RYTELO

1. INDICATIONS AND USAGE RYTELO is indicated for the treatment of adult patients with low- to intermediate-1 risk myelodysplastic syndromes (MDS) with transfusion-dependent anemia requiring 4 or more red blood cell units over 8 weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents (ESA). RYTELO is an oligonucleotide telomerase inhibitor indicated for the treatment of adult patients with low- to intermediate-1 risk myelodysplastic syndromes (MDS) with transfusion-dependent anemia requiring 4 or more red blood cell units over 8 weeks who have not responded to or have lost response to or are ineligible for erythropoiesis-stimulating agents (ESA). ( 1 )

2. DOSAGE AND ADMINISTRATION The recommended dosage of RYTELO is 7.1 mg/kg administered as an intravenous infusion over 2 hours every 4 weeks. ( 2.1 ) Premedicate prior to dosing with RYTELO for potential infusion-related reactions. ( 2.2 ) See full prescribing information for preparation and administration instructions. ( 2.4 ) 2.1. Recommended Dosage The recommended dosage of RYTELO is 7.1 mg/kg administered as an intravenous infusion over 2 hours every 4 weeks. Discontinue RYTELO if a patient does not experience a decrease in red blood cell (RBC) transfusion burden after 24 weeks of treatment (administration of 6 doses) or if unacceptable toxicity occurs at any time [see Dosage and Administration (2.3) ] . 2.2. Recommended Premedications Administer the following pre-treatment medications at least 30 minutes prior to dosing to prevent or reduce potential infusion-related reactions: diphenhydramine (or equivalent) 25 mg to 50 mg, intravenously or orally hydrocortisone (or equivalent) 100 mg to 200 mg, intravenously or orally Monitor patients for adverse reactions for at least one hour after the infusion has been completed [see Warnings and Precautions (5.3) and Adverse Reactions (6.1) ] . 2.3. Dosage Modifications for Adverse Reactions Recommended dose reductions for Grade 3 and Grade 4 adverse reactions are found in Table 1. The management of Grade 3 and Grade 4 adverse reactions may require temporary dose delay, dose reduction, or treatment discontinuation and are presented in Table 2 and Table 3. RYTELO treatment should be permanently discontinued if the patient cannot tolerate the lowest dose level of 4.4 mg/kg. Table 1: Recommended Dose Reduction for RYTELO for Grade 3 and Grade 4 Adverse Reactions Dose Reduction Dose Every 4 Weeks First dose reduction 5.6 mg/kg Second dose reduction 4.4 mg/kg Dosage Modifications for Hematologic (Grade 3 and Grade 4) Adverse Reactions Monitor complete blood cell counts prior to administration of RYTELO, weekly for the first two cycles, prior to each cycle thereafter, and as clinically indicated. Delay the next cycle if absolute neutrophil count is less than 1 × 10 9 /L or platelets are less than 50 × 10 9 /L. Modify dose as described in Table 2. Table 2: Dosage Modifications for Patients with Hematologic Adverse Reactions (Grade 3 and Grade 4) Adverse Reaction Severity Grade Severity based on National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.03. Occurrence Treatment Modification Abbreviation: ANC = absolute neutrophil count Thrombocytopenia [see Warnings and Precautions (5.1) ] Grade 3 First Delay RYTELO until recovery of platelets to 50 × 10 9 /L; restart at same dose level. Second and Third Delay RYTELO until recovery of platelets to 50 × 10 9 /L; restart at one dose level lower. Fourth Discontinue RYTELO. Grade 4 First and Second Delay RYTELO until recovery of platelets to 50 × 10 9 /L; restart at one dose level lower. Third Discontinue RYTELO. Neutropenia [see Warnings and Precautions (5.2) ] Grade 3 First Delay RYTELO until recovery of ANC to 1 × 10 9 /L; restart at same dose level. Second and Third Delay RYTELO until recovery of ANC to 1 × 10 9 /L; restart at one dose level lower. Fourth Discontinue RYTELO. Grade 4 First and Second Delay RYTELO until recovery of ANC to 1 × 10 9 /L; restart at one dose level lower. Third Discontinue RYTELO. Dosage Modifications for Non-hematologic Adverse Reactions Dosage modifications for infusion-related reactions and other adverse drug reactions, including elevated liver function tests (LFTs), are described in Table 3. Monitor liver function tests prior to administration of RYTELO, weekly for the first cycle, prior to each cycle thereafter, and as clinically indicated. Table 3: Dosage Modifications for Patients with Non-hematologic Adverse Reactions Adverse Reaction Severity Grade Severity based on National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.03. Occurrence Treatment Modifica …

