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

SERCA-mediated endoplasmic reticulum stress facilitates hematopoietic stem cell mobilization

BACKGROUND

Hematopoietic stem cell (HSC) transplantation is widely recognized as an effective treatment for various malignant diseases. Enhancing HSC mobilization can improve transplantation outcomes and ultimately increase patient survival rates. Recent studies suggest that mild endoplasmic reticulum (ER) stress promotes HSC self-renewal, anti-apoptotic, and anti-aging capabilities. This led us to investigate whether inducing mild ER stress could facilitate HSC mobilization.

METHODS

The phenotype changes in cells treated with ER stress inducers and Sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) inhibitors were assessed using flow cytometry. The efficacy of these agents on HSC mobilization was evaluated in C57Bl/6 mice, with colony forming unit (CFU) assays used for quantification. Knockdown Jurkat cell lines were constructed to validate the role of SERCA in the mobilization mechanism. Molecular and protein expression levels associated with the pathway were analyzed through quantitative reverse-transcription PCR and western blotting.

RESULTS

Our findings revealed that BHQ, a SERCA inhibitor, efficiently enhanced HSC mobilization in vivo. Mechanistically, BHQ regulated the CaMKII-STAT3-CXCR4 pathway by suppressing SERCA activity. This inhibition led to a reduction in CXCR4 expression on the surface of HSCs, facilitating their migration from the bone marrow into peripheral circulation.

CONCLUSIONS

Our study provides novel insights into the role of the SERCA-ER stress pathway in HSC mobilization. By targeting SERCA activity with BHQ, we observed a significant enhancement in the mobilization of HSCs, facilitated by the modulation of the CaMKII-STAT3-CXCR4 signaling pathway. This research highlights the potential of utilizing mild ER stress as a strategy to promote HSC mobilization, with significant implications for improving stem cell-based therapies, including those used in HSC transplantation.

Autograft composition and outcome-towards an optimal graft?

The amount of CD34+ cells has been for decades the most important marker of autologous graft quality, but other graft cells, including various lymphocyte subsets, have gained some interest. This review attempts to summarize what is known about autograft cellular composition regarding post-transplant outcomes. The amount of CD34+ cells in the graft is associated with tempo of platelet recovery. It also has been associated with improved progression-free (PFS) and overall survival (OS) in many studies in patients with non-Hodgkin lymphoma and in some studies in patients with multiple myeloma. A greater number of lymphocytes in the graft has been linked with earlier lymphocyte recovery, which on the other hand has been associated with better post-transplant outcomes. In prospective studies, a greater number of T lymphocytes has been found to correlate with better PFS and OS in patients with non-Hodgkin lymphoma and multiple myeloma. Some studies also indicate that the number of natural killer cells in grafts is prognostically important. At present, it is challenging to define a so-called optimal graft in the autologous setting. In addition to adequate CD34+ cell counts, more lymphocytes also should be collected to achieve immune autografts, which may translate to improved patient outcomes. More data are needed regarding the functional status of various lymphocyte subset for post-transplant outcomes.

Discovery of Novel, Potent, Orally Bioavailable and Efficacious, Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitors for Hematopoietic Stem Cell Mobilization

Hematopoietic stem cell (HSC) mobilization is often difficult to achieve in patients suffering from multiple myeloma and non-Hodgkin's lymphoma. Granulocyte-colony stimulating factor (G-CSF) therapy alone has often not led to the desired outcomes. Herein, we describe the discovery of 7-cyclohexyl-4-hydroxy-8-oxo-N-(pyridazin-4-ylmethyl)-7,8-dihydro-2,7-naphthyridine-3-carboxamide 13, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, which was discovered by focusing on drug-like properties. Building on a previous discovery that HIF-PH inhibitors can enhance HSC mobilization in combination with G-CSF, we optimized 13 to exhibit high PHD2 potency, improved solubility, and an optimized PK profile. 13 was effective at enhancing G-CSF-induced HSC mobilization in mice at a dose of 2 mg/kg.

Advance in peptide-based drug development: delivery platforms, therapeutics and vaccines

The successful approval of peptide-based drugs can be attributed to a collaborative effort across multiple disciplines. The integration of novel drug design and synthesis techniques, display library technology, delivery systems, bioengineering advancements, and artificial intelligence have significantly expedited the development of groundbreaking peptide-based drugs, effectively addressing the obstacles associated with their character, such as the rapid clearance and degradation, necessitating subcutaneous injection leading to increasing patient discomfort, and ultimately advancing translational research efforts. Peptides are presently employed in the management and diagnosis of a diverse array of medical conditions, such as diabetes mellitus, weight loss, oncology, and rare diseases, and are additionally garnering interest in facilitating targeted drug delivery platforms and the advancement of peptide-based vaccines. This paper provides an overview of the present market and clinical trial progress of peptide-based therapeutics, delivery platforms, and vaccines. It examines the key areas of research in peptide-based drug development through a literature analysis and emphasizes the structural modification principles of peptide-based drugs, as well as the recent advancements in screening, design, and delivery technologies. The accelerated advancement in the development of novel peptide-based therapeutics, including peptide-drug complexes, new peptide-based vaccines, and innovative peptide-based diagnostic reagents, has the potential to promote the era of precise customization of disease therapeutic schedule.

