Procysbi

Important Dosing Instructions

• Initiate cysteamine treatment immediately after diagnosis of nephropathic cystinosis.
• Cysteamine-naïve Patients: Start PROCYSBI at a fraction of the maintenance dosage.
  • Patients 1 year to less than 6 years: Gradually increase the dosage, allowing a minimum of 2 weeks between adjustments [see Dosage and Administration (2.2)].
  • Patients 6 years of age and older: Gradually increase the dosage over 4 to 6 weeks until the maintenance dosage is achieved.
• Patients switching from immediate-release cysteamine: Start the total daily dosage of PROCYSBI at a dosage equal to the previous total daily dosage of immediate-release cysteamine [see Dosage and Administration (2.3)].
• If adverse reactions occur, decrease the PROCYSBI dosage.
• After the maintenance dosage of PROCYSBI is achieved: The dosage may need to be further increased to achieve a therapeutic target WBC cystine concentration. The maximum dosage of PROCYSBI is 1.95 grams/m2 of body surface area per day [see Dosage and Administration (2.4, 2.5)].
• Round dose calculations to the nearest incremental dosage that can be administered using the available strengths of PROCYSBI delayed-release capsules or packets of oral granules. Only use whole capsules or entire contents of the packets.

Starting and Maintenance Dosing in Cysteamine-Naïve Patients

• Start treatment with a dosage equal to ⅙ to ¼ of the maintenance dosage.
• The maintenance dosage after initial dose escalation is 1.3 g/m2 of body surface area per day divided into two doses given every 12 hours. Table 1 shows the recommended starting and maintenance dosages of PROCYSBI, converted from body-surface area to body weight.
  • Patients 1 year to less than 6 years: Increase the dosage in 10% increments to the maintenance dosage, while monitoring WBC cystine concentrations. Allow a minimum of 2 weeks between dosage adjustments [see Dosage and Administration (2.4, 2.5)]. If a patient achieves the therapeutic target WBC cystine concentration at a dosage below the recommended weight-based maintenance dosage, then stop dosage escalation and use the dosage as the patient's maintenance dosage.
  • Patients 6 years of age and older: Gradually increase the dosage over 4 to 6 weeks until the maintenance dosage is achieved.
• If a patient experiences initial intolerance, temporarily discontinue PROCYSBI and then re-start at a lower dosage and gradually increase dosage.

Switching Patients from Immediate-Release Cysteamine Bitartrate

• When switching patients from immediate-release cysteamine bitartrate to PROCYSBI, the starting total daily dose of PROCYSBI is equal to the previous total daily dose of immediate-release cysteamine bitartrate. Divide the total daily dose by two and administer every 12 hours.
• For patients who may experience temporary intolerance upon starting PROCYSBI, decrease the dosage and then gradually increase to the maintenance dosage.
• Measure the WBC cystine concentration two weeks after initiation of PROCYSBI [see Dosage and Administration (2.5)]. Adjust the PROCYSBI dosage as needed to achieve the therapeutic target WBC cystine concentration [see Dosage and Administration (2.4)]. The maximum dosage of PROCYSBI is 1.95 grams/m2 per day.

Dosage Titration to Therapeutic Target WBC Cystine Concentration

• Measure WBC cystine concentration and titrate the PROCYSBI dosage as needed to achieve the therapeutic target WBC cysteine concentration [see Dosage and Administration (2.5)].
• If the measured WBC cystine concentration is above the target level for cystine depletion, consider the following before dose adjustment: adherence to medication and dosing interval, the timing between the last dose and the blood draw for the laboratory measurement, and the timing of PROCYSBI administration in relation to food or other administration instructions.
• If a dose adjustment is required, increase the dosage by 10%, rounded to nearest dosage that can be administered using the available strengths of capsules or packets of oral granules. For patients 1 year to less than 6 years of age, allow a minimum of two weeks between dose increments. The maximum dosage of PROCYSBI is 1.95 grams/m2 per day.
• If adverse reactions occur, decrease the PROCYSBI dosage. Some patients may be unable to achieve their therapeutic target due to poor tolerability of PROCYSBI [see Warnings and Precautions (5), Adverse Reactions (6.1)].

