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Simris Biologics

A preclinical German biotech, owned by Sweden's Simris Group AB, developing nature-derived microcystin compounds as next-generation antibody-drug conjugate payloads for targeted cancer therapy.

Company Overview

Simris Biologics GmbH is a preclinical German biotech developing microcystin compounds, sourced from cyanobacteria, as payloads for antibody-drug conjugates. It is a wholly owned subsidiary of Sweden's Simris Group AB.

The company's case is that cyanobacteria are a lightly worked source of potent non-ribosomal peptides, and can yield payload candidates structurally different from the auristatin and maytansinoid classes that dominate approved ADCs.

Whether that structural difference produces a better therapeutic index has still to be shown. The programs are preclinical, and no Simris payload has entered a clinical trial.

Professor Andreas Pahl took over as chief executive in July 2026, arriving from the top job at another German ADC developer.

Headquarters and Global Presence

Simris Biologics operates from Berlin, Germany. It is a small discovery unit; third-party business directories list around four employees.

The parent, Simris Group AB, is headquartered in Malmo, Sweden, and is listed on Nasdaq First North Growth Market under the ticker SIMRIS, ISIN SE0008091664, with Amudova AB as Certified Adviser.

The group runs a second operating division, Simris Dermalogics. Both draw on the same cyanobacterial expertise and strain library.

Founding and History

Simris Group was founded in 2011 as an algae biotech and cites close to 20 years of cyanobacteria expertise across the group.

The Berlin operation started life as Cyano Biotech GmbH, a specialist in applied research on cyanobacteria and microalgae, natural product libraries for drug discovery, and cyanotoxin standards for research use.

Simris Alg AB acquired Cyano Biotech in August 2022 and later resolved to rename it Simris Biologics GmbH.

The group ran a rights issue in 2023 and has since funded itself through convertible instruments, directed unit issues and warrant exercises.

Therapy Areas and Focus

Simris Biologics works only in oncology, and specifically on the payload half of an antibody-drug conjugate: the cytotoxic warhead a targeting antibody carries to tumor cells.

The rationale is that cyanobacterial natural products offer structural diversity that clinical ADCs have not yet drawn on, which would widen the range of available tumor-killing mechanisms.

The company states its aim is to improve both efficacy and safety relative to existing payload classes. Those are development goals at the preclinical stage, not established results.

Activation inside the tumor microenvironment is a design principle built into the platform.

Technology Platforms and Modalities

The platform draws on a proprietary library of more than 1,200 cyanobacterial strains and over 5,000 novel compounds, which the group describes as the world's largest collection of its kind.

The payloads are structurally modified variants of microcystins, a class of non-ribosomal peptides produced by cyanobacteria.

The engineering task, and the central intellectual property claim, is turning those compounds into controllable warheads: designed to stay inactive in circulation and to become active once a monoclonal antibody has delivered them into the tumor microenvironment.

The work is agnostic about the antibody side, which positions the microcystin variants as assets that could be paired with a range of antibody formats and cancer targets.

Key Pipeline and Programs

Simris Biologics has no named clinical-stage asset. Its programs sit at preclinical discovery and in vivo evaluation.

The lead work covers novel microcystin payload variants. The company reported an update on advanced in vitro evaluation of those compounds on 6 October 2025.

The programs are now moving into in vivo safety and efficacy studies. Up to EUR 1 million expected from the warrant exercise announced on 6 July 2026 is earmarked for that work.

The in vivo evaluation runs through Nuvisan, the contract research organization engaged under an agreement announced on 5 June 2025. Simris reported positive results from that study on 5 November 2025.

Those results are early animal data reported by the company. They do not establish efficacy or safety, and the company has not published a target indication, an antibody pairing or a first-in-human timeline.

Recent Developments

The most material event of 2026 for Simris Biologics is the appointment of Professor Andreas Pahl as chief executive, announced on 15 July 2026 and effective immediately. He fills a permanent leadership gap that had been covered by Daniel Kubitza as interim chief executive since 10 November 2025.

Alongside the appointment, the parent flagged the warrant exercise announced on 6 July 2026, expected to bring gross proceeds of up to EUR 1 million to fund the in vivo work.

On the science, the positive Nuvisan study results reported on 5 November 2025 are the most advanced preclinical data point the company has put out.

Business development has been harder. A potential ADC collaboration reached a non-binding concept sheet in mid-2025, but the counterparty then withdrew.