First Line Treatment of Newly Diagnosed Transplant Eligible Multiple Myeloma Recommendations From a Canadian Consensus Guideline Consortium

The availability of effective therapies for multiple myeloma (MM) has sparked debate on the role of first line autologous stem cell transplantation (ASCT), particularly in standard-risk patients. However, treatment for individuals with high-risk disease continues to display suboptimal outcomes. With novel therapies used earlier, practice is changing rapidly in the field of MM. Presently, quadruplet induction therapy incorporating an anti-CD38 monoclonal antibody to a proteasome inhibitor and an immunomodulatory drug prior to ASCT followed by maintenance therapy stands as the foremost strategy for attaining deep and sustained responses in transplant eligible MM (TEMM). This Canadian Consensus Guideline Consortium (CGC) proposes consensus recommendations for the first line treatment of TEMM. To address the needs of physicians and people diagnosed with MM, this document focuses on ASCT eligibility, induction therapy, mobilization and collection, conditioning, consolidation, and maintenance therapy, as well as, high-risk populations, management of adverse events, assessment of treatment response, and monitoring for disease relapse. The CGC will periodically review the recommendations herein and update as necessary.

How I treat sickle cell disease with gene therapy

ABSTRACT

In 2023, 2 different gene therapies were approved for individuals with severe sickle cell disease (SCD). The small number of patients treated on the pivotal clinical trials that led to these approvals have experienced dramatic short-term reductions in the occurrence of painful vaso-occlusive crises, but the long-term safety and efficacy of these genetic therapies are yet to be ascertained. Several challenges and treatment-related concerns have emerged in regard to administering these therapies in clinical practice. This article discusses the selection and preparation of individuals with SCD who wish to receive autologous gene therapy, as well as the salient features of the care needed to support them through a long and arduous treatment process. I specifically focus on postinfusion care, as it relates to immune monitoring and infection prevention. Compared with allogeneic hematopoietic cell transplantation, delivering autologous gene therapy to an individual with SCD has distinct nuances that require awareness and special interventions. Using clinical vignettes derived from real-life patients, I provide perspectives on the complex decision-making process for gene therapy for SCD based on currently available data and make recommendations for evaluating and supporting these patients.

Molecular regulators of chemotaxis in human hematopoietic stem cells

Hematopoietic stem cells (HSCs), essential for lifelong blood cell regeneration, are clinically utilized to treat various hematological disorders. These cells originate in the aorta-gonad-mesonephros region, expand in the fetal liver, and mature in the bone marrow. Chemotaxis, involving gradient sensing, polarization, and migration, directs HSCs and is crucial for their homing and mobilization. The molecular regulation of HSC chemotaxis involves chemokines, chemokine receptors, signaling pathways, and cytoskeletal proteins. Recent advances in understanding these regulatory mechanisms have deepened insights into HSC development and hematopoiesis, offering new avenues for therapeutic innovations. Strategies including glucocorticoid receptor activation, modulation of histone acetylation, stimulation of nitric oxide signaling, and interference with m6A RNA modification have shown potential in enhancing CXCR4 expression, thereby improving the chemotactic response and homing capabilities of human HSCs. This review synthesizes current knowledge on the molecular regulation of human HSC chemotaxis and its implications for health and disease.

Phase II study of novel CXCR2 agonist and Plerixafor for rapid stem cell mobilization in patients with multiple myeloma

MGTA-145 or GROβT, a CXCR2 agonist, has shown promising activity for hematopoietic stem cell (HSC) mobilization with plerixafor in pre-clinical studies and healthy volunteers. Twenty-five patients with multiple myeloma enrolled in a phase 2 trial evaluating MGTA-145 and plerixafor for HSC mobilization (NCT04552743). Plerixafor was given subcutaneously followed 2 h later by MGTA-145 (0.03 mg/kg) intravenously with same day apheresis. Mobilization/apheresis could be repeated for a second day in patients who collected <6 ×106 CD34+ cells/kg. Lenalidomide and anti-CD38 antibody were part of induction therapy in 92% (n = 23) and 24% (n = 6) of patients, respectively. Median total HSC cell yield (CD34+ cells/kg × 106) was 5.0 (range: 1.1-16.2) and day 1 yield was 3.4 (range: 0.3-16.2). 88% (n = 22) of patients met the primary endpoint of collecting 2 ×106 CD34+ cells/kg in ≤ two days, 68% (n = 17) in one day. Secondary endpoints of collecting 4 and 6 × 106 CD34+ cells/kg in ≤ two days were met in 68% (n = 17) and 40% (n = 10) patients. Grade 1 or 2 adverse events (AE) were seen in 60% of patients, the most common AE being grade 1 pain, usually self-limited. All 19 patients who underwent transplant with MGTA-145 and plerixafor mobilized HSCs engrafted successfully, with durable engraftment at day 100. 74% (17 of 23) of grafts with this regimen were minimal residual disease negative by next generation flow cytometry. Graft composition for HSCs and immune cells were similar to a contemporaneous cohort mobilized with G-CSF and plerixafor.