Laboratory Monitoring

• WBC cystine concentration may be measured using the mixed leukocyte assay or by using assays for specific WBC subsets (e.g., granulocyte method). The methods used for measuring cystine and total protein content may also vary among individual laboratories [see Clinical Pharmacology (12.2)].
• Normal WBC cystine ranges and therapeutic target levels for cystine depletion depend upon the assay method used by the individual laboratory. WBC cystine values obtained from using different assay methods may not be comparable. Refer to the assay-specific therapeutic target for cystine depletion. When using the mixed leukocyte assay, the recommended target WBC cystine concentration is less than 1 nmol ½ cystine/mg protein.
• The recommended frequency of monitoring WBC cystine concentration is as follows:
  • Cysteamine-naïve patients 1 year to less than 6 years: Obtain measurement two weeks after initiation of PROCYSBI treatment and continue monitoring during dosage titration period until the therapeutic target WBC cystine concentration is achieved. Once the therapeutic target is achieved, continue monitoring monthly for 3 months, then quarterly for 1 year, and then twice-yearly, at a minimum.
  • Cysteamine-naïve patients greater than 6 years: Obtain measurement after reaching the maintenance PROCYSBI dosage, then monthly for 3 months, quarterly for 1 year, and then twice-yearly, at a minimum.
  • Patients switching from immediate-release cysteamine to PROCYSBI: Obtain measurement two weeks after initiation of PROCYSBI treatment and continue monitoring if further dosage titration is required to achieve therapeutic target WBC cystine concentration. Once the therapeutic target is achieved, continue monitoring quarterly for 6 months, then twice yearly, at a minimum.
• Obtain blood samples for WBC cystine concentration measurement 12 hours after the patient's last PROCYSBI dose, prior to administration of the next dose (i.e., trough concentration). In addition, it is important to accurately record the time of the last dose, the actual dose, and the time the blood sample was taken.

Preparation and Administration

• PROCYSBI delayed-release capsules:         
  • Swallow capsules whole. Do not crush or chew capsules or capsule contents.
  • Take capsules with fruit juice (except grapefruit juice) or water.
  • For patients who cannot swallow the capsules, the capsules can be opened and the capsule contents sprinkled on and mixed in applesauce, berry jelly or fruit juice (except grapefruit juice) and administered orally, as described below.
  • For patients with a gastrostomy tube, the capsules can be opened and the capsule contents mixed in applesauce and administered via the gastrostomy tube, as described below.
• PROCYSBI delayed-release oral granules:           
  • Do not crush or chew oral granules.
  • Sprinkle and mix the intact granules in applesauce, berry jelly or fruit juice (except grapefruit juice) and administered orally, as described below.
  • For patients with a gastrostomy tube, the oral granules can be mixed in applesauce and administered via a gastrostomy tube, as described below.
• Administer PROCYSBI at least 1 hour before or 1 hour after medications containing bicarbonate or carbonate [see Drug Interactions (7.1)].
• Do not eat for at least 2 hours before taking PROCYSBI and for at least 30 minutes after to maximize absorption. If patients are unable to take PROCYSBI without eating, take with food and limit the amount of food to approximately 4 ounces (½ cup) within 1 hour before taking PROCYSBI through 1 hour after taking PROCYSBI. Take PROCYSBI in a consistent manner in regard to food. Avoid high fat food close to dosing of PROCYSBI.
• Avoid drinking alcohol while taking PROCYSBI [see Drug Interactions (7.2)].

Pregnancy

Lactation

Pediatric Use

The safety and effectiveness of PROCYSBI have been established in pediatric patients 1 year of age and older for the treatment of nephropathic cystinosis. Use of PROCYSBI is supported by evidence from patients switched to PROCYSBI from immediate-release cysteamine bitartrate in two trials: an open-label, randomized, cross-over trial in adults and pediatric patients aged 6 years and older (n=43) and an open-label extension trial in pediatric patients aged 2 years and older (n=59). Another open-label trial was conducted in cysteamine naïve pediatric patients 1 year to less than 6 years of age (n=15) [see Clinical Trials (14.2)]. The safety profile in pediatric patients was similar to adults. In patients less than 6 years of age, vomiting occurred in 12/15 cysteamine treatment naïve patients compared to 11/13 patients switched from immediate-release cysteamine to PROCYSBI.

