Minimal Residual Disease Negativity Does Not Overcome Poor Prognosis in High-Risk Multiple Myeloma: A Single-Center Retrospective Study

Clinical Utility of Next-Generation Flow-Based Minimal Residual Disease Assessment in Patients with Multiple Myeloma

Background

Minimal residual disease (MRD) is an important prognostic factor for evaluating a deeper treatment response in patients with multiple myeloma (MM). We evaluated the clinical utility of next-generation flow (NGF)-based MRD assessment in a heterogeneous MM patient population.

Methods

Patients with suspected morphological remission after or during MM treatment were prospectively enrolled. In total, 108 bone marrow samples from 90 patients were analyzed using NGF-based MRD assessment according to the EuroFlow protocol, and progression-free survival (PFS) was evaluated according to the International Myeloma Working Group response status, cytogenetic risk, and MRD status.

Results

The overall MRD-positive rate was 31.5% (34/108 samples), and MRD-positive patients showed a lower PFS than MRD-negative patients (P=0.005). MRD-positive patients showed inferior PFS than MRD-negative in patients with stringent complete remission (sCR)/complete remission (P=0.014) and high-risk cytogenetic abnormalities (P=0.016). MRD was assessed twice in 18 patients with a median interval of 12 months. Sustained MRD negativity was only observed in patients with sustained sCR, and their PFS was superior to that of patients who were not MRD-negative (P=0.035).

Conclusions

Clinical application of NGF-based MRD assessment can provide valuable information for predicting disease progression in patients with MM in remission, including those with high-risk cytogenetic abnormalities.

Prognostic Significance of the Stage at Which an MRD-Negative Status Is Achieved for Patients With Multiple Myeloma Who Received ASCT

Objective

To explore the prognostic significance of the stage at which a minimal residual disease (MRD)-negative status is achieved for patients with newly diagnosed multiple myeloma (NDMM) who received autologous hematopoietic stem cell transplantation (ASCT).

Cases and Methods

A retrospective analysis of 186 NDMM patients who received "induction therapy-ASCT-maintenance therapy" in our center and achieved an MRD-negative status was performed. Patients were divided into three groups, A (induction therapy), B (3 months after ASCT), and C (maintenance therapy), according to the stage at which an MRD-negative status was achieved.

Results

The median time to progression (TTP) of 186 patients was not reached; the median overall survival (OS) was 113.8 months. The median TTP of the patients in three groups was not reached (P=0.013), and the median OS of the patients in three groups was not reached, not reached, and 71.2 months, respectively (P=0.026). Among patients with standard-risk cytogenetics, the median TTP of those in all three groups was not reached (P=0.121), and the median OS of the patients in three groups was not reached, not reached, and 99.6 months, respectively (P=0.091). Among patients with high-risk cytogenetics, the median TTP of those in three groups was not reached, 53.9 months, and 35.8 months (P=0.060), and the median OS was not reached, 71.2 months, and 60.2 months, respectively (P=0.625). Among patients with R-ISS stage I-II, the median TTP of those in three groups was not reached (P=0.174), and the median OS of the patients in three groups was not reached, not reached, and 99.6 months, respectively (P=0.186). Among the 29 patients with R-ISS stage III, the median TTP of those in the 3 groups were unreached, unreached, and 35.1 months (P<0.001), and the median OS was unreached, unreached, and 48.5 months, respectively (P=0.020). In all enrolled patients, the stage of reaching MRD-negative was an independent prognostic factor for TTP, rather than a prognostic factor for OS. The stage of reaching MRD-negative in patients with R-ISS III was an independent prognostic factor for OS.

Conclusion

For the same patients who are MRD-negative, the prognoses of those who achieve an MRD-negative status at different groups are different. The stage at which an MRD-negative status is achieved can predict the prognosis of patients with R-ISS stage III.

