INDICATION

KRYSTEXXA® (pegloticase) is indicated for the treatment of chronic gout in adult patients who have failed to normalize serum uric acid and whose signs... See more

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  • Reference
    • KRYSTEXXA (pegloticase) [prescribing information] Amgen.

Key Inclusion/Exclusion Criteria2

Inclusion

  • Adult patients ≥18 years old with diagnosis of gout
  • Uncontrolled gout, defined as (all required)
    • Serum uric acid (sUA) ≥7 mg/dL
    • Oral urate-lowering therapy failure/intolerance
    • ≥1 ongoing gout symptom (≥1 tophus, ≥2 flares in the year prior to screening and/or chronic gouty arthritis)

Exclusion

  • Glucose-6-phosphate dehydrogenase (G6PD) deficiency
  • eGFR <40 mL/min/1.73 m2
  • MTX contraindication/known intolerance
  • Elevated LFTs, low albumin, or low blood cell counts
eGFR, estimated glomerular filtration rate; LFTs, liver function tests; MTX, methotrexate.

Family history, health literacy, and socioeconomic environment are contributing factors to gout becoming uncontrolled18,19


Two major factors contribute to uric acid buildup and crystallization18,19

Genetics
Gout runs in the family
Kidney damage
Impaired uric acid elimination
Additional contributing factors include4,20:
  • Diet and lifestyle
  • Age
  • Comorbidities
  • Metabolism
Diet is not a substitute for treatment as dietary restrictions may reduce uric acid levels by only ~1 mg/dL9,10
INFUSING KRYSTEXXA

Steps to a successful infusion day

Stay informed for your
patients and practice.
ON THIS PAGE:

Infusion Steps

  • Step 1: Check and confirm

    • Prior to the first infusion, confirm your patient has normal G6PD activity from lab tests and has discontinued taking urate-lowering therapies (eg, allopurinol, febuxostat)
    • Remind your patient why they are not taking oral urate-lowering therapies and ensure they are taking gout flare prophylaxis
    • Confirm your patient is taking prescribed medications, including methotrexate and oral folic acid, if appropriate
      • If prescribing KRYSTEXXA with methotrexate therapy, this should be maintained throughout treatment with KRYSTEXXA
    • Prior to each subsequent infusion, confirm sUA level was tested in the last 48 hours
      • sUA is a biomarker that informs the safety and efficacy of KRYSTEXXA in clinical practice1
      • Monitoring sUA 48 hours prior to infusions can help identify patients at risk for infusion reactions1
      • Notify prescribing healthcare provider if sUA level has not been tested or if any preinfusion sUA level is >6 mg/dL, and discontinue therapy, particularly after 2 consecutive preinfusion sUA levels are >6 mg/dL
      • See the KRYSTEXXA Monitoring Protocol
    *KRYSTEXXA is contraindicated for patients with G6PD deficiency. G6PD deficiency is an abnormally low level of glucose-6-phosphate dehydrogenase. Patients of African, Mediterranean, and Southern Asian ancestry have a higher risk of deficiency.2
  • Step 2: Counsel your patients

    • Answer your patient’s questions about treatment, including diet changes or limitations, and offer a Medication Guide, which provides details about proper use, side effects, and combination use with methotrexate
    • Describe to your patient how KRYSTEXXA works, including the risk of infusion reactions
    • Remind your patient of the support services available to them through Amgen By Your Side, once they are enrolled (see Helpful Resources)
    • Advise your patient to learn more about what to expect along their journey
  • Step 3: Prepare and infuse