Infiltration of Common Myeloid Progenitor (CMP) Cells is Associated With Less Aggressive Tumor Biology, Lower Risk of Brain Metastasis, Better Response to Immunotherapy, and Higher Patient Survival in Breast Cancer

OBJECTIVE

To investigate the clinical relevance of common myeloid progenitor (CMP) cells in breast tumor microenvironment (TME).

BACKGROUND

The role of rare cells in TME is less studied. In Silico transcriptomic analyses of real-world data enable us to detect and quantify rare cells, including CMP cells.

METHODS

A total of 5176 breast cancer (BC) patients from SCAN-B, METABRIC, and 5 single-cell sequence cohorts were analyzed using the xCell algorithm. The high group was defined as more than two-thirds of the CMP scores in each cohort.

RESULTS

CMP cells consist of 0.07% to 0.25% of bulk breast tumor cells, more in estrogen receptor-positive (ER+) compared with triple-negative (TN) subtype (0.1% to 0.75%, 0.18% to 0.33% of immune cells, respectively). CMP cells did not correlate with any of the myeloid lineages or stem cells in TME. CMP infiltration was higher in smaller tumors, with lower Nottingham grade, and in ER+/HER2- than in TNBC consistently in both SCAN-B and METABRIC cohorts. High CMP was significantly associated with a lower risk of brain metastasis and with better survival, particularly in ER+/HER2-. High CMP enriched epithelial-to-mesenchymal transition and angiogenesis pathways, and less cell proliferation and DNA repair gene sets. High CMP ER+/HER2- was associated with less immune cell infiltration and cytolytic activity ( P <0.001). CMP infiltration correlated with neoadjuvant chemoimmunotherapy response for both ER+/HER2- and TNBC in the ISPY-2 cohort (AUC=0.69 and 0.74, respectively).

CONCLUSIONS

CMP in BC is inversely associated with cell proliferation and brain metastasis, better response to immunotherapy, and survival. This is the first to report the clinical relevance of CMP infiltration in BC.

Development and therapeutic perspectives of CXCR4 antagonists for disease therapy

Chemokine receptor 4 (CXCR4) is a subtype receptor protein of the GPCR family with a seven-transmembrane structure widely distributed in human tissues. CXCR4 is involved in diseases (e.g., HIV-1 infection), cancer proliferation and metastasis, inflammation signaling pathways, and leukemia, making it a promising drug target. Clinical trials on CXCR4 antagonists mainly focused on peptides and antibodies, with a few small molecule compounds, such as AMD11070 (2) and MSX-122 (3), showing promise in cancer treatment. This perspective discusses the structure-activity relationship (SAR) of CXCR4 and its role in diseases, mainly focusing on the SAR of CXCR4 antagonists. It also explores the standard structural features and target interactions of CXCR4 binding in different disease categories. Furthermore, it investigates various modification strategies to propose potential improvements in the effectiveness of CXCR4 drugs.

Gene therapies on the horizon for sickle cell disease: a clinician's perspective

INTRODUCTION

Sickle cell disease (SCD) is a monogenic disorder that exerts several detrimental health effects on those affected, ultimately resulting in significant morbidity and early mortality. There are millions of individuals globally impacted by this disease. Research in gene therapy has been growing significantly over the past decade, now with two FDA approved products, aiming to find another cure for this complex disease.

AREAS COVERED

This perspective article aims to provide a clinician's insight into the current landscape of gene therapies, exploring the novel approaches, clinical advances, and potential impact on the management and prognosis of SCD. A comprehensive literature search encompassing databases such as PubMed, Web of Science and Google Scholar was employed. The search covered literature published from 1980 to 2024, focusing on SCD and curative therapy.

EXPERT OPINION

After careful evaluation of the risks and benefits associated with the use of gene therapy for affected patients, the need for a cure outweighs the risks associated with treatment in most cases of SCD. With advances in current technologies, gene therapies can increase access to cures for patients with SCD.

A comparative review of Aphexda and Mozobil for mobilization prior to stem cell collection

High-dose chemotherapy followed by autologous hematopoietic stem cell transplantation is the standard of care for eligible patients with newly diagnosed multiple myeloma leading to prolonged progression free and overall survival. Successful engraftment following hematopoietic stem cell infusion requires adequate stem cell doses. Current mobilization regimens include granulocyte colony-stimulating factor (G-CSF) with or without plerixafor. Motixafortide is a recently approved agent that can be used in combination with G-CSF for mobilization. In the absence of any head-to-head trials comparing the two products, this article aims to outline the similarities and differences of these two agents. Though moxitafortide has a more favorable pharmacokinetic profile in comparison to plerixafor, in clinical trials, the agents demonstrated similar efficacy. In addition, the use of motixafortide in clinical practice may be limited by product cost as well as administration and monitoring requirements.