Anti-CD19 and anti-BCMA CAR T cell therapy followed by lenalidomide maintenance after autologous stem-cell transplantation for high-risk newly diagnosed multiple myeloma

Few prospective studies have examined posttransplant chimeric antigen receptor (CAR) T cell infusion as candidates for front-line consolidation therapy for high-risk multiple myeloma (MM) patients. This single-arm exploratory clinical trial is the first to evaluate the safety and efficacy of sequential anti-CD19 and anti-BCMA CAR-T cell infusion, followed by lenalidomide maintenance after autologous stem cell transplantation (ASCT), in 10 high-risk newly diagnosed multiple myeloma (NDMM) patients. The treatment was generally well tolerated, with hematologic toxicities being the most common grade 3 or higher adverse events. All patients had cytokine release syndrome (CRS), which was grade 1 in 5 patients (50%) and grade 2 in 5 patients (50%). No neurotoxicity was observed after CAR-T cell infusion. The overall response rate was 100%, with the best response being 90% for a stringent complete response (sCR), and 10% for a complete response (CR). At a median follow-up of 42 (36-49) months, seven (70%) of 10 patients showed sustained minimal residual disease (MRD) negativity for more than 2 years. The median progression-free survival (PFS) and overall survival (OS) were not reached. Although the sample size was small and there was a lack of control in this single-arm study, the clinical benefits observed warrant ongoing randomized controlled trials.

A Cost Impact Analysis of clonoSEQ® as a Valid and CE-Certified Minimal Residual Disease (MRD) Diagnostic Compared to No MRD Testing in Multiple Myeloma in Germany

INTRODUCTION

The measurement of minimal residual disease (MRD) with clonoSEQ® can be used in the assessment of B-cell lymphoid tumor burden throughout treatment with accuracy, sensitivity and standardization when compared to traditional cytomorphology. With the approval of novel treatments, standardized MRD assessment with improved performance is increasingly important. The aim of this analysis is to estimate the cost-effectiveness of MRD testing with clonoSEQ® compared to no MRD testing for patients with multiple myeloma (MM) on maintenance therapy in Germany.

METHODS

The cost impact of clonoSEQ® was analyzed from the German statutory insurance perspective. Clinical data were derived from the literature and expert opinions. Cost input was utilized based on publicly available data and literature. Patients in the MRD arm were tested every 6 months. The deterministic Markov model consists of six health states, and every patient begins at the start of maintenance. Included therapies are lenalidomide for maintenance and carfilzomib, lenalidomide and dexamethasone for relapse.

RESULTS

For a time horizon of 10 years, the deterministic cost impact analysis shows total cost of €279,483 for patients using clonoSEQ® in comparison to €356,623 for simulated patients without MRD testing. The main drivers of the cost differences are saved cost of drug holiday. The savings per patient in 1 year are €18,396. Savings after 3 years are €69,991 per patient. Savings after 10 years are €77,140 per patient.

CONCLUSIONS

Based on the underlying model, clonoSEQ® can support German health insurance funds to use high-cost drugs more efficiently in the treatment of myeloma.

Clinical implications of loss of bone marrow minimal residual disease negativity in multiple myeloma

MRD conversion occurs in 39% of MRD⁻ MM patients and reliably predicts future relapse.

MRD conversion within 10 years of diagnosis confers an inferior overall survival and progress-free survival.

