The first patient has been dosed in the Phase Ib trial evaluating the combination therapy of Telix Pharmaceuticals' targeted radiation therapy, TLX250 (¹⁷⁷Lu-DOTA-girentuximab), and Merck’s DNA-dependent protein kinase (DNA-PK) inhibitor, peposertib (M3814).
The open-label, multicentre dose escalation and expansion Phase I (NCT05868174) study population includes patients with solid tumours that express carbonic anhydrase IX (CAIX).
Telix chief medical officer Dr Colin Hayward stated in a press release: "Preclinical data has shown excellent combination response, which has the potential to translate to additional response or more tolerable treatment regimens in patients.”
TLX250 is also being evaluated as combination therapy with checkpoint inhibitors, namely cabozantinib and/or nivolumab, in two Phase Ib/II trials (NCT05663710 and NCT05239533) for renal carcinoma.
TLX250 is an antibody-based treatment that targets CAIX, a transmembrane protein over-expressed in certain renal and hypoxic solid tumours. The combination therapy of TLX250 and peposertib is hypothesised to synergically induce DNA damage in targeted cancer cells while preventing the repair of the resulting damage.
The study is part of a 2019 strategic research collaboration between Merck and Telix to develop combination therapies of Telix’s targeted radiation therapies and Merck’s DNA damage response inhibitors in preclinical studies.
The preclinical study for TLX250 and peposertib demonstrated that a reduced radiation dose is required for reduction and remission when used with peposertib compared to targeted radiation alone.
In June 2023, the Australian company started its Phase II trial for the TLX250’s companion diagnostic imaging agent TLX250-CDx. Other pipeline drugs in the company’s profile include multiple therapeutic radiopharmaceutical agents namely TLX591 for the treatment of prostate cancer, TLX101 for glioblastoma treatment, and TLX66 for bone marrow conditioning. These therapeutic agents also have accompanying diagnostic agents.
Telix reported $120.7m in global sales from Illuccix, a positron emission tomography (PET) scan imaging agent, in the second quarter of 2023. Much of this is expected to fund future product approvals and launch, as per the company's June 2023 Activities Report.