Development of VLA4 and CXCR4 Antagonists for the Mobilization of Hematopoietic Stem and Progenitor Cells

The treatment of patients diagnosed with hematologic malignancies typically includes hematopoietic stem cell transplantation (HSCT) as part of a therapeutic standard of care. The primary graft source of hematopoietic stem and progenitor cells (HSPCs) for HSCT is mobilized from the bone marrow into the peripheral blood of allogeneic donors or patients. More recently, these mobilized HSPCs have also been the source for gene editing strategies to treat diseases such as sickle-cell anemia. For a HSCT to be successful, it requires the infusion of a sufficient number of HSPCs that are capable of adequate homing to the bone marrow niche and the subsequent regeneration of stable trilineage hematopoiesis in a timely manner. Granulocyte-colony-stimulating factor (G-CSF) is currently the most frequently used agent for HSPC mobilization. However, it requires five or more daily infusions to produce an adequate number of HSPCs and the use of G-CSF alone often results in suboptimal stem cell yields in a significant number of patients. Furthermore, there are several undesirable side effects associated with G-CSF, and it is contraindicated for use in sickle-cell anemia patients, where it has been linked to serious vaso-occlusive and thrombotic events. The chemokine receptor CXCR4 and the cell surface integrin α4β1 (very late antigen 4 (VLA4)) are both involved in the homing and retention of HSPCs within the bone marrow microenvironment. Preclinical and/or clinical studies have shown that targeted disruption of the interaction of the CXCR4 or VLA4 receptors with their endogenous ligands within the bone marrow niche results in the rapid and reversible mobilization of HSPCs into the peripheral circulation and is synergistic when combined with G-CSF. In this review, we discuss the roles CXCR4 and VLA4 play in bone marrow homing and retention and will summarize more recent development of small-molecule CXCR4 and VLA4 inhibitors that, when combined, can synergistically improve the magnitude, quality and convenience of HSPC mobilization for stem cell transplantation and ex vivo gene therapy after the administration of just a single dose. This optimized regimen has the potential to afford a superior alternative to G-CSF for HSPC mobilization.

Efficacy and safety of stem cell mobilization with etoposide +cytarabine plus G-CSF in poor mobilizers with relapsed or refractory lymphoma

Background

Autologous stem cell transplantation (ASCT) is a potentially curative strategy for relapse or refractory(r/r) aggressive lymphoma. However, a proportion of lymphoma patients who are at high risk of mobilization failure fail to mobilize stem cells and cannot proceed to ASCT. The aim of this study is to explore the efficacy and safety of Etoposide combined with Cytarabine (EA) plus G-CSF mobilization in poor mobilizers (PMs) with r/r aggressive lymphoma.

Methods

This retrospective study analyzed the outcomes of chemo-mobilization based on EA (Etoposide 0.1 g/m2, qd d1~3; AraC 0.5 g/m2, q12h d1~3) in 98 patients with r/r aggressive lymphoma. Of these, 39 patients met the criteria for predicted PMs as proposed by the Gruppo Italiano Trapianto di Midollo Osseo working group.

Results

Of the 39 PMs, 38(97.4%) patents harvested adequate mobilization (≥2×106 CD34+ cells/kg), while 31(79.5%) patients achieved optimal mobilization (≥5×106 CD34+ cells/kg). Overall, the mean number of CD34+ cells/kg collected was 17.99(range: 1.08~83.07) ×106 with an average of 1.4 apheresis sessions, and the number was 15.86(range: 0.37~83.07) ×106 for the first apheresis, respectively. A single apheresis procedure was sufficient to reach the target yield of adequate mobilization in 35(89.7%) PMs, while 76.9% of PMs achieved optimal collection within two apheresis sessions. We observed acceptable hematological toxicity and antibiotic usage exposure in 26 patients with a mean duration of 3.6 days. No grade 4 infection or mobilization-related mortality was recorded. Most patients underwent ASCT and achieved successful hematopoietic recovery with prompt engraftment duration, except for one NK/T-cell lymphoma patient who succumbed to severe septicemia after receiving conditioning chemotherapy.

Conclusion

Our findings indicate that EA plus G-CSF is an effective and tolerable CD34+ stem cell mobilization strategy for patients with r/r lymphoma, including those predicted to be PMs. This regimen could be an option for patients with r/r lymphoma, particularly those undergoing mobilization for salvage ASCT therapy.

How to manage poor mobilisers

Autologous hematopoietic progenitor cell transplantation (ASCT) has been used for more than five decades to treat malignant and non-malignant diseases. Successful engraftment after high-dose chemotherapy relies on the ability to collect sufficient CD34 + hematopoietic progenitor cells (HPCs), typically from peripheral blood after mobilization. Commonly, either granulocyte colony-stimulating factor (G-CSF) alone as a single agent (i.e. steady-state mobilization) or G-CSF after chemotherapy is administered to collect adequate numbers of HPCs (minimum ≥2 × 106 CD34 + cells/kg for one ASCT; optimal up to 5 × 106 CD34 + cells/kg). However, a significant proportion of patients fail successful HPC mobilization, which is commonly defined as a CD34+ cell count below 10-15/µL after at least 4 days of 10 µg/kg b.w. G-CSF alone, or after chemo-mobilization in combination with 5-10 µg/kg b.w. G-CSF. In these situations plerixafor, a chemokine receptor inhibitor (CXCR4) can be used to enhance HPC collection in patients with multiple myeloma and malignant lymphoma whose cells mobilize poorly. Risk factors for poor mobilization have been evaluated and several strategies (e.g. plerixafor to rescue the mobilization approach or pre-emptive use) have been suggested to optimize mobilization, especially in patients at risk. This manuscript discusses the risk factors of poor CD34+ mobilization and summarizes the current strategies to optimize mobilization and HPC collection.

