Chemotherapy-based versus chemotherapy-free stem cell mobilization (± plerixafor) in multiple myeloma patients: an Italian cost-effectiveness analysis

Pharmacoeconomic issues in stem cell mobilization

BACKGROUND

recently, stem cell mobilization has made dramatic progress, that ended up in an increasing number of aphereses at target for autologous peripheral stem cell transplantation (ASCT). The aim of this research is investigating the cost-effectiveness of stem cell mobilization.

METHODS

a narrative review of the literature was carried out, searching for primary contributions written in English and published during 2000-2023 on cost-effectiveness analysis (CEA) of stem cell mobilization in patients entitled to ASCT. The PubMed database was searched with the following sets of keywords: cost-effectiveness AND apheresis AND myeloma (PubMed_1); cost-effectiveness AND stem cell mobilization (PubMed_2). Articles included in the analysis were assessed via two different checklists.

RESULTS

sixty-six entries were retrieved. Five out of 66 (PubMed_1: 4 out 17; PubMed_2: 1 out of 49), 4 CEAs and 1 cost-utility analysis (CUA) fit the research goal. Four out of 5 contributions proved to be in line with most of the items included in the two assessment grids. However, the most relevant missing features in some of the included contributions were: study perspective, healthcare resources valuation, and sensitivity analyses.

DISCUSSION

most of the articles included in this research show that chemotherapy-free stem cell mobilization is cost-effective according to different standpoints. Future health economic research on this topic should establish local threshold values for incremental apheresis at target and explore the heterogeneity of CEA (and CUA) to determine oncohaematological diseases and patient categories for which chemotherapy-free stem cell mobilization is cost-effective in different healthcare systems, given local budget constraints.

Overview on novel strategies and current guidelines for hematopoietic stem cell mobilisation and collection

The success of the autologous stem cell transplantation is strictly related to an adequate hematopoietic stem cell mobilization and collection. The minimum threshold for a successful mobilization is currently defined as 2 × 106/kg CD34+ cells. However, the optimal stem cell mobilization strategy is still controversial. The availability of plerixafor, a selective and reversible CXCR4 inhibitor, has been associated with an higher use of chemo-free protocols by many centres. In the near future, it is conceivable that artificial intelligence may became more accurate and comprehensive, possibly guiding clinicians in choosing the optimal mobilisation treatment for the various patients undergoing hematopoietic stem cell transplantation. Machine learning-based scoring models may be the basis for the development of "intelligent" mobilisation algorithms.

A comparison of peripheral blood stem cell collection outcomes for multiple myeloma; mobilization matters in the era of IMiD induction

Collection of peripheral blood stem cells (PBSCs) for autologous stem cell transplant (ASCT) requires mobilization from the bone marrow. There is variation in mobilization choice; during the COVID-19 pandemic BSBMT&CT guidelines recommended using granulocyte-colony stimulating factor (G-CSF) alone to minimize the use of chemotherapy. We report on the impact of mobilization regimen on stem cell collection, and whether IMiD-containing induction therapy impacts on mobilization and consequently transplant engraftment times for 83 patients undergoing ASCT at Leeds Teaching Hospitals. Cyclophosphamide plus G-CSF (cyclo-G) mobilization yielded more CD34+ cells (8.94 vs. 4.88 ×106/kg, p = < 0.0001) over fewer days (1.6 vs. 2.4 days, p = 0.007), and required fewer doses of salvage Plerixafor than G-CSF only (13.6% vs. 35%, p = 0.0407). IMiD-containing induction impaired all of these factors. CD34+ doses > 8×106/kg were more frequent with Cyclo-G (62% vs. 11%, p = 0.0001), including for those receiving IMiD 1st line induction (50% vs. 13.3%, p = 0.0381). Note that 92.6% of those receiving IMiD-free inductions were mobilized with Cyclo-G. The novel agents used in modern induction regimens (e.g Daratumumab) have been shown to impair yields, increasing the importance of optimizing mobilization regimens in the first instance. Furthermore, as cellular therapies become established in the management of multiple myeloma emerging data highlights the potential benefits of stem cell top up in the management of the haematological toxicities of these therapies. Our findings support re-adoption of Cyclo-G as the gold standard for mobilization to optimize PBSC harvesting and ensure sufficient cells for subsequent ASCTs.

