Is Rytelo approved for patients with transfusion-dependent anemia in Myelodysplastic Syndromes?

Rytelo (imetelstat) is a telomerase inhibitor approved by the FDA in June 2024 for a specific group of patients with myelodysplastic syndromes (MDS). It is for adults with low- to intermediate-1 risk MDS who have transfusion-dependent anemia, meaning they need regular red blood cell transfusions. Specifically, the approval covers patients who require 4 or more units of red blood cells over 8 weeks and who have not responded to, lost response to, or are not eligible for erythropoiesis-stimulating agents (ESAs), which are drugs that stimulate red blood cell production ⁴⁶⁸. So yes, Rytelo is approved for transfusion-dependent anemia in MDS, but only for those meeting these exact criteria.

What the research says

The FDA approval of Rytelo was based on a randomized, double-blind, placebo-controlled trial called Study MDS3001 ⁸. In the primary analysis, 39.8% of patients treated with imetelstat achieved red blood cell transfusion independence for at least 8 weeks, compared to 15% in the placebo group ⁸. For at least 24 weeks of transfusion independence, the rates were 28% for imetelstat versus 3.3% for placebo ⁸. These results were statistically significant, meaning the drug clearly helped more patients become transfusion-free ⁸. However, the trial did not show a major difference between groups in other measures like complete remission or overall survival ⁸. Common side effects include low platelets (thrombocytopenia), low white blood cells (leukopenia, neutropenia), elevated liver enzymes, fatigue, and headache ⁸. The recommended dose is 7.1 mg/kg given as a 2-hour intravenous infusion every 4 weeks ⁷. Rytelo works by inhibiting telomerase, an enzyme that helps cancer cells keep dividing ⁷. It is important to note that Rytelo is not the only option for transfusion-dependent MDS. For example, lenalidomide (Revlimid) is approved for transfusion-dependent anemia in MDS patients with a specific chromosome abnormality called deletion 5q ¹. Other treatments, such as donor-derived CAR T-cell therapy, are still experimental for MDS ².

What to ask your doctor

• Do I meet the criteria for Rytelo (low- to intermediate-1 risk MDS, transfusion-dependent anemia requiring 4 or more RBC units over 8 weeks, and no response or ineligibility for ESAs)?
• What are the potential side effects of Rytelo, especially low blood counts and liver enzyme changes, and how will they be monitored?
• How does Rytelo compare to other treatments for my specific MDS subtype, such as lenalidomide if I have a deletion 5q abnormality?
• What is the dosing schedule for Rytelo (intravenous infusion every 4 weeks), and how long would treatment typically continue?
• Are there any clinical trials or newer therapies, like CAR T-cell therapy, that might be options for me if Rytelo is not suitable?