    • Identify your patient’s infusion location (office, hospital, infusion center, or at home)
    • Using a location-based search, you can compile a list of sites of care and their information to support infusion center selection. This could include
      • Location and operating hours
      • Amenities (private infusion rooms, waiting area for caregivers, parking, handicap accessibility, power outlets, etc)
      • Additional patient support services (monitoring/testing, financial counseling, insurance verification, interpreter services, referral coordination, etc)
      • KRYSTEXXA is indicated to be administered in a healthcare setting by professionals trained to manage serious allergic reactions.2 Potential use of home infusion must be determined by healthcare professionals’ assessment of individual patient needs.
    • Administer preinfusion medications per prescribing healthcare provider’s orders
    • Visually inspect vial for particulate matter and ensure solution is clear and colorless
    • Using aseptic technique, withdraw 1 mL into a sterile syringe and inject into a 250-mL bag of normal or half-normal saline. Gently mix the bag by inverting several times and discard any unused portion of the remaining product. Do not shake.
      • No loading dose recommended or required
      • KRYSTEXXA is a single-dose vial
    • The diluted solution should be used within 4 hours
    • Before administration, allow the diluted solution of KRYSTEXXA to reach room temperature
      • Artificial heating should not be used
      • If not administered immediately, it is recommended that the diluted solution be stored in the refrigerator and away from light
    • Initiate infusion at a rate of 125 mL/h or slower via infusion pump or gravity feed
      • Infuse over no less than 2 hours
    • DO NOT ADMINISTER AS INTRAVENOUS PUSH OR BOLUS
    • The sticker on the KRYSTEXXA box is available for use on your patient’s chart, if desired
    • Use your normal protocol to monitor for infusion reactions
      • In the event of an infusion reaction, as clinically indicated, the infusion can be slowed or stopped and restarted at a slower rate
  • Step 4: Postinfusion reminders

    • Observe your patient for approximately 1 hour postinfusion
    • Remind your patient of their next sUA test and KRYSTEXXA infusion appointments along with taking prescribed medications, including methotrexate and folic acid if appropriate
      • KRYSTEXXA should be given every 2 weeks—it is recommended to provide a standing order to the lab to check the patient’s sUA level prior to each infusion
    • Remind your patient that they may experience gout flares, but KRYSTEXXA therapy can be continued regardless of gout flares
sUA, serum uric acid.

Dosing: KRYSTEXXA coadministered with methotrexate2

4-week
4-week-mobile
KRYSTEXXA alone may be used in patients for whom methotrexate is contraindicated or not clinically appropriate.
No dosing adjustments needed with KRYSTEXXA for patients with kidney disease.2
If coadministered with methotrexate and folic acid, this should be maintained throughout treatment with KRYSTEXXA.2

Safety

The addition of methotrexate reduced infusion reactions2

Most common adverse reactions in the MIRROR RCT2,§

ADVERSE REACTION KRYSTEXXA with MTX
(N=96) n (%)
KRYSTEXXA ALONE
(N=49) n (%)
Gout flare** 64 (67%) 35 (71%)
Arthralgia 13 (14%) 5 (10%)
COVID-19 9 (9%) 3 (6%)
Nausea 5 (5%) 6 (12%)
Fatigue 5 (5%) 2 (4%)
Infusion reaction 4 (4%)†† 15 (31%)
Hypertension 1 (1%) 3 (6%)
Pain in extremity 1 (1%) 3 (6%)
Vomiting 0 4 (8%)
§Adverse reactions occurring in 5% or more of patients in either the KRYSTEXXA with methotrexate or KRYSTEXXA alone study arm during a 12-month period.2
**Mobilization flares at the beginning of treatment can be a sign KRYSTEXXA is working.2
††Included one case of anaphylaxis.2
MTX, methotrexate.

Adverse event biomarker: sUA informs the safety and efficacy of KRYSTEXXA


To better predict the occurrence of infusion reactions, a post hoc analysis of the pivotal clinical trials was completed. sUA was identified as a biomarker that informs the safety and efficacy of KRYSTEXXA in clinical practice. This led to the development of the KRYSTEXXA Monitoring Protocol.
sua-biomarker-nursing
sua-biomarker-nursing-mob
Adapted with permission from Baraf HSB, et al. J Clin Rheumatol. 2014;20:427-432.
‡‡Based on infusion reactions per patient.3
sUA, serum uric acid.

Monitoring protocol


Monitoring sUA within 48 hours prior to infusions can help identify patients at risk for infusion reactions1,2
Moitoring-protocal-nursing
Monitoring-protocal-nursing-mob

IMPORTANT SAFETY INFORMATION

WARNING: ANAPHYLAXIS AND INFUSION REACTIONS, G6PD DEFICIENCY ASSOCIATED HEMOLYSIS AND METHEMOGLOBINEMIA

  • Anaphylaxis and infusion reactions have been reported to occur during and after administration of KRYSTEXXA.
  • Anaphylaxis may occur with any infusion, including a first infusion, and generally manifests within 2 hours of the infusion. Delayed hypersensitivity reactions have also been reported.
  • KRYSTEXXA should be administered in healthcare settings and by healthcare providers prepared to manage anaphylaxis and infusion reactions.
  • Premedicate with antihistamines and corticosteroids and closely monitor for anaphylaxis for an appropriate period after administration of KRYSTEXXA.
  • Monitor serum uric acid levels prior to each infusion and discontinue treatment if levels increase to above 6 mg/dL, particularly when 2 consecutive levels above 6 mg/dL are observed.
  • Screen patients at risk for glucose-6-phosphate dehydrogenase (G6PD) deficiency prior to starting KRYSTEXXA. Life threatening hemolytic reactions and methemoglobinemia have been reported with KRYSTEXXA in patients with G6PD deficiency. KRYSTEXXA is contraindicated in patients with G6PD deficiency.

