Plerixafor (Mozobil): A Stem Cell-Mobilizing Agent for Transplantation in Lymphoma Patients Predicted to Be Poor Mobilizers - A Pilot Study

Mobilization and Hematopoietic Stem Cell Collection in Poor Mobilizing Patients with Lymphoma: Final Results of the German OPTIMOB Study

Introduction

Successful mobilization and collection of peripheral hematopoietic stem cells (HSCs) are necessary for lymphoma patients eligible for myeloablative chemotherapy with subsequent autologous stem cell transplantation (ASCT). Albeit G-CSF alone or combined with chemotherapy is well-established methods for HSC mobilization, up to 40% of the patients fail to mobilize (poor mobilizer, PM). Plerixafor (PLX) is commonly used in PM patients resulting in increased migration of HSCs into peripheral blood and thus improves the collection outcome.

Methods

The prospective, multicenter, open-label, non-interventional OPTIMOB study assessed mobilization and collection parameter of patients with lymphoma or multiple myeloma to get deep insights in the treatment of those patients in clinical routine focusing on PM patients. PM was defined as follows: (1) no achievement of ≥20 CD34+ progenitor cells/µL before first apheresis, (2) PLX administration at any time point during the observational period, (3) reduction of the initially planned CD34+ progenitor cell yield as necessity due to failed mobilization or HSC collection, and (4) no performance of apheresis due to low CD34+ progenitor level. Primary objective of the study was to assess mobilization success by the proportion of PM patients achieving >2 × 106 CD34+ progenitor cells/kg body weight on the first day of apheresis. Here, the data of the lymphoma cohort are presented.

Results

Out of 238 patients with lymphoma documented in the study, 32% were classified as PM. 87% of them received PLX. Demographic data revealed no obvious differences between PM and good mobilizing (GM) patients. All patients were treated highly individualized prior to mobilization. Majority of all PM patients were able to undergo apheresis (95%) and reached their individual requested CD34+ progenitor cell target (72%). 57% of the PM patients achieved >2.0 × 106 CD34+ progenitor cells/kg body weight on day 1 of apheresis and nearby 70% of them underwent ASCT. Median time to engraftment was similar in PM and GM patients of the lymphoma cohort.

Conclusions

Majority of PM patients with lymphoma were successfully mobilized and underwent ASCT. Most of them received PLX during the study.

Long-acting granulocyte colony-stimulating factor pegfilgrastim (lipegfilgrastim) for stem cell mobilization in multiple myeloma patients undergoing autologous stem cell transplantation

Autologous stem cell transplantation (ASCT) is a standard of care in newly-diagnosed multiple myeloma (MM) patients. Several studies before the introduction of novel therapies in MM, demonstrated a pegylated G-CSF to be successful in mobilizing peripheral blood stem cells (PBSCs). Lipegfilgrastim is a novel long-acting G-CSF that is produced by the conjugation of a single 20-kDa polyethelene glycol to the natural O-glycosylation site of G-CSF. Twenty-four MM patients were included for PBSCs mobilization with a single SC injection of 6 mg lipegfilgrastim. PBSC collection was started when the CD34⁺ count was > 10 × 10⁶ cells/L. The target progenitor cells were 6 × 10⁶ cells/kg. The median day of apheresis was + 3 (range 2-5) following lipegfilgrastim. Median peripheral blood CD34⁺ count pre-mobilization was of 22.65 (range 3.36-105) × 10⁶ cells/L. The median number of leukaphaeresis procedures was 2 (range 1-4). The median mobilized CD34⁺ cells/kg were 8.26 (range 0.77-12.42). One patient failed to mobilize and two patients mobilized < 6 × 10⁶ cells/kg. Toxicity was mild and transient. Twenty-three patients underwent ASCT following high dose melphalan. All patients engrafted. As lipegfilgrastim is administered only once, it is conceivable that it improves both compliance and quality-of-life (NCT02488382).

The Efficacy and Safety of Plerixafor in Hematopoietic Stem Cell Mobilization in Patients with Non-Hodgkin Lymphoma, Multiple Myeloma, and Hodgkin Lymphoma Who Failed Mobilization with Granulocyte-Colony-Stimulating Factor Alone: A Single-Center Experience

Plerixafor is a CXCR4 antagonist which is administered along with granulocyte-colony-stimulating factor (G-CSF) to mobilize hematopoietic stem cells in patients with Non-Hodgkin lymphoma (NHL) or multiple myeloma (MM), who failed the mobilization with G-CSF alone.

This was a single-center, retrospective study of the efficacy of the plerixafor and G-CSF in 32 patients with NHL (n = 11), MM (n = 11), and Hodgkin lymphoma (HL) (n = 10) who failed mobilization with G-CSF alone.

A median number of 1.21 × 106, 1.32 × 106, and 6.73 × 106 CD34 + cells were mobilized in patients with MM, NHL, and HL, respectively. Overall, 31 (96.8%) patients mobilized more than 2 × 106 CD34 + stem cells and 21 (33.75%) patients mobilized more than 5 × 106 CD34 + stem cells. All 32 (100%) patients underwent hematopoietic stem cell transplantation. There were no adverse drug events reported.

This retrospective study shows that plerixafor is an effective and safe mobilization agent in patients with NHL, MM, and HL who have failed mobilization with G-CSF alone.

