MPLT Stock Plunges 73% — Wipes Out Over $1B In Market Cap After Trial Miss On Once-Daily Dose

• The twice-daily version of the drug met the study’s main goal, but not the once-daily version.
• MapLight plans to meet with the U.S. Food and Drug Administration soon to discuss a confirmatory late-stage trial in schizophrenia. 
• Company leaders also said that the twice-daily results strengthen the case for an ongoing study of the same twice-daily dose in Alzheimer’s disease-related psychosis.

Shares of MapLight Therapeutics (MPLT) closed 73% lower on Monday after the biotech reported mixed results from a mid-stage trial of its experimental schizophrenia drug.

The drop erased more than $1 billion in market value, leaving the company’s valuation around $449 million after the selloff.

Mixed Results From Key Schizophrenia Trial

MapLight announced topline findings from its mid-stage ZEPHYR trial of ML-007C-MA, an oral medicine tested in about 307 adults hospitalized for a sudden worsening of schizophrenia symptoms. Patients received either a placebo, a twice-daily dose, or a once-daily dose for five weeks.

The twice-daily version met the study’s main goal. It produced a clear, statistically meaningful drop in overall symptom scores on the Positive and Negative Syndrome Scale (PANSS), a standard measure of schizophrenia symptom severity, compared with placebo.

Patients who finished the full five weeks saw an even stronger benefit. The same dose showed a solid gain in thinking and memory skills among those who started with cognitive problems, the company said. That cognitive improvement appeared separate from the reduction in psychotic symptoms.

The once-daily version showed some numerical gains and hit statistical significance on a few secondary measures, such as overall severity ratings and certain positive symptom scores. However, it fell short of statistical significance on the primary PANSS endpoint, disappointing investors.

On the safety side, both doses were generally well tolerated, MapLight said. Dropout rates stayed manageable, with no major signals of movement problems, metabolic issues, or other serious burdens common with many older schizophrenia medicines.

MapLight plans to meet with the U.S. Food and Drug Administration soon to discuss a confirmatory late-stage trial in schizophrenia focused on the successful twice-daily regimen, while also exploring optimized once-daily possibilities.

Company leaders also said that the twice-daily results bolster the case for an ongoing study of the same twice-daily dose in Alzheimer’s disease-related psychosis, with results expected in the second half of 2027.

How Did MPLT Retail Traders React?

On Stocktwits, retail sentiment around MPLT jumped from ‘bearish’ to ‘extremely bullish’ over the past 24 hours, while message volume rose from ‘high’ to ‘extremely high’ levels.

A Stocktwits user opined that the selloff is a good opportunity to buy the stock, highlighting the company’s balance sheet. MapLight Therapeutics’ cash, cash equivalents, and investments totaled $395.2 million as of March 31.

Another termed the selloff an overreaction.

A third user commended the trial result as a “strong positive” and not a “disappointment disguised as success.”

“A clinically and strategically important win, with especially encouraging cognition and tolerability—but not an efficacy blowout. ML-007C-MA has now moved from a sophisticated improvement hypothesis built on Cobenfy to a clinically validated potential second-generation muscarinic drug,” they said.

MPLT stock has dropped 44% year to date. 

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