Speaking at the 36th EORTC-NCI-AACR Symposium on Molecular Targets and Cancer Therapeutics in Barcelona, Spain, on Friday, Sathekge, Professor and Head of the Nuclear Medicine Department at the University of Pretoria and Steve Biko Academic Hospital, South Africa, said he and his colleagues have found out that the mini-protein, a radiopharmaceutical, was able to target and bind specifically only to the cancer
Targeted radiation is something new, and this is the first time one will be witnessing totally new technology being employed. It was used to deliver radiation to the tumour. A small protein was made to look for another protein that many cancers produce referred to as Nectin-4 he said.
The mini-protein is known as AKY-1189 and it is the first small molecule to be built to carry a therapeutic amount of Actinium-225, a radioactive element that binds uniquely to Nectin-4.
The researchers sought consent to use AKY-1189 under Section 21 of South African Health Products Regulatory Authority (SAHPRA), and the team scanned 20 patients at Nuclear Medicine Research Infrastructure (NuMeRi) where Sathekge is President/CEO.
They administered in each patient a single injection of desire AKY-1189 (~5mCi of [68Ga] Ga-AKY-1189 the dosage employed for imaging other radiopharmaceuticals. They used PET-CT to obtain scans of the patients after one, two and three hours to determine the effectiveness of the drug at coming to the tumours and the degree to which the tumours had taken up the dose.
To evaluate the dose over time (dosimetry) that could be expected with [225Ac] Ac-AKY-1189 in tumours, kidneys, and whole body, the researchers injected AKY-1189 (10mCI [177Lu]Lu-AKY-1189) into nine patients and SPECT-CT images were taken of the patients after 3h, 24h, and 48h.
Thus, AKY-1189 had no toxicities, including skin toxicity. The salivary glands had a temporary rise which can be considered as not exceeding any substantial radiation effect on the salivary glands.Â
The researchers also established that there was some uptake of radiation in the kidneys, though at a level that indicates that a patient can safely complete the treatment with [225Ac]Ac-AKY-1189 (1200 micro Curies or six doses of ~8 MBq).
The most valuable knowledge gained through the work done here is that the drug is incorporated into various types of cancers, so it has vast potential for treating those patients’ cancers.Â
Similarly, and of great significance, one could observe that the drug does not have a tendency to concentrate in the normal tissues; it may therefore be safe for multiple doses that will greatly enhance the treatment results.
In the imaging results presented today, it is evident how it specializes in identifying Nectin-4 while the radiation hardly harms any other healthy cells. These are initial findings of AKY-1189 in humans and the next clinical trials results will be forthcoming in due course.
Reference:
New “mini-protein” carries radiation dose directly to tumours without harming healthy tissues. EurekAlert
