Rivfloza (nedosiran)
An approved treatment for Primary Hyperoxaluria.
Drug facts
The same compound appears under different names depending on the context. Here is how to identify Nedosiran wherever you encounter it, plus the key facts at a glance.
- Generic name
- Nedosiran
- Brand name
- Rivfloza
- Development code
- DCR-PHXC
- Drug class
- LDHA-directed small interfering RNA (RNAi therapy)
- Manufacturer
- Novo Nordisk (developed by Dicerna Pharmaceuticals)
- How it's taken
- Injected under the skin of the belly (at least 2 inches from the navel) or the upper thigh once a month, with the dose set by age and weight.
A once-monthly injection under the skin approved by the FDA on September 29, 2023 to lower urinary oxalate in people 9 and older with primary hyperoxaluria type 1 (PH1) whose kidneys still work relatively well, and extended on March 27, 2025 to children as young as 2.
- In its main trial, 24-hour urinary oxalate fell by an average of 37% on nedosiran over months 3 to 6, against a 12% rise on placebo.
- The pre-filled syringe can be used by a caregiver or by patients 12 and older.
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Where Nedosiran fits
The second RNAi medicine for PH1, after lumasiran (Oxlumo, 2020). The 2 drugs silence different liver genes, LDHA for nedosiran and HAO1 for lumasiran, and no head-to-head trial has compared them.
How Nedosiran works
In PH1, a faulty liver enzyme called AGT (alanine-glyoxylate aminotransferase) cannot clear a substance called glyoxylate, so the liver turns it into oxalate instead. The kidneys then have to get rid of the extra oxalate, which binds calcium and forms kidney stones and deposits that can damage the kidneys. Nedosiran is a small interfering RNA, a short piece of genetic material, with sugar tags that steer it into liver cells.
There it silences the LDHA gene, lowering lactate dehydrogenase (LDH), an enzyme the liver uses to make oxalate. Less oxalate made by the liver means less oxalate for the kidneys to clear.
Side effects and safety
- No routine safety lab tests are listed in the label
- Tell your care team about injection site reactions that do not settle
Rivfloza has no boxed warning, no contraindications and no warnings section in its label. The most common side effect is injection site reactions such as redness, pain, bruising or rash, reported in 39% of people with PH1 on nedosiran against none on placebo in the main trial; they were generally mild and did not lead anyone to stop. In the longer extension study, 1 person developed skin thinning (atrophy) at an injection site, and in a study of 15 children aged 2 to 11, injection site reactions occurred in 13%[1].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Nedosiran
Injected under the skin of the belly (at least 2 inches from the navel) or the upper thigh once a month, with the dose set by age and weight. People 12 and older get 160mg if they weigh 50kg or more and 128mg if they weigh less. Children aged 2 to 11 get 3.3mg/kg if they weigh under 39kg, 128mg from 39kg to under 50kg, and 160mg at 50kg or more.
The pre-filled syringe can be used by a healthcare provider, a caregiver or a patient 12 or older, and vials are meant for use under a healthcare provider's guidance. If a dose is more than 7 days late, give it as soon as possible and restart monthly dosing from that date. It is kept in the refrigerator and can be stored at room temperature for up to 28 days[1].
Availability and cost
Only available as the brand-name product.
Help paying for Rivfloza
With private insurance, the drugmaker's copay card can lower what you pay for Rivfloza. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE, but charity funds often can. Of the 2 charity funds for Primary Hyperoxaluria, 1 was open on October 26, 2026. Without insurance, you can apply to the drugmaker's free medicine program, which sets its own eligibility rules. Pick your insurance below to see which offers fit you.
- Copay help
Rivfloza Savings Offer: commercially insured patients with Rivfloza coverage, including those in their deductible phase, may pay as little as $0 per fill, up to $15,000 in savings per calendar year, valid for 48 months from enrollment. Not for patients enrolled in Medicaid, Medicare, Medigap, VA, DoD, TRICARE or similar programs, or for cash-paying patients.
