treosulfan 250 MG Oral Capsule

INDICATIONS AND USAGE GRAFAPEX is an alkylating drug indicated for: Use in combination with fludarabine as a preparative regimen for allogeneic hematopoietic stem cell transplantation (alloHSCT) in adult and pediatric patients 1 year of age and older with acute myeloid leukemia (AML). ( 1.1 ). Use in combination with fludarabine as a preparative regimen for allogeneic hematopoietic stem cell transplantation in adult and pediatric patients 1 year of age and older with myelodysplastic syndrome (MDS). ( 1.2 ). 1.1 Acute Myeloid Leukemia GRAFAPEX is indicated in combination with fludarabine as a preparative regimen for allogeneic hematopoietic stem cell transplantation in adult and pediatric patients 1 year of age and older with acute myeloid leukemia (AML). 1.2 Myelodysplastic Syndrome GRAFAPEX is indicated in combination with fludarabine as a preparative regimen for allogeneic hematopoietic stem cell transplantation in adult and pediatric patients 1 year of age and older with myelodysplastic syndrome (MDS).

DOSAGE AND ADMINISTRATION Recommended dosage: 10 g/m² body surface area (BSA) per day as a two hour intravenous infusion, given on three consecutive days (day -4, -3, -2) in conjunction with fludarabine before hematopoietic stem cell infusion (day 0). ( 2.1 , 2.2 ) See Full Prescribing Information for instructions on preparation and administration. ( 2.2 ) 2.1 Recommended Dosage The recommended dosage of GRAFAPEX is 10 g/m 2 by intravenous infusion given daily for three days, beginning on Day -4 prior to transplantation in combination with fludarabine as outlined in Table 1. Table 1: Dosage Regimen for GRAFAPEX-Based Allogeneic HSCT Treatment Day -6 Day -5 Day -4 Day-3 Day -2 Day -1 Day 0 GRAFAPEX 10 g/m 2 /day intravenous infusion X X X Fludarabine 30 mg/m 2 /day intravenous infusion X X X X X Allogeneic hematopoietic stem cell infusion X Premedicate patients with antiemetics prior to the first dose of GRAFAPEX and continue antiemetics on a fixed schedule through completion of treosulfan administration. 2.2 Preparation and Administration Instructions Reconstitute GRAFAPEX prior to intravenous infusion. GRAFAPEX is a hazardous drug. Follow applicable special handling and disposal procedures. 1 Use aseptic technique to prepare GRAFAPEX. Calculate the dose, the total volume of reconstituted GRAFAPEX solution required, and the number of GRAFAPEX vials needed. Reconstitute each vial with 0.45% Sodium Chloride Injection, 0.9% Sodium Chloride Injection, 5% Dextrose Injection, or Sterile Water for Injection, in its original glass container using volumes described in Table 2 to obtain a final concentration of approximately 0.05 g/mL of GRAFAPEX. Reconstitution with Sterile Water for Injection alone is not recommended in children less than or equal to 12 years of age due to the resulting hypo-osmolarity of the final solution. Table 2: Reconstitution Solution Volume Strength Volume 1 g/vial 20 mL 5 g/vial 100 mL Shake the vial(s) to dissolve. Inspect the reconstituted solution for discoloration and particulate matter. The reconstituted solution appears as a clear colorless solution. Solutions showing any sign of precipitation should not be used. In case that solubility issues occur, prolonged standing time or slight warming of the reconstituted solution (hand warm) may be useful. Determine the volume of 0.05 g/mL reconstituted solution needed based on the required dose. Reconstituted solutions of GRAFAPEX may be combined into a larger glass vial, ethylene-vinyl acetate (EVA) bag or polyolefin (PO) bag. Discard any unused portion left in the vial(s). If not used immediately store reconstituted GRAFAPEX solution at room temperature 20°C to 25°C (68°F to 77°F) for up to 24 hours. Do not use if the solution contains a precipitate. Do not refrigerate. Infuse GRAFAPEX intravenously over 2 hours. Confirm patency of the intravenous line prior to infusion. Monitor for extravasation; if extravasation occurs, stop the infusion [see Warnings and Precautions ( 5.4 )] .