Optimizing autologous stem cell collections for patients with multiple myeloma receiving G-CSF and Plerixafor: A single center project

BACKGROUND

Increasing indications for cellular therapy collections have stressed our healthcare system, with autologous collections having a longer than desired wait time until apheresis collection. This quality improvement initiative was undertaken to accommodate more patients within existing resources.

STUDY DESIGN AND METHODS

Patients with multiple myeloma who underwent autologous peripheral blood stem cell collection from October 2022 to April 2023 were included. Demographic, mobilization, laboratory, and apheresis data were retrospectively collected from the medical record.

RESULTS

This cohort included 120 patients (49.2% male), with a median age of 60 years. All received G-CSF and 95% received pre-emptive Plerixafor approximately 18 hours pre-collection. Most (79%) had collection goals of at least 8 × 106/kg CD34 cells, with 63% over 70 years old having this high collection goal (despite 20 years of institutional data showing <1% over 70 years old have a second transplant). With collection efficiencies of 55.9%, 44% of patients achieved their collection goal in a single day apheresis collection. A platelet count <150 × 103/μL on the day of collection was a predictor for poor mobilization; among 27 patients with a low baseline platelet count, 17 did not achieve the collection goal and 2 failed to collect a transplantable dose.

CONCLUSIONS

With minor collection goal adjustments, 15% of all collection appointments could have been avoided over this 6-month period. Other strategies to accommodate more patients include mobilization modifications (Plerixafor timing or substituting a longer acting drug), utilizing platelet counts to predict mobilization, and modifying apheresis collection volumes or schedule templates.

CXCR4: From Signaling to Clinical Applications in Neuroendocrine Neoplasms

There are several well-described molecular mechanisms that influence cell growth and are related to the development of cancer. Chemokines constitute a fundamental element that is not only involved in local growth but also affects angiogenesis, tumor spread, and metastatic disease. Among them, the C-X-C motif chemokine ligand 12 (CXCL12) and its specific receptor the chemokine C-X-C motif receptor 4 (CXCR4) have been widely studied. The overexpression in cell membranes of CXCR4 has been shown to be associated with the development of different kinds of histological malignancies, such as adenocarcinomas, epidermoid carcinomas, mesenchymal tumors, or neuroendocrine neoplasms (NENs). The molecular synapsis between CXCL12 and CXCR4 leads to the interaction of G proteins and the activation of different intracellular signaling pathways in both gastroenteropancreatic (GEP) and bronchopulmonary (BP) NENs, conferring greater capacity for locoregional aggressiveness, the epithelial-mesenchymal transition (EMT), and the appearance of metastases. Therefore, it has been hypothesized as to how to design tools that target this receptor. The aim of this review is to focus on current knowledge of the relationship between CXCR4 and NENs, with a special emphasis on diagnostic and therapeutic molecular targets.

Historical Perspective of High-Dose Therapy Followed by Autologous Stem Cell Transplantation in Multiple Myeloma

BACKGROUND

High-dose therapy (HDT) followed by autologous stem cell transplantation (ASCT) has become part of standard of care (SOC) in newly diagnosed multiple myeloma. In this review, we provide a historical perspective on ASCT since its introduction in the 1990s.

SUMMARY

Overall survival (OS) benefit for HDT followed by ASCT was demonstrated in studies comparing HDT with ASCT to standard-dose therapy (SDT) before the era of novel agents. Conditioning is done with melphalan 200 mg/m2. Lower doses (MEL140, MEL150) for older patients with comorbidities are safe and have comparable results. The addition of busulfan to melphalan improves progression-free survival (PFS) but not OS. HDT with ASCT after induction with novel agents prolongs PFS but not OS compared to SDT alone. The benefit is more evident in patients with high-risk cytogenetics. Mobilization can be achieved with granulocyte colony-stimulating factor alone, but is improved with the addition of chemotherapy. Plerixafor reduces mobilization failure and enables sufficient stem cell collection after induction with novel agents. ASCT is safe with a low rate of mortality (1%), and selected patients can be managed as outpatients.

KEY MESSAGES

HDT followed by ASCT remains part of SOC due to its PFS benefit and relatively low toxicity.

