Neurosterix Raises $105M for Schizophrenia Phase 2 Plans

Andrew Miller and Stephen Brannan have already helped bring muscarinic medicine into schizophrenia care. Their arrival at Neurosterix puts that experience beside a different molecular approach as the Boston-and-Geneva biotechnology company prepares its lead candidate for Phase 2 development.

Neurosterix has closed a $105M Series B led by RTW Investments, with proceeds primarily intended for NTX-253, an investigational oral drug for schizophrenia. Addex Therapeutics first disclosed the financing on November 11, 2026; Neurosterix's full announcement followed on November 12 with the investor roster and leadership appointments. The round also supports a broader pipeline targeting neuropsychiatric disorders.

The financing brings clinical judgment and money into the same assignment. NTX-253 targets the muscarinic M4 receptor through positive allosteric modulation, and Neurosterix reports that it has completed Phase 1 studies. The company's planned work now moves toward examining a selective approach in schizophrenia, where a promising mechanism must eventually answer the practical questions patients and clinicians bring to treatment.

Who is financing Neurosterix's clinical expansion?

RTW Investments led the Series B alongside new investors Janus Henderson Investors, GV, Ikarian Capital, Affinity Asset Advisors and Dellora Investments. Existing investors Perceptive Advisors and Acorn Bioventures also participated. That combination extends the company's original investor relationships while adding institutions to support the next stage of development.

The company emerged in 2024 from neuroscience assets and a discovery platform developed at Addex Therapeutics. Neurosterix's original launch announcement described a $63M Series A led by Perceptive Xontogeny Venture Fund II. Its current investor page reports $170M raised to date; the historical launch figure and that newer aggregate are differently reported figures, so the launch amount should not be used to reconstruct a supposedly exact financing history.

Addex's disclosure says it did not participate in the Series B and now holds 8.5% of Neurosterix. Addex assigned an $18.6M value to that interest. That figure describes Addex's holding rather than a disclosed company valuation, an important distinction for readers trying to understand the economics of the spinout.

The operating consequence is more straightforward than the ownership arithmetic. An existing neuroscience platform has secured a larger syndicate around an identified clinical priority. Investors are funding a company with additional programs, while the near-term deployment of proceeds is anchored primarily to NTX-253's planned Phase 2 work.

How does NTX-253 fit the muscarinic treatment field?

Neurosterix describes NTX-253 as a selective, brain-penetrant positive allosteric modulator of M4. In the company's explanation of its science, an allosteric modulator binds at a different site from the receptor's primary signaling site. A positive modulator enhances the receptor's response, an approach intended to give drug developers more selective control over signaling.

That distinction matters because selecting a biological target and designing a useful medicine around it are separate pieces of work. Neurosterix is pursuing the possibility that selective modulation can support a differentiated treatment profile. Its discussion of better efficacy, safety or tolerability describes a development ambition, with clinical evidence still needed to establish the candidate's benefits and risks.

The wider field has changed since Neurosterix's launch. In September 2024, the FDA approved Cobenfy for schizophrenia in adults, introducing an antipsychotic treatment directed at cholinergic receptors rather than the dopamine receptors targeted by established approaches. Cobenfy provides regulatory precedent for the broader biological territory; it is a different medicine and does not establish NTX-253's clinical performance.

For operators assessing this financing, that history helps explain the relevance of the new appointments. Experience with muscarinic development can inform which questions to ask, how to interpret evidence and how to organize subsequent work. The company still has to generate the evidence specific to NTX-253, with its own molecule, development plan and eventual patient population.

Which people connect discovery to the clinical program?

Neurosterix's current leadership page identifies Fred Callori as CEO and co-founder, alongside co-founders Jeremiah Paskus and Keyvan Mirsaeedi-Farahani. Callori is also a managing director at Perceptive Advisors. Paskus and Mirsaeedi-Farahani hold investment roles there, making the company's original capital relationships part of its founding history as well as its present investor roster.

Within the operating team, Robert Lütjens serves as CSO, Doug Feltner as CMO and Ted Keysor as COO. Those responsibilities span discovery, medicine and execution. For a company advancing an existing pharmacology platform into further clinical work, the quality of the handoff among those disciplines belongs inside the financing story.

Miller, Karuna Therapeutics' founder and former R&D president, becomes Executive Chair. Brannan, Karuna's former CMO, chairs Neurosterix's Clinical Advisory Board. Edmund Harrigan joins as an independent director, bringing drug-development and regulatory experience, while RTW's Connor Williams is announced to join the board.

The appointments give the company access to people who have worked through muscarinic development and broader pharmaceutical decisions. Their experience can shape the work around NTX-253 without making its outcome predetermined. A trial program still depends on what its own data show, and that dependence gives these roles a more demanding purpose than decorating a financing announcement.

What work sits behind the Series B?

Neurosterix's pipeline page reports completed Phase 1 single- and multiple-ascending-dose studies for NTX-253, with a pharmacokinetic profile supportive of evaluating once-daily oral dosing. The announced Phase 2 program for schizophrenia remains planned. The reviewed releases do not establish an enrollment target, detailed protocol or readout date, so a precise clinical timetable would go beyond the disclosed information.

The broader portfolio includes NTX-819, a negative allosteric modulator of mGlu7 in preclinical development for mood and anxiety disorders, and NTX-529, another M4 program aimed at additional psychosis- and mood-related applications. These programs give the company further uses for its discovery capabilities. They also create resource decisions around how much work to advance alongside the lead candidate.

Neurosterix reports a discovery library exceeding 80,000 compounds and more than 200 CNS-relevant functional assays. Those capabilities supply material for research rather than a count of future medicines. The business is now organizing that accumulated discovery work around a clinical program with a clearer financing base and an expanded set of experienced decision-makers.

For the clinicians and patients who may eventually evaluate the approach, the useful output will be information about treatment: what improves, what complications arise and how a regimen fits into life with schizophrenia. The Series B supports the work needed to bring those questions into NTX-253's clinical development, with Callori's team and its new advisers responsible for the decisions along the way.