Nulibry

fosdenopterin hydrobromide · Injection, Powder, Lyophilized, For Solution · Intravenous

Prescription (Rx) Cyclic Pyranopterin Monophosphate

Uses

1 INDICATIONS AND USAGE NULIBRY is indicated to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A. NULIBRY is cyclic pyranopterin monophosphate (cPMP) indicated to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A. ( 1 )

Dosage and administration

Start NULIBRY if known or presumed MoCD Type A. Promptly discontinue if MoCD Type A is not confirmed by genetic testing. ( 2.1 ) NULIBRY is intended for administration by a healthcare provider. If deemed appropriate by a healthcare provider, NULIBRY may be administered at home by the patient's caregiver. ( 2.2 ) See the table below for the recommended dosage in patients less than one year of age. Administer NULIBRY by intravenous infusion once daily. For dose volumes less than 2 mL, consider administering by slow intravenous push. ( 2.3 ) Titration Duration Preterm Neonates (Gestational Age Less than 37 Weeks) Term Neonates (Gestational Age 37 weeks and Above) Initial Dosage 0.4 mg/kg once daily 0.55 mg/kg once daily Dosage at Month 1 and Month 2 0.7 mg/kg once daily 0.75 mg/kg once daily Dosage at Month 3 to Month 12 0.9 mg/kg once daily 0.9 mg/kg once daily Recommended Dosage in Patients One Year of Age or Older: 0.9 mg/kg given as an intravenous infusion once daily. ( 2.3 ) 2.1 Patient Selection Start NULIBRY if the patient has a diagnosis or presumptive diagnosis of MoCD Type A. In patients with a presumptive diagnosis of MoCD Type A, confirm the diagnosis of MoCD Type A immediately after initiation of NULIBRY treatment. In such patients, discontinue NULIBRY if the MoCD Type A diagnosis is not confirmed by genetic testing. 2.2 Important Recommendation Prior to NULIBRY Treatment NULIBRY is intended for administration by a healthcare provider. If deemed appropriate by a healthcare provider, NULIBRY may be administered at home by the patient's caregiver. If NULIBRY can be administered by a caregiver/patient, advise them to read the detailed instructions on the preparation, administration, storage, and disposal of NULIBRY for caregivers [see Instructions for Use ]. 2.3 Recommended Dosage and Administration Recommended Dosage and Administration in Patients Less Than One Year of Age (by gestational age) The recommended dosage regimen of NULIBRY in patients less than one year of age (by gestational age), is based on actual body weight as shown in Table 1 . Administer NULIBRY by intravenous infusion once daily. For dose volumes less than 2 mL, consider administering by slow intravenous push using syringe administration [ see Dosage and Administration ( 2.4 ) ] . Table 1 Recommended Initial Dosage and Titration Schedule of NULIBRY for Patients Less Than One Year of Age by Gestational Age Titration Duration Preterm Neonates (Gestational Age Less than 37 Weeks) Term Neonates (Gestational Age 37 Weeks and Above) Initial Dosage 0.4 mg/kg once daily 0.55 mg/kg once daily Dosage at Month 1 and Month 2 0.7 mg/kg once daily 0.75 mg/kg once daily Dosage at Month 3 to Month 12 0.9 mg/kg once daily 0.9 mg/kg once daily Recommended Dosage and Administration in Patients One Year of Age or Older For patients one year of age or older, the recommended dosage of NULIBRY is 0.9 mg/kg (based on actual body weight) administered as an intravenous infusion once daily. Missed Dose If a NULIBRY dose is missed, administer the missed dose as soon as possible. Administer the next scheduled dose at least 6 hours after the administration of the missed dose. 2.4 Preparation and Administration Instructions Preparation NULIBRY must be reconstituted prior to use. Use aseptic technique during preparation and follow these instructions: Calculate the dose based on the patient's weight to determine the number of vials needed and total reconstituted dose volume. More than one vial may be needed to achieve the calculated dose. Remove the required number of vials from the freezer to allow them to reach room temperature (by hand warming for 3 to 5 minutes or exposing to ambient air for approximately 30 minutes). Reconstitute each NULIBRY vial with 5 mL of Sterile Water for Injection, USP. Gently swirl the vial continuously until the powder is completely dissolved. DO NOT shake. After reconstitution, the final concentration of NULIBRY reconstituted solution is 9.5 mg/5 mL (1.9 mg/mL). Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Reconstituted NULIBRY is a clear and colorless to pale yellow solution. Do not use if there are particles present or if the solution is discolored. Withdraw the calculated dose volume from the vial(s) using a syringe. Discard any unused solution remaining in the vial(s). Administration If reconstituted NULIBRY solution in the vial is refrigerated, allow it to come to room temperature (by hand warming for 3 to 5 minutes or exposing to ambient air for approximately 30 minutes) before administration. Administer NULIBRY as an intravenous infusion using an infusion pump at a rate of 1.5 mL per minute. Use non-DEHP tubing and a 0.2 micron filter to administer the total reconstituted dose volume. For dose volumes less than 2 mL, consider administering by slow intravenous push over 1 to 2 minutes using syringe administration. Complete administration of NULIBRY within 4 hours of reconstitution [ see Dosage and Administration ( 2.6 ) ] . Do not mix NULIBRY with other drugs. Do not administer as an infusion with other drugs. 2.5 Home Administration If deemed appropriate by a healthcare provider, NULIBRY may be administered at home by the patient's caregiver. If NULIBRY can be administered by a caregiver/patient, advise them to read the detailed instructions on the preparation, administration, storage, and disposal of NULIBRY for caregivers [see Instructions for Use ]. 2.6 Storage of Reconstituted Solution If the reconstituted NULIBRY solution in the vial is not used immediately, store at room temperature at 15°C to 25°C (59°F to 77°F) or refrigerate at 2°C to 8°C (36°F to 46°F) for up to 4 hours (inclusive of infusion time), or discard. Do not heat. Do not re-freeze NULIBRY after reconstitution. Do not shake.

