A comparison of chemo-free strategy with G-CSF plus plerixafor on demand versus intermediate-dose cyclophosphamide and G-CSF as PBSC mobilization in newly diagnosed multiple myeloma patients: An Italian explorative cost Analysis

Comparing stem cell mobilization with chemotherapy and cytokine (G-CSF) versus cytokine alone in myeloma patients (MOCCCA): a randomized phase II, open-label, non-inferiority trial

In fit patients with newly diagnosed myeloma, high-dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is considered standard of care. For mobilization of CD34+ cells for ASCT, combined cytotoxic chemotherapy and G-CSF is commonly used. However, the importance of cytostatic chemotherapy for reliable mobilization remains unclear. This prospective randomized phase II non-inferiority trial compared G-GSF only (G) compared to standard chemotherapy/G-CSF (CG) for CD34+ mobilization. The primary endpoint was a less than 15% difference in successful stem cell collection ( ≥ 5.0 × 106 CD34+ cells/kg b.w. in a single day collection procedure without additional stimulation with plerixafor) with the G regimen. 136 patients were 1:1 randomized. With an 18% difference in favor of the CG therapy, the non-inferiority margin was not maintained (95% CI 1%, 34%, p = 0.04). The median total CD34+ yield was 9.99 × 106/kg b.w. in CG patients and 7.42 × 106/kg b.w. in patients with G-CSF alone (p < 0.001). Ultimately, 130 (96%) patients proceeded to HDCT with ASCT. There were no differences in adverse events, hematologic engraftment, quality of life, or pain perception between the groups. Our data indicate that G-CSF only is inferior to chemotherapy with G-CSF for peripheral CD34+ stem cell mobilization. Trial registration SNCTP #: SNCTP000002952; Trials.gov #: NCT03442673.

Examining external control arms in oncology: A scoping review of applications to date

OBJECTIVES

Randomized controlled trials (RCTs) are the gold standard for evaluating the comparative efficacy and safety of new cancer therapies. However, enrolling patients in control arms of clinical trials can be challenging for rare cancers, particularly in the context of precision oncology and targeted therapies. External Control Arms (ECAs) are a potential solution to address these challenges in clinical research design. We conducted a scoping review to explore the use of ECAs in oncology.

METHODS

We systematically searched four databases, namely MEDLINE, EMBASE, Web of Science, and Scopus. We screened titles, abstracts, and full texts for eligible articles focusing on patients undergoing therapy for cancer, employing ECAs, and reporting clinical outcomes.

RESULTS

Of the 629 articles screened, 23 were included in this review. The earliest included studies were published in 1996, while most studies were published in the past 5 years. 44% (10/23) of ECAs were employed in blood-related cancer studies. Geographically, 30% (7/23) of studies were conducted in the United States, 22% (5/23) in Japan, and 9% (2/23) in South Korea. The primary data sources used to construct the ECAs involved pooled data from previous trials (35%, 8/23), administrative health databases (17%, 4/23) and electronic medical records (17%, 4/23). While 52% (12/23) of the studies employed methods to align treatment and ECAs characteristics, 48% (11/23) lacked explicit strategies.

CONCLUSION

ECAs offer a valuable approach in oncology research, particularly when alternative designs are not feasible. However, careful methodological planning and detailed reporting are essential for meaningful and reliable results.

Comparison of two autologous hematopoietic stem cell mobilization strategies in patients with multiple myeloma: CE plus G-CSF versus G-CSF only: A single-center retrospective analysis

BACKGROUND

Despite recent advances in the treatment of multiple myeloma, high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (ASCT) remains an essential therapeutic keystone. As for the stem cell mobilization procedure, different regimens have been established, usually consisting of a cycle of chemotherapy followed by application of granulocyte-colony stimulating factor (G-CSF), although febrile neutropenia is a common complication. Following national guidelines, our institution decided to primarily use G-CSF only mobilization during the COVID-19 pandemic to minimize the patients' risk of infection and to reduce the burden on the health system.

STUDY DESIGN AND METHODS

In this retrospective single-center analysis, the efficacy and safety of G-CSF only mobilization was evaluated and compared to a historic control cohort undergoing chemotherapy-based mobilization by cyclophosphamide and etoposide (CE) plus G-CSF.

RESULTS

Although G-CSF only was associated with a higher need for plerixafor administration (p < .0001) and a higher number of apheresis sessions per patient (p = .0002), we were able to collect the target dose of hematopoietic stem cells in the majority of our patients. CE mobilization achieved higher hematopoietic stem cell yields (p = .0015) and shorter apheresis sessions (p < .0001) yet was accompanied by an increased risk of febrile neutropenia (p < .0001). There was no difference in engraftment after ASCT.

