Geron Announces European Commission Approval of RYTELO® (imetelstat), a First-in-Class Telomerase Inhibitor, for the Treatment of Adults With Transfusion-Dependent Anemia Due to Lower-Risk MDS

• Approval across ESA ineligible and ESA relapsed/refractory non-del 5q patients with transfusion-dependent anemia due to LR-MDS, regardless of ring sideroblast (RS) status
• RYTELO is the first and only telomerase inhibitor approved in the U.S. and Europe

Geron Corporation (NASDAQ:GERN), a commercial-stage biopharmaceutical company aiming to change lives by changing the course of blood cancer, today announced that the European Commission (EC) has granted marketing authorization for RYTELO® (imetelstat) as a monotherapy for the treatment of adult patients with transfusion-dependent (TD) anemia due to very low, low or intermediate risk myelodysplastic syndromes (lower-risk MDS or LR-MDS) without an isolated deletion 5q cytogenetic (non-del 5q) abnormality and who had an unsatisfactory response to or are ineligible for erythropoietin-based therapy (ESAs). Lower-risk MDS is a progressive blood cancer with high unmet need, where many patients with anemia become dependent on red blood cell transfusions, which can be associated with clinical consequences and decreased quality of life.

"As the first and only treatment of its kind, RYTELO represents an important new option – significantly reducing the need for red blood cell transfusions for people living with LR-MDS who are battling debilitating symptoms like anemia and fatigue," said Joseph Eid, M.D., Geron's Executive Vice President, Research and Development. "This approval from the European Commission, just nine months following approval in the U.S., underscores the positive benefit for these patients demonstrated in our clinical trials and we look forward to making this innovative therapy accessible to eligible patients in Europe."

"I am thrilled that the European Commission has approved RYTELO in LR-MDS. The long-term and durable responses observed in the Phase 3 IMerge study reinforce the practice-changing potential of telomerase inhibition as a clinically meaningful and differentiated option for the treatment of lower-risk MDS," said Uwe Platzbecker, M.D., Chief Medical Officer at the University Hospital Carl Gustav Carus Dresden in Germany, who was an IMerge investigator and a co-lead author of the Phase 3 results published in The Lancet. "Physicians and patients in Europe are now one step closer to accessing a novel treatment that, in addition to having a generally manageable safety profile, has the potential to provide extended and continuous red blood cell transfusion independence."

The marketing authorization of RYTELO approved by the EC is supported by data from the IMerge Phase 3 clinical trial, which demonstrated the significant clinical benefit of RYTELO in patients with transfusion-dependent anemia due to LR-MDS, reducing the need for red blood cell transfusions in the first 24 weeks of treatment compared to placebo, as observed in the double-blind controlled study. The safety profile of RYTELO was well-characterized with generally manageable and short-lived thrombocytopenia and neutropenia, which are familiar side effects for hematologists who are experienced with managing cytopenias. The most commonly reported adverse reactions ≥ Grade 3 were neutropenia (69%), thrombocytopenia (63%), which lasted a median duration of less than two weeks, and in more than 80% of patients were resolved to Grade < 2 in under four weeks.

RYTELO is the first and only telomerase inhibitor approved by the EC, and the marketing authorization applies to all 27 European Union member states, and Iceland, Norway and Liechtenstein. Geron is preparing to commercialize RYTELO in select EU countries beginning in 2026, pending country-by-country reimbursement. Additionally, Geron is exploring opportunities to make RYTELO available to eligible patients through Expanded Access Programs (EAP), including Named Patient Programs (NPP), which are designed to support access for individual patients on a case-by-case basis.

In connection with the approval, the EMA's Committee of Orphan Medicinal Products (COMP) reviewed and issued a positive opinion to maintain RYTELO's orphan drug designation in the EU for MDS, which is expected to provide market exclusivity for ten years after approval, subject to maintaining orphan designation. Patent exclusivity in the EU for LR-MDS is anticipated into 2038, subject to approval of patent term extension by the European Patent Office.

About Lower-Risk Myelodysplastic Syndromes (LR-MDS)

Lower-risk myelodysplastic syndromes (LR-MDS) is a blood cancer that often progresses to require increasingly intensified management of key symptoms such as anemia and resulting fatigue¹. These symptomatic LR-MDS patients frequently become red blood cell transfusion dependent, which has been shown to be associated with short- and long-term clinical consequences that reduce quality of life and shorten survival^2,3. There is a high unmet need for many LR-MDS patients, particularly those with characteristics having poorer prognosis. Current treatment options for those failing ESA are limited to select sub-populations and there is an unmet need for treatments that can provide extended and continuous red blood cell transfusion independence.

