Anti-CD38 monoclonal antibody impairs CD34+ mobilization and affects clonogenic potential in multiple myeloma patients

BACKGROUND

Induction with daratumumab-based regimens followed by autologous stem cell transplantation is the current standard for newly diagnosed multiple myeloma (NDMM) patients eligible for intensive chemotherapy. However, concerns emerged regarding potential negative effects following daratumumab-based treatment on CD34+ mobilization. We here compared CD34+ mobilization and clonogenic potential between daratumumab and non-daratumumab based therapy without upfront plerixafor administration among patients affected by NDMM.

MATERIALS AND METHODS

Clinical, mobilization and clonogenic data from 41 consecutively enrolled NDMM patients were analyzed. Patients underwent collection of autologous CD34+ by apheresis at the ASST Grande Ospedale Metropolitano Niguarda, Milan, Italy, from January 2021 to March 2023. Clonogenicity analysis was performed on BFU-E and CFU-GM.

RESULTS

Seventy-five percent of daratumumab-treated patients underwent >1 apheresis, compared to 24% of non-daratumumab patients (p=0.0017). Daratumumab-treated patients had significantly lower CD34+ count (mean 38 vs 79/μL, respectively; p=0.0011), with a median CD34+ harvest of 3.98×106/kg (range 1.68-9.18) vs 6.87×106/kg (range 1.63-16.85) in non-daratumumab-treated (p=0.0006). In multivariate analysis the likelihood of undergoing >1 apheresis was significantly higher in older patients (OR 1.2, 95% CI 1-1.4, Z=2.10, p=0.03) and daratumumab-treated patients (OR 15, 95% CI 2.8-129, p=0.004). Moreover, daratumumab-based induction therapy demonstrated an independent negative association with BFU-E colony formation (p=0.0148), even when accounting for patient age and CD34+ levels.

DISCUSSION

Our findings underscore the impact of daratumumab-based treatment on CD34+ mobilization in a real-life, upfront plerixafor-free population of NDMM patients. Higher probability of requiring multiple apheresis occurred among daratumumab-treated patients. Interestingly, the observation that daratumumab might negatively impact BFU-E colony formation, independent of CD34+ cell count, offers novel biological perspectives. Appropriate strategies should be adopted by the Apheresis teams to mitigate these potential negative effects.

Nilotinib-induced bone marrow CD34+/lin-Ph+ cells early clearance in newly diagnosed CP-Chronic Myeloid Leukemia: Final report of the PhilosoPhi34 study

Chronic Myeloid Leukemia is a clonal disorder characterized by the presence of the Ph‐chromosome and the BCR‐ABL tyrosine‐kinase (TK). Target‐therapy with Imatinib has greatly improved its outcome. Deeper and faster responses are reported with the second‐generation TKI Nilotinib. Sustained responses may enable TKI discontinuation. However, even in a complete molecular response, some patients experience disease recurrence possibly due to persistence of quiescent leukemic CD34+/lin−Ph+ stem cells (LSCs). Degree and mechanisms of LSCs clearance during TKI treatment are not clearly established. The PhilosoPhi34 study was designed to verify the in‐vivo activity and timecourse of first‐line Nilotinib therapy on BM CD34+/lin−Ph+ cells clearance. Eighty‐seven CP‐CML patients were enrolled. BM cells were collected and tested for Ph+ residual cells, at diagnosis, 3, 6 and 12 months of treatment. FISH analysis of unstimulated CD34+/lin− cells in CCyR patients were positive in 8/65 (12.3%), 5/71 (7%), 0/69 (0%) evaluable tests, respectively. Per‐Protocol analysis response rates were as follows: CCyR 95% at 12 months, MR4.5 31% and 46% at 12 and 36 months, respectively. An exploratory Gene Expression Profiling (GEP) study of CD34+/lin− cells was performed on 30 patients at diagnosis and after, on 79 patients at diagnosis vs 12 months of nilotinib treatment vs 10 healthy subjects. Data demonstrated some genes significantly different expressed: NFKBIA, many cell cycle genes, ABC transporters, JAK‐STAT signaling pathway (JAK2). In addition, a correlation between different expression of some genes (JAK2, OLFM4, ICAM1, NFKBIA) among patients at diagnosis and their achievement of an early and deeper MR was observed.

Second primary malignancies in ruxolitinib-treated myelofibrosis: real-world evidence from 219 consecutive patients

We present real-world data on all ruxolitinib-treated myelofibrosis patients in a 10-million-resident region, with a follow-up of 2 years. We found no evidence of an increased risk of developing lymphomas.