DISCUSSION

G-CSF only mobilization is a useful option in selected patients with comorbidities and an increased risk of serious infections, especially in the wintertime or in future pandemics.

On-demand plerixafor added to high-dose cyclophosphamide and pegylated recombinant human granulocyte colony-stimulating factor in the mobilization of patients with multiple myeloma: a treatment with high effectiveness, convenient, and affordable cost

Objective

The combination of high-dose cyclophosphamide (HD-Cy) (3g/m2) plus granulocyte colony-stimulating factor (G-CSF) and on-demand plerixafor (PXF) has been considered an effective mobilization regimen of patients with multiple myeloma(MM). However, the daily multi-injection regimen of G-CSF poses challenges. This study delves into the efficiency and cost implications of a novel approach, using HD-Cy alongside pegylated G-CSF (PEG G-CSF) and on-demand PXF. Unlike G-CSF, which necessitates daily injections, the half-life of PEG G-CSF extended allows for a single injection.

Methods

A retrospective analysis was conducted on 350 MM patients, which were categorized based on their mobilization regimens: Cy+PEG G-CSF+/-PXF (n=66), Cy+PEG G-CSF (n=91), Cy+ G-CSF (n=169), and G-CSF+PXF (n=24).

Results

Mobilization with Cy+PEG G-CSF+/-PXF(8.79)yielded a notably higher median CD34+ cell count compared to the other regimens: Cy+PEG G-CSF(4.96), Cy+G-CSF (4.65), and G-CSF+PXF (2.99) (P<0.001). The percentage of patients who achieved >6×106/kg CD34+ cells was significantly higher in the Cy+PEG G-CSF+/-PXF group (77.3%) than in the other mobilization regimens: Cy+PEG G-CSF (41.8%), Cy+ G-CSF (37.3%), and G-CSF+PXF (8.3%) (P<0.001). From a cost perspective, the Cy+PEG G-CSF+/-PXF approach was more economical than the G-CSF+PXF strategy but was marginally costlier than the other two methods. A multivariate assessment highlighted that the combination of Cy+PEG G-CSF with on-demand PXF had a superior potential to achieve the desired harvest (6×106/kg) compared to the Cy+PEG G-CSF protocol without PXF. The incremental cost-effectiveness ratio for each 1% increase in the probability of achieving a successful optimal harvest was $ 97.02 per patient. The incidence of neutropenic fever was 3.0% in the Cy+PEG G-CSF+/-PXF group.

Conclusion

The combination of on-demand PXF with HD-Cy and PEG G-CSF offers a cost-effective approach with a high mobilization success rate, manageable side effects, and the convenience of fewer injections. It stands as a promising mobilization strategy for MM patients.

Are we choosing mobilization regimens for autologous stem cell transplantation in multiple myeloma wisely: A single center comparison of GCSF+/-plerixafor vs cyclophosphamide/GCSF+/-plerixafor

BACKGROUND

Autologous stem cell transplantation (ASCT) is a standard consolidation treatment for eligible patients with multiple myeloma (MM). There is no standardized mobilization regimen for collection of CD34+ stem cells, which is crucial to the success of ASCT. Cyclophosphamide/GCSF is an effective regimen, although reported associated toxicities include risk of febrile neutropenia (FN). Since plerixafor was introduced in Canada, this mobilization agent has been increasingly used as needed with GCSF at Kingston Health Science Centre (KHSC), with elimination of cyclophosphamide. This single center, retrospective, quality improvement study evaluates mobilization and ASCT outcomes of MM patients who had undergone stem cell mobilization at KHSC with cyclophosphamide/GCSF+/-plerixafor without antibiotics, cyclophosphamide/GCSF+/-plerixafor with antibiotics, and GCSF+/-plerixafor without antibiotics.

METHODS

A retrospective chart review was conducted evaluating 137 patients. The primary outcome measure was FN rates with mobilization. Balancing measures include CD34+ cell collected, plerixafor usage, days of apheresis and transplant outcomes. Chi-square, ANOVA, or Kruskal-Wallis methods were used to test statistical significance where appropriate.

