Version July 2025
Dosage guidance:
Safety: Premedicate as recommended at least 30 minutes prior to imetelstat infusion with diphenhydramine 25 to 50 mg IV or orally (or equivalent) and hydrocortisone 100 to 200 mg IV or orally (or equivalent) to prevent or reduce potential infusion-related reactions.
Dosage form information: Imetelstat 47 mg is equivalent to imetelstat sodium 50 mg.
Myelodysplastic syndromes, low- to intermediate-1 risk: IV: 7.1 mg/kg once every 4 weeks; discontinue if patient does not experience a decrease in RBC transfusion burden after 24 weeks (after 6 doses) or for unacceptable toxicity.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
CrCl ≥30 mL/minute: There are no dosage adjustments provided in the manufacturer's labeling; however, no clinically significant difference in imetelstat pharmacokinetics was observed based on CrCl 30 to <90 mL/minute.
CrCl 15 to <30 mL/minute: There are no dosage adjustments provided in the manufacturer's labeling (effects on imetelstat pharmacokinetics have not been established).
End-stage kidney disease (CrCl <15 mL/minute): There are no dosage adjustments provided in the manufacturer's labeling (effects on imetelstat pharmacokinetics have not been established).
Hepatic impairment prior to treatment initiation:
Mild (total bilirubin ≤ ULN and AST > ULN or total bilirubin >1 to 1.5 times ULN and any AST) or moderate (total bilirubin >1.5 to 3 times ULN and any AST) impairment: There are no dosage adjustments provided in the manufacturer's labeling; however, no clinically significant difference in imetelstat pharmacokinetics was observed based on mild or moderate hepatic impairment.
Severe impairment (total bilirubin >3 times ULN with any AST): There are no dosage adjustments provided in the manufacturer's labeling (effects on imetelstat pharmacokinetics have not been established).
Hepatotoxicity during treatment:
|
Adverse reaction |
Severity |
Occurrence |
Imetelstat dosage modification |
|---|---|---|---|
|
Elevated LFTs |
Grade 3 or 4 |
First and second |
Delay imetelstat infusion until recovery of adverse reaction to grade 1 or baseline; then restart at one dose level lower. |
|
Third |
Permanently discontinue imetelstat. |
American S ociety of Clinical Oncology guidelines for appropriate systemic therapy dosing in adults with cancer with a BMI ≥30 kg/m2: The dosing in the FDA-approved prescribing information should be followed in all patients, regardless of obesity status. If a patient with a BMI ≥30 kg/m2 experiences high-grade toxicity from systemic anticancer therapy, the same dosage modification recommendations should be followed for all patients, regardless of obesity status. If dose reduction for toxicity is recommended in the prescribing information, the dose should be increased back to the initial or previously tolerated dose ONLY if dose escalations are allowed in the prescribing information, if contributing underlying factors (eg, hepatic or kidney impairment) are sufficiently resolved, AND if performance status has markedly improved or is considered adequate (Ref).
|
Dose level |
Imetelstat dose |
|---|---|
|
a Permanently discontinue imetelstat if unable to tolerate 4.4 mg/kg once every 4 weeks. | |
|
Initial (usual) dose |
7.1 mg/kg once every 4 weeks |
|
First dose reduction |
5.6 mg/kg once every 4 weeks |
|
Second dose reduction |
4.4 mg/kg once every 4 weeksa |
|
Adverse reaction |
Severity |
Occurrence |
Imetelstat dosage modification |
|---|---|---|---|
|
a Administer growth factors and anti-infective therapies for treatment or prophylaxis as appropriate. | |||
|
b Administer platelet transfusions as appropriate. | |||
|
c Also manage symptoms of infusion-related reactions with supportive care as clinically indicated. | |||
|
Hematologic toxicity | |||
|
Neutropeniaa |
Grade 3 |
First |
Delay imetelstat until ANC recovers to 1,000/mm3, then restart at the same dose level. |
|
Second or third |
Delay imetelstat until ANC recovers to 1,000/mm3, then restart at one dose level lower. | ||
|
