Brilaroxazine

Brilaroxazine sits in the same conceptual lineage as aripiprazole and cariprazine: a dopamine and serotonin partial-agonist antipsychotic intended to stabilize rather than simply block dopamine signaling. Its receptor profile is broad, combining partial agonism at dopamine D2, D3 and D4 and serotonin 5-HT1A with antagonism at 5-HT2A, 5-HT2B, 5-HT2C, 5-HT6 and 5-HT7, plus reported agonist activity at the alpha4beta2 nicotinic acetylcholine receptor and moderate serotonin-transporter affinity ^[1][2]. Reviva has marketed this as a "dopamine serotonin stabilizer," a positioning label rather than a distinct mechanistic class.

The main human efficacy signal comes from a single completed phase 2 study, REFRESH (NCT01490086). This 28-day, multicenter, double-blind trial randomized 234 adults with acute exacerbation of schizophrenia or schizoaffective disorder to brilaroxazine 15, 30 or 50 mg, aripiprazole, or placebo. PANSS total score improved by roughly 20.2, 15.4 and 19.2 points on the 15, 30 and 50 mg arms versus 11.4 on placebo, with the 15 mg (p=0.021) and 50 mg (p=0.016) arms reaching statistical significance; the 30 mg arm did not separate from placebo ^[1]. The aripiprazole arm was included only to demonstrate assay sensitivity and was not powered for efficacy. The trial drew published methodological criticism over its design and analysis, to which the investigators responded, so the phase 2 result should be read as promising but contested rather than definitive ^[12].

Early-phase clinical work characterized the drug's tolerability and pharmacokinetics. Phase 1 single-dose studies in healthy volunteers and 10-day multiple-dose studies in stable schizophrenia patients found the most common adverse events to be orthostatic hypotension, nausea and dizziness after single doses, and akathisia and somnolence with repeat dosing, with no clinically significant shifts in glucose, prolactin, lipids, weight or ECG ^[3][4]. A population pharmacokinetic and pharmacodynamic analysis of the phase 2 data described roughly dose-linear kinetics and a calculated half-life near 44 hours (reported range 40 to 71 hours across the phase 1 work), supporting once-daily dosing ^[4][5].

Beyond psychiatry, the same serotonergic activity (particularly 5-HT2B antagonism) motivated a preclinical pulmonary arterial hypertension programme. In rat models, brilaroxazine reduced pulmonary pressures, vascular remodeling and Fulton's index in both monocrotaline-induced and Sugen 5416 plus hypoxia models, and it retained benefit when combined with sildenafil, bosentan or treprostinil ^[6][7][8]. A topical lipogel formulation also showed antipsoriatic activity in an imiquimod-induced mouse model ^[9]. These indications remain preclinical; no completed human PAH, fibrosis or psoriasis efficacy trial has been reported.

The current pivotal effort is RECOVER (NCT05184335), a phase 3 study running fixed 15 mg and 50 mg doses against placebo over 28 days, followed by a 52-week open-label extension at flexible 15 to 50 mg dosing. The sponsor reported positive topline results for the double-blind portion by press release, describing a roughly 10-point PANSS separation on the 50 mg arm; those figures come from company communications and had not been posted as trial results or published in a peer-reviewed journal at the time of writing, so they should be treated as sponsor-reported. Brilaroxazine is reviewed within the broader wave of emerging schizophrenia agents alongside drugs such as lumateperone and xanomeline ^[10][11].

Nothing about brilaroxazine is available for use. It is an investigational compound in active clinical development, not a research chemical sold to consumers and not a prescription medicine. It appears here for completeness of the pharmacology record, not as something to source.

Human safety data are limited to phase 1 and phase 2 studies plus sponsor-reported phase 3 topline data, so the profile is provisional. In early studies the drug was generally well tolerated; single doses most often produced orthostatic hypotension, nausea and dizziness, while repeat dosing was associated mainly with akathisia and somnolence ^[3][4]. In the phase 2 trial the most common treatment-emergent events were mild and transient, and discontinuation for any reason was lower on brilaroxazine arms than on placebo or aripiprazole ^[1].

Reported early data showed little effect on glucose, prolactin, lipids, weight or ECG parameters, and the sponsor has emphasized a favorable metabolic and extrapyramidal profile in phase 3 ^[3]. Because this is a partial dopamine agonist, akathisia and activation are the plausible class risks to watch, as with aripiprazole. Long-term safety, rare adverse events, drug interactions in real-world use, and any signal in vulnerable populations are simply not yet established, and no regulator has reviewed the full dataset.

Brilaroxazine was developed by Reviva Pharmaceuticals as RP5063, a dopamine and serotonin "stabilizer" designed around the aripiprazole scaffold. A phase 2 trial (REFRESH, NCT01490086) ran from 2011 to 2013 and was published in 2017, reporting significant PANSS improvement on the 15 and 50 mg arms and drawing subsequent published methodological critique and rebuttal ^[1][12]. Phase 1 pharmacokinetic and safety studies were published around the same period ^[3][4][5].

In parallel the company pursued preclinical pulmonary arterial hypertension and idiopathic pulmonary fibrosis work, for which orphan drug designations were obtained, and a topical psoriasis formulation ^[6][7][9]. The pivotal phase 3 RECOVER trial in schizophrenia (NCT05184335) began in 2022, with the sponsor reporting positive topline results and signaling an intended NDA submission. As of this writing brilaroxazine has not been approved by the FDA or any other regulator for any indication.

Within psychiatry brilaroxazine is regarded as a credible but not yet proven late-stage candidate: another dopamine and serotonin partial agonist in the aripiprazole and cariprazine family, of interest mainly for a claimed clean metabolic and extrapyramidal profile and for possible activity on negative symptoms and cognition. Reviews of emerging antipsychotics generally list it among the agents to watch while noting the evidence base still rests on one contested phase 2 trial and sponsor-reported phase 3 topline data ^[10][11]. The published exchange over the phase 2 trial's methodology means experienced readers treat the efficacy claims with some caution ^[12]. It has essentially no presence in nootropics or self-experimentation communities, which is appropriate given that it is an investigational antipsychotic with no consumer supply and a serious-drug risk profile.