Dosage forms and strengths

For injection: 9.5 mg of fosdenopterin, as a white to pale yellow lyophilized powder or cake in a single-dose vial for reconstitution. For injection: 9.5 mg of fosdenopterin as a lyophilized powder or cake in a single-dose vial for reconstitution. ( 3 )

Contraindications

None. None. ( 4 )

Warnings and precautions

Potential for Photosensitivity : Advise patients/caregivers to avoid patient exposure to sunlight, and to have the patient wear sunscreen, protective clothing, and sunglasses when exposed to the sun. If photosensitivity occurs, advise caregivers/patients to seek medical attention immediately and consider a dermatological evaluation. ( 5.1 , 13.2 ) 5.1 Potential for Photosensitivity Animal studies have identified that NULIBRY has phototoxic potential [ see Nonclinical Toxicology ( 13.2 ) ]. Advise NULIBRY-treated patients or their caregivers to avoid or minimize patient exposure to direct sunlight and artificial UV light exposure (i.e., UVA or UVB phototherapy) and adopt precautionary measures (e.g., have the patient wear protective clothing and hats, use broad spectrum sunscreen with high sun protection factor (SPF) in patients 6 months of age and older, and wear sunglasses when exposed to the sun). If photosensitivity occurs, advise caregivers/patients to seek medical attention immediately and consider a dermatological evaluation.