Fourth |
Discontinue imetelstat. | ||
|
Grade 4 |
First and second |
Delay imetelstat until ANC recovers to 1,000/mm3, then restart at one dose level lower. | |
|
Third |
Discontinue imetelstat. | ||
|
Thrombocytopeniab |
Grade 3 |
First |
Delay imetelstat until platelets recover to 50,000/mm3, then restart at the same dose level. |
|
Second or third |
Delay imetelstat until platelets recover to 50,000/mm3, then restart at one dose level lower. | ||
|
Fourth |
Discontinue imetelstat. | ||
|
Grade 4 |
First and second |
Delay imetelstat until platelets recover to 50,000/mm3, then restart at one dose level lower. | |
|
Third |
Discontinue imetelstat. | ||
|
Nonhematologic adverse reactions | |||
|
Infusion-related reactionsc |
Grade 2 or 3 |
First and second |
Interrupt imetelstat infusion until resolution of the adverse reaction or until the reaction intensity decreases to grade 1, then restart infusion with the rate reduced by 50% of the rate administered prior to adverse reaction. |
|
Third |
For grade 2, stop infusion; may restart at the next cycle. For grade 3, permanently discontinue imetelstat. | ||
|
Grade 4 |
First |
Stop imetelstat infusion, administer supportive management as appropriate, and permanently discontinue imetelstat. | |
|
Other adverse reactions |
Grade 3 or 4 |
First and second |
Delay imetelstat infusion until recovery of adverse reaction to grade 1 or baseline, then restart at one dose level lower. |
|
Third |
Permanently discontinue imetelstat. | ||
Refer to adult dosing.
The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified. Adverse reactions reported in adults.
>10%:
Hematologic & oncologic: Decreased neutrophils (92%), decreased platelet count (97%), decreased white blood cell count (94%), prolonged prothrombin time (26%)
Hepatic: Increased serum alanine aminotransferase (43%), increased serum alkaline phosphatase (48%), increased serum aspartate aminotransferase (53%)
Immunologic: Antibody development (17%)
Nervous system: Fatigue (29%), headache (13%)
Neuromuscular & skeletal: Arthralgia (≤25%), myalgia (≤25%)
1% to 10%:
Cardiovascular: Atrial arrhythmia (6%), heart failure (3%), hypertension (<5%), syncope (7%)
Dermatologic: Pruritus (6%)
Gastrointestinal: Gastrointestinal hemorrhage (<5%)
Genitourinary: Urinary tract infection (9%)
Hematologic & oncologic: Hematoma (6%), hemorrhage (grades 3/4: 3%)
Hypersensitivity: Infusion-related reaction (8%)
Infection: Sepsis (4%)
Neuromuscular & skeletal: Bone fracture (5%)
Respiratory: Epistaxis (7%)
<1%:
Genitourinary: Hematuria (grades 3/4)
Hematologic & oncologic: Febrile neutropenia
There are no contraindications listed in the manufacturer's labeling.
Concerns related to adverse effects:
• Infusion-related reactions: Imetelstat is associated with infusion-related reactions. In the clinical trial, infusion-related reactions occurred in 8% of patients who received imetelstat for management of myelodysplastic syndromes (MDS); grade 3 or 4 infusion-related reactions occurred in a small percentage of patients, including some cases of hypertensive crisis. The most common infusion-related reaction was headache. Infusion-related reactions usually occur during or shortly after the end of the infusion.
• Neutropenia: Imetelstat may cause neutropenia (based on laboratory values). In the clinical trial, new or worsening grade 3 or 4 neutropenia occurred in nearly three-fourths of patients with MDS treated with imetelstat. The median time to onset of first occurrence of grade 3 or 4 neutropenia was 4.6 weeks (range: 1 to 81 weeks). The median time to recovery from each grade 3 or 4 neutropenia occurrence (to ≤ grade 2 or last value available) was 1.9 weeks (range: up to 16 weeks). Grade 3 or 4 neutropenia occurred throughout imetelstat treatment, with nearly two-thirds of patients experiencing during cycles 1 to 3, approximately one-third during cycles 4 to 12, and over one-third during cycles 13 and beyond. Febrile neutropenia occurred rarely and sepsis occurred in a small percentage of patients.
