Study Confirms Safety, Efficacy of New Radiopharmaceutical

There may be a new player in the radioimmunotherapy category, but is anybody listening?

Investigators looking into the potential of a low-energy beta-emitter radiopharmaceutical as a treatment for B-cell non-Hodgkin's lymphomas have published their findings in the Journal of Nuclear Medicine. They say that the use of 177Lu-DOTA-Rituximab as a radioimmunotherapy can achieve high rates of tumor response without using the levels of radiation found in other therapies.

Andreas Lohri, MD, and colleagues conducted a phase I/II study of radioimmunotherapy using 177Lu-DOTA-Rituximab among 31 patients with various relapsed B-cell NHLs, including follicular lymphoma and mantle cell lymphoma.

Said Lohri, who was the lead author:

Twelve years ago, when we started the study, it seemed that radioimmunotherapy could be a highly interesting tool that was both easy for clinicians to use and well-tolerated in patients. It also was clear that the use of iodine radionuclides was inconvenient for handling and not practical for patients because of the need for prolonged in hospital days due to radiation protection measures. Although 90Y ibritumomab tiuxetan – Zevalin – was introduced shortly after we started the study, we felt it was important to do clinical experiments with other radionuclides.

Patients with follicular lymphoma had an overall response rate of 82 percent, while those with mantle cell lymphoma had a much lower overall response rate of 21 percent.

"With 177Lu-DOTA Rituximab we can essentially do CD20 imaging," added Lohri. "At the moment, this may be academically interesting and could potentially be used in daily practice if compared to all forms of current PET imaging."

Radioimmunotherapy (RIT) may be a fantastic treatment for indolent NHLs – and in fact Zevalin has shown itself to be just that – but the economics have always put Zevalin in a precarious position, leaving one to wonder how another RIT could do any better.

Source: JNM