Side effects

The most common adverse reactions (>25%) were catheter-related complications, pyrexia, viral infection, pneumonia, otitis media, vomiting, cough/sneezing, viral upper respiratory infection, gastroenteritis, bacteremia, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sentynl Therapeutcis, Inc. at 888-507-5206 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. Overview of Safety Evaluation The safety of NULIBRY was assessed in 37 pediatric patients and healthy adults who received at least one intravenous infusion of NULIBRY or an E. coli derived non-salt, anhydrous form of cPMP (recombinant cPMP or rcPMP, which has the same active moiety and therefore the same biologic activity as NULIBRY). Of these 37 patients/healthy adults, 13 were pediatric patients with MoCD Type A in Studies 1, 2, and 3 [ see Clinical Studies ( 14 )] , 6 were pediatric patients with presumptive MoCD Type A but who were later confirmed to not have MoCD Type A, and 18 were healthy adults (without MoCD Type A) in a Phase 1 study. Adverse Reactions Assessment of adverse reactions for NULIBRY is based on data from two open-label, single-arm studies, Study 1 (n=8) and Study 2 (n=1), in patients with a confirmed diagnosis of MoCD Type A (8 of the 9 patients were previously treated with rcPMP). In these studies, patients received a daily intravenous infusion of NULIBRY. The median exposure to NULIBRY was 4.3 years and ranged from 8 days to 5.6 years [ see Clinical Studies ( 14 )]. In these studies, 44% of patients were males and 56% were females, 67% were White and 33% were Asian. The mean age was 14 days and ranged from 1 day to 69 days at time of first infusion. Table 2 presents the most common adverse reactions that occurred in NULIBRY-treated patients in Studies 1 and 2. Table 2 Common Adverse Reactions Reported in Two or More NULIBRY-Treated Patients with MoCD Type A (Studies 1 and 2) Adverse Reactions NULIBRY-Treated Patients (N=9) n (%) Abbreviations: MoCD = molybdenum cofactor deficiency 1 Catheter-related complications included complication associated with device, catheter site abscess, catheter site discharge, catheter site extravasation, catheter site pain, catheter site infection, catheter site inflammation, device dislocation, device leakage, device occlusion, and vascular device infection. Catheter-related complications 1 8 (89%) Pyrexia 7 (78%) Viral infection 5 (56%) Pneumonia 4 (44%) Otitis Media 4 (44%) Vomiting 4 (44%) Cough/Sneezing 4 (44%) Upper viral respiratory infection 3 (33%) Gastroenteritis 3 (33%) Diarrhea 3 (33%) Bacteremia 3 (33%) Abdominal pain 2 (22%) Influenza 2 (22%) Lower respiratory tract infection 2 (22%) Viral tonsillitis 2 (22%) Oropharyngeal pain 2 (22%) Rash maculo-papular 2 (22%) Anemia 2 (22%) Eye swelling 2 (22%) Seizure 2 (22%) Agitation 2 (22%) Safety data are also available from 10 patients with MoCD Type A who received rcPMP in Study 3 (an observational study) [ see Clinical Studies ( 14 )]. The median time on rcPMP treatment was 1.5 years and ranged from 6 days to 4.4 years. In Study 3, the patient population was evenly distributed between males and females with a mean age of 18 days (range 1, 69) at time of first infusion, 70% were White, and 30% were Asian. In Study 3, one patient died of necrotizing enterocolitis. Adverse reactions for the rcPMP-treated patients were similar to the NULIBRY-treated patients, except for the following additional adverse reactions that were reported in more than one patient: sepsis, oral candidiasis, varicella, fungal skin infection, and eczema.

