Is Rytelo (Imetelstat) on the market?

Rytelo (Imetelstat) is a novel, first-in-class investigational telomerase inhibitor exclusively owned by Geron and developed by Geron for hematological malignancies. It has been approved in the United States in June 2024 by the U.S. Food and Drug Administration (FDA) approved Rytelo, an oligonucleotide telomerase inhibitor, for medical use to treat adult patients with low-to-moderate risk myelodysplastic syndrome (MDS) with transfusion-dependent anemia.

Data fromimetelstat's nonclinical studies and clinical trials provide strong evidence that imetelstat targets telomerase to inhibit the uncontrolled proliferation of malignant stem and progenitor cells in myeloid hematological malignancies, leading to malignant cell apoptosis. Imetelstat has received Fast Track designation from the FDA for the treatment of adult patients with transfusion-dependent anemia due to low- or intermediate-risk MDS unrelated to DEL (5q) who are refractory or resistant to erythropoiesis-stimulating agents, and adult patients with intermediate-risk or high-risk MDS whose disease has relapsed or been refractory after treatment with a Janus kinase (JAK) inhibitor.

Rytelo is the first telomerase inhibitor to enter clinical trials. Chemically, Rytelo is a synthetic conjugate consisting of three parts: GRN163, a thiophosphoramide oligonucleotide, and a palmitoyl lipid group. GRN163 is a pharmacological ingredient with telomerase inhibitory effect, and its efficacy has been studied experimentally. The most common adverse reactions include thrombocytopenia, leukopenia, neutropenia, increased aspartate aminotransferase, increased alkaline phosphatase, increased alanine aminotransferase, fatigue, prolonged partial thromboplastin time, arthralgia/myalgia, COVID-19 infection, and headache.