3. DOSAGE FORMS AND STRENGTHS For injection: 47 mg of imetelstat supplied as a white to off-white or slightly yellow lyophilized powder in a single-dose vial for reconstitution. For injection: 188 mg of imetelstat supplied as a white to off-white or slightly yellow lyophilized powder in a single-dose vial for reconstitution. For injection: 47 mg powder in a single-dose vial for reconstitution. ( 3 ) For injection: 188 mg powder in a single-dose vial for reconstitution. ( 3 )

4. CONTRAINDICATIONS None. None. ( 4 )

6. ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Thrombocytopenia [see Warnings and Precautions (5.1) ] Neutropenia [see Warnings and Precautions (5.2) ] Infusion-Related Reactions [see Warnings and Precautions (5.3) ] Most common adverse reactions (incidence ≥10% with a difference between arms of >5% compared to placebo), including laboratory abnormalities are decreased platelets, decreased white blood cells, decreased neutrophils, increased AST, increased alkaline phosphatase, increased ALT, fatigue, prolonged partial thromboplastin time, arthralgia/myalgia, COVID-19 infections, and headache. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Geron Corporation at 1-855-437-6664 (1-855-GERONMI) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1. Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Low- to Intermediate-Risk Myelodysplastic Syndromes The safety of RYTELO was evaluated in a randomized, double-blind, placebo-controlled, multicenter trial (IMerge) in 177 adult patients with International Prognostic Scoring System (IPSS) low- to intermediate-1 risk MDS who were transfusion-dependent and relapsed or refractory to or ineligible for ESA treatment [see Clinical Studies (14) ] . The safety population included patients who received at least one dose of either RYTELO (n=118) or placebo (n=59) at 7.1 mg/kg as an intravenous infusion administered over two hours every 4 weeks. The median time on treatment with RYTELO was 8 months (range, 0 to 38 months); 69% of patients were exposed to RYTELO for 24 weeks or longer and 45% were exposed for 48 weeks or longer. The median age of patients who received at least one dose of RYTELO was 72 years (range: 44 to 87 years) with 77% of patients 65 years of age and older and 30% of patients 75 years of age and older. Participants were 60% male, 81% White, 7% Asian, and 0.8% Black. Serious adverse reactions occurred in 32% of patients who received RYTELO. Serious adverse reactions in > 2% of patients included sepsis (4.2%), fracture (3.4%), cardiac failure (2.5%), and hemorrhage (2.5%). Fatal adverse reactions occurred in 0.8% of patients who received RYTELO, including sepsis (0.8%). Permanent discontinuation of RYTELO due to an adverse reaction occurred in 15% of patients. Adverse reactions which resulted in permanent discontinuation of RYTELO in > 2% of patients included neutropenia and thrombocytopenia. Dosage interruptions of RYTELO due to an adverse reaction occurred in 80% of patients. Adverse reactions which required dosage interruption in > 5% of patients included neutropenia, thrombocytopenia and infections. Dose reductions of RYTELO due to an adverse reaction occurred in 49% of patients. Adverse reactions which required dose reductions in > 2% of patients included neutropenia and thrombocytopenia. The most common (≥10% with a difference between arms of >5% compared to placebo) adverse reactions, including laboratory abnormalities, were decreased platelets, decreased white blood cells, decreased neutrophils, increased AST, increased alkaline phosphatase, increased ALT, fatigue, prolonged partial thromboplastin time, arthralgia/myalgia, COVID-19 infections, and headache. Table 5 summarizes the adverse reactions in IMerge. Table 5: Adverse Reactions (≥5%) in Patients with MDS Who Received RYTELO with a Difference Between Arms of >2% Compared to Placebo in IMerge Adverse Reaction RYTELO (N=118) Placebo (N=59) All Grades % Grades 3 or 4 % All Grades % Grades 3 or 4 % Graded according to National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.03. General disorders and administrative site conditions Fatigue Fatigue: asthenia, fatigue, and malaise. 29 …

