MapLight Therapeutics (MPLT) stock closed 73% lower on Monday after the biotech company reported mixed results from a mid-stage trial of its experimental schizophrenia drug ML-007C-MA. The selloff erased more than $1 billion in market value, reducing the company's valuation to approximately $449 million. The twice-daily version of the drug met the study's primary endpoint on the Positive and Negative Syndrome Scale (PANSS), while the once-daily version failed to achieve statistical significance on the primary measure despite hitting some secondary endpoints. The ZEPHYR trial tested both dosing regimens in about 307 adults hospitalized for acute schizophrenia symptom worsening over five weeks. Biotech stocks frequently experience sharp volatility around clinical trial readouts, with investors reacting swiftly to efficacy and safety data that determine regulatory and commercial pathways.
MapLight Reports ZEPHYR Trial Results for ML-007C-MA
MapLight announced topline findings from its mid-stage ZEPHYR trial of ML-007C-MA, an oral medicine tested in approximately 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, producing a statistically meaningful drop in overall symptom scores on the Positive and Negative Syndrome Scale (PANSS) compared with placebo. Patients who completed the full five weeks saw an even stronger benefit. The same dose showed improvement 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 achieved 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.
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 FDA Meeting for Confirmatory Late-Stage Trial
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 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.
Retail Investors Shift Sentiment to Extremely Bullish
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.
FAQ
Why did MPLT stock drop 73% on Monday?
MPLT stock dropped 73% on Monday after MapLight Therapeutics reported that the once-daily version of its experimental schizophrenia drug ML-007C-MA failed to achieve statistical significance on the primary endpoint in the mid-stage ZEPHYR trial, despite the twice-daily version meeting the primary goal.
What did the ZEPHYR trial results show for ML-007C-MA?
The ZEPHYR trial tested ML-007C-MA in approximately 307 adults hospitalized for acute schizophrenia symptoms over five weeks. The twice-daily dose met the primary endpoint with a statistically meaningful drop in PANSS symptom scores compared with placebo and showed cognitive improvements. The once-daily dose showed some numerical gains and hit some secondary measures but missed the primary PANSS endpoint. Both doses were generally well tolerated.
What are MapLight's next steps after the ZEPHYR trial?
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 twice-daily regimen. The company is also conducting an ongoing study of the same twice-daily dose in Alzheimer's disease-related psychosis, with results expected in the second half of 2027.
