Imetelstat
Rytelo · ATC code L01XX80
Also known as: İmetelstat
- Key facts
- Active substance
- Imetelstat
- ATC code
- L01XX80
- Authorisation
- centrally authorised across the EU (EMA)
- Dosage forms
- Rytelo 47 mg powder for concentrate for solution for infusion / Rytelo 188 mg powder for concentrate for solution for infusion
- Marketing authorisation holder
- Geron Netherlands B.V.
- Information as of
- 2026-10-28
Key facts
Imetelstat is a telomerase inhibitor used to treat transfusion-dependent anaemia in lower-risk myelodysplastic syndromes in adults (Rytelo, intravenous infusion).
What it is used for
- Monotherapy in adults with transfusion-dependent anaemia due to very low, low or intermediate risk myelodysplastic syndromes (MDS) without an isolated deletion 5q abnormality, with unsatisfactory response to or ineligibility for erythropoietin-based therapy.
Dosing
- Rytelo: 7.1 mg/kg body weight as an intravenous infusion once every 4 weeks.
- Discontinue if there is no reduction in transfusion burden after 24 weeks (6 doses) or if unacceptable toxicity occurs.
- Premedicate at least 30 minutes before every dose with diphenhydramine (25 to 50 mg) and hydrocortisone (100 to 200 mg), or equivalent.
- For Grade 3 or 4 adverse reactions reduce to 5.6 mg/kg, then 4.4 mg/kg; permanently discontinue if 4.4 mg/kg is not tolerated. Delay dosing if neutrophils are below 1.0 × 10⁹/L or platelets below 50 × 10⁹/L.
- Blood counts and liver tests before each dose, plus weekly blood counts after the first two doses; pregnancy test before the first dose.
- No dose adjustment in mild to moderate renal impairment.
Contraindications
- Hypersensitivity to the active substance or any excipient.
Important warnings
- Thrombocytopenia (including Grade 3 or 4): monitor for bleeding and assess need for platelet transfusions.
- Neutropenia (including Grade 3 or 4); febrile neutropenia may occur: monitor for infections including sepsis.
- Infusion-related reactions (mainly headache and back pain; also hypotension or hypertensive crisis); monitor for at least one hour after the infusion.
- May cause embryo-foetal harm.
Side effects
- Most common: thrombocytopenia (94%), leukopenia (93%), neutropenia (92%), AST increased (48%), ALT increased (42%), alkaline phosphatase increased (41%), asthenia (26%) and headache (16%).
- Most common severe (Grade ≥ 3): neutropenia (69%) and thrombocytopenia (63%).
- Serious, including: sepsis (1.7%), urinary tract infection (1.7%), atrial fibrillation (1.1%), oesophageal varices haemorrhage (1.1%), syncope (1.1%).
Interactions
- No human interaction studies; in vitro imetelstat inhibits BCRP, OAT1, OATP1B1 and OATP1B3, but a relevant effect on the following days of the dose interval is unlikely.
Pregnancy and breastfeeding
- Not recommended during pregnancy; women of childbearing potential should use effective contraception during treatment and for at least 1 week after the last dose.
- Do not breastfeed during treatment and for 1 week after the last dose.
Summary of the official product information, written with AI on 2026-10-29. Every number was checked automatically against the original text. Not reviewed by a physician – the full official text is authoritative.
Common questions – ask Medelix
For patients
Package leaflet, verbatim
This product has no separate US patient information.
Authorisation and brand names by country
Medicines with exactly this active-substance composition, as listed in the national registers – alphabetical and without ranking. Whether a product is currently available is not shown here.
EU – centrally authorised (all member states)
- RyteloGeron Netherlands B.V. · EMEA/H/C/006105
Source: European Medicines Agency (EMA), product information
Brand names in 3 more European countries
- Iceland
- Rytelo
- Liechtenstein
- Rytelo
- Norway
- Rytelo
EMA – Article 57 product data (EU/EEA), 2026-10-29
Medelix receives no money from pharmaceutical companies. Brand names are listed alphabetically and without ranking.
Other substances in the same group
Another question about this substance?
Medelix answers clinical questions from guidelines, studies and product information – every claim with its source.
Sources
- European Medicines Agency. Rytelo – EPAR, Product Information. 2026-10-28. https://www.ema.europa.eu/en/documents/product-information/rytelo-epar-product-information_en.pdf
Editorial: Medelix editorial team · last updated 2026-10-28 · How these pages are made · Report an error
Source: European Medicines Agency (EMA), product information. Not advertising, not a treatment recommendation. For questions about your own treatment, ask your doctor or pharmacist.