WARNINGS AND PRECAUTIONS Seizures: Monitor signs of neurological adverse reactions and consider clonazepam prophylaxis for patients at higher risk. ( 5.2 ) Skin disorders: Keep skin clean and dry on days of GRAFAPEX infusion and change occlusive dressings after infusion. Change diapers frequently during the 12 hours after each infusion of GRAFAPEX. ( 5.3 ) Injection Site Reactions and Tissue Necrosis: May cause local tissue necrosis and injection site reactions, including erythema, pain, and swelling, in case of extravasation. If extravasation occurs, stop the infusion immediately and manage medically as required. ( 5.4 ) Secondary Malignancies: There is an increased risk of a secondary malignancy with use of GRAFAPEX. ( 5.5 ) Increased Early Morbidity and Mortality at Dosages Higher than Recommended: Avoid exceeding the recommended dosage of 10 g/m 2 daily for three consecutive days. ( 5.6 ) Embryo-fetal toxicity: Can cause fetal harm. Advise patients of reproductive potential of the potential risk to a fetus and to use effective contraception. ( 5.7 , 8.1 , 8.3 ) 5.1 Myelosuppression Profound myelosuppression with pancytopenia is the desired therapeutic effect of GRAFAPEX-based preparative regimens, occurring in all patients. Time to neutrophil counts > 0.5 Gi/L occurred at a median of 18 days (range 7-42 days) after allogeneic hematopoietic stem cell transplantation in adult patients treated using GRAFAPEX in combination with fludarabine as the preparative regimen. Do not begin the preparative regimen if the stem cell donor is not available. Monitor blood cell counts daily until hematopoetic recovery. Provide standard supportive care for infections, anemia and thrombocytopenia until there is adequate hematopoietic recovery. 5.2 Seizures There have been reports of seizures in patients following treatment with treosulfan. Monitor patients for signs of neurological adverse reactions. Clonazepam prophylaxis may be considered for patients at higher risk for seizures, including infants. 5.3 Skin Disorders An increase of skin disorders (e.g. rash, dermatitis) was observed when patients received sodium bicarbonate-containing hydration in the course of treosulfan infusion, potentially because of acceleration of the pH‑dependent formation of alkylating epoxides [see Adverse Reactions ( 6.1 ) and Clinical Pharmacology ( 12.1 )]. Keep skin clean and dry on days of GRAFAPEX infusion. Diaper dermatitis may occur because of excretion of treosulfan in the urine. Change diapers frequently during the 12 hours after each infusion of GRAFAPEX. Dermatitis may occur under occlusive dressings; change occlusive dressings after each infusion of GRAFAPEX. 5.4 Injection Site Reactions and Tissue Necrosis GRAFAPEX may cause local tissue necrosis and injection site reactions, including erythema, pain, and swelling, in case of extravasation. Assure venous access patency prior to starting GRAFAPEX infusion, and monitor the intravenous infusion site for redness, swelling, pain, infection, and necrosis during and after administration of GRAFAPEX. If extravasation occurs, stop the infusion immediately and manage medically as required. Do not administer by the intramuscular or subcutaneous routes. 5.5 Secondary Malignancies There is an increased risk of a secondary malignancy with use of GRAFAPEX. Treosulfan is carcinogenic and genotoxic [see Nonclinical Toxicology ( 13.1 )] . The risk of secondary malignancy is increased in patients with Fanconi anemia and other DNA breakage disorders. The safety and efficacy of GRAFAPEX have not been established for patients with these disorders. 5.6 Increased Early Morbidity and Mortality at Dosages Higher than Recommended In MC‑FludT.14/L Trial I (NCT00822393), 330 adult patients were randomized to treosulfan at 14 g/m 2 /day (1.4 times the recommended dose) for three consecutive days or busulfan at 3.2 mg/kg/day for two days, in combination with fludarabine as a preparative regimen for allogeneic transplantation. This trial was discontinued early due to a higher incidence of early fatal and/or serious adverse reactions in patients receiving treosulfan. Avoid exceeding the recommended GRAFAPEX dosage of 10 g/m 2 daily for three consecutive days. 5.7 Embryo-Fetal Toxicity Based on its mechanism of action, GRAFAPEX can cause fetal harm when administered to a pregnant woman because it is genotoxic and affects dividing cells [see Clinical Pharmacology ( 12 ) and Nonclinical Toxicology ( 13 )]. Advise pregnant women of the potential risk to the fetus. Advise females of reproductive potential to use effective contraception during treatment with GRAFAPEX and for 6 months following the last dose of GRAFAPEX. Advise males with female partners of reproductive potential to use effective contraception during treatment with GRAFAPEX and for 3 months after the last dose [see Use in Specific Populations ( 8.1 ) and ( 8.3 )].