The Biological and Clinical Relevance of G Protein-Coupled Receptors to the Outcomes of Hematopoietic Stem Cell Transplantation: A Systematized Review

Hematopoietic stem cell transplantation (HSCT) remains the only curative treatment for several malignant and non-malignant diseases at the cost of serious treatment-related toxicities (TRTs). Recent research on extending the benefits of HSCT to more patients and indications has focused on limiting TRTs and improving immunological effects following proper mobilization and engraftment. Increasing numbers of studies report associations between HSCT outcomes and the expression or the manipulation of G protein-coupled receptors (GPCRs). This large family of cell surface receptors is involved in various human diseases. With ever-better knowledge of their crystal structures and signaling dynamics, GPCRs are already the targets for one third of the current therapeutic arsenal. The present paper assesses the current status of animal and human research on GPCRs in the context of selected HSCT outcomes via a systematized survey and analysis of the literature.

CXCR4/CXCR7/CXCL12-Axis in Follicular Thyroid Carcinoma

Background: Follicular thyroid carcinoma's (FTC) often benign course is partially due to adjuvant radioactive iodine (RAI) treatment. However, once the tumour has spread and fails to retain RAI, the therapeutic options are limited and the outcome is poor. In this subset of patients, the identification of novel druggable biomarkers appears invaluable. Here, we investigated the stage dependent expression and functional role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in FTC.

Methods: CXCR4/7 expression was examined in 44 FTC and corresponding non-neoplastic thyroid specimens as well as 10 FTC distant metastases and 18 follicular adenomas using tissue microarray technology. Expression levels were correlated with clinicopathological variables as well as overall and recurrence free survival. Changes regarding cell cycle activation, tumour cell invasiveness and mRNA expression of genes related to epithelial-mesenchymal transition (EMT) were investigated after treatment with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811.

Results: CXCR4/7 expression was associated with large tumour size, advanced UICC stage as well as shorter overall and recurrence free survival. CXCR4 was significantly higher expressed in distant metastases than in primary tumour cores. In addition, rh-SDF1α induced invasive growth, cell cycle activation and EMT, while CXCR4 antagonists significantly reduced FTC invasiveness in vitro.

Conclusion: Here we provide first evidence of the biological importance of the CXCR4/CXCR7/CXCL12 axis in FTC. Our findings underscore the therapeutic potential of this chemokine receptor family in advanced FTC and offer new valuable insight into the oncogenesis of metastatic FTC.

Plerixafor Plus Granulocyte Colony-Stimulating Factor for Patients with Non-Hodgkin Lymphoma and Multiple Myeloma: Long-Term Follow-Up Report

The purpose of this report is to analyze long-term clinical outcomes of patients exposed to plerixafor plus granulocyte colony-stimulating factor (G-CSF) for stem cell mobilization. This was a study of patients with non-Hodgkin lymphoma (NHL; n = 167) and multiple myeloma (MM; n = 163) who were enrolled in the long-term follow-up of 2 pivotal phase III studies (NCT00741325 and NCT00741780) of 240 µg/kg plerixafor plus 10 µg/kg G-CSF, or placebo plus 10 µg/kg G-CSF to mobilize and collect CD34⁺ cells for autologous hematopoietic stem cell transplantation. Overall survival (OS) and progression-free survival (PFS) were evaluated over a 5-year period following the first dose of plerixafor or placebo. The probability of OS was not significantly different in patients with NHL or MM treated with plerixafor or placebo (NHL: 64%; 95% confidence interval [CI], 56% to 71% versus 56%; 95% CI, 44% to 67%, respectively; MM: 64%; 95% CI, 54% to 72% versus 64%; 95% CI, 53% to 73%, respectively). In addition, there was no statistically significant difference in the probability of PFS over 5 years between treatment groups in patients with NHL (50%; 95% CI, 44% to 67% for plerixafor versus 43%; 95% CI, 31% to 54% for placebo) or those with MM (17%; 95% CI, 10% to 24% for plerixafor versus 30%; 95% CI, 21% to 40% for placebo). In this long-term follow-up study, the addition of plerixafor to G-CSF for stem cell mobilization did not affect 5-year survival in patients with NHL or patients with MM.

CXCR4/CXCR7/CXCL12 axis promotes an invasive phenotype in medullary thyroid carcinoma

Background:

Medullary thyroid carcinoma (MTC) is a rare and challenging endocrine malignancy. Once spread, the therapeutic options are limited and the outcome poor. For these patients, the identification of new druggable biological markers is of great importance. Here, we investigated the prognostic and biological role of the C-X-C chemokine receptors type 4 and 7 (CXCR4/7) in MTC.

Methods:

Eighty-six MTC and corresponding non-neoplastic thyroid specimens were immunohistochemically stained for CXCR4/7 using tissue microarray technology and expression levels correlated with clinicopathological variables. Medullary thyroid carcinoma cell line TT was treated with recombinant human SDF1α/CXCL12 (rh-SDF1α) and CXCR4 antagonists AMD3100 and WZ811. Changes in cell cycle activation, tumour cell invasiveness as well as changes in mRNA expression levels of genes associated with epithelial–mesenchymal transition (EMT) were investigated.

Results:

High CXCR4 expression was associated with large tumour size and metastatic disease. CXCR4 antagonists significantly reduced tumour cell invasiveness, while the treatment with rh-SDF1α stimulated invasive growth, caused cell cycle activation and induced EMT.

Conclusions:

The CXCR4/CXCR7/CXCL12 axis plays an important role in MTC. We provide first evidence that the chemokine receptors might serve as potential therapeutic targets in patients with advanced MTC and offer new valuable insight into the underlying molecular machinery of metastatic MTC.