An insight into the pharmacology of cysteine/methionine containing peptide drugs

Since last century, peptides have emerged as potential drugs with >90 FDA approvals for various targets with several in the pipeline. Sulphur, in peptides is present either as thiol (-SH) from Cys or thioether from Met. In this review, all the peptides approved by FDA since 2000 containing sulphur have been included. Among them ∼50 % contains disulphide bridges. This clearly demonstrates the significance of disulphide bonds in peptide drugs. This can be achieved synthetically by using orthogonal protecting groups (PGs) for -SH. These PGs are compatible with Solid Phase Peptide Synthesis (SPPS), which is still the method of choice for peptide synthesis. The orthogonal PGs used for Cys thiol side chain protecting for disulphide bond formation have been included which are currently in use both by academia and industry from small scale to large scale synthesis. In addition, the details of the FDA approved drugs containing Cys and Met (or both) have also been discussed.

A year in pharmacology: new drugs approved by the US Food and Drug Administration in 2023

With 54 new drugs and seven cellular and gene therapy products, the approvals by the US Food and Drug Administration (FDA) recovered 2023 from the 2022 dent back to the levels of 2020-2021. As in previous years of this annual review, we assign these new drugs to one of three levels of innovation: first drug against a condition ("first-in-indication"), first drug using a novel molecular mechanism ("first-in-class"), and "next-in-class," i.e., a drug using an already exploited molecular mechanism. We identify four (7%) "first-in-indication," 22 (36%) "first-in-class," and 35 (57%) "next-in-class" drugs. By treatment area, rare diseases (54%) and cancer drugs (23%) were once again the most prevalent (and partly overlapping) therapeutic areas. Other continuing trends were the use of accelerated regulatory approval pathways and the reliance on biopharmaceuticals (biologics). 2023 marks the approval of a first therapy based on CRISPR/Cas9 gene editing.

Hematopoietic stem cell collection for sickle cell disease gene therapy

PURPOSE OF REVIEW

Gene therapy for sickle cell disease (SCD) is advancing rapidly, with two transformative products recently approved by the US Food and Drug Administration and numerous others under study. All current gene therapy protocols require ex vivo modification of autologous hematopoietic stem cells (HSCs). However, several SCD-related problems impair HSC collection, including a stressed and damaged bone marrow, potential cytotoxicity by the major therapeutic drug hydroxyurea, and inability to use granulocyte colony stimulating factor, which can precipitate severe vaso-occlusive events.

RECENT FINDINGS

Peripheral blood mobilization of HSCs using the CXCR4 antagonist plerixafor followed by apheresis collection was recently shown to be safe and effective for most SCD patients and is the current strategy for mobilizing HSCs. However, exceptionally large numbers of HSCs are required to manufacture an adequate cellular product, responses to plerixafor are variable, and most patients require multiple mobilization cycles, increasing the risk for adverse events. For some, gene therapy is prohibited by the failure to obtain adequate numbers of HSCs.

SUMMARY

Here we review the current knowledge on HSC collection from individuals with SCD and potential improvements that may enhance the safety, efficacy, and availability of gene therapy for this disorder.

A comparative analysis of transcriptomics of newly diagnosed multiple myeloma: exploring drug repurposing

Multiple myeloma (MM) is an incurable malignant plasma cell disorder characterized by the infiltration of clonal plasma cells in the bone marrow compartment. Gene Expression Profiling (GEP) has emerged as a powerful investigation tool in modern myeloma research enabling the dissection of the molecular background of MM and allowing the identification of gene products that could potentially serve as targets for therapeutic intervention. In this study we investigated shared transcriptomic abnormalities across newly diagnosed multiple myeloma (NDMM) patient cohorts. In total, publicly available transcriptomic data of 7 studies from CD138+ cells from 281 NDMM patients and 44 healthy individuals were integrated and analyzed. Overall, we identified 28 genes that were consistently differentially expressed (DE) between NDMM patients and healthy donors (HD) across various studies. Of those, 9 genes were over/under-expressed in more than 75% of NDMM patients. In addition, we identified 4 genes (MT1F, PURPL, LINC01239 and LINC01480) that were not previously considered to participate in MM pathogenesis. Meanwhile, by mining three drug databases (ChEMBL, IUPHAR/BPS and DrugBank) we identified 31 FDA-approved and 144 experimental drugs that target 8 of these 28 over/under-expressed MM genes. Taken together, our study offers new insights in MM pathogenesis and importantly, it reveals potential new treatment options that need to be further investigated in future studies.

Therapeutic Peptides, Proteins and their Nanostructures for Drug Delivery and Precision Medicine

Peptide and protein nanostructures with tunable structural features, multifunctionality, biocompatibility and biomolecular recognition capacity enable development of efficient targeted drug delivery tools for precision medicine applications. In this review article, we present various techniques employed for the synthesis and self-assembly of peptides and proteins into nanostructures. We discuss design strategies utilized to enhance their stability, drug-loading capacity, and controlled release properties, in addition to the mechanisms by which peptide nanostructures interact with target cells, including receptor-mediated endocytosis and cell-penetrating capabilities. We also explore the potential of peptide and protein nanostructures for precision medicine, focusing on applications in personalized therapies and disease-specific targeting for diagnostics and therapeutics in diseases such as cancer.

