South African Researcher Awarded R3m Grant to Advance Trop2-Targeted Theranostics for Breast Cancer
Key Insights
Professor Mike Sathekge receives the 2025 Harry Oppenheimer Fellowship Award, a R3 million grant, to develop a Trop2 (search)-targeted theranostic approach for breast cancer (search).
The research combines nanobody-based PET/CT imaging with actinium-225 (search) targeted alpha therapy to enable earlier detection and personalised treatment of aggressive breast cancers.
In South Africa, 67% of breast cancer (search) patients are diagnosed at late stage, highlighting the urgent need for improved diagnostic and therapeutic strategies.
Professor Mike Sathekge, head of Nuclear Medicine at the University of Pretoria and Steve Biko Academic Hospital, has been awarded the 2025 Harry Oppenheimer Fellowship Award — a R3 million grant from the Oppenheimer Memorial Trust (search) (OMT) — to advance a theranostic approach that could fundamentally reshape how aggressive breast cancer (search) is detected and treated.
The award, selected from 80 nominations spanning a wide range of academic fields, will support Sathekge's work at the South African Nuclear Medicine Research Infrastructure (NuMeRI (search)) to develop a system that links diagnosis and therapy through a single molecular target: trophoblast cell-surface antigen 2, or Trop2 (search).
Breast cancer (search) remains the leading type of cancer among women in South Africa and globally. A comprehensive study published recently in the South African Medical Journal found that 67% of patients in the public healthcare sector are diagnosed at a late stage, when their cancer has already metastasised and their prognosis is poor. The same study warned that South Africa is expected to face a substantial rise in cancer cases over the coming decades, driven by population growth, ageing and changing disease patterns.
“Theranostics, which brings diagnosis and treatment together, is a combination of early diagnosis with treatment that is personalised and precise down to mere cells, which allows us to exactly detect and assess tumours, devise specific treatment regimens and assessment of treatment response over time,” said Sathekge. “The earlier the breast cancer (search) is detected, the more accurately it is assessed and the more precise the treatment, the exponentially better the patient’s prognosis.”
Targeting Trop2 (search) with nanobody technology
Sathekge’s solution centres on Trop2 (search), a protein found in high levels in breast cancers as well as cervical, pancreatic and lung cancers. Trop2 helps the cancer multiply and makes it stubborn to treat. Although Trop2 is already recognised as an important target in several cancers, there is still no widely established, clinically scalable way to precisely map its distribution across a patient’s entire cancer burden.
The answer may lie in nanobodies: tiny, engineered antibody fragments designed to bind specifically to Trop2 (search) on cancer cells. Their small size allows them to reach tumours rapidly and clear from the bloodstream faster than conventional antibodies, making them particularly attractive for same-day PET imaging.
Through a long-standing collaboration with Professor Frederik Cleeren, assistant professor in the Laboratory for Radiopharmaceutical Research at KU Leuven in Belgium, and the Joint Research Centre (JRC) in Karlsruhe, Sathekge’s team is combining nanobody engineering and radiolabelling with South Africa’s capabilities in molecular imaging, actinium-225 (search) radiopharmaceutical development and targeted radionuclide therapy.
From imaging to therapy: a two-step approach
The first step uses a nanobody labelled with fluorine-18, a short-lived radioactive tracer, to help doctors visualise Trop2 (search)-positive tumours on a PET/CT scan. This advanced imaging method could help clinicians map Trop2 expression across a patient’s full cancer burden and monitor changes in the target and treatment response over time.
Where imaging confirms sufficient Trop2 (search) expression, the same targeting strategy can be applied to actinium-225 (search)-based treatment. Actinium-225 is a powerful alpha-emitting isotope that can deliver highly localised radiation over very short distances, concentrating treatment in Trop2-positive cancer cells while limiting radiation exposure to surrounding healthy tissue.
The ambition is to move beyond treating patients based on limited information from a single biopsy, towards a more personalised approach: seeing the target throughout the body, selecting patients more accurately, and laying the foundation for future Trop2 (search)-targeted alpha therapy.
South African leadership in global cancer research
Rebecca Oppenheimer, chairperson of the Oppenheimer Memorial Trust (search), described the selection as an exciting choice with far-reaching implications. “In developing a technology that makes diagnosing and treating cancers more effective, affordable and available, Prof. Sathekge and his colleagues hold in their hands the potential for a quantum leap forward in improving South African patients’ health outcomes and human dignity, as well as for beating breast cancer (search) globally,” she said.
University of Pretoria vice-chancellor Professor Francis Petersen emphasised the urgency of the work. “South Africa urgently needs better ways to detect, understand and treat aggressive breast cancer (search). Too many patients still present late, when the disease is more difficult to manage, and treatment options are limited,” said Petersen. “Prof. Sathekge’s work at NuMeRI (search) brings together advanced imaging, radiopharmaceutical science and targeted treatment in a way that could help doctors make more informed, patient-specific decisions.”
Petersen added that the research demonstrates the depth of scientific talent in South Africa and that “African researchers are not only responding to local health challenges, but helping to shape the global future of cancer care.”
For Sathekge, the work is fundamentally patient-centred. “Our goal is not simply to find cancer earlier. It is to understand each patient’s cancer better, select treatment more intelligently, and reduce the uncertainty that patients face when standard treatment no longer works,” he said. “This award supports a South African-led effort to see the biology of aggressive breast cancer (search) more clearly, select patients more accurately and lay the foundation for targeted treatment.”