8. USE IN SPECIFIC POPULATIONS Lactation: Advise not to breastfeed. ( 8.2 ) 8.1. Pregnancy Risk Summary Based on findings in animal studies, RYTELO can cause embryo-fetal harm when administered to a pregnant woman. There are no available data on RYTELO use in pregnant women to evaluate for drug-associated risk. In embryo-fetal developmental toxicity studies, administration of imetelstat to pregnant mice and rabbits during the period of organogenesis resulted in embryo-fetal mortality, which in mice occurred at maternal exposures approximately 2.5 times the human exposure at the recommended clinical dose. Advise pregnant women of the potential risk to a fetus [see Data ] . In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data In embryo-fetal developmental toxicity studies, imetelstat was administered by IV bolus injection at doses of 4.7, 9.4, 14.1 or 28.2 mg/kg/day on gestation days 6, 9, and 12 in mice, or by 2-hour intravenous infusion at doses of 4.7, 14.1, or 28.2 mg/kg on gestation days 6 and 13 in rabbits. In rabbits, the dose of 28.2 mg/kg was maternally toxic. Increased post-implantation loss due to an increase in early resorptions, resulting in a decrease in viable fetuses and litter was noted in mice at 28.2 mg/kg and in rabbits starting at 14.1 mg/kg; corresponding to exposures (based on AUC) that are approximately 2.5-times (mice) or 9.3-times (rabbits) the human exposure at the recommended clinical dose. 8.2. Lactation Risk Summary There is no data on the presence of imetelstat in human milk, or the effects RYTELO on the breastfed child, or milk production. Because of the potential for adverse reactions in breastfed children, advise women not to breastfeed during treatment with RYTELO and for 1 week after the last dose. 8.3. Females and Males of Reproductive Potential Based on findings from animal studies, RYTELO can cause embryo-fetal harm when administered to a pregnant woman [see Use in Specific Populations (8.1) ] . Pregnancy Testing Verify the pregnancy status of females of reproductive potential prior to initiating treatment with RYTELO. Contraception Females Advise females of reproductive potential to use effective contraception during treatment with RYTELO and for 1 week after the last dose [see Use in Specific Populations (8.1) ] . Infertility Females Based on findings in animals, RYTELO may impair fertility in females of reproductive potential. The effect on fertility is reversible [see Nonclinical Toxicology (13.1) ] . 8.4. Pediatric Use Safety and effectiveness of RYTELO in pediatric patients have not been established. 8.5. Geriatric Use Of the 118 patients with low- to intermediate-1 risk myelodysplastic syndromes (MDS) in the clinical trial who received RYTELO, 91 (77.1%) patients were 65 years of age and older and 35 (29.7%) patients 75 years of age and older. No differences in safety or efficacy were observed between older (≥ 65 years) and younger patients.

12.1. Mechanism of Action Imetelstat is an oligonucleotide human telomerase inhibitor that binds to the template region of the RNA component of human telomerase (hTR), inhibits telomerase enzymatic activity and prevents telomere binding. Increased telomerase activity and human telomerase reverse transcriptase (hTERT) RNA expression have been reported in MDS and malignant stem and progenitor cells. Nonclinical studies showed imetelstat treatment led to reduction of telomere length, reduction of malignant stem and progenitor cell proliferation, and induction of apoptotic cell death.

11. DESCRIPTION RYTELO for injection contains imetelstat, an oligonucleotide telomerase inhibitor for intravenous use. Imetelstat sodium is a white to off-white or slightly yellow, amorphous, solid powder. It is highly soluble in aqueous solutions, including in 0.9% Sodium Chloride Injection, at both refrigerated and room temperatures. Imetelstat sodium is hygroscopic. The chemical name for the imetelstat sodium drug substance is DNA, d(3'-amino-3'-deoxy-P-thio) (T-A-G-G-G-T-T-A-G-A-C-A-A), 5'-[ O -[2-hydroxy-3-(hexadecanoylamino)propyl] phosphorothioate], sodium salt (1:13). The molecular formula is C 148 H 198 N 68 O 53 P 13 S 13 Na 13 (as sodium salt), which equates to a formula weight of 4896 g/mol. The molecular formula for the free acid form is C 148 H 211 N 68 O 53 P 13 S 13 which equates to a formula weight of 4610 g/mol. The structural formula for imetelstat sodium is: RYTELO (imetelstat) for injection is a sterile, preservative-free, white to off-white or slightly yellow lyophilized powder for intravenous infusion after reconstitution and dilution. Each single-dose vial provides either 47 mg of imetelstat (equivalent to 50 mg imetelstat sodium) or 188 mg of imetelstat (equivalent to 200 mg imetelstat sodium). The following inactive ingredients may be added during manufacturing: sodium carbonate anhydrous (for the 47 mg preparation) / sodium carbonate monohydrate (for the 188 mg preparation) or hydrochloric acid (to adjust to pH of 7.0 to 8.5). Chemical Structure

16. HOW SUPPLIED/STORAGE AND HANDLING How Supplied RYTELO (imetelstat) for injection is a preservative free, white to off-white or slightly yellow, lyophilized powder available as: Carton Contents NDC One RYTELO 47 mg single-dose vial 82959-112-01 One RYTELO 188 mg single-dose vial 82959-111-01 Storage Store vials refrigerated at 2°C to 8°C (36°F to 46°F) in original carton. Do not freeze.