For: private insurance · source - Bridge or quick-start supply
JumpStart may provide a limited supply of free Rivfloza to people with a delay or gap in insurance. Eligibility and restrictions apply.
The official page does not say who qualifies. Ask the program. · source - Free medicine program
The Patient Assistance Program may provide Rivfloza free of charge to eligible people with no insurance.
For: no insurance · source - Insurance and case manager help
A dedicated Patient Liaison with a nursing background checks coverage, shares prior authorization and appeal information, coordinates the specialty pharmacy and offers injection training.
The official page does not say who qualifies. Ask the program. · source
Good to know: Hours Monday to Friday, 8 AM to 8 PM ET. Questions about the savings offer itself go to 1-833-664-5443.
Charity funds for Primary Hyperoxaluria
- From a charity · HealthWell FoundationHyperoxaluria fundOpen
Pays for: Copays, premiums or other treatment costs.
- From a charity · The Assistance FundPrimary Hyperoxaluria fundWaitlist
Pays for: Copays, coinsurance, deductibles and other health-related expenses.
Access and eligibility
Approved for children 2 and older and adults with primary hyperoxaluria type 1 and relatively preserved kidney function, such as an eGFR of at least 30. The approval covers PH1 only. It has not been studied in people with an eGFR below 30, and safety and effectiveness in children younger than 2 have not been established.
Source: NovoCare for Rivfloza
Access program details are provided for informational purposes and may vary based on insurance coverage, geographic location, and individual circumstances. Confirm current eligibility directly with the manufacturer or your specialty pharmacy.
Clinical trial results
Approval rested on PHYOX2 (NCT03847909), a 6-month trial that randomized 35 people aged 9 to 46 with PH1 or PH2 and an eGFR of at least 30 to monthly nedosiran (23 people) or placebo (12 people). Averaged over days 90 to 180, 24-hour urinary oxalate fell by 37% on nedosiran and rose by 12% on placebo, a difference of 49%; among people with PH1 the difference was 56%[1][4].
Too few people with PH2 enrolled to judge that type, so the approval covers PH1 only. The 2025 approval for younger children rested on PHYOX8 (NCT05001269), a single-arm study of 15 children aged 2 to 10 in which the urinary oxalate to creatinine ratio fell by 64% at month 6[1].
Development history
Nedosiran was developed by Dicerna Pharmaceuticals under the code DCR-PHXC[5]. The FDA approved it as Rivfloza on September 29, 2023 for people 9 and older with PH1 and relatively preserved kidney function, in a letter addressed to Novo Nordisk care of Dicerna Pharmaceuticals[2]. On March 27, 2025, the FDA extended the approval to children aged 2 to 8[3]. It was the second RNAi medicine approved for PH1, after lumasiran (Oxlumo) in 2020[7].
Explore Primary Hyperoxaluria trials
Other Primary Hyperoxaluria treatments
PH1 has 2 FDA-approved RNAi medicines that lower the liver's oxalate production. Lumasiran (Oxlumo) is approved for children and adults with PH1, is given by a healthcare professional monthly for 3 doses and then monthly or every 3 months depending on weight, and was also studied in people with advanced kidney disease. Nedosiran (Rivfloza) is a monthly injection for people 2 and older with PH1 and an eGFR of at least 30, and patients 12 and older can inject it themselves.
Common questions about Nedosiran
▸What is Nedosiran (Rivfloza)?
A once-monthly injection under the skin approved by the FDA on September 29, 2023 to lower urinary oxalate in people 9 and older with primary hyperoxaluria type 1 (PH1) whose kidneys still work relatively well, and extended on March 27, 2025 to children as young as 2. In its main trial, 24-hour urinary oxalate fell by an average of 37% on nedosiran over months 3 to 6, against a 12% rise on placebo. The pre-filled syringe can be used by a caregiver or by patients 12 and older.
▸How does Nedosiran work?