• Thrombocytopenia: Imetelstat may cause thrombocytopenia (based on laboratory values). In the clinical trial, new or worsening grade 3 or 4 thrombocytopenia occurred in nearly two-thirds of patients with MDS who received imetelstat. The median time to onset of the first occurrence of grade 3 or 4 platelet decrease was 6 weeks (range: 2 to 88 weeks). The median time to recovery from each grade 3 or 4 thrombocytopenia occurrence (to ≤ grade 2 or last value available) was 1.3 weeks (range: up to 13 weeks). Grade 3 or 4 thrombocytopenia occurred throughout imetelstat treatment, with almost half of patients experiencing during cycles 1 to 3, and nearly one-third during cycles 4 to 12, and nearly one-fourth during cycles 13 and beyond. Grade 3 or 4 bleeding was observed in a small percentage of patients, including GI bleeding and hematuria. Higher imetelstat exposure is associated with a higher incidence of grade 3 and 4 thrombocytopenia.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Solution Reconstituted, Intravenous, as sodium [preservative free]:
Rytelo: 47 mg (1 ea); 188 mg (1 ea)
No
Solution (reconstituted) (Rytelo Intravenous)
47 mg (per each): $3,054.16
188 mg (per each): $12,216.62
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Imetelstat is available through specialty distributors and specialty pharmacies. Access information from the manufacturer may be found at https://www.rytelohcp.com/how-to-order.
IV: Infuse over 2 hours. Premedications are recommended to prevent or reduce potential infusion-related reactions. Infusion-related reactions may require interruption of infusion, decreased infusion rate, and/or discontinuation. Monitor for at least 1 hour after completion of infusion for adverse reactions.
Myelodysplastic syndromes, low- to intermediate-1 risk: Treatment of low- to intermediate-1 risk myelodysplastic syndromes in adults with transfusion-dependent anemia requiring ≥4 RBC units over 8 weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents.
Imetelstat may be confused with belinostat, Imdelltra, vorinostat.
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes (chemotherapeutic agent, parenteral and oral) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Acute Care, Community/Ambulatory Care, and Long-Term Care Settings).
None known.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
5-Aminosalicylic Acid Derivatives: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Abrocitinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Antithymocyte Globulin (Equine): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Antithymocyte Globulin (Equine). Specifically, these effects may be unmasked if the dose of immunosuppressive therapy is reduced. Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Antithymocyte Globulin (Equine). Specifically, infections may occur with greater severity and/or atypical presentations. Risk C: Monitor
Antithyroid Agents: Myelosuppressive Agents may increase neutropenic effects of Antithyroid Agents. Risk C: Monitor
Baricitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Baricitinib. Risk X: Avoid
BCG (Intravesical): Myelosuppressive Agents may decrease therapeutic effects of BCG (Intravesical). Myelosuppressive Agents may increase adverse/toxic effects of BCG (Intravesical). Risk X: Avoid
BCG Products: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of BCG Products. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of BCG Products. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Brincidofovir: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Brincidofovir. Risk C: Monitor
Brivudine: May increase adverse/toxic effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Chikungunya Vaccine (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Chikungunya Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Chikungunya Vaccine (Live). Risk X: Avoid
Chloramphenicol (Ophthalmic): May increase adverse/toxic effects of Myelosuppressive Agents. Risk C: Monitor
Chloramphenicol (Systemic): Myelosuppressive Agents may increase myelosuppressive effects of Chloramphenicol (Systemic). Risk X: Avoid
Cladribine: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Cladribine. Risk X: Avoid
Cladribine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk X: Avoid
CloZAPine: Myelosuppressive Agents may increase adverse/toxic effects of CloZAPine. Specifically, the risk for neutropenia may be increased. Risk C: Monitor
Coccidioides immitis Skin Test: Coadministration of Immunosuppressants (Miscellaneous Oncologic Agents) and Coccidioides immitis Skin Test may alter diagnostic results. Management: Consider discontinuing these oncologic agents several weeks prior to coccidioides immitis skin antigen testing to increase the likelihood of accurate diagnostic results. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Inactivated Virus): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (Inactivated Virus). Risk C: Monitor
COVID-19 Vaccine (mRNA): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (mRNA). Management: Give a 3-dose primary series for all patients aged 6 months and older taking immunosuppressive medications or therapies. Booster doses are recommended for certain age groups. See CDC guidance for details. Risk D: Consider Therapy Modification
