Neurosterix, a biotech founded in Geneva in 2024 as a spin-off of Addex Therapeutics, has closed a 105 million dollar Series B led by RTW Investments, according to the press release relayed by Startupticker.ch on 12 November 2026. The money is meant to take its molecule NTX-253 into phase 2 against schizophrenia.

The press release earmarks most of the funds for the planned move of NTX-253 into phase 2 clinical trials. The rest is to finance the company's other programmes, all based on allosteric modulators. This is an equity fundraising: no industrial partnership or product launch has been announced. In October, 2clics had already reported on Neurosterix's clinical milestones, alongside Muvon and Nuclidium.

Who is funding Neurosterix's Series B?

RTW Investments leads the round, according to the press release carried by Startupticker.ch. Five new investors join it:

  • Janus Henderson Investors;
  • GV;
  • Ikarian Capital;
  • Affinity Asset Advisors;
  • Dellora Investments.

Existing shareholders Perceptive Advisors and Acorn Bioventures are putting in more money. The split of the 105 million among these investors has not been published, nor has the company's valuation.

RTW Investments is no stranger to Swiss biotech. The fund is among the lead investors in the rounds of Windward Bio, the Basel-based company that applied for a Nasdaq listing in October 2026, according to our article on that listing.

The financing comes with three appointments, announced at the same time as the raise. Andrew Miller becomes executive chairman of the board of directors, Edmund Harrigan an independent director and Stephen Brannan chair of the clinical advisory board. According to the press release, all three held senior positions at Karuna Therapeutics, which developed COBENFY, the first muscarinic therapy approved for schizophrenia.

Where does this Geneva-born biotech come from?

Neurosterix was launched on 3 April 2024 by Addex Therapeutics and funds linked to Perceptive Advisors, according to Startupticker.ch at the time. Neurosterix SA was then, like Addex, based in Geneva.

Addex contributed a portfolio of preclinical neuroscience assets and its allosteric modulator discovery platform. In exchange, the listed company received 5 million francs and 20% of Neurosterix's capital. Tim Dyer, chief executive of Addex, also took the helm of the new company.

The launch round amounted to 63 million dollars, provided by the Perceptive Xontogeny Venture Fund II, together with the Perceptive Life Sciences Fund and Acorn Bioventures. In its press release of 8 October 2026, Addex refers to a 65 million dollar Series A. The same text places its 20% stake in "Neurosterix US Holdings LLC". The Series B press release does not specify the company's current headquarters.

What does phase 1 measure, and what must phase 2 show?

NTX-253 is a positive allosteric modulator (PAM) of the muscarinic M4 receptor, a clinically validated target in schizophrenia. Rather than directly activating or blocking the receptor, the molecule fine-tunes its signal. According to Addex, it could reduce psychotic symptoms without the movement disorders or metabolic complications associated with dopamine antagonists. This is a stated potential, not a result demonstrated in humans.

Phase 1, completed according to Addex on 8 October 2026, comprised single and then multiple ascending doses. It included healthy volunteers and patients with stabilised schizophrenia. Measurements of the effect of food and of cerebrospinal fluid were built in. It provided safety and pharmacokinetic data, that is, data on what happens to the molecule in the body.

According to the Series B press release, this pharmacokinetic profile is compatible with once-daily oral dosing. Phase 2 is now to involve patients with schizophrenia, as Tim Dyer indicated. The data released so far concern safety and pharmacokinetics, not efficacy against the disease.

Behind NTX-253, Neurosterix is developing two other candidates, according to Startupticker.ch:

  • NTX-819, a negative allosteric modulator of the metabotropic glutamate receptor 7 (mGlu7), at the preclinical stage, studied in models related to stress, mood and aggression;
  • NTX-529, a second M4 receptor PAM, targeted at other psychotic and mood disorders.

The company claims more than 100 patent filings, a library of more than 80,000 compounds and more than 200 functional assays related to the central nervous system.

How do 105 million compare with recent Swiss fundraisings?

The table places this round among other Swiss startup financings reported by 2clics since October. The stages differ: the table gives an order of magnitude, not a ranking.

CompanyFieldTransactionAmount
Neurosterix (founded in Geneva)Schizophrenia, neuropsychiatric disordersSeries B, November 2026105 million dollars
Nouscom (Basel)Cancer immunotherapySeries D, October 2026135 million dollars
Windward Bio (Basel)Asthma, COPD, atopic dermatitisTotal raised since January 2025Up to 365 million dollars
Enact Intelligence (Zurich)RoboticsPre-seed, October 202630 million dollars

The most telling comparison remains Nouscom, whose 135 million Series D is to fund a registrational trial. Neurosterix is raising slightly less, at an earlier stage, for a phase 2.

The context matters too. In 2025, Swiss biotech reached a record 946 million francs in venture capital, according to the figures cited in our feature on venture capital in Switzerland. In the first half of 2026, however, large biotech rounds were lacking, according to swissinfo.ch as cited in the same feature.

As is often the case, the amount is public but the valuation is not. Our guides to the startup term sheet and to calculating dilution help read what such an announcement leaves unsaid.

What we don't know yet

  • The phase 2 timetable: no start date, number of patients or trial countries have been published.
  • The detailed phase 1 results: Addex and Neurosterix refer to safety and pharmacokinetic data without giving details.
  • Addex's stake after the Series B: Addex Therapeutics, listed on the SIX Swiss Exchange and the Nasdaq, reported holding 20% of the capital in October 2026, before this round.

Sources