About RYTELO® (imetelstat)

RYTELO is an oligonucleotide telomerase inhibitor approved in the U.S. for the treatment of adult patients with low-to-intermediate-1 risk myelodysplastic syndromes (LR-MDS) with transfusion-dependent anemia requiring four or more red blood cell units over eight weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents (ESAs). It is indicated to be administered as an intravenous infusion over two hours every four weeks.

In addition, RYTELO is approved in the European Union as a monotherapy for the treatment of adult patients with transfusion-dependent anemia due to very low, low or intermediate risk myelodysplastic syndromes without an isolated deletion 5q cytogenetic (non-del 5q) abnormality and who had an unsatisfactory response to or are ineligible for erythropoietin-based therapy.

RYTELO is a first-in-class treatment that works by inhibiting telomerase enzymatic activity. Telomeres are protective caps at the end of chromosomes that naturally shorten each time a cell divides. In LR-MDS, abnormal bone marrow cells often express the enzyme telomerase, which rebuilds those telomeres, allowing for uncontrolled cell division. Developed and exclusively owned by Geron, RYTELO is the first and only telomerase inhibitor approved by the U.S. Food and Drug Administration and the European Commission.

U.S. IMPORTANT SAFETY INFORMATION

WARNINGS AND PRECAUTIONS

Thrombocytopenia

RYTELO can cause thrombocytopenia based on laboratory values. In the clinical trial, new or worsening Grade 3 or 4 decreased platelets occurred in 65% of patients with MDS treated with RYTELO.

Monitor patients with thrombocytopenia for bleeding. Monitor complete blood cell counts prior to initiation of RYTELO, weekly for the first two cycles, prior to each cycle thereafter, and as clinically indicated. Administer platelet transfusions as appropriate. Delay the next cycle and resume at the same or reduced dose, or discontinue as recommended.

Neutropenia

RYTELO can cause neutropenia based on laboratory values. In the clinical trial, new or worsening Grade 3 or 4 decreased neutrophils occurred in 72% of patients with MDS treated with RYTELO.

Monitor patients with Grade 3 or 4 neutropenia for infections, including sepsis. Monitor complete blood cell counts prior to initiation of RYTELO, weekly for the first two cycles, prior to each cycle thereafter, and as clinically indicated. Administer growth factors and anti-infective therapies for treatment or prophylaxis as appropriate. Delay the next cycle and resume at the same or reduced dose, or discontinue as recommended.

Infusion-Related Reactions

RYTELO can cause infusion-related reactions. In the clinical trial, infusion-related reactions occurred in 8% of patients with MDS treated with RYTELO; Grade 3 or 4 infusion-related reactions occurred in 1.7%, including hypertensive crisis (0.8%). The most common infusion-related reaction was headache (4.2%). Infusion-related reactions usually occur during or shortly after the end of the infusion.

Premedicate patients at least 30 minutes prior to infusion with diphenhydramine and hydrocortisone as recommended and monitor patients for one hour following the infusion as recommended. Manage symptoms of infusion-related reactions with supportive care and infusion interruptions, decrease infusion rate, or permanently discontinue as recommended.

Embryo-Fetal Toxicity

RYTELO can cause embryo-fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use effective contraception during treatment with RYTELO and for 1 week after the last dose.

ADVERSE REACTIONS

Serious adverse reactions occurred in 32% of patients who received RYTELO. Serious adverse reactions in >2% of patients included sepsis (4.2%) and fracture (3.4%), cardiac failure (2.5%), and hemorrhage (2.5%). Fatal adverse reactions occurred in 0.8% of patients who received RYTELO, including sepsis (0.8%).

Most common adverse reactions (≥10% with a difference between arms of >5% compared to placebo), including laboratory abnormalities, were decreased platelets, decreased white blood cells, decreased neutrophils, increased AST, increased alkaline phosphatase, increased ALT, fatigue, prolonged partial thromboplastin time, arthralgia/myalgia, COVID-19 infections, and headache.

Please see RYTELO (imetelstat) full Prescribing Information, available at https://pi.geron.com/products/US/pi/rytelo_pi.pdf.