COVID-19 Vaccine (Subunit): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of COVID-19 Vaccine (Subunit). Risk C: Monitor
Deferiprone: Myelosuppressive Agents may increase neutropenic effects of Deferiprone. Management: Avoid the concomitant use of deferiprone and myelosuppressive agents whenever possible. If this combination cannot be avoided, monitor the absolute neutrophil count more closely. Risk D: Consider Therapy Modification
Dengue Tetravalent Vaccine (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Dengue Tetravalent Vaccine (Live). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Dengue Tetravalent Vaccine (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Denosumab: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Management: Consider the risk of serious infections versus the potential benefits of coadministration of denosumab and immunosuppressants. If combined, monitor patients for signs/symptoms of serious infections. Risk D: Consider Therapy Modification
Deucravacitinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Etrasimod: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Fexinidazole: Myelosuppressive Agents may increase myelosuppressive effects of Fexinidazole. Risk X: Avoid
Filgotinib: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Inebilizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Inebilizumab. Risk C: Monitor
Influenza Virus Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Influenza Virus Vaccines. Management: Administer influenza vaccines at least 2 weeks prior to initiating immunosuppressants if possible. If vaccination occurs less than 2 weeks prior to or during therapy, revaccinate at least 3 months after therapy discontinued if immune competence restored. Risk D: Consider Therapy Modification
Leflunomide: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Leflunomide. Management: Increase the frequency of chronic monitoring of platelet, white blood cell count, and hemoglobin or hematocrit to monthly, instead of every 6 to 8 weeks, if leflunomide is coadministered with immunosuppressive agents. Risk D: Consider Therapy Modification
Linezolid: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Mumps- Rubella- or Varicella-Containing Live Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Mumps- Rubella- or Varicella-Containing Live Vaccines. Mumps- Rubella- or Varicella-Containing Live Vaccines may increase adverse/toxic effects of Immunosuppressants (Miscellaneous Oncologic Agents). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Nadofaragene Firadenovec: Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Nadofaragene Firadenovec. Specifically, the risk of disseminated adenovirus infection may be increased. Risk X: Avoid
Natalizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Natalizumab. Risk X: Avoid
Ocrelizumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ocrelizumab. Risk C: Monitor
Ofatumumab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ofatumumab. Risk C: Monitor
Olaparib: Myelosuppressive Agents may increase myelosuppressive effects of Olaparib. Risk C: Monitor
Pidotimod: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Pidotimod. Risk C: Monitor
Pimecrolimus: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk X: Avoid
Pneumococcal Vaccines: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Pneumococcal Vaccines. Risk C: Monitor
Poliovirus Vaccine (Live/Trivalent/Oral): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Poliovirus Vaccine (Live/Trivalent/Oral). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Polymethylmethacrylate: Immunosuppressants (Miscellaneous Oncologic Agents) may increase hypersensitivity effects of Polymethylmethacrylate. Management: Use caution when considering use of bovine collagen-containing implants such as the polymethylmethacrylate-based Bellafill brand implant in patients who are receiving immunosuppressants. Consider use of additional skin tests prior to administration. Risk D: Consider Therapy Modification
Promazine: May increase myelosuppressive effects of Myelosuppressive Agents. Risk C: Monitor
Rabies Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Rabies Vaccine. Management: Complete rabies vaccination at least 2 weeks before initiation of immunosuppressant therapy if possible. If combined, check for rabies antibody titers, and if vaccination is for post exposure prophylaxis, administer a 5th dose of the vaccine. Risk D: Consider Therapy Modification
Ritlecitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ritlecitinib. Risk X: Avoid
Ropeginterferon Alfa-2b: Myelosuppressive Agents may increase myelosuppressive effects of Ropeginterferon Alfa-2b. Management: Avoid coadministration of ropeginterferon alfa-2b and other myelosuppressive agents. If this combination cannot be avoided, monitor patients for excessive myelosuppressive effects. Risk D: Consider Therapy Modification
Ruxolitinib (Topical): Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ruxolitinib (Topical). Risk X: Avoid
Sipuleucel-T: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Sipuleucel-T. Management: Consider reducing the dose or discontinuing the use of immunosuppressants prior to initiating sipuleucel-T therapy. Risk D: Consider Therapy Modification
