The FDA has approved a Geron Corporation treatment for anemia stemming from a particular type of blood cancer, giving the company its first commercialized product and the opportunity to compete against a blockbuster Bristol Myers Squibb drug.
The Geron drug, imetelstat, is approved to treat adults with low- to intermediate-risk myelodysplastic syndromes. The regulatory decision comes three months after an FDA advisory committee voted that the benefits of the drug outweigh its risks. Foster City, California-based Geron will commercialize its new drug under the brand name Rytelo.
Myelodysplastic syndromes (MDS) are a group of blood cancers in which immature blood cells in the bone marrow do not mature to become healthy red blood cells. According to the American Cancer Society, the number of people in the U.S. diagnosed annually with this type of cancer is unknown, but estimates top 10,000. The risk of MDS increases with age, and this cancer is most commonly diagnosed in people who are in their 70s.
Standard treatment for lower-risk MDS is erythropoiesis-stimulating agents, which are drugs that stimulate the production of red blood cells. But if these drugs don’t work or stop working, MDS patients require frequent blood transfusions to boost their red blood cell levels. Approval of Rytelo covers the treatment of MDS patients whose transfusion-dependent anemia requires four or more red blood cell units over eight weeks. These patients must also be unresponsive to or ineligible for treatment with erythropoiesis-stimulating agents.
Geron’s approach to MDS is based on Nobel prize-winning research on telomeres, repetitive DNA sequences located at the ends of chromosomes. Telomeres form a protective cap that stabilize and maintain the chromosome. An enzyme called telomerase maintains telomeres. In cancer, upregulated activity of this enzyme enables the uncontrolled proliferation of malignant cells that drive the disease. Rytelo is an oligonucleotide designed to bind to a particular region of the RNA component of human telomerase. In its annual report, Geron says this approach of blocking the telomere-protecting enzyme enables the recovery of bone marrow and normal red blood cell production, which suggests the drug offers the potential for disease modifying-activity.
“We believe this potential for disease modification could differentiate imetelstat from currently approved treatments in myeloid hematologic malignancies,” Geron said in the report.
Rytelo was evaluated in a placebo-controlled Phase 3 test whose main goal was measuring the percentage of patients without any red blood cell transfusions during any consecutive eight-week period. Results showed 39.8% of Rytelo-treated patients achieved this mark compared to 15% in the placebo group. The trial also showed the drug had durable effects. At 24 weeks, 28% of patients in the study drug group were transfusion independent compared to 3.3% in the placebo group. The most common adverse reactions included lower levels of platelets, neutrophils, and white blood cells. The drug’s label states clinicians should obtain complete blood counts and monitor for signs of these complications. The Phase 3 results were published late last year in the journal The Lancet.
The Geron drug’s mechanism of action is different than that of Reblozyl, a Bristol Myers Squibb MDS drug. The BMS product is a fusion protein engineered to suppress a signaling pathway that impedes red blood cell production. Reblozyl accounted for $1 billion in revenue in 2023, a 41% increase over sales in the prior year, according to the pharmaceutical giant’s financial reports.
Rytelo is administered as a two-hour intravenous infusion every two weeks. The recommended dose is 7.1 mg per kilogram of patient weight. A single-dose 47 mg vial of Rytelo carries a wholesale price of $2,741. The wholesale price of a single-dose 188 mg vial of the drug carries a $9,884 wholesale price.
The affirmative regulatory decision for Rytelo in MDS makes it the first FDA-approved telomerase inhibitor. The Geron drug is still under review by the European Medicines Agency. In addition to MDS, Geron’s clinical research with the drug spans other types of blood cancer.
Photo: Getty Images, Sarah Silbiger