In PH1, a faulty liver enzyme called AGT (alanine-glyoxylate aminotransferase) cannot clear a substance called glyoxylate, so the liver turns it into oxalate instead. The kidneys then have to get rid of the extra oxalate, which binds calcium and forms kidney stones and deposits that can damage the kidneys. Nedosiran is a small interfering RNA, a short piece of genetic material, with sugar tags that steer it into liver cells. There it silences the LDHA gene, lowering lactate dehydrogenase (LDH), an enzyme the liver uses to make oxalate. Less oxalate made by the liver means less oxalate for the kidneys to clear.
▸What are the side effects of Nedosiran?
Rivfloza has no boxed warning, no contraindications and no warnings section in its label. The most common side effect is injection site reactions such as redness, pain, bruising or rash, reported in 39% of people with PH1 on nedosiran against none on placebo in the main trial; they were generally mild and did not lead anyone to stop. In the longer extension study, 1 person developed skin thinning (atrophy) at an injection site, and in a study of 15 children aged 2 to 11, injection site reactions occurred in 13%[1].
▸How is Nedosiran taken?
Injected under the skin of the belly (at least 2 inches from the navel) or the upper thigh once a month, with the dose set by age and weight. People 12 and older get 160mg if they weigh 50kg or more and 128mg if they weigh less. Children aged 2 to 11 get 3.3mg/kg if they weigh under 39kg, 128mg from 39kg to under 50kg, and 160mg at 50kg or more. The pre-filled syringe can be used by a healthcare provider, a caregiver or a patient 12 or older, and vials are meant for use under a healthcare provider's guidance. If a dose is more than 7 days late, give it as soon as possible and restart monthly dosing from that date. It is kept in the refrigerator and can be stored at room temperature for up to 28 days[1].
▸Is Nedosiran FDA approved?
Yes, Nedosiran (Rivfloza) is FDA approved (2023) for the treatment of Primary Hyperoxaluria.
▸What is the difference between Rivfloza and Oxlumo?
Both are RNAi injections that lower the liver's oxalate production in primary hyperoxaluria type 1, but they silence different genes: nedosiran (Rivfloza) targets LDHA and lumasiran (Oxlumo) targets HAO1. Rivfloza is given monthly, can be self-injected from age 12 and is approved for people 2 and older with an eGFR of at least 30. Oxlumo is given by a healthcare professional, monthly or every 3 months depending on weight. No trial has compared them directly.
▸Can Rivfloza be used for primary hyperoxaluria type 2?
No. The main trial included some people with PH2, but too few to judge whether it works for them, so the FDA approval covers PH1 only.
▸How is Rivfloza given?
Rivfloza is injected under the skin of the belly or upper thigh once a month. The dose depends on age and weight, from 3.3mg/kg in smaller children up to 160mg. The pre-filled syringe can be used by a caregiver or by patients 12 and older, and NovoCare offers injection training.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine, DailyMed. RIVFLOZA (nedosiran) injection, for subcutaneous use: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ace9d4bc-4d20-4beb-9e9d-888690424833
- U.S. Food and Drug Administration · 2023-09-29. NDA 215842 approval letter. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2023/215842Orig1s000ltr.pdf
- U.S. Food and Drug Administration · 2025-03-27. NDA 215842/S-002 supplement approval letter. https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2025/215842Orig1s002ltr.pdf
- Kidney International · 2023. PHYOX2: a pivotal randomized study of nedosiran in primary hyperoxaluria type 1 or 2. https://doi.org/10.1016/j.kint.2022.07.025
- ClinicalTrials.gov. A Study to Evaluate DCR-PHXC in Children and Adults With Primary Hyperoxaluria Type 1 and Primary Hyperoxaluria Type 2 (PHYOX2). https://clinicaltrials.gov/study/NCT03847909
- ClinicalTrials.gov. PHYOX8: nedosiran in children 2 to less than 12 years of age with PH1. https://clinicaltrials.gov/study/NCT05001269
- U.S. National Library of Medicine, DailyMed. OXLUMO (lumasiran) injection, for subcutaneous use: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=16985a31-f5e4-4557-9266-fc78d4bc5055
- Novo Nordisk. Rivfloza (nedosiran) injection Savings Offer Program: eligibility and restrictions. https://www.novocare.com/eligibility/rivfloza-offer.html