The Health Related Quality of Life Is Maintained Following Treatment of Indolent Non-Hodgkin's Lymphoma Patients with the Novel Effective Antibody Radionuclide Conjugate ¹⁷⁷lu-Satetraxetan-Lilotomab

Betalutin (¹⁷⁷Lu-satetraxetan-lilotomab) is an antibody radionuclide conjugate (ARC) in development for the treatment of Non-Hodgkin's lymphoma (NHL). The FACT-Lym is a validated health related quality of life instrument specifically designed to assess lymphoma patients. This questionnaire has been used previously to demonstrate significant reductions in the quality of life of patients undergoing treatment, likely as a result of treatment related toxicities (Hlubocky FJ, et al, Lymphoma 2013).

Methods

Patients with relapsed incurable NHL of follicular grade I-IIIA, marginal zone, mantle cell, lymphoplasmacytic and small lymphocytic subtypes who had received at least one prior treatment regimen were eligible for enrolment. All patients received a single dose of 15 MBq/kg of ¹⁷⁷Lu-satetraxetan-lilotomab.

The FACT-Lym instrument used in the study has 42 questions grouped into 5 subscales (physical, social/family, emotional and functional well-being and additional concerns). Questionnaires were completed by all subjects in the phase 2 stage of the study during screening, at month 3 and month 12. Responses were categorised on a 5-point Likert scale from "0- not at all" to "4-very much" with a higher score indicating a better quality of life. The analysis is conducted as part of a protocol specified interim analysis of efficacy, safety and quality of life.

Results

A total of 36 patients have been enrolled into this phase 1/2 study of which 15 patients who have undergone treatment in the phase 2 part are included in the current analysis. The median age of the patients was 68 years and the median number of prior regimens was 2 (range: 1-9). All 15 subjects have completed the screening assessment and 7 patients have completed the 3 month assessment, data from all subjects at both screening and the month 3 assessment will be presented at the annual meeting. To date 907 responses to questions have been collected including 622 questions at screening and 285 responses at 3 months post-treatment.

At enrolment patients overall had a good health-related quality of life with a median baseline score of 121 and this was similar at 3 months post-treatment (median score: 132, p-value: 0.558). This maintenance of the patients quality of life was achieved while 5/7 patients (71%) showed a complete or partial response to treatment. Of the 7 patients who have so far completed the month 3 assessment, 3 had grade 3 thrombocytopenia or neutropenia (none had grade 4), the quality of life assessment of these patients (median score: 158) was similar to or higher than the 4 patients who did not have grade 3 thrombocytopenia/neutropenia (median score: 110). This indicates no negative impact on the health related quality of life when patients experienced haematological side effects associated with ¹⁷⁷Lu-satetraxetan-lilotomab. When the 3-month assessment has been completed by all patients a subscale analysis and a correlation with ECOG performance status will be performed.

Conclusion

The health related quality of life as measured by the validated FACT-Lym questionnaire was maintained following treatment with Betalutin, while also achieving a durable tumour response in a significant proportion of the patients assessed. The treatment related hematological side effects experienced by patients were modest and appeared not to have a negative effect on the quality of life. Further analysis is required to confirm these findings when the 3 month assessment has been completed by all patients.