Informed by Cancer Stem Cells of Solid Tumors: Advances in Treatments Targeting Tumor-Promoting Factors and Pathways

Cancer stem cells (CSCs) represent a subpopulation within tumors that promote cancer progression, metastasis, and recurrence due to their self-renewal capacity and resistance to conventional therapies. CSC-specific markers and signaling pathways highly active in CSCs have emerged as a promising strategy for improving patient outcomes. This review provides a comprehensive overview of the therapeutic targets associated with CSCs of solid tumors across various cancer types, including key molecular markers aldehyde dehydrogenases, CD44, epithelial cellular adhesion molecule, and CD133 and signaling pathways such as Wnt/β-catenin, Notch, and Sonic Hedgehog. We discuss a wide array of therapeutic modalities ranging from targeted antibodies, small molecule inhibitors, and near-infrared photoimmunotherapy to advanced genetic approaches like RNA interference, CRISPR/Cas9 technology, aptamers, antisense oligonucleotides, chimeric antigen receptor (CAR) T cells, CAR natural killer cells, bispecific T cell engagers, immunotoxins, drug-antibody conjugates, therapeutic peptides, and dendritic cell vaccines. This review spans developments from preclinical investigations to ongoing clinical trials, highlighting the innovative targeting strategies that have been informed by CSC-associated pathways and molecules to overcome therapeutic resistance. We aim to provide insights into the potential of these therapies to revolutionize cancer treatment, underscoring the critical need for a multi-faceted approach in the battle against cancer. This comprehensive analysis demonstrates how advances made in the CSC field have informed significant developments in novel targeted therapeutic approaches, with the ultimate goal of achieving more effective and durable responses in cancer patients.

Is There Still a Role for Stem Cell Transplantation in Multiple Myeloma?

No therapy in multiple myeloma has been as extensively investigated as stem cell transplantation following high-dose chemotherapy. A search of the national library of medicine in February 2023 revealed over 27,000 publications covering stem cell transplantation. No other treatment for multiple myeloma has been so vigorously investigated. However, given the rapid advances seen in the treatment of multiple myeloma, it is legitimate to ask whether the technique first introduced in 1983 by Thomas McIlwain still has relevance. In 1984,Barlogie introduced infusional vincristine, doxorubicin, and dexamethasone and in 1986 published a first series on high-dose therapy with autologous marrow-derived stem cells. At this point, the only available therapies were melphalan, prednisone, other intensive steroids such as methylprednisolone, and interferon. Cyclophosphamide was used both orally and parenterally. VBMCP was introduced as a combination therapy at Memorial Hospital subsequently shown not to be superior to melphalan and prednisone.

Stem Cells Collection and Mobilization in Adult Autologous/Allogeneic Transplantation: Critical Points and Future Challenges

Achieving successful hematopoietic stem cell transplantation (HSCT) relies on two fundamental pillars: effective mobilization and efficient collection through apheresis to attain the optimal graft dose. These cornerstones pave the way for enhanced patient outcomes. The primary challenges encountered by the clinical unit and collection facility within a transplant program encompass augmenting mobilization efficiency to optimize the harvest of target cell populations, implementing robust monitoring and predictive strategies for mobilization, streamlining the apheresis procedure to minimize collection duration while ensuring adequate yield, prioritizing patient comfort by reducing the overall collection time, guaranteeing the quality and purity of stem cell products to optimize graft function and transplant success, and facilitating seamless coordination between diverse entities involved in the HSCT process. In this review, we aim to address key questions and provide insights into the critical aspects of mobilizing and collecting hematopoietic stem cells for transplantation purposes.

Research progress of the chemokine/chemokine receptor axes in the oncobiology of multiple myeloma (MM)

BACKGROUND

The incidence of multiple myeloma (MM), a type of blood cancer affecting monoclonal plasma cells, is rising. Although new drugs and therapies have improved patient outcomes, MM remains incurable. Recent studies have highlighted the crucial role of the chemokine network in MM's pathological mechanism. Gaining a better understanding of this network and creating an overview of chemokines in MM could aid in identifying potential biomarkers and developing new therapeutic strategies and targets.

PURPOSE

To summarize the complicated role of chemokines in MM, discuss their potential as biomarkers, and introduce several treatments based on chemokines.

METHODS

Pubmed, Web of Science, ICTRP, and Clinical Trials were searched for articles and research related to chemokines. Publications published within the last 5 years are selected.

RESULTS

Malignant cells can utilize chemokines, including CCL2, CCL3, CCL5, CXCL7, CXCL8, CXCL12, and CXCL13 to evade apoptosis triggered by immune cells or medication, escape from bone marrow and escalate bone lesions. Other chemokines, including CXCL4, CCL19, and CXCL10, may aid in recruiting immune cells, increasing their cytotoxicity against cancer cells, and inducing apoptosis of malignant cells.

CONCLUSION

Utilizing anti-tumor chemokines or blocking pro-tumor chemokines may provide new therapeutic strategies for managing MM. Inspired by developed CXCR4 antagonists, including plerixafor, ulocuplumab, and motixafortide, more small molecular antagonists or antibodies for pro-tumor chemokine ligands and their receptors can be developed and used in clinical practice. Along with inhibiting pro-tumor chemokines, studies suggest combining chemokines with chimeric antigen receptor (CAR)-T therapy is promising and efficient.