RESULTS

Our study noted a higher total and day one CD34+ count in the two groups utilizing cyclophosphamide in mobilization. All nine cases of FN occurred in these two groups (P < .05). Addition of antibiotics decreased, but did not eliminate risk of FN. There were no significant differences in the rate of plerixafor usage and number of apheresis days. Difference in transplant outcomes, including engraftment and transfusion support, were statistically but not clinically significant. A larger sample size may be needed to explore this fully. There was no significant difference in length of transplant hospital stay.

CONCLUSION

The elimination of cyclophosphamide from mobilization regimens for MM appears to significantly reduce FN rates, without increasing balancing measures such as total number of apheresis days, plerixafor usage, duration of transplant hospitalization or mortality outcomes.

Autologous Stem Cell Transplantation in Multiple Myeloma: Where Are We and Where Do We Want to Go?

The introduction of high-dose therapy in the 1990s as well as the development of drugs such as thalidomide, lenalidomide, and bortezomib in the 2000s led to an impressive improvement in outcome of patients with multiple myeloma (MM) eligible for autologous stem cell transplantation (ASCT). Clinical trials conducted in the first ten years of the twenty-first century established as standard therapy for these patients a therapeutic approach including induction, single or double ASCT, consolidation, and maintenance therapy. More recently, incorporating second-generation proteasome inhibitors carfilzomib and monoclonal antibody daratumumab into each phase of treatment significantly improved the efficacy of ASCT in terms of measurable residual disease (MRD) negativity, Progression Free Survival (PFS), and Overall Survival (OS). The availability of techniques such as multiparameter flow cytometry (MFC) and next-generation sequencing (NGS) for MRD assessment allowed the design of MRD-based response-adjusted trials that will define, in particular, the role of consolidation and maintenance therapies. In this review, we will provide an overview of the most recent evidence and the future prospects of ASCT in MM patients.

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.

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

Given the availability and efficacy of the mobilizing agent plerixafor in augmenting hematopoietic progenitor cell mobilization with granulocyte colony-stimulating factor (G-CSF), there is a strong case for comparing the cost-effectiveness of mobilization with G-CSF + cyclophosphamide versus G-CSF alone. This study investigated the cost and effectiveness (i.e., successful 4 million-CD34⁺ collection) of G-CSF alone versus high-dose cyclophosphamide (4 g/m²) + G-CSF mobilization (± on-demand plerixafor) in patients with multiple myeloma (MM) eligible for autograft in Italy. A decision tree-supported cost-effectiveness analysis (CEA) model in MM patients was developed from the societal perspective. The CEA model compared G-CSF alone with cyclophosphamide 4 g/m² + G-CSF (± on-demand plerixafor) and was populated with demographic, healthcare and non-healthcare resource utilization data collected from a questionnaire administered to six Italian oncohematologists. Costs were expressed in Euro (€) 2019. The CEA model showed that G-CSF alone was strongly dominant versus cyclophosphamide + G-CSF ( ± on-demand plerixafor), with incremental savings of €1198.59 and an incremental probability of a successful 4 million-CD34⁺ apheresis (+0.052). Sensitivity analyses confirmed the robustness of the base-case results. In conclusion, chemotherapy-free mobilization (± on-demand plerixafor) is a “good value for money” option for MM patients eligible for autograft.

Autologous stem-cell collection following VTD or VRD induction therapy in multiple myeloma: a single-center experience

Triplet-drug regimen bortezomib-thalidomide-dexamethasone (VTD) and bortezomib-lenalidomide-dexamethasone (VRD) are considered as standard of care induction prior autologous stem-cell transplantation (ASCT) in myeloma. In addition to improve response rate, induction therapy should preserve an adequate stem-cell collection. In the present retrospective study, we analyzed stem-cell collection in 325 newly diagnosed myeloma patients who received either VTD or VRD induction before ASCT. Stem-cell mobilization consisted of intravenous cyclophosphamide plus G-CSF. Plerixafor was administered preemptively to rescue mobilization. In comparison with VTD, VRD induction was associated with a more frequent use of plerixafor (19.3% versus 5.4%, p = 0.004) and with an increased number of apheresis to reach adequate collection (>2 apheresis required in 42.3% versus 30.2%, p = 0.05). Moreover, more patients experienced collection failure in the VRD group (6% versus 1.8%, p = 0.004). The median number of CD34-positive cells (×10⁶/kg) was lower in the VRD group: 8.5 versus 9.3 (p = 0.05) in the VTD group. The vast majority of patients underwent ASCT (93% versus 98%, in VRD and VTD group, respectively). These data highlight the need of optimal stem-cell collection strategy, especially in the context of tandem transplantation and incorporation of anti-CD38 monoclonal antibody into induction.