The LYMRIT 37-01 Phase 1/2 trial assessing Betalutin in non-Hodgkin’s lymphoma patients will continue to evaluate Betalutin administered after pre-dosing with lilotomab in a Phase 2 expansion cohort of Arm 4.
The dose of Betalutin will be 20 MBq/kg, or megabecquerels per kilogram body weight. The becquerel is a unit of radioactivity.
The decision to open this new escalation group follows a recommendation from the trial’s Safety Review Committee (SRC) after reviewing safety data from the study. It will enable Nordic Nanovector, Betalutin’s manufacturer, to gather additional safety and effectiveness data confirming the selected dose for use in the pivotal PARADIGME Phase 2 trial, set to begin in the second half of 2017.
“This recommendation from the SRC represents another important milestone for the development of Betalutin, in line with our strategy and established timelines,” Luigi Costa, CEO of Nordic Nanovector, said in a news release. “It supports the hypothesis that a higher pre-dosing regimen may enable the use of a higher dose of Betalutin. The enrollment of new patients in Phase 2 provides the opportunity to collect additional safety and preliminary efficacy data to support the selection of the dosing regimen we will use in PARADIGME later this year.”
Betalutin, also known as 177Lu-satetraxetan-lilotomab, is an antibody against the protein CD37, attached to a radioactive compound. According to the company, the treatment is the first of a new generation of antibody-radionuclide-conjugates (ARCs).
This approach is a bit like localized radiotherapy, but radiation is delivered inside the body and in a local and specific manner. CD37 is a molecule found on the surface of most B-cell lymphoma cells. When the antibodies bind to the tumor, it delivers the radioactive compound to the malignant cells.
LYMRIT 37-01 is an open-label study in which all patients receive Betalutin. Patients are divided into four groups that receive increasing doses of the treatment with different pre-dosing treatments with Rituxan (rituximab) or a CD37 antibody.
Efficacy data released in December 2016 and presented at the ASH Annual Meeting showed that 62 percent of patients included in Arm 1 receiving 15 MBq/kg of Betalutin responded to the treatment. Thirty-eight percent were seen to have complete responses.
This was consistent with data from the Phase 2 escalation cohort of Arm 1. Among the 16 patients enrolled, 69 percent responded to the therapy, with 38 percent showing complete responses.
Patients in Arm 1 also had durable responses that lasted a median of 20.7 months. Safety data was also promising, with most side effects being both predictable and manageable.
While the company did not disclose safety and efficacy data from other arms of the study, they will be presenting updated results from the trial at the International Conference on Malignant Lymphoma (ICML), June 14-17 in Lugano, Switzerland.