CONTRAINDICATIONS GRAFAPEX is contraindicated in patients with hypersensitivity to any component of the drug product. Hypersensitivity to any component of the drug product. ( 4 )

CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Treosulfan is an alkylating agent. DNA alkylation is thought to be responsible for the cytotoxic activities of treosulfan. Treosulfan showed hematopoietic stem cell depleting activity as well as immunosuppressive and antitumor activity in mouse models of leukemia. 12.2 Pharmacodynamics Increase in treosulfan exposure was associated with an increased incidence of infection-related death. Treosulfan time course of pharmacodynamic response is unknown. 12.3 Pharmacokinetics Treosulfan pharmacokinetic parameters were observed at the approved recommended dosage, unless otherwise specified. Treosulfan is a prodrug. Treosulfan mean ± SD area under the curve (AUC) is 1,200 ± 211 hr mcg/mL. There was no dose accumulation. Distribution Treosulfan mean (CV%) volume of distribution is approximately 41 liters (CV%: 19%). Treosulfan does not bind to plasma albumin. Elimination Treosulfan mean (± standard deviation) terminal half-life is 1.7 ± 0.4 hours. Metabolism The pharmacologically inactive treosulfan is converted spontaneously under physiological conditions into the active monoepoxide intermediate (2S,3S)‑1,2‑epoxybutane‑3,4‑diol‑4‑methanesulfonate) and finally to active L‑diepoxibutane (2S,3S)‑1,2:3,4‑diepoxybutane). Excretion A median of 42% of the treosulfan dose is excreted unchanged in the urine within 24 hours, and 89% of this unchanged fraction is excreted within the first 8 hours after administration. Specific Populations No clinically significant differences in the pharmacokinetics of treosulfan based on sex, mild renal impairment (CLcr 60‑89 mL/min), or mild hepatic impairment (total bilirubin less than or equal to ULN with AST greater than ULN or total bilirubin greater than 1 to 1.5 times ULN with any AST). The effect of moderate or severe renal impairment, moderate or severe hepatic impairment, and age ≥ 65 years on treosulfan pharmacokinetics is unknown. Pediatric Patients Treosulfan exposure in pediatric patients with BSA < 0.7 m 2 and with BSA 0.7 to < 1.1 m 2 are 11% and 5% higher, respectively, compared to adults. No clinically significant difference in treosulfan median terminal half‑life was observed between pediatric patients and adults. The median terminal half‑life of the active monoepoxide intermediate was 1.6 hrs in pediatric patients. Drug Interaction Studies In Vitro Studies CYP Enzymes : Treosulfan is a CYP2D6 substrate and its monoepoxide intermediate is a CYP2C8 substrate. Treosulfan inhibits CYP2C19 and CYP3A4 (using midazolam as substrate), but does not inhibit CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2D6, or CYP3A4 (using testosterone as substrate). Transporter Systems : Treosulfan does not inhibit BCRP, BSEP, MATE1, OATP1B1, OATP1B3, OAT1, OAT3, OCT1, or OCT2.