What Is Nemifitide? Definition and What Research Reports

Definition

Nemifitide (development code INN 00835) is a synthetic pentapeptide — a short chain of five amino acids — that was developed as an investigational antidepressant compound and profiled under that description in a 2003 drug-development review of the Innapharma programme (PMID 14619408). In human studies the compound was given by subcutaneous injection, and a 2005 report compared systemic exposure in healthy volunteers following two different methods of subcutaneous administration (PMID 16130176). The word "nemifitide" therefore refers to one specific molecule with a defined structure and development history — it is not a category, a family of peptides, or a general term for peptide antidepressants.

Quick Reference

Where the Molecule Comes From

Nemifitide is a laboratory-synthesised peptide rather than an extract or a naturally circulating hormone. It was advanced through preclinical and clinical evaluation by Innapharma, and a 2003 review in a drug-development journal summarised the compound's profile at that stage of its programme (PMID 14619408). Because peptides of this size are poorly suited to oral dosing, the human work that reached publication used parenteral delivery: a 2002 paper described clinical pharmacokinetic studies with INN 00835 in people (PMID 11891671), and the 2005 volunteer study examined how systemic exposure differed between two subcutaneous administration methods (PMID 16130176).

How the Term Is Used in Peptide Research

In the scientific literature, "nemifitide" functions as a proper noun for a single investigational agent. Authors typically introduce it with a descriptor such as "a novel pentapeptide antidepressant" before reporting whatever their specific experiment measured (PMID 18090505). Three usage patterns are common:

• As a test article in animal pharmacology. A 2004 paper in Psychopharmacology examined antidepressant-like effects of the pentapeptide in an animal model of depression (PMID 14985919).
• As the analyte in pharmacokinetic work. Human studies measured how the peptide behaved after dosing, including the 2002 clinical pharmacokinetic report (PMID 11891671) and the 2005 comparison of two subcutaneous administration methods (PMID 16130176).
• As the intervention in clinical trial reports. Published clinical papers describe depressed outpatients, severely depressed treatment-refractory patients, and a placebo-controlled comparison of two daily dose levels (PMID 16259645).

Outside of these contexts the term has no separate technical meaning. This page is for educational purposes only and is not medical advice; consult a licensed physician about anything relating to depression, medication, or personal health.

What the Published Literature Reports

Preclinical work

The animal literature on this compound is small. Researchers published a 2004 study describing antidepressant-like effects of the novel pentapeptide nemifitide in an animal model of depression (PMID 14985919). That work sat upstream of the human programme summarised in the 2003 development review (PMID 14619408).

Human pharmacokinetics

Two pharmacokinetic papers form the core of the human exposure literature. The 2002 report described clinical pharmacokinetic studies with INN 00835, the same molecule later named nemifitide (PMID 11891671). The 2005 follow-up compared systemic exposure to nemifitide after two different methods of subcutaneous administration in healthy volunteers, a question that matters for peptides because injection technique and site can alter how much of a dose reaches the circulation (PMID 16130176).

Clinical reports in depression

Three clinical papers are indexed. A 2003 report in the International Journal of Neuropsychopharmacology examined clinical effectiveness in depressed outpatients and compared follow-up re-treatment with the patients' initial treatment course (PMID 12974986). A 2006 paper in the same journal reported on the efficacy and safety of 30 mg/d and 45 mg/d nemifitide compared with placebo in major depressive disorder — the only published trial title in this set that names specific daily dose levels (PMID 16259645). A 2008 paper in International Clinical Psychopharmacology described the clinical effect of the pentapeptide in severely depressed refractory patients, meaning people who had not responded adequately to prior treatment (PMID 18090505).

Taken together, the published record is a short, mostly mid-2000s development trail: one animal-model paper, two pharmacokinetic papers, three clinical papers and a development review. No approval followed in the published record, and there is no large modern evidence base for this molecule of the kind that exists for established antidepressant drug classes.

Safety and Tolerability: What Studies Report

Safety information for nemifitide comes from the same small set of publications rather than from any post-marketing surveillance, because the compound did not reach the market. The 2006 placebo-controlled trial explicitly framed its aim as efficacy and safety of the 30 mg/d and 45 mg/d dose levels in major depressive disorder, meaning tolerability data were collected alongside symptom measures (PMID 16259645). The 2003 development review summarised the compound's status across its programme, including the pharmacological and developmental profile available at that time (PMID 14619408). The refractory-patient report likewise described clinical effect in a severely ill population under study conditions (PMID 18090505). Anyone summarising adverse events for this compound has to work from these primary reports directly; the abstract-level record does not support broad tolerability generalisations.

Common Points of Confusion

• Nemifitide is not an approved antidepressant. The literature describes it as an investigational novel pentapeptide antidepressant studied in clinical trials (PMID 12974986), not as a prescribed medicine.
• INN 00835 and nemifitide refer to the same molecule. The earlier pharmacokinetic literature used the development code (PMID 11891671).
• "Pentapeptide" describes size, not mechanism. Many unrelated research peptides are five residues long; the descriptor appears in the titles of the nemifitide papers simply as a structural label (PMID 14985919).
• Route matters for interpreting the data. Human exposure data were generated subcutaneously, and the 2005 study showed that administration method was itself a variable worth testing (PMID 16130176).

Bottom Line

Nemifitide is best defined as a synthetic five–amino-acid peptide developed as an investigational antidepressant, studied by subcutaneous administration, and documented in a compact 2002–2008 literature covering animal pharmacology, human pharmacokinetics, and small clinical reports including a placebo-controlled comparison of 30 mg/d and 45 mg/d in major depressive disorder (PMID 16259645). Readers encountering the term in a research context should treat it as a historical investigational compound with a limited published evidence base. Again, this entry is educational only and is not medical advice.

References

• Nemifitide. Innapharma (Current Opinion in Investigational Drugs, 2003)
• Efficacy and safety of 30 mg/d and 45 mg/d nemifitide compared to placebo in major depressive disorder (The International Journal of Neuropsychopharmacology, 2006)
• Clinical effect of nemifitide, a novel pentapeptide antidepressant, in the treatment of severely depressed refractory patients (International Clinical Psychopharmacology, 2008)
• Antidepressant-like effects of a novel pentapeptide, nemifitide, in an animal model of depression (Psychopharmacology, 2004)
• Clinical pharmacokinetic studies with INN 00835 (nemifitide), a novel pentapeptide antidepressant (Biopharmaceutics & Drug Disposition, 2002)
• Comparison of systemic exposure to nemifitide following two methods of subcutaneous administration to healthy volunteers (Biopharmaceutics & Drug Disposition, 2005)
• Clinical effectiveness of nemifitide, a novel pentapeptide antidepressant, in depressed outpatients: comparison of follow-up re-treatment with initial treatment (The International Journal of Neuropsychopharmacology, 2003)