Rivfloza Drug Information

RIVFLOZA is an LDHA -directed small interfering RNA indicated to lower urinary oxalate levels in children 2 years of age and older and adults with primary hyperoxaluria type 1 (PH1) and relatively preserved kidney function, e.g., eGFR ≥30 mL/min/1.73 m 2. (‎ 1 )

Recommended Dosage RIVFLOZA is administered subcutaneously once monthly at the recommended doses shown in Table 1. Dosing is based on actual body weight. Table 1: RIVFLOZA Dose Regimen in Adults and Pediatric Patients (2 years of age and older) Missed Dose If a planned dose is missed, administer RIVFLOZA as soon as possible.

If the planned dose is missed by more than 7 days, administer RIVFLOZA as soon as possible and resume monthly dosing from the most recently administered dose.

Administration Instructions

Pre-filled syringe: A healthcare provider, caregiver, or patient 12 years of age and older may inject RIVFLOZA using the pre-filled syringe. In pediatric patients 2 to less than 12 years of age who weigh ≥39 kg, a healthcare provider or caregiver may inject RIVFLOZA using the pre-filled syringe. Vials: RIVFLOZA vials are intended for use under the guidance and supervision of a healthcare provider.

Adult patients or caregivers may administer RIVFLOZA after proper training in preparing RIVFLOZA vials for administration, if a healthcare provider determines that it is appropriate, and with medical follow-up as necessary. Administer RIVFLOZA by subcutaneous injection to the abdomen (at least 2 inches from the navel) or the upper thigh. Do not inject into a vein or into scarred or bruised skin.

Inspect visually for particulate matter and discoloration prior to injection. RIVFLOZA should be colorless-to-yellow and particle free. If the solution is cloudy or contains particulate matter, do not use.

Instructions for delivering the dosage are provided in the Instructions for Use leaflets enclosed with the RIVFLOZA Pre-filled Syringe and single-dose vial. Discard the unused portion of the drug.

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. The safety of RIVFLOZA has been evaluated in one placebo-controlled clinical trial (PHYOX2) and one open-label extension study (PHYOX3). Across these studies, 29 adults and 12 children with PH1 have been treated with RIVFLOZA.

Patients with PH1 in these studies ranged in age from 9 to 46 years at first dose. The median duration of exposure was approximately 15 months (range 1-29 months). Of the 18 patients treated with RIVFLOZA, 17 patients received ≥5 months of active treatment.

The most common adverse reactions were injection site reactions, which were reported in 7 patients with PH1 (39%) on RIVFLOZA as compared to no patients on placebo. Injection site reactions included erythema, pain, bruising, and rash and were generally mild and did not lead to discontinuation of treatment. In the single-arm extension study (PHYOX3) that included 40 patients with PH1, additional injection site reactions included atrophy in 1 patient (3%).

Injection site reactions were reported in 2 patients (13%). Overall, the RIVFLOZA safety profile was similar to that seen in PHYOX2.

Pregnancy Risk Summary Available data from reports of pregnancy in clinical trials with RIVFLOZA are insufficient to evaluate for a drug-associated risk of major birth defects, miscarriage or other adverse maternal or fetal outcomes. In animal reproduction studies, no adverse developmental effects were observed when nedosiran was administered to pregnant mice at doses up to approximately 58 times the maximum recommended human dose (MRHD) of 160 mg nedosiran (equivalent to 170 mg nedosiran sodium) per dose, based on body surface area (BSA) or upon administration of a mouse-specific (pharmacologically active) analog. Subcutaneous administration of nedosiran to pregnant rabbits during the period of organogenesis at doses approximating the MRHD resulted in increased fetal loss in the presence of maternal toxicity.

Adverse developmental outcomes (fetal cardiovascular and skeletal malformations) were observed at a dose approximately 2 times the MRHD (see Data). Nedosiran is not pharmacologically active in rabbits or mice. The cause for the embryo-fetal toxicities observed in rabbits remains unclear.

The estimated background risk of major birth defects and miscarriage in the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is respectively.

Data Animal Data In mice, subcutaneous administration of nedosiran at doses up to 2000 mg/kg/dose (approximately 58 times the MRHD based on BSA) or a mouse-specific (pharmacologically active) analog (10 mg/kg/dose) during organogenesis (dosing on gestation days for nedosiran; gestation days 3 and 10 for the analog) did not have adverse effects on embryo-fetal development. Subcutaneous administration of nedosiran mg/kg/dose to pregnant rabbits during organogenesis dosing on gestation days resulted in maternal toxicity on the basis of body weight loss of up to 6.5% following the first dose in the 6 and 20 mg/kg/dose groups. Higher post-implantation loss and lower numbers of live fetuses occurred at ≥6 mg/kg/dose (exposures equivalent to the MRHD based on BSA), and fetal cardiovascular and skeletal malformations occurred at the 20 mg/kg/dose (2 times the MRHD based on BSA).

At the 2 mg/kg/dose, which is below the MRHD, no adverse findings were seen. In a pre- and postnatal study in mice, subcutaneous administration of nedosiran mg/kg/dose or a mouse-specific (pharmacologically active) analog (10 mg/kg/dose) from implantation dosing on gestational days to weaning dosing on lactation days did not have adverse effects on the growth, viability, development and reproductive performance of the offspring.

Pediatric Use The safety and effectiveness of RIVFLOZA have been established in pediatric patients aged 2 years and older. Use of RIVFLOZA in these age groups is supported by evidence from an adequate and well-controlled trial in adult and pediatric patients 9 years of age and older (PHYOX2), and a single-arm study in pediatric patients 2 to less than 12 years of age (PHYOX8). The safety and effectiveness of RIVFLOZA in patients younger than 2 years of age have not been established.