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MethemoglobinemiaPhase 1NCT02493283

Pharmacokinetics and Distribution of Dapsone in Leucocytes After Single-dose and Multiple-dose Administration

A Phase 1 study testing Dapsone single dose, Dapsone multiple dose and leucocytes in people with Methemoglobinemia and Linear IgA Bullous Dermatosis, run by University Medicine Greifswald at 1 site in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The objectives of the study are to evaluate pharmacokinetics, distribution in blood leucocytes, metabolism and methemoglobinemia after single-dose and repeated-dose administration of 100 mg of dapsone in healthy subjects genotyped for CYP2C9 and NAT2 to evaluate serum through levels, distribution in blood leucocytes… Read more about this study

Who is it for?
Ages 18 to 45 yearsHealthy volunteers can take part
What is being tested?
Dapsone single dose, Dapsone multiple dose and leucocytes
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
23 participants
Where
1 siteGermany
Study dates
Sep 2011to Mar 2015
Phase
Phase 1
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 45 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 18 - 45 years
  • preferably males (females will be included if there are not enough males which fulfill the inclusion criteria)
  • Caucasian
  • body weight: > 19 kg/m² and < 27 kg/m²
  • good health as evidenced by the results of the clinical examination, ECG, and the laboratory check-up, which are judged by the clinical investigator not to differ in a clinical relevant way from the normal state
  • written informed consent given by volunteer after being provided with detailed information about the nature, risks, and scope of the clinical trial as well as the expected desirable and adverse effects of the drug

Who cannot join

  • results of the medical examination or laboratory screening which are judged by the clinical investigator to differ in a clinically relevant way from the normal state
  • female subjects not willing to apply a highly effective method of birth control, which means contraceptive methods with a low failure rate of less than 1% per year during the entire study as stated in the Note for Guidance on Non-Clinical Safety Studies for the Conduct of Human Clinical Trials for Pharmaceuticals (CPMP/ICH/286/95, modifications). These methods include implants, injectables, combined oral contraceptives, some IUDs, sexual abstinence or vasectomised partner.
  • subjects with existing cardiac or hematological diseases and/ or pathological findings which might interfere with safety, pharmacodynamic effect and/ or pharmacokinetics of dapsone
  • subjects with existing gastrointestinal diseases and/ or pathological findings which might interfere with safety, pharmacodynamic effect and/ or pharmacokinetics of dapsone
  • subjects with acute or chronic organ diseases which could affect drug absorption, metabolism or excretion of dapsone and its metabolites
  • subjects liable to orthostatic dysregulation, fainting, or blackout
Show all 24Show fewer
  • subjects with known allergic reactions to the investigational product and its adjuvants
  • deficiency of glucose-6-phosphate dehydrogenase (G6PD)
  • subjects positive of HBsAG, HIV and /or drugs
  • subjects with history of psychiatric disorders (depressions, other psychotic disorders)
  • subjects with history of epilepsy
  • gravidity
  • breast feeding mothers, lactation
  • alcohol consumption more than 20 g/day
  • special or uniform nutritional habits, e.g. vegetarians or undercaloric diet
  • intake of grapefruit containing food or beverages and poppy seeds containing products (will not be allowed) 14 days prior to the first drug administration (and) until the last blood sampling of the study
  • subjects with uncommon physical exercise (competitive athletes), excessive physical activity one week before the trial
  • excessive smoking (more than 10 cigarettes or equivalents per day)
  • less than 14 days after last acute disease
  • less than 14 days after last systemic or local drug administration or less than 10 half-lives of the respective drugs
  • blood donation within the last 3 months
  • blocking time due to another clinical trial with investigational products
  • subjects suspected or known not to follow instructions
  • subjects who are unable to understand the written and verbal instructions, in particular regarding the risks and inconveniences they will be exposed to as a result of their participation in the study

Trial locations and contacts

1 site in 1 country.

