Available no-cost testing for PBD‑ZSD
If you have patients you suspect may have peroxisomal biogenesis disorder-Zellweger spectrum disorder (PBD‑ZSD), Mirum Pharmaceuticals offers no-cost testing programs to help diagnose PBD‑ZSD and/or identify if a patient’s liver is at risk.
Genetic Panel*
In partnership with PreventionGenetics, Mirum offers a no-cost genetic testing program for qualifying patients to help identify PBD‑ZSD, a rare autosomal recessive disorder caused by mutations in one of 13 PEX genes and characterized by an impaired peroxisome assembly, leading to multiple enzyme deficiencies.1,2
To qualify, patients must meet one of the criteria below:
- Diagnosed PBD‑ZSD.
- Clinical suspicion of PBD‑ZSD (eg, neurological, vision, hearing, or hepatic deterioration).
The genetic test will be processed at PreventionGenetics, and the results will be sent to you about 21 days after the lab receives the specimens and all appropriately completed paperwork.
Atypical bile acid test*
Mirum Pharmaceuticals has partnered with Cincinnati Children’s Hospital Medical Center to offer liquid chromatography—mass spectrometry analysis of bile acid profile—at no cost to qualifying patients.
Highlights
- Provided at no cost to patients who qualify.
- Specimen preparation: 0.5–1 mL serum.
- Results are available in approximately 2 weeks.
Utility
- This test is easy to use and will help identify the presence and concentration levels of DHCA/THCA, atypical bile acids that can be hepatotoxic and associated with liver disease.3,4
Criteria
Patients must meet 1 of the criteria below:
- Diagnosed PBD‑ZSD.
- Severe form, often referred to as Zellweger syndrome.
- Moderate form, often referred to as neonatal adrenoleukodystrophy.
- Mild form, often referred to as infantile Refsum disease.
- Genetic result with pathogenic or likely pathogenic heterozygous mutation on any PEX gene, other than PEX7 gene.
*These resources are provided at no cost to patients, physicians, or payers. Programs may be canceled or changed at any time.
DHCA, dihydroxycholestanoic acid; PBD-ZSD, peroxisomal biogenesis disorder-Zellweger spectrum disorder; THCA, trihydroxycholestanoic acid.
Help get your PBD‑ZSD patients started on CHOLBAM
REFERENCES: 1. Jansen RLM, Santana-Molina C, van den Noort M, Devos DP, van der Klei IJ. Comparative genomics of peroxisome biogenesis proteins: making sense of the PEX proteins. Front Cell Dev Biol. 2021;9:654163. doi:10.3389/fcell.2021.654163 2. Waterham HR, Ebberink MS. Genetics and molecular basis of human peroxisome biogenesis disorders. Biochim Biophys Acta. 2012;1822(9):1430-1441. doi:10.1016/j.bbadis.2012.04.006 3. Klouwer FCC, Berendse K, Ferdinandusse S, Wanders RJA, Engelen M, Poll-The BT. Zellweger spectrum disorders: clinical overview and management approach. Orphanet J Rare Dis. 2015;10:151. doi: 10.1186/s13023-015-0368-9
INDICATION
CHOLBAM® (cholic acid) is a bile acid indicated for- Treatment of bile acid synthesis disorders due to single enzyme defects.
- Adjunctive treatment of peroxisomal disorders, including Zellweger spectrum disorders, in patients who exhibit manifestations of liver disease, steatorrhea, or complications from decreased fat-soluble vitamin absorption.
LIMITATIONS OF USE
The safety and effectiveness of CHOLBAM on extrahepatic manifestations of bile acid synthesis disorders due to single enzyme defects or peroxisomal disorders, including Zellweger spectrum disorders, have not been established.IMPORTANT SAFETY INFORMATION
WARNINGS AND PRECAUTIONS – Exacerbation of liver impairment
- Monitor liver function and discontinue CHOLBAM in patients who develop worsening of liver function while on treatment.
- Concurrent elevations of serum gamma glutamyltransferase (GGT) and alanine aminotransferase (ALT) may indicate CHOLBAM overdose.
- Discontinue treatment with CHOLBAM at any time if there are clinical or laboratory indicators of worsening liver function or cholestasis.
ADVERSE REACTIONS
- The most common adverse reactions (≥1%) are diarrhea, reflux esophagitis, malaise, jaundice, skin lesion, nausea, abdominal pain, intestinal polyp, urinary tract infection, and peripheral neuropathy.
DRUG INTERACTIONS
- Inhibitors of Bile Acid Transporters: Avoid concomitant use of inhibitors of the bile salt efflux pump (BSEP) such as cyclosporine. Concomitant medications that inhibit canalicular membrane bile acid transporters such as the BSEP may exacerbate accumulation of conjugated bile salts in the liver and result in clinical symptoms. If concomitant use is deemed necessary, monitoring of serum transaminases and bilirubin is recommended.
- Bile Acid Binding Resins: Bile acid binding resins such as cholestyramine, colestipol, or colesevelam adsorb and reduce bile acid absorption and may reduce the efficacy of CHOLBAM. Take CHOLBAM at least 1 hour before or 4 to 6 hours (or at as great an interval as possible) after a bile acid binding resin.
- Aluminum-Based Antacids: Aluminum-based antacids have been shown to adsorb bile acids in vitro and can reduce the bioavailability of CHOLBAM. Take CHOLBAM at least 1 hour before or 4 to 6 hours (or at as great an interval as possible) after an aluminum-based antacid.
PREGNANCY
No studies in pregnant women or animal reproduction studies have been conducted with CHOLBAM.LACTATION
Endogenous cholic acid is present in human milk. Clinical lactation studies have not been conducted to assess the presence of CHOLBAM in human milk, the effects of CHOLBAM on the breastfed infant, or the effects of CHOLBAM on milk production. The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for CHOLBAM and any potential adverse effects on the breastfed infant from CHOLBAM or from the underlying maternal condition.GERIATRIC USE
It is not known if elderly patients respond differently from younger patients.HEPATIC IMPAIRMENT
- Discontinue treatment with CHOLBAM if liver function does not improve within 3 months of the start of treatment.
- Discontinue treatment with CHOLBAM at any time if there are clinical or laboratory indicators of worsening liver function or cholestasis. Continue to monitor laboratory parameters of liver function and consider restarting at a lower dose when the parameters return to baseline.