MPLT ML-007 Schizophrenia Phase 2: BID Hits, QD Miss

MapLight Therapeutics (NASDAQ: MPLT) reported Phase 2 ZEPHYR results on July 27 for ML-007C-MA, an oral M1/M4 muscarinic agonist for acute schizophrenia. The twice-daily dose hit the primary endpoint. The once-daily dose missed. Investors focused on the miss, and the stock crashed 73% from $36.56 to $9.91 before recovering to $12.31 on July 28.

The 210/3 mg twice-daily (BID) dose achieved a statistically significant improvement in PANSS total score versus placebo at Week 5 (LS mean difference -4.5 points, effect size 0.37, p=0.015). In completers, the effect size grew to 0.50 (LS mean difference -6.0, p=0.002). The BID arm also hit key secondary endpoints: CGI-S (effect size 0.48, p=0.002) and PANSS Positive Marder factor (effect size 0.39, p=0.012).

The 330/6 mg once-daily (QD) dose showed numerical improvement but did not reach statistical significance on the primary endpoint. It did separate on CGI-S (p=0.036), PANSS positive (p=0.045), and Readiness for Discharge (p=0.027), suggesting a signal but at lower daily exposure than BID dosing.

The standout result was cognitive performance. In participants with baseline cognitive impairment, ML-007C-MA showed an effect size of 0.51 on the Cogstate battery (0.44 points versus placebo, p=0.041). Critically, the cognitive benefit did not correlate with PANSS improvement, suggesting the muscarinic mechanism independently addresses cognitive dysfunction, a symptom domain where no therapy is approved in schizophrenia.

ML-007C-MA is betovumeline, an M1/M4 muscarinic agonist, co-formulated with fesoterodine, a peripherally acting anticholinergic that blocks GI and other peripheral cholinergic side effects. It follows the same mechanism as Bristol-Myers Squibb’s Cobenfy (xanomeline-trospium), the first antipsychotic with a new mechanism approved in 50 years (FDA approval September 2024). MapLight’s design uses a different anticholinergic partner and targets lower GI discontinuation rates than Cobenfy’s registrational trials reported.

ZEPHYR enrolled 307 participants randomized 1:1:1 to placebo, BID, or QD across 25 US sites in a 5-week inpatient design. Safety was clean: no serious or drug-related severe adverse events, 19.9% all-cause discontinuation across active arms, and 2% GI-related discontinuations. TEAEs at the BID dose were 74.7% versus 48.1% placebo, mostly mild.

The stock action tells the story. MPLT IPO’d at $17 in October 2025, traded above $36 on July 24, and fell to $9.91 on July 27 after results. The July 28 rebound to $12.31 (up 24% on the day, open $9.56, close $12.31) reflects the BID efficacy and cognitive signal, but the market cap is still down roughly $900 million from the pre-announcement level at approximately $449 million. The core investor concern: once-daily dosing is critical for real-world adherence in schizophrenia, and a drug that only works BID may struggle commercially against Cobenfy and its successors.

MapLight plans an End-of-Phase 2 meeting with the FDA and a confirmatory Phase 3 trial designed to be registrational alongside ZEPHYR. The company is also running VISTA, a Phase 2 in Alzheimer’s disease psychosis using the same BID dose.

What to watch next: the Phase 3 trial design and whether it tests only BID or attempts to salvage a QD regimen. The cognitive signal, if replicated, could differentiate ML-007C-MA from Cobenfy in a market that has waited decades for mechanistic innovation in neuroscience.