI

^®
, its potential impact on patients and anticipated benefits associated with its use, future commercial and regulatory milestone and royalty payments from Norgine,and potential access to further funding after the date of this release. Forward-looking statements are subject to certain risks and uncertainties inherent in the Company’s business that could cause actual results to vary, including the risks and uncertainties that regulatory and guideline developments may change, scientific data and/or manufacturing capabilities may not be sufficient to meet regulatory standards or receipt of required regulatory clearances or approvals, clinical results may not be replicated in actual patient settings, unforeseen global instability, including political instability, or instability from an outbreak of pandemic or contagious disease, such as the novel coronavirus (COVID-19), or surrounding the duration and severity of an outbreak, protection offered by the Company’s patents and patent applications may be challenged, invalidated or circumvented by its competitors, the available market for the Company’s products will not be as large as expected, the Company’s products will not be able to penetrate one or more targeted markets, revenues will not be sufficient to fund further development and clinical studies, our ability to obtain necessary capital when needed on acceptable terms or at all, the Company may not meet its future capital requirements in different countries and municipalities, and other risks detailed from time to time in the Company’s filings with the Securities and Exchange Commission including its Annual Report on Form 10-K for the year ended December 31, 2025. Fennec disclaims any obligation to update these forward-looking statements except as required by law.

For a more detailed discussion of related risk factors, please refer to our public filings available at 

www.sec.gov

 and 

www.sedar.com

.

PEDMARK^® PEDMARQSI^® and Fennec^® are registered trademarks of Fennec Pharmaceuticals Inc.

©2026 Fennec Pharmaceuticals Inc. All rights reserved.

For further information, please contact:

Investors:

Robert Andrade
Chief Financial Officer
Fennec Pharmaceuticals Inc.
+1 919-246-5299

Corporate and Media:

Lindsay Rocco
Elixir Health Public Relations
+1 862-596-1304
[email protected]

¹ Rybak L. Mechanisms of Cisplatin Ototoxicity and Progress in Otoprotection. Current Opinion in Otolaryngology & Head and Neck Surgery. 2007, Vol. 15: 364-369.
² Langer T, am Zehnhoff-Dinnesen A, Radtke S, Meitert J, Zolk O. Trends Pharmacol Sci. 2013;34(8):458-469
³ Landier W. Ototoxicity and Cancer Therapy. Cancer. June 2016 Vol. 122, No.11: 1647-1658.
⁴ Clemens E, van den Heuvel-Eibrink MM, Mulder RL, et al. Recommendations for ototoxicity surveillance for childhood, adolescent, and young adult cancer survivors: a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group in collaboration with the PanCare Consortium. Lancet Oncol. 2019;20(1):e29-e41
⁵. Bass JK, Knight KR, Yock TI, Chang KW, Cipkala D, Grewal SS. Evaluation and management of hearing loss in survivors of childhood and adolescent cancers: a report from the children’s oncology group. Pediatr Blood Cancer. 2016;63(7):1152-1162.
⁶ Chattaraj A et al. Cisplatin-Induced Ototoxicity: A Concise Review of the Burden, Prevention, and Interception Strategies. JCO Oncol Pract. 2023;19
⁷ Freyer DR et al. Effects of sodium thiosulfate versus observation on development of cisplatin-induced hearing loss in children with cancer (ACCL0431): a multicentre, randomised, controlled, open-label, phase 3 trial. Lancet Oncol. 2017;18(1):63-74.
⁸ Rajput K, Edwards L, Brock P, Abiodun A, Simpkin P, Al-Malky G. Ototoxicity-induced hearing loss and quality of life in survivors of paediatric cancer. Int J Pediatr Otorhinolaryngol. 2020;138:110401. doi:10.1016/j.ijporl.2020.110401
⁹ Bass JK, Knight KR, Yock TI, Chang KW, Cipkala D, Grewal SS. Evaluation and management of hearing loss in survivors of childhood and adolescent cancers: a report from the children’s oncology group. Pediatr Blood Cancer. 2016;63(7):1152-1162.

• The Phase 2b LUMA study of BIIB122 in early-stage Parkinson’s disease did not meet its primary or secondary endpoints 
• Based on data from the Phase 2b LUMA study, Biogen and Denali will discontinue development of BIIB122 in idiopathic Parkinson’s disease
• Denali continues to independently conduct the Phase 2a BEACON study in carriers of a pathogenic LRRK2 variant