Multiple myeloma (MM) patients frequently attain a bone marrow (BM) minimal residual disease (MRD) negativity status in response to treatment. We identified 568 patients who achieved BM MRD negativity following autologous stem cell transplantation (ASCT) and maintenance combination therapy with an immunomodulatory agent and a proteasome inhibitor. BM MRD was evaluated by next-generation flow cytometry (sensitivity of 10⁻⁵ cells) at 3- to 6-month intervals. With a median follow-up of 9.9 years from diagnosis (range, 0.4-30.9), 61% of patients maintained MRD negativity, whereas 39% experienced MRD conversion at a median of 6.3 years (range, 1.4-25). The highest risk of MRD conversion occurred within the first 5 years after treatment and was observed more often in patients with abnormal metaphase cytogenetic abnormalities (95% vs 84%; P = .001). MRD conversion was associated with a high risk of relapse and preceded it by a median of 1.0 years (range, 0-4.9). However, 27% of MRD conversion-positive patients had not yet experienced a clinical relapse, with a median follow-up of 9.3 years (range, 2.2-21.2). Landmark analyses using time from ASCT revealed patients with MRD conversion during the first 3 years had an inferior overall and progression-free survival compared with patients with sustained MRD negativity. MRD conversion correctly predicted relapse in 70%, demonstrating the utility of serial BM MRD assessment to complement standard laboratory and imaging to make informed salvage therapy decisions.

The detection of circulating plasma cells may improve the Revised International Staging System (R-ISS) risk stratification of patients with newly diagnosed multiple myeloma

The Revised International Staging System (R-ISS) stratifies patients affected by Multiple Myeloma (MM) into three distinct risk groups: R-ISS I [ISS Stage I, Standard-Risk cytogenetics and normal Lactase DeHydrogenase (LDH)], R-ISS III (ISS stage III and either high-risk cytogenetics or high LDH) and R-ISS II (any other characteristics). With the aim to verify whether the three R-ISS groups could be divided into subgroups with different prognostic factors based on the detection of Circulating Plasma Cells (CPCs) at diagnosis, in this retrospective analysis, we evaluated 161 patients with MM treated at our centre between 2005 and 2017. In all, 57 patients (33·9%) were staged as R-ISS III, 98 (58·3%) as R-ISS II and six (3·6%) as R-ISS I. CPCs were detected in 125 patients (74·4%), while in 43 patients (25·6%) no CPCs were seen. Our analysis revealed that Overall Survival (OS) and progression-free survival (PFS) rates in R-ISS II patients were higher in the subgroup without CPCs compared to the subgroup with ≥1 CPCs (OS: 44·7% vs. 16·3%, P = 0·0089; PFS: 27·8% vs. 8·1%, P = 0·0118). Our present findings suggest that the detection of CPCs at diagnosis may be used as a further prognostic biomarker to improve the risk stratification of patients with MM staged as R-ISS II.

Minimal residual disease in multiple myeloma: defining the role of next generation sequencing and flow cytometry in routine diagnostic use

For patients diagnosed with multiple myeloma (MM) there have been significant treatment advances over the past decade, reflected in an increasing proportion of patients achieving durable remissions. Clinical trials repeatedly demonstrate that achieving a deep response to therapy, with a bone marrow assessment proving negative for minimal residual disease (MRD), confers a significant survival advantage. To accurately assess for minute quantities of residual cancer requires highly sensitive methods; either multiparameter flow cytometry or next generation sequencing are currently recommended for MM response assessment. Under optimal conditions, these methods can detect one aberrant cell amongst 1,000,000 normal cells (a sensitivity of 10^-6). Here, we will review the practical use of MRD assays in MM, including challenges in implementation for the routine diagnostic laboratory, standardisation across laboratories and clinical trials, the clinical integration of MRD status assessment into MM management and future directions for ongoing research.

Measurable residual disease in multiple myeloma and light chain amyloidosis: more than meets the eye

The emergence of highly effective multiple myeloma (MM) treatments may bring cure within reach and highlights the need for highly sensitive measurable residual disease (MRD) techniques to replace conventional response assessments. MRD is being incorporated as an endpoint in an increasing number of studies and had been repeatedly shown to be both a predictive marker of response to treatment and a prognostic marker for future relapse. However, those results should be cautiously interpreted due to non-uniform reporting and the need for longer follow up to assess for sustained MRD negativity. This review aims to critically analyze the key MRD aspects including the current evidence supporting the use of MRD in clinical practice and the pitfalls of the various methods used to assess MRD. The utility of MRD for light chain (AL) amyloidosis will also be discussed.