Graft CD8 T-cell-based risk system predicts survival in antithymocyte globulin-based myeloablative haploidentical peripheral blood stem cell transplantation

Objective

This study investigated the cellular composition of peripheral blood grafts for anti-thymocyte globulin (ATG)-based myeloablative haploidentical haematopoietic stem cell transplantation (haplo-HSCT).

Methods

Clinical characteristics were retrospectively evaluated in a training cohort with ATG-based myeloablative haplo-HSCT between January 2016 and February 2020 and confirmed in a validation cohort between March 2020 and June 2021.

Results

A higher dose of graft CD8+ T cells (≥ 0.85 × 108 kg-1) was significantly improved overall survival (OS; hazard ratio [HR], 1.750; P = 0.002) and disease-free survival (DFS; HR, 1.751; P < 0.001) in the training cohort, according to multivariate Cox regression analysis. Higher doses of mononuclear cells (MNCs) demonstrated better OS (HR, 1.517; P = 0.038) and DFS (HR, 1.532; P = 0.027). Older patient age (> 46 years), older donor age (≥ 50 years) and a higher refined disease risk index (rDRI) were also related to OS. A graft CD8+ T-cell risk system based on graft CD8+ T-cell dose, donor age and rDRI was constructed using a nomogram model after LASSO Cox regression analysis. It showed acceptable discrimination, with a C-index of 0.62 and 0.63, respectively. Graft CD8+ T-cell dose was negatively correlated with donor age (P < 0.001) and positively correlated with a higher lymphocyte percentage in the peripheral blood before mobilisation (P < 0.001).

Conclusion

A higher CD8+ T-cell dose in peripheral blood-derived grafts improves patients' survival with ATG-based myeloablative haplo-HSCT. Younger donors with higher lymphocyte percentages improved patients' survival with an intermediate rDRI risk.

Microarray-Based CD38 Peptide Probe Screening for Multiple Myeloma Imaging

Assessing CD38 expression in vivo has become a significant element in multiple myeloma (MM) therapy, as it can be used to detect lesions and forecast the effectiveness of treatment. Accurate diagnosis requires a multifunctional, high-throughput probe screening platform to develop molecular probes for tumor-targeted multimodal imaging and treatment. Here, we investigated a microarray chip-based strategy for high-throughput screening of peptide probes for CD38. We obtained two new target peptides, CA-1 and CA-2, from a 105 peptide library with a dissociation constant (KD) of 10-7 M. The specificity and affinity of the target peptides were confirmed at the molecular and cellular levels. Peptide probes were labeled with indocyanine green (ICG) dye and 68Ga-DOTA, which were injected into a CD38-positive Ramos tumor-bearing mouse via its tail vein, and small animal fluorescence and positron emission tomography (PET) imaging showed that the peptide probes could show specific enrichment in the tumor tissue. Our study shows that a microchip-based screening of peptide probes can be used as a promising imaging tool for MM diagnosis.

Motixafortide: First Approval

Motixafortide (APHEXDATM) is a selective C-X-C motif chemokine receptor 4 (CXCR4) inhibitor being developed by BioLineRx under licence from Biokine Therapeutics for the mobilization of haematopoietic stem cells (HSCs) and the treatment of various cancers. On 11 September 2023, motixafortide was approved in the USA for use in combination with filgrastim [granulocyte colony stimulating factor (G-CSF)] to mobilize HSCs to the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma. Motixafortide has been granted Orphan Drug Designation for the treatment of pancreatic cancer in the EU and the USA, and for the treatment of acute myeloid leukaemia in the USA. Clinical development is ongoing for the mobilization of CD34+ HSCs for gene therapy in patients with sickle cell disease. This article summarizes the milestones in the development of motixafortide leading to this first approval.

Circulating IRF8-expressing CD123+CD127+ lymphoid progenitors: key players in human hematopoiesis

Lymphopoiesis is the process in which B and T cells, and innate lymphoid cells (ILCs) develop from hematopoietic progenitors that exhibit early lymphoid priming. The branching points where lymphoid-primed human progenitors are further specified to B/T/ILC differentiation trajectories remain unclear. Here, we discuss the emerging role of interferon regulatory factor (IRF)8 as a key factor to bridge human lymphoid and dendritic cell (DC) differentiation, and the current evidence for the existence of circulating and tissue-resident CD123+CD127+ lymphoid progenitors. We propose a model whereby DC/B/T/ILC lineage programs in circulating CD123+CD127+ lymphoid progenitors are expressed in balance. Upon tissue seeding, the tissue microenvironment tilts this molecular balance towards a specific lineage, thereby determining in vivo lineage fates. Finally, we discuss the translational implication of these lymphoid precursors.

Industry updates from the field of stem cell research and regenerative medicine in April 2023

Latest developments in the field of stem cell research and regenerative medicine compiled from publicly available information and press releases from non-academic institutions in April 2023.