CONTRAINDICATIONS:

  • In patients with G6PD deficiency.
  • In patients with history of serious hypersensitivity reactions, including anaphylaxis, to KRYSTEXXA or any of its components.

WARNINGS AND PRECAUTIONS

Anaphylaxis
In a 52-week controlled trial of KRYSTEXXA co-administered with methotrexate (MTX) compared to KRYSTEXXA alone, one patient treated with KRYSTEXXA co-administered with MTX (1%) experienced anaphylaxis during the first infusion and no patients experienced anaphylaxis treated with KRYSTEXXA alone. Patients were pre-treated with infusion reaction prophylaxis and KRYSTEXXA was discontinued following 2 consecutive serum uric acid levels above 6 mg/dL to reduce the risk of anaphylaxis and infusion reactions. These risks are higher in patients whose uric acid level increases to above 6 mg/dL, particularly when 2 consecutive levels above 6 mg/dL are observed.
During pre-marketing clinical trials with KRYSTEXXA alone, KRYSTEXXA was not discontinued following 2 consecutive serum uric acid levels above 6 mg/dL. Anaphylaxis was reported with 6.5% (8/123) of patients treated with KRYSTEXXA every 2 weeks and 4.8% (6/126) for the every 4-week dosing regimen. There were no cases of anaphylaxis in patients receiving placebo. Anaphylaxis generally occurred within 2 hours after treatment.
Diagnostic criteria of anaphylaxis were skin or mucosal tissue involvement, and, either airway compromise, and/or reduced blood pressure with or without associated symptoms, and a temporal relationship to KRYSTEXXA or placebo injection with no other identifiable cause. Manifestations included wheezing, peri-oral or lingual edema, or hemodynamic instability, with or without rash or urticaria, nausea or vomiting. Cases occurred in patients being pre-treated with one or more doses of an oral antihistamine, an intravenous corticosteroid and/or acetaminophen, which may have resulted in an underestimate of anaphylaxis frequency reported. Patients should be informed of the symptoms and signs of anaphylaxis and instructed to seek immediate medical care should anaphylaxis occur after discharge from the healthcare setting.
It is recommended that before starting KRYSTEXXA patients discontinue oral urate-lowering medications and not institute therapy with oral urate-lowering agents while taking KRYSTEXXA.

Infusion Reactions
In the 52-week trial, infusion reactions were reported in 4% of patients in the KRYSTEXXA co-administered with MTX group compared to 31% of patients treated with KRYSTEXXA alone. In both treatment groups, the majority of infusion reactions occurred at the first or second KRYSTEXXA infusion and during the time of infusion.
During pre-marketing 24-week controlled clinical trials with KRYSTEXXA alone, infusion reactions were reported in 26% of patients treated with KRYSTEXXA 8 mg every 2 weeks, and 41% of patients treated with KRYSTEXXA 8 mg every 4 weeks, compared to 5% of patients treated with placebo. These infusion reactions occurred in patients being pre-treated with an oral antihistamine, intravenous corticosteroid and/or acetaminophen, which may have resulted in an underestimate of infusion reaction frequency reported.
Manifestations of these reactions included urticaria (10.6%), dyspnea (7.1%), chest discomfort (9.5%), chest pain (9.5%), erythema (9.5%), and pruritus (9.5%). These manifestations overlap with the symptoms of anaphylaxis, but in a given patient did not occur together to satisfy the clinical criteria for diagnosing anaphylaxis. Infusion reactions occurred at any time during a course of treatment with ~3% occurring with the first infusion, and ~91% occurred during the time of infusion.
KRYSTEXXA should be infused slowly over no less than 120 minutes. In the event of an infusion reaction, the infusion should be slowed, or stopped and restarted at a slower rate.

