Blue Therapeutics gets financing to push radiotherapies

British radiopharmaceuticals specialist Blue Earth Therapeutics Ltd has closed a U$76.5m Series A financing enabling the  spin-out company of Italian radiodiagnostics specialist Bracco Imaging SpA to advance its PSMA-targeted radioligand therapies currently undergoing Phase I clinical testing. With the money, the company will prepare Phase II studies of Lutetium (177-Lu) rhPSMA-10.1 and Actinium (225-Ac) rhPSMA-10.1, and collect data comparing 1st generation prostate cancer radioligand therapies with its rhPSMA candidates.

rhPSMA compounds are referred to as radiohybrid (rh) because each molecule possesses four distinct domains. The first consists of a Prostate‐Specific Membrane Antigen‐targeted receptor (PSMA) ligand. It is attached to two labelling moieties which may be radiolabelled with diagnostic isotopes such as 18-F or 68-Ga for PET imaging. This is the business of Blue Earth Diagnostics, who licenced the rhPSMA from Scintomics GmbH, a spin out company of the Technical University Munich, one year before being acquired by Braco Imaging SpA in 2019.

Braco Imaging spun out Blue Earth Therapeutics in 2020 and licenced rhPSMA rights for therapeutic purposes to its subsidiary because the PSMA receptor ligand can be also attached to therapeutic isotopes such as 177-Lu or 225-Ac for radioligand therapy. All four rhPSMA domains are joined together by a modifiable linker which can be used to modulate important pharmacokinetic characteristics.

The Series A financing was led by Soleus Capital and co-led by new investor Sands Capital Management as well as existing investor Bracco Imaging SpA. New investors Woodline Partners and PBM Capital also participated.  

“With the new investors and the team we have assembled, we now have a great mix of expertise and the resources to further our mission to develop radioligand therapies with the potential to improve patient outcomes by delivering high radiation doses to tumours without compromising on normal organ safety” commented David Gauden, Blue Earth Therapeutics CEO. “With our recent announcement on completion of the Phase 1 clinical trial, we are making excellent progress on both our beta emitter Lutetium (177-Lu) rhPSMA-10.1 and alpha emitter Actinium (225-Ac) rhPSMA-10.1 agents and look forward to sharing further progress updates.” 

In March 2022, the first 177-Lu radiopharmaceutical was approved by the US regulatory authority FDA. Six month later lutetium 177 vipivotide tetraxetan (Pluvicto) got the EU stamp by the European Medicines Agency (EMA) for the treatment of adult patients with PSMA-positive metastatic castration-resistant prostate cancer retractive to androgen receptor (AR) pathway inhibition and taxane-based chemotherapy. Pluvicto sales have been growing steeply since Novartis French subsidiary Advanced Accelerator Applications SA/Inc (taken over in 2018 for US$3.9bn) started distribution. In Q2/2024 is was US$345m, up 44% compared to Q2/2023.

Radiohybrid PSMA offers not only the potential for targeted treatment for men with prostate cancer, whose tumours and neovasculature all overexpress PSMA. Since PSMA is also expressed in other cancers, 177-Lu-PSMA–based radiopharmaceuticals holds the promise of expanding into new indications. The global theranostics market is forecasted to grow exponentially from US$7.2bn in 2022 to US$39bn by 2032, indicating the potential transformative value of radiopharmaceuticals in oncology. This developments might have motivated investors to go with Blue Earth Therapeutics’ second generation radioligands.