Use in specific populations

8.1 Pregnancy Risk Summary There are no available data on NULIBRY use in pregnant females 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 outcomes occurred at dose exposures 32-89 times the human exposure at the maximum recommended human dose (MRHD) of 0.9 mg/kg/day (see Data ). The background risk of major birth defects and miscarriage for 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 2% to 4% and 15% to 20%, respectively. Data Animal Data In an embryofetal development study, intravenous administration of fosdenopterin to pregnant rabbits once daily during the period of organogenesis (GD 7 to GD 20) at doses up to 200 mg/kg/day (approximately 89 times the human exposure at the MRHD, based on AUC) did not result in adverse developmental effects. In a pre- and postnatal development study, subcutaneous administration of fosdenopterin to pregnant mice once daily throughout pregnancy and lactation (GD 6 to Lactation Day 20) at doses of 50, 100, or 200 mg/kg/day (up to 32 times the human exposure at the MRHD, based on AUC) did not result in adverse developmental effects. 8.2 Lactation Risk Summary There are no human or animal data available to assess the presence of NULIBRY or its metabolites in human milk, the effects on the breastfed infant, or the effects on milk production for the mother. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for NULIBRY and any potential adverse effects on the breastfed infant from NULIBRY or from the underlying maternal condition. 8.4 Pediatric Use Safety and effectiveness of NULIBRY for the treatment of MoCD Type A have been established in pediatric patients starting from birth. Use of NULIBRY for this indication is supported by evidence from two open-label studies (Studies 1 and 2) and one observational study (Study 3), in which 13 pediatric patients aged birth to 6 years of age were treated with NULIBRY or rcPMP. Pediatric use information is discussed throughout the labeling. Animal studies have identified that NULIBRY has phototoxic potential. Advise NULIBRY-treated patients or their caregivers to avoid patient exposure to direct sunlight and artificial UV light exposure (i.e., UVA or UVB phototherapy) and adopt precautionary measures [ see Warnings and Precautions ( 5.1 ) and Nonclinical Toxicology ( 13.2 ) ]. 8.5 Geriatric Use MoCD Type A is largely a disease of pediatric patients. Clinical studies of NULIBRY did not include patients 65 years of age and older. 8.6 Adult Use The safety and effectiveness of NULIBRY for the treatment of adults with MoCD Type A have been established. Use of NULIBRY in adults for this indication is based on an adequate and well- controlled clinical investigation in pediatric patients [ see Clinical Studies ( 14 ) ].

Pregnancy

8.1 Pregnancy Risk Summary There are no available data on NULIBRY use in pregnant females 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 outcomes occurred at dose exposures 32-89 times the human exposure at the maximum recommended human dose (MRHD) of 0.9 mg/kg/day (see Data ). The background risk of major birth defects and miscarriage for 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 2% to 4% and 15% to 20%, respectively. Data Animal Data In an embryofetal development study, intravenous administration of fosdenopterin to pregnant rabbits once daily during the period of organogenesis (GD 7 to GD 20) at doses up to 200 mg/kg/day (approximately 89 times the human exposure at the MRHD, based on AUC) did not result in adverse developmental effects. In a pre- and postnatal development study, subcutaneous administration of fosdenopterin to pregnant mice once daily throughout pregnancy and lactation (GD 6 to Lactation Day 20) at doses of 50, 100, or 200 mg/kg/day (up to 32 times the human exposure at the MRHD, based on AUC) did not result in adverse developmental effects.

Pediatric use

8.4 Pediatric Use Safety and effectiveness of NULIBRY for the treatment of MoCD Type A have been established in pediatric patients starting from birth. Use of NULIBRY for this indication is supported by evidence from two open-label studies (Studies 1 and 2) and one observational study (Study 3), in which 13 pediatric patients aged birth to 6 years of age were treated with NULIBRY or rcPMP. Pediatric use information is discussed throughout the labeling. Animal studies have identified that NULIBRY has phototoxic potential. Advise NULIBRY-treated patients or their caregivers to avoid patient exposure to direct sunlight and artificial UV light exposure (i.e., UVA or UVB phototherapy) and adopt precautionary measures [ see Warnings and Precautions ( 5.1 ) and Nonclinical Toxicology ( 13.2 ) ].

Geriatric use

8.5 Geriatric Use MoCD Type A is largely a disease of pediatric patients. Clinical studies of NULIBRY did not include patients 65 years of age and older.

Description

(fosdenopterin) for injection is cyclic pyranopterin monophosphate (cPMP). Fosdenopterin is present as a dihydrate of the hydrobromide salt with the chemical name (4a R ,5a R ,11a R ,12a S )-8-amino-4a,5a,6,9,11,11a,12,12a-octahydro-2,12,12-trihydroxy-1,3,2-dioxaphosphorino[4',5':5,6]pyrano[3,2- g ]pteridin-10(4 H )-one 2-oxide. Fosdenopterin hydrobromide as a dihydrate is a crystalline solid. The molecular formula is C 10 H 14 N 5 O 8 P
• HBr
• 2H 2 O and the molecular weight is 480.16. The chemical structure is: NULIBRY is supplied as a sterile, preservative-free, white to pale yellow lyophilized powder or cake in a single-dose, clear glass vial for reconstitution for intravenous infusion. Each vial contains 9.5 mg fosdenopterin (equivalent to 12.5 mg fosdenopterin hydrobromide as a dihydrate). Each vial also contains the following inactive ingredients: 10 mg ascorbic acid USP, 187.5 mg mannitol USP, and 62.5 mg sucrose NF. Sodium hydroxide NF and hydrochloric acid NF are used to adjust pH to 5.0-7.0. chemical structure

