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Nuclidium

Company Overview

A clinical-stage Swiss biotech developing next-generation copper-based radiotheranostics that pair Copper-61 diagnostics with Copper-67 therapeutics to address unmet needs across prostate cancer, breast cancer, and neuroendocrine tumors. Nuclidium's central thesis is that using the same radiometal for both imaging and treatment — rather than mixing isotope families — enables more precise dosimetry and a cleaner theranostic workflow than current lutetium- or actinium-based approaches. The company's two lead clinical programs target PSMA-positive prostate cancer and SSTR2-positive metastatic breast cancer, with early data already comparing favorably against established standards of care.

Headquarters and Global Presence

Nuclidium AG is headquartered in Basel, Switzerland, with additional operations in Munich, Germany. The company is expanding its manufacturing and production network across Europe and North America to support clinical-stage supply requirements and hospital collaborations.

Founding and History

Nuclidium was founded in 2017 by Leila Jaafar-Thiel, who serves as CEO, and co-founder Gustav Schulthess, a double board-certified nuclear medicine practitioner and radiologist. Schulthess previously served as director of Nuclear Medicine and co-director of MR at University Hospital Zurich, and held a visiting professorship in Radiology at Stanford University. In July 2025 the company closed a CHF 79 million Series B, followed in May 2026 by an oversubscribed CHF 26 million extension that brought the total round to CHF 105 million — a signal of sustained institutional confidence in the copper radiotheranostics thesis.

Therapy Areas and Focus

Nuclidium's clinical programs span three solid tumor indications where radiopharmaceutical targeting is well established: metastatic castration-resistant prostate cancer (mCRPC), metastatic breast cancer (mBC), and gastroenteropancreatic and bronchopulmonary neuroendocrine tumors. In prostate cancer, PSMA overexpression provides a validated, high-contrast target; in breast cancer and NETs, SSTR2 expression defines the patient population. The strategic logic is to build a copper-specific theranostic franchise across indications where a common isotope pair can be deployed without redesigning the chemistry.

Technology Platforms and Modalities

Nuclidium's platform links tumor-targeting peptides to two copper isotopes via the NODAGA chelator: Copper-61 emits positrons for PET imaging, while Copper-67 emits beta particles for targeted radiotherapy. The critical differentiation is isotope matching — the same chelator-peptide backbone can be radiolabeled with either isotope, meaning the diagnostic scan directly predicts the therapeutic biodistribution. This contrasts with the lutetium-177/gallium-68 pairing dominant in approved PSMA therapies, where different metals and different pharmacokinetics introduce dosimetry uncertainty. Copper-67 also offers a half-life and beta-energy profile suited to solid tumor targeting.

Key Pipeline and Programs

NU101 is Nuclidium's lead theranostic program for mCRPC, comprising 61Cu-NuriPro (61Cu-NODAGA-PSMA I&T) for imaging and 67Cu-NuriPro (67Cu-NODAGA-PSMA I&T) for treatment. Phase I data for the diagnostic component, presented at SNMMI 2025, showed a safety profile comparable to established PSMA tracers and detected more lesions up to four hours post-administration in 50% of patients versus F-18 piflufolastat PET — a direct competitive benchmark against one of the field's leading agents. Proceeds from the May 2026 Series B extension are earmarked to advance NU101 into advanced clinical trials.

NU201 targets SSTR2-positive metastatic breast cancer and shares its diagnostic backbone with the NuriPro platform, deploying the copper isotope pair against a different receptor. Breast cancer is a deliberate expansion: Phase I/II data for 61Cu-TraceNet in SSTR-positive NETs, presented at EANM 2025, showed independent blinded readers rating copper-61 images superior to the standard-of-care gallium-68 SSTR2 agonist on tumor-to-background ratio. Nuclidium is now extending that imaging agent into mBC trials, broadening the addressable population beyond NETs.

61Cu-TraceNet, the somatostatin receptor-targeting imaging agent, is the third disclosed clinical asset and represents the diagnostic wing of what would become NU201's full theranostic pair. Its Phase I/II NET data are the most mature imaging comparison against an approved benchmark in Nuclidium's portfolio to date.

Recent Developments

The Series B extension closed in May 2026 at CHF 26 million — oversubscribed and led by returning investors Kurma Growth Opportunities Fund and Angelini Ventures, with EIB co-investment facility Aurea, Wellington Partners and Neva SGR also participating, bringing the total Series B to CHF 105 million. In January 2026, Nuclidium secured a new U.S. patent covering its 61Cu-based radiodiagnostic program for PSMA-positive prostate cancer, strengthening IP around the core copper platform. Phase I/II data for 61Cu-TraceNet in NETs were presented at EANM 2025, and Phase I data for 61Cu-NuriPro were presented at SNMMI 2025, giving the company two positive clinical data packages within a short window.