Germany1 site
  • Department of Clinical Pharmacology, Ernst-Moritz-Arndt-University Greifswald

    Greifswald, Mecklenburg-Vorpommern, 17487

Other trials in Germany

About this study

Official title: Pharmacokinetics and Distribution of Dapsone (DDS) in Leucocytes After Single-dose and Multiple-dose Administration in Healthy Subjects Genotyped for CYP2C9 and NAT2 and in Patients With Autoimmune Bullous Dermatoses

The objectives of the study are

  • to evaluate pharmacokinetics, distribution in blood leucocytes, metabolism and methemoglobinemia after single-dose and repeated-dose administration of 100 mg of dapsone in healthy subjects genotyped for CYP2C9 and NAT2
  • to evaluate serum through levels, distribution in blood leucocytes and methemoglobinemia after repeated-dose treatment with dapsone in patients with autoimmune bullous dermatoses before and after concomitant treatment with glucocorticoids
Read the detailed description

Dapsone (diamino diphenyl sulphone, DDS) was synthesized by Emil Fromm and Jakob Wittmann in Freiburg (Germany) in 1908. In 1937, the anti-inflammatory potency of dapsone was discovered in experimentally-induced infections in mice. Since 1941, dapsone (as Promin®) is used with great success in the therapy of leprosy. Dapsone is a mainstay in the treatment of leprosy, being one of the components of the multidrug regimen advised by the World Health Organization (WHO).

In 1950, Esteves and Brandão confirmed the efficacy of the drug in patients with dermatitis herpetiformis Duhring. Sneddon and Wilkinson in England reported a remission as caused by dapsone in a patient with subcorneal pustulosis. The efficacy of dapsone in treatment of pemphigus vulgaris was initially reported by Winkelmann and Roth in 1960.

After oral administration, dapsone is almost completely absorbed from the gastrointestinal tract with bioavailability of more than 86 %. Maximum serum concentrations between 0,63 and 4,82 mg/l are attained within 2-8 hours after single doses between 50 mg and 300 mg. At steady-state, the serum concentration fluctuate between 3,26 mg/l and 1,95 mg/l chronic treatment with 100 mg dapsone once daily (s.i.d.).

Dapsone is distributed to all organs, it crosses the blood-brain barrier and placenta and is detected in breast milk.

About 20% of dapsone is excreted unchanged into the urine, 70-85% as water-soluble metabolites additionally to a small amount in feces.

Dapsone is nearly completely metabolized in the liver and in activated polymorphic neutrophils (PMN) and/or mononuclear cells. The major metabolic pathway in the liver is N-acetylation by the polymorphic N-acetyltransferase 2 (NAT2) and N-oxidation by cytochrome P-450 (CYP) enzymes. Major metabolites are monoacetyl-dapsone (MADDS) and dapsone hydroxylamine (DDS-NOH). Dapsone undergoes enterohepatic circulation.

MADDS is subjected also to significant deacetylation. A constant equilibrium between acetylation and deacetylation is reached within a few hours after the oral administration of either dapsone or MADDS. The acetylation ratio shows a large interindividual variation, ranging from 0.1 to 2.0. These ratios show a bimodal distribution pattern.

Acetylation is not the rate-determining step in overall elimination of dapsone. The amount of MADDS excreted in urine is very low because it is largely deacetylated to dapsone before excretion into the urine. Between slow acetylators (SA) and rapid acetylators (RA), there are no differences neither in dapsone serum concentrations nor any pharmacokinetic parameters of dapsone. Also, the therapeutic response is the same in both acetylator phenotypes.

However, excretion of both MADDS and its conjugated derivatives is higher in RA. Therefore, dapsone may be used for determination of the NAT2 phenotype even though these metabolites represent only a very small fraction of the dose.

MADDS is highly bound to plasma proteins (> 98%), about 20-25 times more tightly than dapsone. Presumably, the small fraction of unbound MADDS and its strong binding to plasma proteins are reasons for its low availability in erythrocytes (erythrocyte/plasma ratio = 0.33). Tight protein binding is also the reason behind low glomerular filtration rate of the metabolite; therefore the half-life for MADDS is approximately 20-25 hours, similar like for dapsone.

Microsomal N-hydoxylation is the second major metabolic route of dapsone which seems to be associated with hematological side effects of the drug. However, the data on excretion of free and conjugated DDS-NOH vary widely in the literature. No reliable information is available on excretion of hydroxylated MADDS compounds.

In terms of efficacy and safety of dapsone, most important is the generation of DDS-NOH, that also occurs in inflamed lesions of the skin as mediated by activated PMN. Thus, over the years, dapsone became a first-line drug in the treatment of dermatitis herpetiformis Duhring, Sneddon-Wilkinson-Syndrome and further bullous autoimmune dermatoses. Most recently was found, that formation of DDS-NOH is mainly under control of CYP2C9 in-vitro.(Lit.) Because of the known CYP2C9 gene polymorphisms (about 4-6 % are poor metabolizers, PM), efficacy of the drug in bullous autoimmune dermatoses may be dependent on the metabolizer status of the patients.