Mechanism of action

12.1 Mechanism of Action Patients with MoCD Type A have mutations in the MOCS1 gene leading to deficient MOCS1A/B dependent synthesis of the intermediate substrate, cPMP. Substrate replacement therapy with NULIBRY provides an exogenous source of cPMP, which is converted to molybdopterin. Molybdopterin is then converted to molybdenum cofactor, which is needed for the activation of molybdenum-dependent enzymes, including sulfite oxidase (SOX), an enzyme that reduces levels of neurotoxic sulfites.

How supplied

How Supplied NULIBRY (fosdenopterin) for injection is a white to pale yellow lyophilized powder or cake in a single-dose clear glass vial for reconstitution. Each NULIBRY vial contains 9.5 mg of fosdenopterin. Each carton of NULIBRY contains one vial (NDC 42358-295-01). Components are not made with natural rubber latex. Storage Store NULIBRY frozen between -25°C and -10°C (-13°F and 14°F). Store vial in original carton to protect from light. For storage recommendations for the reconstituted solution [ see Dosage and Administration ( 2.6 ) ] .

Storage

Storage Store NULIBRY frozen between -25°C and -10°C (-13°F and 14°F). Store vial in original carton to protect from light. For storage recommendations for the reconstituted solution [ see Dosage and Administration ( 2.6 ) ] .

Patient information

Advise patients/caregivers to read the FDA-approved patient labeling (Instructions for Use) and complete the treatment logs as appropriate. Photosensitivity Advise patients and/or caregivers of the potential for photosensitivity reactions and to ensure that the patient avoids or minimizes exposure to sunlight and artificial UV light exposure (i.e., UVA or UVB phototherapy) during use of NULIBRY, uses broad spectrum sunscreen with high sun protection factor (patients 6 months of age and older), and wears clothing, a hat, and sunglasses that protects against sun exposure. Instruct patients/caregivers to seek medical attention immediately if the patient develops a rash or if they notice symptoms of photosensitivity reactions (redness, burning sensation of the skin, blisters) [ see Warnings and Precautions ( 5.1 ) and Nonclinical Toxicology ( 13.2 ) ] . Manufactured by: Alcami Carolinas Corporation, Charleston, SC 29405 Distributed by: Sentynl Therapeutics, Inc., Solana Beach, CA 92075

Label text from the FDA structured product label by Sentynl Therapeutics, Inc. (revised May 26, 2026). Long sections are shortened; the complete label is on DailyMed.

Active ingredients

Nulibry NDC products (1)

NDCStrength & formLabelerType
42358-295Fosdenopterin Hydrobromide 9.5 mg/1
Injection, Powder, Lyophilized, For Solution
Sentynl Therapeutics, Inc.NDA

Frequently asked questions

What is Nulibry used for?

1 INDICATIONS AND USAGE NULIBRY is indicated to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A. NULIBRY is cyclic pyranopterin monophosphate (cPMP) indicated to reduce the risk of mortality in patients with molybdenum cofactor deficiency (MoCD) Type A. ( 1 )

What are the side effects of Nulibry?

The most common adverse reactions (>25%) were catheter-related complications, pyrexia, viral infection, pneumonia, otitis media, vomiting, cough/sneezing, viral upper respiratory infection, gastroenteritis, bacteremia, and diarrhea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Sentynl Therapeutcis, Inc. at 888-507-5206 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical… See the full label for the complete list.

Who makes Nulibry?

Nulibry is listed by 1 labeler in the FDA NDC directory, including Sentynl Therapeutics, Inc..