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Study · Not a test of the peptide alone · 2014

7 results

Sustained exposure to the investigational Kisspeptin analog, TAK-448, down-regulates testosterone into the castration range in healthy males and in patients with prostate cancer: results from two phase 1 studies.

MacLean DB, Matsui H, Suri A, Neuwirth R, Colombel M

The Journal of clinical endocrinology and metabolism24 Apr 2014Cited by 55 (Europe PMC)

PMID24762108 (opens in a new tab)DOI10.1210/jc.2013-4236 (opens in a new tab)PepBankPUB-24762108
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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study7

No result from this study comes from a test of the peptide.

Studies that did not test the peptide alone7

In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking Kisspeptin-54 (metastin).

  1. 01HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialSafety outcome

    In healthy subjects, grade 1-2 adverse events were reported in 26% of subjects during TAK-448 (a kisspeptin‑54 analog) treatment.

    In plain wordsIn healthy people, mild adverse events occurred in 26% of those given TAK-448, an analog of kisspeptin‑54.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    Not applicableGrade 1-2 adverse events
    Study

    n = 82

    Outcome group
    Adverse events · Whole body

    Measurements

    Grade 1-2 adverse events
    26%
    TAK-448

    Source sentences

    Summary
    Grades 1-2 adverse events were reported in 26% of subjects during TAK-448 treatment.
    2 context sentences
    Summary · context
    Eighty-two healthy subjects received TAK-448; 30 received placebo.
    Summary · context
    Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B).

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  2. 02HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialEfficacy outcome

    In patients with prostate cancer, testosterone fell below 20 ng/dL in four of five patients given 12 or 24 mg TAK-448 (a kisspeptin‑54 analog) depot injections.

    In plain wordsIn men with prostate cancer, TAK-448, an analog of kisspeptin‑54, lowered testosterone to very low levels in four of five men.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    DecreaseTestosterone with depot TAK-448 in prostate cancer
    Study

    n = 5

    Outcome group
    Sex hormones and fertility · Endocrine and hormones

    Source sentences

    Summary
    In PC patients, T decreased to less than 20 ng/dL in four of five patients dosed with 12 or 24 mg TAK-448 sc-depot injections.
    1 context sentence
    Summary · context
    In a subsequent, open-label, phase 1 study in PC patients aged 40-78 years, TAK-448 was given as a 1-month depot formulation.

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  3. 03HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialPharmacokinetics

    In healthy subjects, all TAK-448 (a kisspeptin‑54 analog) dosing regimens gave dose-proportional exposures.

    In plain wordsIn healthy people, higher doses of TAK-448, an analog of kisspeptin‑54, gave proportionally higher blood levels.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    Not applicableDose proportionality of TAK-448 exposure
    Study

    n: not reported in source

    Outcome group
    Pharmacokinetics · Pharmacology

    Source sentences

    Summary
    All dosing regimens resulted in dose-proportional exposures.
    1 context sentence
    Summary · context
    Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B).

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  4. 04HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialPharmacokinetics

    In healthy subjects, TAK-448 (a kisspeptin‑54 analog) reached maximum plasma concentration after 0.25-0.5 hours with a median terminal half-life of 1.4-5.3 hours.

    In plain wordsIn healthy people, TAK-448, an analog of kisspeptin‑54, peaked in blood within half an hour and had a half-life of 1.4 to 5.3 hours.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    Not applicableTime to maximum concentration and half-life of TAK-448
    Study

    n: not reported in source

    Outcome group
    Pharmacokinetics · Pharmacology

    Measurements

    Time to maximum concentration
    0.25 to 0.5 hours
    TAK-448
    Median terminal elimination half-life
    1.4 to 5.3 hours
    TAK-448

    Source sentences

    Summary
    The maximum observed plasma concentration occurred after 0.25-0.5 hours, and median terminal elimination half-life was 1.4-5.3 hours.
    1 context sentence
    Summary · context
    Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B).

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  5. 05HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialActivity measurement

    In healthy subjects, testosterone increased approximately 1.3- to 2-fold by 48 hours after a single bolus or 2 hour injection of TAK-448 (a kisspeptin‑54 analog).

    In plain wordsIn healthy people, one injection of TAK-448, an analog of kisspeptin‑54, raised testosterone up to about twofold within 48 hours.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    IncreaseTestosterone after single bolus or 2-hour injection
    Study

    n: not reported in source

    Outcome group
    Sex hormones and fertility · Endocrine and hormones

    Source sentences

    Summary
    T increased approximately 1.3- to 2-fold by 48 hours after a single bolus or 2 hour injections
    1 context sentence
    Summary · context
    Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B).

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  6. 06HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialEfficacy outcome

    In healthy subjects, during 14-day TAK-448 (a kisspeptin‑54 analog) infusion above 0.1 mg/d, testosterone fell below baseline by 60 hours and stayed below castration level by day 8.

    In plain wordsIn healthy people, 14 days of TAK-448, an analog of kisspeptin‑54, pushed testosterone down to very low levels.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    DecreaseTestosterone during 14-day TAK-448 infusion
    Study

    n: not reported in source

    Outcome group
    Sex hormones and fertility · Endocrine and hormones

    Source sentences

    Summary
    whereas during the 14-day infusion, at doses above 0.1 mg/d, T dropped to below-baseline values by 60 hours and reached a subsequently sustained below-castration level by day 8.
    1 context sentence
    Summary · context
    Healthy subjects aged 50 years or older received TAK-448 sc as a single-bolus or 2-hour infusion (0.01-6 mg/d; part A) and as a 14-day sc administration (0.01-1 mg/d; part B).

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

  7. 07HumanNot a test of Kisspeptin-54 (metastin) aloneNon-randomized trialEfficacy outcome

    In patients with prostate cancer, prostate-specific antigen decreased by more than 50% in all patients given 24 mg TAK-448 (a kisspeptin‑54 analog).

    In plain wordsIn men with prostate cancer, TAK-448, an analog of kisspeptin‑54, cut prostate-specific antigen by more than half in all men at the 24 mg dose.

    Peptide
    Kisspeptin-54 (metastin)
    Outcome
    DecreaseProstate-specific antigen with 24 mg depot TAK-448
    Study

    n: not reported in source

    Outcome group
    Tumor growth · Cancer

    Source sentences

    Summary
    The prostate-specific antigen decreased greater than 50% in all patients dosed with 24 mg.
    1 context sentence
    Summary · context
    In a subsequent, open-label, phase 1 study in PC patients aged 40-78 years, TAK-448 was given as a 1-month depot formulation.

    In this study, Kisspeptin-54 (metastin) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking Kisspeptin-54 (metastin).

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

  1. Version 2Current

    13 Oct 2026, 21:44 UTC

    Study results updated

  2. Version 1

    13 Oct 2026, 16:31 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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