CAMBRIDGE, Mass. and SOUTH SAN FRANCISCO, Calif., May 21, 2026 (GLOBE NEWSWIRE) — Biogen Inc. (Nasdaq: BIIB) and Denali Therapeutics Inc. (Nasdaq: DNLI) today announced topline results from the Phase 2b LUMA study evaluating BIIB122 (DNL151), an investigational small molecule inhibitor of LRRK2 (leucine-rich repeat kinase 2), in individuals with early-stage Parkinson’s disease. Results from the study show that BIIB122 did not slow the progression of Parkinson’s disease versus placebo, as measured by the primary endpoint of Time to Confirmed Worsening in the modified Movement Disorder Society Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) Part II and III combined score. Secondary endpoints also did not show a benefit with BIIB122. Exploratory biomarker endpoints demonstrated >90% kinase inhibition of peripheral LRRK2 (phosphoserine 935) and, in a cerebrospinal fluid (CSF) sub-study, up to approximately 30% reduction observed in a biomarker of LRRK2 activity (phosphorylated Rab10). Expected levels of BIIB122 in the blood and CSF were sustained across the study. BIIB122 was generally well tolerated with an acceptable safety profile. Based on these results, Biogen and Denali will discontinue further development of BIIB122 in idiopathic Parkinson’s disease. Denali will continue to independently conduct the Phase 2a BEACON study evaluating the small molecule inhibitor in carriers of a pathogenic LRRK2 variant.

“While these are not the results we hoped for, these data provide important information to the Parkinson’s community and will be presented at an upcoming scientific conference,” said Diana Gallagher, MD, Senior Vice President and Head of Neurodegeneration Clinical Development at Biogen. “We are profoundly grateful to the patients, families, and investigators who participated in this study and contributed to our understanding of Parkinson’s disease.”

LUMA was a Phase 2b multi-center, randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of BIIB122 compared to placebo in 648 people with early-stage Parkinson’s disease between the ages of 30 and 80. Participants received BIIB122 or placebo for a minimum of 48 weeks and up to 144 weeks. The study included individuals with early-stage Parkinson’s disease with or without a pathogenic LRRK2 variant. The LUMA study was designed to evaluate the potential of LRRK2 inhibition to address the underlying biology of Parkinson’s disease.

“While we are disappointed with these results, we believe the LUMA study was a robust test of LRRK2 inhibition using BIIB122 in idiopathic Parkinson’s disease and there is more to be learned about LRRK2 as a potential therapeutic target,” said Peter Chin, M.D., Chief Medical Officer and Head of Development of Denali Therapeutics. “Independently, we continue to study this small molecule inhibitor in the Phase 2a BEACON study in individuals with Parkinson’s disease who are confirmed by genetic testing to be carriers of a pathogenic LRRK2 variant, which is associated with increased LRRK2 kinase activity. We look forward to further analysis of the LUMA data and the results from BEACON to inform next steps for development.”

The global Phase 2a BEACON study is designed to assess safety, pharmacokinetics and biomarkers of lysosomal pathway engagement, which will inform the biomarker profile in LRRK2 pathogenic variant carriers and the impact of LRRK2 inhibition. Data from the BEACON study is anticipated in the first half of 2027. The BEACON study is being operationalized by Denali and funded under a Collaboration and Development Funding Agreement between Denali and a third party.

Biogen and Denali will share detailed findings from the LUMA study at an upcoming scientific conference to contribute to the broader understanding of Parkinson’s disease and LRRK2 biology.

About Parkinson’s Disease

Parkinson’s disease is a progressive neurodegenerative disorder that affects movement and a wide range of non-motor functions. It is characterized by motor symptoms such as tremor, muscle stiffness, slowness of movement, and balance difficulty, as well as non-motor symptoms including sleep disturbances, mood changes, and cognitive impairment. One million people in the U.S. and more than 10 million people worldwide are estimated to have Parkinson’s disease. Parkinson’s disease is especially difficult to develop drugs for because of its complexity, with patients presenting differently and responding variably to treatment. The lack of reliable biomarkers, along with diverse and often unknown biological causes of the disease, also makes it challenging to track disease progression in clinical trials.

About LRRK2

Following discovery of the LRRK2 (leucine-rich repeat kinase 2) mutation as a pathogenic genetic factor for Parkinson’s disease, further research has uncovered that it has the potential to be a novel therapeutic target for Parkinson’s disease. Mutations in LRRK2 account for 4-5% of familial and 1-2% of sporadic Parkinson’s disease.^{1, 2} In addition, common variants in and around LRRK2 have been identified as risk factors for sporadic Parkinson’s disease.