Nilotinib interferes with cell cycle, ABC transporters and JAK-STAT signaling pathway in CD34+/lin- cells of patients with chronic phase chronic myeloid leukemia after 12 months of treatment

Chronic myeloid leukemia (CML) is characterized by the constitutive tyrosine kinase activity of the oncoprotein BCR-ABL1 in myeloid progenitor cells that activates multiple signal transduction pathways leading to the leukemic phenotype. The tyrosine-kinase inhibitor (TKI) nilotinib inhibits the tyrosine kinase activity of BCR-ABL1 in CML patients. Despite the success of nilotinib treatment in patients with chronic-phase (CP) CML, a population of Philadelphia-positive (Ph+) quiescent stem cells escapes the drug activity and can lead to drug resistance. The molecular mechanism by which these quiescent cells remain insensitive is poorly understood. The aim of this study was to compare the gene expression profiling (GEP) of bone marrow (BM) CD34+/lin- cells from CP-CML patients at diagnosis and after 12 months of nilotinib treatment by microarray, in order to identify gene expression changes and the dysregulation of pathways due to nilotinib action. We selected BM CD34+/lin- cells from 78 CP-CML patients at diagnosis and after 12 months of first-line nilotinib therapy and microarray analysis was performed. GEP bioinformatic analyses identified 2,959 differently expressed probes and functional clustering determined some significantly enriched pathways between diagnosis and 12 months of nilotinib treatment. Among these pathways, we observed the under expression of 26 genes encoding proteins belonging to the cell cycle after 12 months of nilotinib treatment which led to the up-regulation of chromosome replication, cell proliferation, DNA replication, and DNA damage checkpoint at diagnosis. We demonstrated the under expression of the ATP-binding cassette (ABC) transporters ABCC4, ABCC5, and ABCD3 encoding proteins which pumped drugs out of the cells after 12 months of nilotinib. Moreover, GEP data demonstrated the deregulation of genes involved in the JAK-STAT signaling pathway. The down-regulation of JAK2, IL7, STAM, PIK3CA, PTPN11, RAF1, and SOS1 key genes after 12 months of nilotinib could demonstrate the up-regulation of cell cycle, proliferation and differentiation via MAPK and PI3K-AKT signaling pathways at diagnosis.

Incidence of Sepsis in Central Venous Catheter-Bearing Patients with Hematologic Malignancies: Preliminary Results

Background

Indwelling central venous catheters (CVCs) are essential devices in the management of patients with hematological disorders treated with chemotherapy. However, their nature predisposes patients to unwanted complications.

Methods

CVC-related complications were retrospectively analyzed in 227 hematologic patients who were consecutively admitted to our hematology department between May 2002 and April 2004. Patients’ diagnoses comprised acute myeloid leukemia (36.8%), acute lymphoid leukemia (7.3%), lymphoproliferative disorders (28.3%), multiple myeloma (19.5%), myeloproliferative syndromes (5%) and others (3.1%). The CVCs used were polyurethane three lumen 7-Fr (111 patients) for chemotherapy and 12-Fr (114 patients) for chemotherapy and peripheral blood stem cell apheresis, plus two tunneled catheters.

Results

The pathological events were: bacteriaemias (n=46); occlusions (n=10); exit tunnel infections (n=8); thrombosis (n=6); lung emboli (n=2). Among febrile patients the bacteriemia frequency was 20%, of which 13.6% were CVC-related (with a higher incidence in leukemia patients (p=0.027). Among the isolates, gram-positive bacteria were found in 29 cases (23 CVC-related cases), and gram-negative bacteria in 16 cases (8 CVC-related cases). Only one patient had Candida albicans sepsis. At univariate and multivariate analysis significant risk factors for infection (p<0.0001) were only the number of days/catheters and neutropenia duration.

Conclusions

In our hematologic patients, the CVC complications were mainly septic, with only 10.1% of CVC-related bacteriemias, despite prolonged catheterization duration. Acute leukemia patients were at major risk for sepsis, probably due to a more severe neutropenia and prolonged catheterization duration.

Utility of percutaneous lung biopsy for diagnosing filamentous fungal infections in hematologic malignancies

BACKGROUND AND OBJECTIVES

The incidence of invasive filamentous fungal infections in hematologic patients is increasing as a consequence of high dose chemotherapy and bone marrow transplant procedures. Mortality is usually very high. The diagnosis is often difficult and yet a fast, accurate diagnosis is of fundamental importance for treating the infection and planning subsequent management of the hematologic disease. We evaluated the sensitivity of computed tomography (CT)-guided percutaneous biopsy in diagnosing pulmonary fungal infections.

DESIGN AND METHODS

Between 1997 and 2002 we performed 17 CT-guided percutaneous transthoracic lung biopsies in 17 hematologic patients with suspected filamentous fungi infection with negative BAL, to obtain a certain diagnosis and to know what species of fungi was responsible for infection. In all cases suspected mycosis began during the post-chemotherapy aplastic period. Patients were receiving antifungal therapy at the time of all biopsies. When the platelet count rose above 50 x 10(9)/L, CT-guided percutaneous lung biopsy with fine-needle aspiration for cytology was performed.

RESULTS

Twelve of 17 patients had histologic confirmation of the fungal infection (70.5%), 8 with Aspergillus spp. 4 with Mucorales spp. Biopsies provided non-specific results in 4 cases; in 2 of these cases, clinical course and response to therapy confirmed the diagnosis of mycosis; in the last case bronchoalveolar carcinoma was found as a new diagnosis. Cultures were positive in only 6 cases, all for Aspergillus spp. The sensitivity of CT-guided percutaneous lung biopsy was 70.6% and its positive predictive value (PPV) was 100%. This procedure provided an immediate diagnosis and only one side-effect (1 pneumothorax, without complications).

INTERPRETATION AND CONCLUSIONS

Histologic discrimination between aspergillosis and mucormycosis is very important for deciding secondary prophylaxis during transplant procedures, because Mucor is usually resistant to azoles.