Gout Flares:
In the 52-week trial of KRYSTEXXA co-administered with MTX vs KRYSTEXXA alone, patients were administered gout flare prophylaxis, resulting in 66% and 69% of patients with any flare for the first 3 months, respectively. In the KRYSTEXXA co-administered with MTX group, the percentages of patients with any flare for the subsequent 3 month increments of treatment were 27%, 8%, and 9% during Months 6, 9, and 12, respectively; in the group treated with KRYSTEXXA alone, 14%, 9%, and 21% during Months 6, 9, and 12, respectively.
During the 24-week pre-marketing, controlled trials, with KRYSTEXXA alone the frequencies of gout flares were high in all treatment groups, but more so with KRYSTEXXA treatment during the first 3 months, and decreased in the subsequent 3 months. The percentages of patients with any flare for the first 3 months were 74%, 81%, and 51%, for KRYSTEXXA 8 mg every 2 weeks, KRYSTEXXA 8 mg every 4 weeks, and placebo, respectively. The percentages of patients with any flare for the subsequent 3 months were 41%, 57%, and 67%, for KRYSTEXXA 8 mg every 2 weeks, KRYSTEXXA 8 mg every 4 weeks, and placebo, respectively. Patients received gout flare prophylaxis with colchicine and/or NSAIDs starting at least one week before receiving KRYSTEXXA. Gout flares may occur after initiation of KRYSTEXXA. An increase in gout flares is frequently observed upon initiation of anti-hyperuricemic therapy, due to changing serum uric acid levels resulting in mobilization of urate from tissue deposits. Gout flare prophylaxis with a NSAID or colchicine is recommended starting at least 1 week before initiation of KRYSTEXXA therapy and lasting at least 6 months, unless medically contraindicated or not tolerated. KRYSTEXXA does not need to be discontinued because of a gout flare. The gout flare should be managed concurrently as appropriate for the individual patient.

Congestive Heart Failure (CHF)
KRYSTEXXA has not been formally studied in patients with CHF, but some patients in the pre-marketing placebo-controlled clinical trials experienced exacerbation. Two cases of CHF exacerbation occurred during the trials in patients receiving treatment with KRYSTEXXA 8 mg every 2 weeks. No cases were reported in placebo-treated patients. Four subjects had exacerbations of pre-existing CHF while receiving KRYSTEXXA 8 mg every 2 weeks during the OLE study. Exercise caution in patients who have congestive heart failure and monitor patients closely following infusion.

Re-treatment with KRYSTEXXA
No controlled trial data are available on re-treatment after stopping treatment for longer than 4 weeks. Due to the immunogenicity of KRYSTEXXA, patients receiving re-treatment may be at increased risk of anaphylaxis and infusion reactions. Therefore, patients receiving re-treatment after a drug-free interval should be monitored carefully.

ADVERSE REACTIONS

The most common adverse reactions (≥5%) are:

Co-administration with MTX:

Gout flares, arthralgia, COVID-19, nausea, and fatigue.

KRYSTEXXA alone:

Gout flares, infusion reactions, nausea, contusion or ecchymosis, nasopharyngitis, constipation, chest pain, anaphylaxis, and vomiting.

INDICATION

KRYSTEXXA® (pegloticase) is indicated for the treatment of chronic gout in adult patients who have failed to normalize serum uric acid and whose signs and symptoms are inadequately controlled with xanthine oxidase inhibitors at the maximum medically appropriate dose or for whom these drugs are contraindicated.

Limitations of Use: KRYSTEXXA is not recommended for the treatment of asymptomatic hyperuricemia.

Please see Full Prescribing Information, including Boxed Warning.

  • References
    • Keenan RT, et al. Rheumatol Ther. 2019;6:299-304.
    • KRYSTEXXA (pegloticase) [prescribing information] Horizon.
    • Baraf HSB, et al. J Clin Rheumatol. 2014;20:427-432.

IMPORTANT SAFETY INFORMATION

WARNING: ANAPHYLAXIS AND INFUSION REACTIONS, G6PD DEFICIENCY ASSOCIATED HEMOLYSIS AND METHEMOGLOBINEMIA

  • Anaphylaxis and infusion reactions have been reported to occur during and after administration of KRYSTEXXA.
  • Anaphylaxis may occur with any infusion, including a first infusion, and generally manifests within 2 hours of the infusion. Delayed hypersensitivity reactions have also been reported.
  • KRYSTEXXA should be administered in healthcare settings and by healthcare providers prepared to manage anaphylaxis and infusion reactions.