Sphingosine 1-Phosphate (S1P) Receptor Modulators: May increase immunosuppressive effects of Immunosuppressants (Miscellaneous Oncologic Agents). Risk C: Monitor
Tacrolimus (Topical): Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Tacrolimus (Topical). Risk X: Avoid
Talimogene Laherparepvec: Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Talimogene Laherparepvec. Specifically, the risk of infection from the live, attenuated herpes simplex virus contained in talimogene laherparepvec may be increased. Risk X: Avoid
Tertomotide: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Tertomotide. Risk X: Avoid
Tofacitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Tofacitinib. Risk X: Avoid
Typhoid Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Typhoid Vaccine. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Typhoid Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Ublituximab: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Ublituximab. Risk C: Monitor
Upadacitinib: Immunosuppressants (Miscellaneous Oncologic Agents) may increase immunosuppressive effects of Upadacitinib. Risk X: Avoid
Vaccines (Live): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Vaccines (Live). Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Vaccines (Live). Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Vaccines (Non-Live/Inactivated/Non-Replicating): Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Vaccines (Non-Live/Inactivated/Non-Replicating). Management: Give non-live/inactivated/non-replicating vaccines at least 2 weeks prior to initiation of immunosuppressants when possible. Patients vaccinated less than 14 days before or during therapy should be revaccinated at least 3 months after therapy is complete. Risk D: Consider Therapy Modification
Yellow Fever Vaccine: Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Yellow Fever Vaccine. Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Yellow Fever Vaccine. Specifically, the risk of vaccine-associated infection may be increased. Risk X: Avoid
Zoster Vaccine (Live/Attenuated): Immunosuppressants (Miscellaneous Oncologic Agents) may increase adverse/toxic effects of Zoster Vaccine (Live/Attenuated). Specifically, the risk of vaccine-associated infection may be increased. Immunosuppressants (Miscellaneous Oncologic Agents) may decrease therapeutic effects of Zoster Vaccine (Live/Attenuated). Risk X: Avoid
Verify pregnancy status prior to initiating treatment in patients who could become pregnant.
Patients who could become pregnant should use effective contraception during therapy and for 1 week after the last dose of imetelstat.
Based on data from animal reproduction studies, in utero exposure to imetelstat may cause fetal harm; embryo-fetal mortality was observed in mice following IV doses ~2.5 times the human exposure.
It is not known if imetelstat is present in breast milk.
Due to the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended by the manufacturer during therapy and for 1 week after the last dose of imetelstat.
Monitor complete blood cell counts prior to treatment initiation, weekly for the first 2 cycles, prior to each cycle thereafter, and as clinically indicated. Monitor RBC transfusion requirement. Monitor LFTs prior to treatment initiation, weekly for the first cycle, prior to each cycle thereafter, and as clinically indicated. Verify pregnancy status prior to treatment initiation (in patients who could become pregnant). Monitor patients with thrombocytopenia for bleeding. Monitor patients with grade 3 or 4 neutropenia for infections (including sepsis). Monitor for adverse reactions for at least 1 hour following completion of the infusion.
The American Society of Clinical Oncology hepatitis B virus (HBV) screening and management provisional clinical opinion (Ref) recommends HBV screening with hepatitis B surface antigen, hepatitis B core antibody, total Ig or IgG, and antibody to hepatitis B surface antigen prior to beginning (or at the beginning of) systemic anticancer therapy; do not delay treatment for screening/results. Detection of chronic or past HBV infection requires a risk assessment to determine antiviral prophylaxis requirements, monitoring, and follow-up.
Imetelstat is an oligonucleotide, which is a potent, competitive inhibitor of enzymatic telomerase activity. Imetelstat targets cells with increased telomerase activity to selectively induce apoptosis of malignant cells while sparing the normal cells and enabling recovery of bone marrow function and erythropoiesis (Ref). Increased telomerase activity and human telomerase reverse transcriptase RNA expression have been reported in myelodysplastic syndromes. Imetelstat binds to the RNA component of human telomerase, inhibits telomerase enzymatic activity, and prevents telomere binding, leading to reduction of telomere length, reduction of malignant cell proliferation, and induction of apoptosis (Ref).
Distribution: ~14.1 L.
Protein binding: >94%.
Metabolism: Imetelstat is expected to be metabolized by nucleases to nucleotides (of varying lengths).
Half-life elimination: ~4.9 hours.