The safety and effectiveness of PROCYSBI have not been established in patients less than 1 year of age.

Geriatric Use

No studies with PROCYSBI have been conducted in geriatric patients.

Ehlers-Danlos-like Syndrome

Skin and bone lesions that resemble clinical findings for Ehlers-Danlos-like syndrome have been reported in patients treated with high doses of immediate-release cysteamine bitartrate or other cysteamine salts. These include molluscoid pseudotumors (purplish hemorrhagic lesions), skin striae, bone lesions (including osteopenia, compression fractures, scoliosis and genu valgum), leg pain, and joint hyperextension. One patient on immediate-release cysteamine bitartrate with serious skin lesions subsequently died of acute cerebral ischemia with marked vasculopathy. Monitor patients for development of skin or bone lesions and interrupt PROCYSBI dosing if patients develop these lesions. PROCYSBI may be restarted at a lower dose under close supervision, then slowly increase to the appropriate therapeutic dose [see Dosage and Administration (2.1, 2.4)].

Skin Rash

Severe skin rashes such as erythema multiforme bullosa or toxic epidermal necrolysis have been reported in patients receiving immediate-release cysteamine bitartrate. If severe skin rashes develop, permanently discontinue use of PROCYSBI [see Contraindications (4)].

Gastrointestinal Ulcers and Bleeding

Gastrointestinal (GI) ulceration and bleeding have been reported in patients receiving immediate-release cysteamine bitartrate. GI tract symptoms including nausea, vomiting, anorexia and abdominal pain, sometimes severe, have been associated with cysteamine. If severe GI tract symptoms develop, consider decreasing the dose of PROCYSBI [see Dosage and Administration (2.1, 2.4)].

 Fibrosing Colonopathy

Fibrosing colonopathy, including colonic stricture formation, has been reported with postmarketing use of PROCYSBI in pediatric and young adult patients with nephropathic cystinosis. Some of these patients had been treated with PROCYSBI for prolonged periods of time. Reported symptoms include: abdominal pain, vomiting, bloody or persistent diarrhea, and fecal incontinence. Evaluate patients with severe, persistent, and/or worsening abdominal symptoms for fibrosing colonopathy. If the diagnosis is confirmed, permanently discontinue PROCYSBI and switch to immediate-release cysteamine bitartrate capsules. An association between methacrylic acid-ethyl acrylate copolymer (an inactive ingredient in PROCYSBI) and fibrosing colonopathy cannot be ruled out.

Central Nervous System Symptoms

Central Nervous System (CNS) symptoms such as seizures, lethargy, somnolence, depression, and encephalopathy have been associated with immediate-release cysteamine. Neurological complications have also been described in some patients with cystinosis who have not been treated with cysteamine. Carefully evaluate and monitor patients who develop CNS symptoms. Interrupt medication or adjust the dose as necessary for patients with severe symptoms or with symptoms that persist or progress. Inform patients that PROCYSBI may impair their ability to perform tasks such as driving or operating machinery.

Leukopenia and/or Elevated Alkaline Phosphatase Levels

Cysteamine has been associated with reversible leukopenia and elevated alkaline phosphatase levels. Monitor white blood cell counts and alkaline phosphatase levels. If tests values remain elevated, consider decreasing the dose or discontinuing the drug until values revert to normal.

Benign Intracranial Hypertension

Benign intracranial hypertension (pseudotumor cerebri; PTC) and/or papilledema have been reported in patients receiving immediate-release cysteamine bitartrate treatment. Monitor patients for signs and symptoms of PTC, including headache, tinnitus, dizziness, nausea, diplopia, blurry vision, loss of vision, pain behind the eye or pain with eye movement. If signs/symptoms persist, interrupt dosing or decrease the dose and refer the patient to an ophthalmologist. If the diagnosis is confirmed, permanently discontinue use of PROCYSBI.