The investigators hypothesize, that subjects which are slow acetylators of NAT2 (SA) but extensive metabolizers of CYP2C9 (EM) may form significantly higher levels of the active metabolite DDS-NOH than rapid acetylators of NAT2 (RA) being PM of CYP2C9 (PM).

Being tested
Dapsone single dose, Dapsone multiple dose, leucocytes, Met-Hb
Keywords
dapsone, blood leucocytes, pharmacokinetics, metabolism
Medical subject headings
Methemoglobinemia, Linear IgA Bullous Dermatosis

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Dapsone single doseDrug

    Administration of two tablets Dapson-Fatol 50 mg Tabletten (= 100 mg dapsone) and sampling of blood (before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 h after single-dose administration), urine (0-24 h, 24-48 h, 48-72 h, 72-96 h, 96 -120 h) and feces (on treatment days 1-5)

  • Dapsone multiple doseDrug

    Administration of two tablets Dapson-Fatol 50 mg Tabletten (= 100 mg dapsone) s.i.d. for 7 days and sampling of blood (before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 h after last repeated-dose administration), urine (last treatment day 0-24 h) and feces (on treatment days 12-15)

  • leucocytesBiological

    sampling for leucocytes collection: study days -1, 1, 14 and 15

  • Met-HbBiological

    sampling before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 h after single-dose administration, before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 h after last repeated-dose administration and sampling for additional safety analyses (Met-Hb): study days 10, 12, 14 and hematology on study day 12

Study groups in NCT02493283
Study groupRoleWhat they receive
Treatment AActive comparatorsingle-dose administration of 100 mg dapsone; sampling of blood, urine and feces; sampling for leucocytes collection and sampling for additional safety analyses (Met-Hb)
Receives: Drug: Dapsone single dose; Biological: leucocytes; Biological: Met-Hb
Treatment BActive comparatormultiple-dose administration of 100 mg dapsone s.i.d. for 7 days; sampling of blood, urine and feces; sampling for leucocytes collection and sampling for additional safety analyses (Met-Hb)
Receives: Drug: Dapsone multiple dose; Biological: leucocytes; Biological: Met-Hb

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Area under the curve (AUC) for dapsone (DDS) and MA-DDS

    AUC0-∞ for single dose administration and AUC0-24h for multiple dose

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration

Secondary outcomes (14)
  1. maximal serum concentration (Cmax) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration

  2. minimal serum concentration (Cmin) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration on study-day 15

  3. peak trough fluctuation (PTF) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration on study-day 15

  4. timepoint of maximal serum concentration (Tmax) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after single -dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration

  5. terminal half live (T1/2) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after last repeated-dose administration

  6. renal clearance (CLR) for dapsone (DDS) and MA-DDS

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96 and 120 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96 and 120 hours after last repeated-dose administration

  7. metabolic clearance (CLM) for dapsone (DDS)

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96 and 120 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96 and 120 hours after last repeated-dose administration

  8. rate of adverse events

    Measured: participants will be followed for the duration of hospital stay (3 weeks) and up to 2 weeks after last study medication, an expected average of 5 weeks

  9. Met-Hb

    Measured: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72, 96 on study day 1 and 14 and additional once on study day 10 and 12

  10. leucocytes

    Measured: study day 12

  11. erythrocytes

    Measured: study day 12

  12. hemoglobin

    Measured: study day 12

  13. hematocrit

    Measured: study day 12

  14. platelets

    Measured: study day 12

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted9 Jul 2015 (estimated)
  2. Study startSep 2011
  3. Primary completionJun 2012
  4. Study completionMar 2015

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 1
Primary purpose
Basic science
Allocation
Non-randomised
Intervention model
Single group
Masking
None (open label)
Enrolment
23 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02493283
Sponsor's protocol ID
Dapson - 2010
Status last verified
Jul 2015
First submitted
30 Jun 2015
Last updated
9 Jul 2015
Results posted
No
Data monitoring committee
Yes

Questions about this trial

What is this clinical trial studying?

A Phase 1 study testing Dapsone single dose, Dapsone multiple dose and leucocytes in people with Methemoglobinemia and Linear IgA Bullous Dermatosis, run by University Medicine Greifswald at 1 site in Germany.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 6 inclusion and 24 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 9 Jul 2015. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Area under the curve (AUC) for dapsone (DDS) and MA-DDS (time frame: before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48, 72 and 96 hours after single-dose administration and before and 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 16 and 24 hours after last repeated-dose administration). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jul 2015.

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