While the exact pathogenic mechanisms remain unknown, LRRK2 is believed to play a role in intracellular trafficking in the endolysosomal system, and the endolysosomal system is overrepresented among rare and common risk gene variants for Parkinson’s disease.^3,4,5 Lysosomal dysfunction is a central pathogenic driver of Parkinson’s disease, characterized by failure of the cell’s waste disposal system (lysosomes) to break down proteins, which then accumulate and create aggregates that can cause neuronal degeneration.⁶  

About Biogen

Founded in 1978, Biogen is a leading biotechnology company that pioneers innovative science to deliver new medicines to transform patients’ lives and to create value for shareholders and our communities. We apply deep understanding of human biology and leverage different modalities to advance first-in-class treatments or therapies that deliver superior outcomes. Our approach is to take bold risks, balanced with return on investment to deliver long-term growth. We routinely post information that may be important to investors on our website at www.biogen.com. Follow us on social media – Facebook, Instagram, LinkedIn, X, YouTube.

About Denali Therapeutics 

Denali Therapeutics Inc. is a biotechnology company pioneering a new class of biotherapeutics designed to cross the blood-brain barrier using its proprietary TransportVehicle™ platform. With a clinically validated delivery platform and a growing portfolio of therapeutic candidates across all stages of development, Denali is advancing toward its goal of delivering effective medicines to transform life for people with neurodegenerative diseases, lysosomal storage disorders and other serious diseases. For more information, please visit www.denalitherapeutics.com.

Biogen Safe Harbor

This press release contains forward-looking statements including, among others, relating to the potential benefits and results that may be achieved through Biogen’s collaboration with Denali; our efforts to contribute to and advance the understanding of Parkinson’s disease; the clinical development program, clinical trials, data readouts and presentations related to BIIB122; the treatment of Parkinson’s disease and the relation between LRRK2 biology and Parkinson’s disease; the potential of Biogen’s commercial business and pipeline programs; and risks and uncertainties associated with drug development and commercialization. These forward-looking statements may be accompanied by words such as “aim,” “anticipate,” “believe,” “could,” “estimate,” “expect,” “forecast,” “goal,” “intend,” “may,” “plan,” “potential,” “possible,” “will,” “would” and other words and terms of similar meaning. Drug development and commercialization involve a high degree of risk, and only a small number of research and development programs result in commercialization of a product. Results in early stage clinical trials may not be indicative of full results or results from later stage or larger scale clinical trials and do not ensure regulatory approval. You should not place undue reliance on these statements or the scientific data presented. Given their forward-looking nature, these statements involve substantial risks and uncertainties that may be based on inaccurate assumptions and could cause actual results to differ materially from those reflected in such statements.

These forward-looking statements are based on management’s current beliefs and assumptions and on information currently available to management. Given their nature, we cannot assure that any outcome expressed in these forward-looking statements will be realized in whole or in part. We caution that these statements are subject to risks and uncertainties, many of which are outside of our control and could cause future events or results to differ materially from those stated or implied in this document, including, among others, uncertainty of our long-term success in developing, licensing, or acquiring other product candidates or additional indications for existing products; expectations, plans, prospects and timing of actions relating to product approvals, approvals of additional indications for our existing products, sales, pricing, growth, reimbursement and launch of our marketed and pipeline products; the potential impact of increased product competition in the biopharmaceutical and healthcare industry, as well as any other markets in which we compete, including increased competition from new originator therapies, generics, prodrugs and biosimilars of existing products and products approved under abbreviated regulatory pathways; our ability to effectively implement our corporate strategy; difficulties in obtaining and maintaining adequate coverage, pricing, and reimbursement for our products; the drivers for growing our business, including our dependence on collaborators and other third parties for the development, regulatory approval, and commercialization of products and other aspects of our business, which are outside of our full control; risks related to commercialization of biosimilars, which is subject to such risks related to our reliance on third-parties, intellectual property, competitive and market challenges and regulatory compliance; the risk that positive results in a clinical trial may not be replicated in subsequent or confirmatory trials or success in early stage clinical trials may not be predictive of results in later stage or large scale clinical trials or trials in other potential indications; risks associated with clinical trials, including our ability to adequately manage clinical activities, unexpected concerns that may arise from additional data or analysis obtained during clinical trials, regulatory authorities may require additional information or further studies, or may fail to approve or may delay approval of our drug candidates; and the occurrence of adverse safety events, restrictions on use with our products, or product liability claims; and any other risks and uncertainties that are described in other reports we have filed with the U.S. Securities and Exchange Commission, which are available on the SEC’s website at www.sec.gov.

These statements speak only as of the date of this press release and are based on information and estimates available to us at this time. Should known or unknown risks or uncertainties materialize or should underlying assumptions prove inaccurate, actual results could vary materially from past results and those anticipated, estimated or projected. Investors are cautioned not to put undue reliance on forward-looking statements. A further list and description of risks, uncertainties and other matters can be found in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025, and in our subsequent reports on Form 10-Q. Except as required by law, we do not undertake any obligation to publicly update any forward-looking statements whether as a result of any new information, future events, changed circumstances or otherwise.

