Longitudinal minimal residual disease assessment in multiple myeloma patients in complete remission - results from the NMSG flow-MRD substudy within the EMN02/HO95 MM trial.

BACKGROUND: Multiple myeloma remains an incurable disease with multiple relapses due to residual myeloma cells in the bone marrow of patients after therapy. Presence of small number of cancer cells in the body after cancer treatment, called minimal residual disease, has been shown to be prognostic for progression-free and overall survival. However, for multiple myeloma, it is unclear whether patients attaining minimal residual disease negativity may be candidates for treatment discontinuation. We investigated, if longitudinal flow cytometry-based monitoring of minimal residual disease (flow-MRD) may predict disease progression earlier and with higher sensitivity compared to biochemical assessments. METHODS: Patients from the Nordic countries with newly diagnosed multiple myeloma enrolled in the European-Myeloma-Network-02/Hovon-95 (EMN02/HO95) trial and undergoing bone marrow aspiration confirmation of complete response, were eligible for this Nordic Myeloma Study Group (NMSG) substudy. Longitdudinal flow-MRD assessment of bone marrow samples was performed to identify and enumerate residual malignant plasma cells until observed clinical progression. RESULTS: Minimal residual disease dynamics were compared to biochemically assessed changes in serum free light chain and M-component. Among 20 patients, reaching complete response or stringent complete response during the observation period, and with ≥3 sequential flow-MRD assessments analysed over time, increasing levels of minimal residual disease in the bone marrow were observed in six cases, preceding biochemically assessed disease and clinical progression by 5.5 months and 12.6 months (mean values), respectively. Mean malignant plasma cells doubling time for the six patients was 1.8 months (95% CI, 1.4-2.3 months). Minimal malignant plasma cells detection limit was 4 × 10-5. CONCLUSIONS: Flow-MRD is a sensitive method for longitudinal monitoring of minimal residual disease dynamics in multiple myeloma patients in complete response. Increasing minimal residual disease levels precedes biochemically assessed changes and is an early indicator of subsequent clinical progression. TRIAL REGISTRATION: NCT01208766.

Burden of Treatment-Induced Peripheral Neuropathy in Patients with Multiple Myeloma in Sweden.

INTRODUCTION: Treatment-induced peripheral neuropathy (TIPN) is a complication of multiple myeloma (MM) treatment. OBJECTIVE: This real-world, retrospective study used electronic medical record (EMR) data from 3 Swedish clinics to assess the occurrence and economic burden of TIPN in patients with MM. METHODS: Eligible patients had an MM diagnosis in the Swedish Cancer Registry between 2006 and 2015 and initiated treatment during that period. Follow-up was until last EMR visit, death, or study end (April 2017). The current analyses included patients receiving bortezomib, lenalidomide, carfilzomib, or thalidomide at any treatment line. To discern healthcare resource utilization (HCRU) and costs associated with TIPN from other causes, patients with TIPN were matched with those without on baseline characteristics, treatment, and line of therapy. All analyses were descriptive. RESULTS: Overall, 457 patients were included; 102 (22%) experienced TIPN. Patients experiencing TIPN during first-line treatment mostly received bortezomib-based regimens (n = 48/57 [84%]); those with TIPN during second- and third/fourth-line treatment mostly received lenalidomide/thalidomide-based regimens (19/31 [61%], 8/14 [57%], respectively). Patients with TIPN had higher HCRU/costs than those without TIPN (mean differences in hospital outpatient visits: 5.2, p = 0.0031; total costs per patient-year: EUR 17,183, p = 0.0007). CONCLUSIONS: Effective MM treatments associated with a reduced incidence of TIPN could result in decreased healthcare expenditure.

Cost effectiveness of pomalidomide in patients with relapsed and refractory multiple myeloma in Sweden.

BACKGROUND: Multiple myeloma (MM) patients who have progressed following treatment with both bortezomib and lenalidomide have a poor prognosis. In this late stage, other effective alternatives are limited, and patients in Sweden are often left with best supportive care. Pomalidomide is a new anti-angiogenic and immunomodulatory drug for the treatment of MM. Our objective was to evaluate the cost effectiveness of pomalidomide as an add-on to best supportive care in patients with relapsed and refractory MM in Sweden. MATERIAL AND METHODS: We developed a health-economic discrete event simulation model of a patient's course through stable disease and progressive disease, until death. It estimates life expectancy, quality-adjusted life years (QALYs) and costs from a societal perspective. Effectiveness data and utilities were taken from the MM-003 trial comparing pomalidomide plus low-dose dexamethasone with high-dose dexamethasone (HIDEX). Cost data were taken from official Swedish price lists, government sources and literature. RESULTS: The model estimates that, if a patient is treated with HIDEX, life expectancy is 1.12 years and the total cost is SEK 179 976 (€19 100), mainly indirect costs. With pomalidomide plus low-dose dexamethasone, life expectancy is 2.33 years, with a total cost of SEK 767 064 (€81 500), mainly in drug and indirect costs. Compared to HIDEX, pomalidomide treatment gives a QALY gain of 0.7351 and an incremental cost of SEK 587 088 (€62 400) consisting of increased drug costs (59%), incremental indirect costs (33%) and other healthcare costs (8%). The incremental cost-effectiveness ratio is SEK 798 613 (€84 900) per QALY gained. CONCLUSION: In a model of late-stage MM patients with a poor prognosis in the Swedish setting, pomalidomide is associated with a relatively high incremental cost per QALY gained. This model was accepted by the national Swedish reimbursement authority TLV, and pomalidomide was granted reimbursement in Sweden.