Key Personnel

Leila Jaafar-Thiel serves as CEO and co-founder, having built Nuclidium from inception in 2017. Gustav Schulthess, co-founder, brings rare dual board certification in nuclear medicine and radiology, with senior clinical and academic roles at University Hospital Zurich and Stanford University underpinning the scientific credibility of the copper-isotope thesis.

Strategic Partnerships

Nuclidium is actively expanding collaborations with hospitals and academic centers across Europe and North America to support its clinical network and manufacturing scale-up. The Series B investor syndicate — which spans Kurma, Angelini Ventures, Wellington Partners, Neva SGR (Intesa Sanpaolo Group), DeepTech & Climate Fonds, Bayern Kapital, and NRW.BANK — reflects both private and public-sector conviction, with the EIB co-investment facility Aurea joining in the Series B extension.

FAQ Section

Lutetium-177 is paired diagnostically with gallium-68 — two chemically distinct metals whose different pharmacokinetics limit dosimetry precision. Nuclidium's copper pair uses the same NODAGA chelator backbone for both imaging and treatment, meaning what the scan shows is what the therapy delivers. The company views this isotope-matching principle as a structural advantage in dose optimization, not merely a differentiation story.

Both PSMA and SSTR2 are high-density, tumor-selective surface receptors with well-validated biology and existing clinical precedent in radiolabeled peptide therapies. PSMA is overexpressed in mCRPC with limited expression in normal tissue; SSTR2 is expressed in a subset of breast cancers as well as NETs, broadening the addressable patient population. Choosing clinically validated targets reduces the scientific risk and allows the platform to compete directly against approved standards of care on imaging quality and therapeutic efficacy.

Phase I data presented at SNMMI 2025 showed 61Cu-NuriPro detected more lesions up to four hours post-administration in 50% of patients compared with F-18 piflufolastat PET, one of the leading approved PSMA tracers. The safety profile was described as comparable to established PSMA agents. These are early Phase I results in a relatively small cohort, so the signal is promising rather than definitive, but benchmarking directly against an approved competitor gives the data clinical context from the outset.

61Cu-TraceNet is Nuclidium's copper-61-labeled PET diagnostic targeting somatostatin receptor-positive tumors, initially evaluated in gastroenteropancreatic and bronchopulmonary NETs. Phase I/II results presented at EANM 2025 showed the agent was well tolerated, and in a blinded independent reader analysis, image quality was rated superior to a standard-of-care gallium-68 SSTR2 agonist on tumor-to-background ratio. Nuclidium is now extending the program into SSTR2-positive metastatic breast cancer trials as the diagnostic component of NU201.

Oncology is the sole focus, with three solid tumor indications currently in clinical or near-clinical development: mCRPC via the NuriPro PSMA program (NU101), metastatic breast cancer via the SSTR2-targeted NU201 program, and neuroendocrine tumors via 61Cu-TraceNet. Beyond these, the Series B extension funds are allocated to preclinical expansion into additional solid tumor indications, suggesting the copper theranostic platform is being applied systematically wherever a high-density targetable receptor exists on tumor cells.

Nuclidium is firmly clinical-stage, with Phase I data packages now in hand for both its PSMA and SSTR programs, and a CHF 105 million total Series B financing closed as of May 2026 to fund advancement into later-stage trials. The stated use of proceeds is to move NU101 (mCRPC) and NU201 (mBC) into advanced clinical trials — Phase II or beyond. Manufacturing network expansion across Europe and North America is a parallel priority, given that radiopharmaceutical supply logistics are a well-recognized bottleneck in the sector.

The company has positive early clinical data and strong financing, but several watchpoints define the near-term investment case:

Phase II design and endpoints for NU101 in mCRPC: how Nuclidium benchmarks against approved lutetium-177 PSMA therapy will be the pivotal competitive test.
NU201 breast cancer trial initiation: translating the SSTR2 NET imaging win into a therapeutic program in mBC is the pipeline's most speculative step.
Copper-67 isotope supply: securing reliable production capacity for a non-standard medical isotope at clinical scale remains a sector-wide challenge.
IP strength: the January 2026 U.S. patent on the 61Cu PSMA diagnostic is a positive signal, but the breadth of coverage against competitors using similar chelator chemistry will matter as the field matures.
Partnership or out-licensing activity: Nuclidium has not yet announced a major pharma collaboration; given the valuation premiums seen in radiopharma M&A, any deal announcement would be a significant catalyst.

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