FDA Approves Geron’s First-in-Class Telomerase Inhibitor for Blood Disorder

Pictured: FDA sign at its office in Washington, DC

Pictured: FDA sign at its office in Washington, DC

JHVEPhoto/Getty Images

Approved for patients with low- to intermediate-risk myelodysplastic syndromes, Geron’s Rytelo is the first telomerase inhibitor to hit the market and the company’s first approved drug after 34 years in business.

Pictured: FDA sign at its office in Washington, DC/iStock, JHVEPhoto

Geron Corporation announced Friday the FDA has approved Rytelo (imetelstat) for patients with lower- to intermediate-risk myelodysplastic syndromes, a group of blood cancers caused by blood cells that are poorly formed or don’t function properly. Rytelo’s approval sent Geron’s stock surging more than 30% in Friday morning trading.

Rytelo is approved for myelodysplastic syndromes (MDS) patients with transfusion-dependent anemia who do not respond or are ineligible for the standard-of-care treatment, erythropoiesis-stimulating agents (ESA). In addition to being first-in-its class, the treatment is also Geron’s first approved drug after 34 years in business.

“For patients with lower-risk MDS and anemia who are transfusion dependent, we have very few options today and often cycle through available therapies, making the approval of Rytelo potentially practice changing for us,” Rami Komrokji, vice chair of the Malignant Hematology Department at Moffitt Cancer Center and an investigator in the pivotal IMerge trial, said in a statement.

MDS is a group of blood cancers in which blood cells in the bone marrow do not mature or become healthy blood cells. In lower-risk MDS, it often progresses to require intense management of its key symptoms like anemia and can eventually cause organ dysfunction and heart complications.

In the Phase III IMerge trial, patients on Rytelo had significantly higher rates of red blood cell transfusion independence (RBC-TI) over placebo for at least 24 weeks—28% in the treatment arm versus 3% on placebo. In these responders, RBC-TI was sustained for a median of 1.5 years.

Administered every four weeks intravenously, Geron described the most common side effects of the drug as “manageable and short-lived” with Grade 3/4 adverse reactions of neutropenia (72%) and thrombocytopenia (65%) lasting a median of less than two weeks.

In August 2023, Bristol Myers Squibb’s Reblozyl snagged a label expansion to position it as a first line treatment for anemia in patients with low-risk MDS with no prior ESA treatment. BMS’ molecule is an erythroid maturation agent that drives the production of red blood cells, minimizing the need for transfusion. When pitted against ESA treatments in a Phase III trial, 58.5% of patients on Reblozyl achieved RBC-TI that lasted at least 12 weeks, versus 31.2% for ESA-treated patients.

GlobalData analysts project Reblozyl sales to reach $3.2 billion by 2029, while BMS has set its sights on $4 billion-plus aspirations for the drug.

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.

Kate Goodwin is a freelance life science writer based in Des Moines, Iowa. She can be reached at kate.goodwin@biospace.com and on LinkedIn.
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