The funding position stays tight. The group took a directed issue of convertible debentures worth EUR 678,000 in July 2025, entered a bridge loan agreement in November 2025, and has run a series of warrant exercises through the first half of 2026.

Key Personnel

Professor Andreas Pahl is Chief Executive Officer of Simris Biologics GmbH, appointed on 15 July 2026 with immediate effect.

Daniel Kubitza was appointed interim chief executive on 10 November 2025. Jonathan Royce is chairman of the parent, Simris Group AB.

Strategic Partnerships

The firmest external relationship is with Nuvisan, the contract research organization running in vivo evaluation of the microcystin payload candidates under an agreement announced on 5 June 2025. Simris reported positive results from that study on 5 November 2025.

Simris Biologics received EUR 200,000 in non-dilutive funding on 12 September 2025 for an R&D program to develop microcystin payloads for antibody-drug conjugates.

A wider pharma partnership was explored in 2025 and reached a non-binding concept sheet, but the prospective counterparty withdrew before it converted. Landing a payload licensing deal remains the company's central commercial test.

The rationale is chemical novelty. The dominant ADC payload classes, auristatins and maytansinoids, are closely related, so resistance or tolerability problems with one can carry across to another.

Microcystins are non-ribosomal peptides from a different structural family, which gives Simris a differentiated starting point for payload discovery.

The commercial logic follows: large ADC developers looking to diversify their payloads would have reason to license novel chemistry rather than build it. That thesis has yet to be proven in a completed partnership deal, and one 2025 approach fell away when the counterparty withdrew.

Microcystins are potently cytotoxic cyanobacterial peptides. In unmodified form they are far too toxic for systemic use, which is exactly the profile that makes a compound worth engineering into an ADC payload.

Simris modifies them structurally so they are designed to stay inactive in circulation and become cytotoxic once a targeting antibody has delivered them into the tumor microenvironment.

The non-ribosomal peptide scaffold also offers medicinal chemistry handles that the more heavily worked tubulin-binding and DNA-damaging payload classes do not.

The starting material is the differentiator: a proprietary library of more than 1,200 cyanobacterial strains and over 5,000 novel compounds, which the group describes as the world's largest of its kind.

That biodiversity asset lets Simris mine an under-explored natural product space for new chemical matter instead of trying to out-engineer established synthetic payloads.

The limitation is scale and stage. The company is small and preclinical, so the outcome depends on in vivo data that is still being generated.

The lead microcystin payload program completed in vitro characterization, with an advanced in vitro update reported on 6 October 2025, and is moving into in vivo safety and efficacy studies.

That work is funded in part by the up to EUR 1 million expected from the warrant exercise announced on 6 July 2026, and is run through the contract research organization Nuvisan, engaged under an agreement announced on 5 June 2025.

Simris reported positive results from the Nuvisan study on 5 November 2025. No IND filing, clinical stage or target indication has been announced, so the program sits firmly in preclinical development.

Simris Biologics works entirely in oncology, supplying novel payloads for antibody-drug conjugates.

Its scope stops at the payload. The company is not advancing its own antibody-target pairs or tumor-specific indications at this stage, so its value depends on partners bringing the antibody and the target.

The parent group's second division, Simris Dermalogics, operates separately and has no bearing on the oncology work.

The company is preclinical, moving from in vitro payload characterization into in vivo efficacy and safety studies.

The critical near-term milestone is data from the in vivo program with Nuvisan, which will be the first proper test of whether the modified microcystin compounds show an acceptable therapeutic index in animal models.

After that, Simris would need to nominate a lead payload candidate, settle an antibody and target pairing, and complete IND-enabling studies before a clinical trial becomes realistic. No timeline for those steps has been published.

The case rests on preclinical execution over the next year or so, and there are three things to watch.

The first is in vivo data from the Nuvisan study. It is the first real test of the therapeutic index of the modified microcystins, and everything downstream depends on it.

The second is partnering. Simris sells a payload, so a licensing deal with an antibody developer is how the platform converts into revenue. A 2025 approach reached a non-binding concept sheet and then lapsed when the counterparty withdrew, which shows how contingent that route is.

The third is cash. The group has funded itself through convertibles, a bridge loan and warrant exercises, and the up to EUR 1 million from the July 2026 warrants is earmarked for the in vivo program rather than for a long runway. New leadership under Professor Pahl arrives with a small balance sheet and a single scientific bet.

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