The Summary of Product Characteristics (SmPC) for RYTELO in the EU is available at https://pi.geron.com/products/rytelo/eu/rytelo_smpc_eu.pdf

About Geron

Geron is a commercial-stage biopharmaceutical company aiming to change lives by changing the course of blood cancer. Our first-in-class telomerase inhibitor RYTELO™ (imetelstat) is approved in the United States and the European Union for the treatment of certain adult patients with lower-risk myelodysplastic syndromes (LR-MDS) with transfusion-dependent anemia. We are also conducting a pivotal Phase 3 clinical trial of imetelstat in JAK-inhibitor relapsed/refractory myelofibrosis (R/R MF), as well as studies in other hematologic malignancies. Inhibiting telomerase activity, which is increased in malignant stem and progenitor cells in the bone marrow, aims to potentially reduce proliferation and induce death of malignant cells. To learn more, visit www.geron.com or follow us on LinkedIn.

Use of Forward-Looking Statements

Except for the historical information contained herein, this press release contains forward-looking statements made pursuant to the "safe harbor" provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned that such statements, include, without limitation, those regarding: (i) that lower-risk MDS is a progressive blood cancer with high unmet need, where many patients with anemia become dependent on red blood cell transfusions, which can be associated with clinical consequences and decreased quality of life; (ii) that RYTELO represents an important new option – significantly reducing the need for red blood cell transfusions for LR-MDS patients battling debilitating symptoms like anemia and fatigue, (iii) that approval of RYTELO in the European Union underscores the positive benefit demonstrated in Geron's clinical trials and that Geron looks forward to making this innovative therapy accessible to eligible patients in Europe; (iv) that the long-term and durable responses observed in patients in the Phase 3 IMerge study reinforce the practice-changing potential of telomerase inhibition as a clinically meaningful and differentiated option for the treatment of lower-risk MDS, and that physicians and patients in Europe are now one step closer to accessing a novel treatment that, in addition to having a generally manageable safety profile, has the potential to provide extended and continuous red blood cell transfusion independence; (v) that Geron is preparing to commercialize RYTELO in select EU countries in 2026, pending country-by-country reimbursement, and is exploring opportunities to make RYTELO available to eligible patients through Expanded Access Programs (EAP), including Named Patient Programs (NPP) which are designed to support access for individual patients on a case-by-case basis; (vi) that RYTELO's orphan drug designation in the EU for MDS is expected to provide market exclusivity for ten years after approval, subject to maintaining such orphan designation, and that patent exclusivity in the EU for LR-MDS is anticipated into 2038, subject to approval of patent term extension by the European Patent Office; and (vii) other statements that are not historical facts, constitute forward-looking statements. These forward-looking statements involve risks and uncertainties that can cause actual results to differ materially from those in such forward-looking statements. These risks and uncertainties, include, without limitation, risks and uncertainties related to: (a) whether Geron is successful in commercializing RYTELO (imetelstat) for the treatment of certain patients with lower-risk MDS with transfusion dependent anemia; (b) Geron's plans to commercialize RYTELO in the European Union and to offer early access programs; (c) whether Geron overcomes potential delays and other adverse impacts caused by enrollment, clinical, safety, efficacy, technical, scientific, intellectual property, manufacturing and regulatory challenges in order to have the financial resources for and meet expected timelines and planned milestones; (d) whether regulatory authorities permit the further development of imetelstat on a timely basis, or at all, without any clinical holds; (e) whether any future safety or efficacy results of imetelstat treatment cause the benefit-risk profile of imetelstat to become unacceptable; (f) whether imetelstat actually demonstrates disease-modifying activity in patients and the ability to target the malignant stem and progenitor cells of the underlying disease; (g) whether Geron meets its post-marketing requirements and commitments in the U.S. and EU for RYTELO; (h) whether there are failures or delays in manufacturing or supplying sufficient quantities of imetelstat or other clinical trial materials that impact commercialization of RYTELO or the continuation of the IMpactMF trial; (i) that the projected timing for the interim and final analyses of the IMpactMF trial may vary depending on actual enrollment and death rates in the trial; (j) whether Geron stays in compliance with and satisfies its obligations under its debt and royalty financing agreements; and (k) whether the FDA and European Commission will approve imetelstat for other indications on the timelines expected, or at all. Additional information on the above risks and uncertainties and additional risks, uncertainties and factors that could cause actual results to differ materially from those in the forward-looking statements are contained in Geron's filings and periodic reports filed with the Securities and Exchange Commission under the heading "Risk Factors" and elsewhere in such filings and reports, including Geron's annual report on Form 10-K for the year ended December 31, 2024, and subsequent filings and reports by Geron. Undue reliance should not be placed on forward-looking statements, which speak only as of the date they are made, and the facts and assumptions underlying the forward-looking statements may change. Except as required by law, Geron disclaims any obligation to update these forward-looking statements to reflect future information, events, or circumstances.

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