Motixafortide and G-CSF to mobilize hematopoietic stem cells for autologous transplantation in multiple myeloma: a randomized phase 3 trial

Autologous hematopoietic stem cell transplantation (ASCT) improves survival in multiple myeloma (MM). However, many individuals are unable to collect optimal CD34+ hematopoietic stem and progenitor cell (HSPC) numbers with granulocyte colony-stimulating factor (G-CSF) mobilization. Motixafortide is a novel cyclic-peptide CXCR4 inhibitor with extended in vivo activity. The GENESIS trial was a prospective, phase 3, double-blind, placebo-controlled, multicenter study with the objective of assessing the superiority of motixafortide + G-CSF over placebo + G-CSF to mobilize HSPCs for ASCT in MM. The primary endpoint was the proportion of patients collecting ≥6 × 106 CD34+ cells kg-1 within two apheresis procedures; the secondary endpoint was to achieve this goal in one apheresis. A total of 122 adult patients with MM undergoing ASCT were enrolled at 18 sites across five countries and randomized (2:1) to motixafortide + G-CSF or placebo + G-CSF for HSPC mobilization. Motixafortide + G-CSF enabled 92.5% to successfully meet the primary endpoint versus 26.2% with placebo + G-CSF (odds ratio (OR) 53.3, 95% confidence interval (CI) 14.12-201.33, P < 0.0001). Motixafortide + G-CSF also enabled 88.8% to meet the secondary endpoint versus 9.5% with placebo + G-CSF (OR 118.0, 95% CI 25.36-549.35, P < 0.0001). Motixafortide + G-CSF was safe and well tolerated, with the most common treatment-emergent adverse events observed being transient, grade 1/2 injection site reactions (pain, 50%; erythema, 27.5%; pruritis, 21.3%). In conclusion, motixafortide + G-CSF mobilized significantly greater CD34+ HSPC numbers within two apheresis procedures versus placebo + G-CSF while preferentially mobilizing increased numbers of immunophenotypically and transcriptionally primitive HSPCs. Trial Registration: ClinicalTrials.gov , NCT03246529.

Systematic literature review of health economic models developed for multiple myeloma to support future analyses

AIMS

The goal of this study was to review the economic evaluations of health technologies in multiple myeloma (MM) and provide guidance and recommendations for future health economic analyses.

MATERIALS AND METHODS

A systemic literature review (SLR) was conducted on original economic assessment studies and structured review papers focusing on the studies in MM. The search was limited to English language papers published from 1 January 2000 onwards. Publications not applying any type of modelling methodology to describe disease progression and patient pathways over a specific time horizon were excluded.

RESULTS

A total of 2,643 publications were initially identified, of which 148 were eligible to be included in the full-text review phase. From these, 49 publications were included in the final analysis. Most published health economic analyses supported by models came from high-income countries. Evaluations from middle-income countries were rarely published. Diagnostic technologies were rarely modelled and integrated care had not been modelled. Very few models investigated MM treatments from a societal perspective and there was a relative lack of evaluations regarding minimal residual disease (MRD).

LIMITATIONS

Limitations of the publications included differences between trial populations and modelled populations, justification of methods, lack of confounder analyses, and small trial populations. Limitations of our study included the infeasibility of comparing MM economic evaluations due to the significant variance in modelled therapeutic lines and indications, and the relative scarcity of published economic evaluations from non-high-income countries.

CONCLUSIONS

As published economic models lacked many of the elements of the complex and heterogeneous patient pathways in MM and they focused on single decision problems, a thorough, open-source economic whole disease modelling framework is needed to assess the economic value of a wide range of technologies across countries with various income levels with a more detailed view on MM, by including patient-centric and societal aspects.

The Efficacy and Safety of Chemotherapy-Based Stem Cell Mobilization in Multiple Myeloma Patients Who Are Poor Responders to Induction: The Mayo Clinic Experience

We report the outcomes of 117 patients with newly diagnosed multiple myeloma who received novel agent induction, had a poor response to induction, and were mobilized using intravenous intermediate-dose cyclophosphamide (82%) or VD-PACE (18%) plus granulocyte colony-stimulating factor (G-CSF) and on-demand plerixafor. The median progression-free survival and overall survival of the chemo-mobilized cohort were 21 months (95% confidence interval [CI], 15-71) and 58 months (95% CI, 47-80), respectively. We compared our cohort to a 117-patient cohort matched by the level of response at pretransplant evaluation. The matched patients were mobilized with G-CSF and on-demand plerixafor without chemotherapy. Patients receiving chemo-mobilization had higher stem cell yields than the growth-factor-only cohort (median, 10.7 × 10⁶ cells/kg vs. 8.77 × 10⁶ cells/kg, respectively; P < .001). The safety profile of chemo-mobilization was favorable, and there was no difference between the two groups in length of hospitalization during autologous stem cell transplantation (P = .95), days to neutrophil engraftment (P = .22), days to platelet engraftment (P = .27), or risk of bacteremia (P = .52). Twenty-nine percent of the chemo-mobilized cohort and 65% of the matched cohort required plerixafor for adequate mobilization (P < .001). Chemo-mobilization enhances stem cell collection without adversely impacting the post-transplant clinical course.