Digital Media Disclosure

From time to time we have used, or expect in the future to use, our investor relations website (investors.biogen.com), the Biogen LinkedIn account (linkedin.com/company/biogen-) and the Biogen X account (https://x.com/biogen) as a means of disclosing information to the public in a broad, non-exclusionary manner, including for purposes of the SEC’s Regulation Fair Disclosure (Reg FD). Accordingly, investors should monitor our investor relations website and this social media channel in addition to our press releases, SEC filings, public conference calls and webcasts, as the information posted on them could be material to investors.

Denali Safe Harbor

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements expressed or implied in this press release include, but are not limited to, statements by Denali Therapeutics Inc. (“Denali” or the “Company”) regarding plans, timelines and expectations related to the ongoing Phase 2a BEACON study of BIIB122 in LRRK2-associated Parkinson’s disease, including the timing and availability of clinical data; the presentation of data related to the Phase 2b LUMA study; the discontinuation of development of DNL151 in idiopathic Parkinson’s disease; the continued evaluation of DNL151 based on its safety profile; the potential of LRRK2 as a therapeutic target; Denali’s plans to share detailed findings from the LUMA study at an upcoming scientific conference; and statements by Denali’s Chief Medical Officer and Head of Development. Actual results may differ materially from those expressed or implied by these forward-looking statements due to a variety of risks and uncertainties. These include, but are not limited to, uncertainties related to the FDA’s policies; risks arising from adverse economic conditions and their impact on Denali’s business and operations; the possibility of events or changes that could lead to the termination of Denali’s collaboration agreements; challenges associated with Denali’s transition to a commercial company; the ability of Denali and its collaborators to complete the development and, if approved, the commercialization of product candidates; difficulties in patient enrollment for ongoing and future clinical trials; reliance on third-party manufacturers and suppliers for clinical trial materials; potential delays or failures in meeting expected clinical trial timelines; discrepancies between preclinical, early-stage or preliminary clinical results and outcomes from later-stage trials; the risk that interim or topline clinical results may not be predictive of final study results or longer-term outcomes; the occurrence of significant adverse events or other undesirable side effects; the uncertainty surrounding regulatory approvals required for commercialization in the U.S., Europe or other international jurisdictions; Denali’s ability to advance a pipeline of product candidates or develop commercially successful products; developments relating to Denali’s competitors and competing product candidates; Denali’s ability to obtain, maintain or protect intellectual property rights related to its product candidates; the implementation and success of Denali’s strategic plans for its business, product candidates and blood-brain barrier platform technology; Denali’s ability to obtain additional capital to finance its operations, as needed; Denali’s ability to accurately forecast future financial results in the current environment; and other risks and uncertainties, including those described in Denali’s most recent Annual and Quarterly Reports on Forms 10-K and 10-Q filed with the Securities and Exchange Commission (SEC) on February 26, 2026 and May 7, 2026, respectively, and Denali’s future reports to be filed with the SEC. Except for AVLAYAH™ (tividenofusp alfa-eknm), Denali’s product candidates are investigational, and their safety and efficacy profiles have not yet been established. Denali does not undertake any obligation to update or revise any forward-looking statements, to conform these statements to actual results or to make changes in Denali’s expectations, except as required by law.

References:

1. Healy DG, Falchi M, O’Sullivan SS, et al. Phenotype, genotype, and worldwide genetic penetrance of LRRK2-associated Parkinson’s disease: a case-control study. Lancet Neurol. 2008;7(7):583-90.
2. Hernandez DG, Reed X, Singleton AB. Genetics in Parkinson disease: Mendelian versus non-Mendelian inheritance. J Neurochem. 2016;139 Suppl 1:59-74. Epub 2016/04/18.
3. Bonet-Ponce, Luis et al. “LRRK2 mediates tubulation and vesicle sorting from lysosomes.” Science advances vol. 6,46 eabb2454. 11 Nov. 2020, doi:10.1126/sciadv.abb2454
4. Robak, Laurie A et al. “Excessive burden of lysosomal storage disorder gene variants in Parkinson’s disease.” Brain : a journal of neurology vol. 140,12 (2017): 3191-3203. doi:10.1093/brain/awx285
5. Smolders, Stefanie, and Christine Van Broeckhoven. “Genetic perspective on the synergistic connection between vesicular transport, lysosomal and mitochondrial pathways associated with Parkinson’s disease pathogenesis.” Acta neuropathologica communications vol. 8,1 63. 6 May. 2020, doi:10.1186/s40478-020-00935-4
6. Moors, Tim et al. “Lysosomal Dysfunction and α-Synuclein Aggregation in Parkinson’s Disease: Diagnostic Links.” Movement disorders : official journal of the Movement Disorder Society vol. 31,6 (2016): 791-801. doi:10.1002/mds.26562