Nemifitide (INN-00835) is a novel

antidepressant Antidepressants are a class of medication used to treat major depressive disorder, anxiety disorders, chronic pain conditions, and to help manage addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, hea ...

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via insuffla ...

with a pentapeptide

structure A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

similar to that of melanocyte-inhibiting factor (MIF-1) and the

amino acid sequence Protein primary structure is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end. Protein biosynthes ...

4-F-Phe-4-OH-Pro-Arg-Gly-Trp-NH₂. It is under development by Tetragenex (previously Innapharma, Inc.) for the treatment of

major depressive disorder Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introdu ...

. It has been given to over 430 people over the course of 12

clinical trial Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...

s throughout a little over the past decade and has reached Phase III studies, but has not yet been approved for marketing in any country. Nemifitide has shown mixed efficacy in alleviating depressive symptoms, but in the cases in which it has worked it has proven to have a rapid

onset of action Onset of action is the duration of time it takes for a drug's effects to come to prominence upon administration. With oral administration, it typically ranges anywhere from 20 minutes to over an hour, depending on the drug in question. Other meth ...

(~5–7 days), few to no

side effect In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...

s, and an excellent

safety profile Term Given By Tushar Sharma (UPES Batch 2025) Pharmacovigilance (PV, or PhV), also known as drug safety, is the pharmaceutical science relating to the "collection, detection, assessment, monitoring, and prevention" of adverse effects with pharma ...

. However, it is inactive orally and must be administered via

subcutaneous injection Subcutaneous administration is the insertion of medications beneath the skin either by injection or infusion. A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, ...

. Remarkably, despite having a very short

half-life Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...

of only 15–30 minutes, in most or all studies assessing its efficacy nemifitide has been administered merely once daily via the subcutaneous route and yet is effective for depression. The

mechanism of action In pharmacology, the term mechanism of action (MOA) refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect. A mechanism of action usually includes mention of the specific molecular targe ...

of nemifitide is unclear, but since MIF-1 has been demonstrated to have similar antidepressant effects it may act in an analogous manner. Possibly of interest however is that nemifitide binds to several

receptor Receptor may refer to: * Sensory receptor, in physiology, any structure which, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds to a ...

s including 5-HT_2A (where it has been shown to act as an

antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...

), NPY₁,

bombesin Bombesin is a 14-amino acid peptide originally isolated from the skin of the European fire-bellied toad (''Bombina bombina'') by Vittorio Erspamer ''et al.'' and named after its source. NIHMSID 45053. It has two known homologs in mammals called ...

, and MC₄ and MC₅, though at only micromolar concentrations. Whether any of these relatively weak actions are of any clinical significance is unclear.

See also

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Further reading