LY-404,039 is a drug used in scientific research that acts as a selective agonist

Agonist

An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...

 for the metabotropic glutamate receptor

Metabotropic glutamate receptor

The metabotropic glutamate receptors, or mGluRs, are a type of glutamate receptor that are active through an indirect metabotropic process. They are members of the group C family of G-protein-coupled receptors, or GPCRs...

 group II subtypes mGluR₂

Metabotropic glutamate receptor 2

Metabotropic glutamate receptor 2 is a protein that in humans is encoded by the GRM2 gene.-PAMs:The development of subtype-2-selective positive allosteric modulators experienced steady advance in recent years...

 and mGluR₃

Metabotropic glutamate receptor 3

Metabotropic glutamate receptor 3 is a protein that in humans is encoded by the GRM3 gene.-Ligands:Though truly mGluR3 selective agents still await their discovery, mixed mGluR2/3 ligands with selectivity over other mGluR-subtypes are known...

. It has anxiolytic

Anxiolytic

An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...

 and antipsychotic

Antipsychotic

An antipsychotic is a tranquilizing psychiatric medication primarily used to manage psychosis , particularly in schizophrenia and bipolar disorder. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s...

 effects in animal studies, but without causing sedation.

Early human trials using a prodrug

Prodrug

A prodrug is a pharmacological substance administered in an inactive form. Once administered, the prodrug is metabolised in vivo into an active metabolite, a process termed bioactivation. The rationale behind the use of a prodrug is generally for absorption, distribution, metabolism, and...

 form of LY-404,039 called LY-214,0023 have also given encouraging results. A trial in 2009 failed to prove superiority over placebo or Olanzapine

Olanzapine

Olanzapine is an atypical antipsychotic, approved by the FDA for the treatment of schizophrenia and bipolar disorder...

, but Lilly explained this as being due to an exceptionally high placebo response.

Lilly initiated Phase III clinical trials of the drug in March 2011.