Evaluating 177Lu-lilotomab satetraxetan in relapsed/refractory indolent non-Hodgkin lymphoma

The study evaluated the safety and effectiveness of ¹⁷⁷Lu-lilotomab satetraxetan (177LLS; Betalutin) in patients with relapsed/refractory (r/r) indolent non-Hodgkin lymphoma (iNHL). The main finding was that 177LLS was proven to be a valuable alternative treatment in such patients.

NHL is a type of lymphoma that spreads slowly and generally shows no symptoms. Relapsed refers to cancer’s return and refractory means cancer which stopped responding to treatment. New therapies are lacking for patients with r/r-iNHL, especially the older ones with other medical conditions who cannot tolerate intensive chemotherapy.

177LLS is an immunotherapy drug coupled with a radiotherapy agent. It has shown promising anti-tumor activity in experimental studies. However, its safety and effectiveness in patients with r/r iNHL are unexplored.

The study included 74 adult patients with r/r-iNHL. 57 patients had follicular lymphoma (FL) which is the most common type of iNHL. All patients received 2 prior therapies on average. All patients received 177LLS after pretreatment with immunotherapy with rituximab (Rituxan) and lilotomab.

After an average follow-up of 24.5 months, the overall response rate (ORR) for all patients was 61%. ORR defines the proportion of patients with complete response (CR; absence of all cancer symptoms) or partial response (PR; tumor shrinkage) to treatment. Almost 50% of recorded clinical responses were CR for all patients.

Treatment response lasted for an average of 13.6 months for all patients and 32 months for patients with CR. On average, all patients survived for 8.8 months without cancer progression. This period was 9 months in patients with FL.

Non-blood-related side effects were mostly mild or moderate. Among them, nausea occurred in 15.8% of patients, upper respiratory tract infections in 10.5%, and urinary tract infections in 10.5% of the patients. The most common blood-related side effects were severe neutropenia (11%; low blood white blood cell level counts) and thrombocytopenia (8%; low blood levels of platelets) occurred in 11% and 8% of patients. 

The authors concluded that 177LLS was a promising alternative for patients with r/r-iNHL who previously received other therapies.

This study was sponsored by Nordic Nanovector ASA, the manufacturer of 177LLS. The number of patients in this study was very small. Also, there was no control group. Further, larger studies are needed.