A phase II study of ibrutinib in combination with ixazomib in patients with Waldenström macroglobulinaemia.

This phase II study evaluated time-limited (24 cycles) treatment with ibrutinib and ixazomib in newly diagnosed (NDWM; n = 9) and relapsed/refractory (RRWM; n = 12) Waldenström macroglobulinaemia (WM). The overall response rate (ORR) was 76.2% (n = 16) in 21 evaluable patients with no patient achieving a complete response (CR). The median duration of treatment was 15.6 months, and after a median follow-up time of 25.7 months, the median progression-free survival (PFS) was 22.9 months. While the primary end-point was not met (CR rate at any time) and 28.5% discontinued treatment due to toxicity, ibrutinib plus ixazomib led to a clinically meaningful ORR and PFS. Combined Bruton's tyrosine kinase (BTK) and proteasome inhibition merits further evaluation in WM.

MicroRNA and long non-coding RNA analysis in IgM monoclonal gammopathies reveals epigenetic influence on cellular functions and oncogenesis.

Not available.

The digital divide: Racial disparities in adoption and utilization of health information technology among patients with lymphoid cancers.

INTRODUCTION: Health information technology (HIT) has the potential to improve healthcare delivery and engagement. Studying racial-ethnic disparities in HIT engagement will help understand and overcome challenges to healthcare utilization. METHODS: We undertook a patient-reported survey among patients with lymphoid malignancies at two campuses of Mayo Clinic, Florida to explore HIT-related disparities. Variables between Whites and non-Whites, and non-Whites from the two campuses were compared. RESULTS: The survey was completed by 1004 respondents, with 71% whites, 27% non-Whites (race-ethnicity not reported by 2%). Non-Whites included 30% responders at the main campus and 64% at an inner-city campus. Whites were significantly older and had higher education, while non-Whites had lesser access to a computer. Only 51% of non-Whites were registered to use electronic medical records (EMR) as compared to 72% Whites (p < 0.001) and significantly lesser number of non-Whites even knew that EMR existed (81% vs. 92%, p < 0.001). Encouragingly, a higher number of non-Whites wanted to engage in EMR. Non-Whites from the main campus were older, more educated and had more access to a computer as compared to those from the inner-city campus. Similar disparate factors were noted among minorities from the two campuses, suggesting impact of socioeconomic backgrounds on EMR usage among non-Whites. Linguistic barriers were more striking among inner-city campus non-Whites. CONCLUSIONS: Non-Whites continue to struggle with suboptimal utilization of the healthcare system and barriers related to integration in HIT, including disparities representing socioeconomic differences. Efforts need to be made at several levels to help racial-ethnic minorities overcome awareness, access, and linguistic barriers to HIT utilization.

Novel BCL-2 Inhibitor Lisaftoclax in Relapsed or Refractory Chronic Lymphocytic Leukemia and Other Hematologic Malignancies: First-in-Human Open-Label Trial.

PURPOSE: This global phase I trial investigated the safety, efficacy, pharmacokinetics, and pharmacodynamics of lisaftoclax (APG-2575), a novel, orally active, potent selective B-cell lymphoma 2 (BCL-2) inhibitor, in patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (R/R CLL/SLL) and other hematologic malignancies (HMs). PATIENTS AND METHODS: Maximum tolerated dose (MTD) and recommended phase II dose were evaluated. Outcome measures were safety and tolerability (primary) and pharmacokinetic variables and antitumor effects (secondary). Pharmacodynamics in patient tumor cells were explored. RESULTS: Among 52 patients receiving lisaftoclax, MTD was not reached. Treatment-emergent adverse events (TEAEs) included diarrhea (48.1%), fatigue (34.6%), nausea (30.8%), anemia and thrombocytopenia (28.8% each), neutropenia (26.9%), constipation (25.0%), vomiting (23.1%), headache (21.2%), peripheral edema and hypokalemia (17.3% each), and arthralgia (15.4%). Grade ≥ 3 hematologic TEAEs included neutropenia (21.2%), thrombocytopenia (13.5%), and anemia (9.6%), none resulting in treatment discontinuation. Clinical pharmacokinetic and pharmacodynamic results demonstrated that lisaftoclax had a limited plasma residence and systemic exposure and elicited rapid clearance of malignant cells. With a median treatment of 15 (range, 6-43) cycles, 14 of 22 efficacy-evaluable patients with R/R CLL/SLL experienced partial responses, for an objective response rate of 63.6% and median time to response of 2 (range, 2-8) cycles. CONCLUSIONS: Lisaftoclax was well tolerated, with no evidence of tumor lysis syndrome. Dose-limiting toxicity was not reached at the highest dose level. Lisaftoclax has a unique pharmacokinetic profile compatible with a potentially more convenient daily (vs. weekly) dose ramp-up schedule and induced rapid clinical responses in patients with CLL/SLL, warranting continued clinical investigation.

AT-101 Enhances the Antitumor Activity of Lenalidomide in Patients with Multiple Myeloma.

Bcl-2 and Mcl-1 proteins play a role in multiple myeloma (MM) cell survival, for which targeted inhibitors are being developed. AT-101 is an oral drug, which disrupts Bcl-2 and Mcl-1 function, impedes mitochondrial bioenergetic processes and induces apoptosis in MM cells. When combined with lenalidomide and dexamethasone (Rd), AT-101 significantly reduced tumor burden in an in vivo xenograft model of MM. These data provided rationale for a phase I/II study to establish the effective dose of AT-101 in combination with Rd (ARd regimen) in relapsed/refractory MM. A total of 10 patients were enrolled, most with high-risk cytogenetics (80%) and prior stem cell transplant (70%). Three patients were lenalidomide-refractory, 2 were bortezomib-refractory and 3 were daratumumab-refractory. The ARd combination was well tolerated with most common grade 3/4 adverse events being cytopenia's. The overall response rate was 40% and clinical benefit rate was 90%. The median progression free survival was 14.9 months (95% CI 7.1-NE). Patients responsive to ARd showed a decrease in Bcl-2:Bim or Mcl-1:Noxa protein complexes, increased CD8+ T and NK cells and depletion of T and B-regulatory cells. The ARd regimen demonstrated an acceptable safety profile and promising efficacy in patients with relapsed/refractory MM prompting further investigation in additional patients.

Molecular Clusters and Tumor-Immune Drivers of IgM Monoclonal Gammopathies.

PURPOSE: IgM monoclonal gammopathy of undetermined significance (MGUS) and Waldenström macroglobulinemia (WM) represent a disease spectrum with highly varied therapeutic management, ranging from observation to chemoimmunotherapy. The current classification relies solely on clinical features and does not explain the heterogeneity that exists within each of these conditions. Further investigation is warranted to shed light on the biology that may account for the clinical differences. EXPERIMENTAL DESIGN: We used bone marrow (BM) clonal CD19+ and/or CD138+ sorted cells, matched BM supernatant, and peripheral blood serum from 32 patients (7 MGUS, 25 WM) to perform the first multi-omics approach including whole-exome sequencing, RNA sequencing, proteomics, metabolomics, and mass cytometry. RESULTS: We identified three clusters with distinct pathway activation, immune content, metabolomic, and clinical features. Cluster 1 included only patients with WM and was characterized by transcriptional silencing of genes involved in cell cycle and immune response, enrichment of mitochondrial metabolism, infiltration of senescent T effector memory cells, and aggressive clinical behavior. Genetic/structural alterations of TNFAIP3 were distinct events of this cluster. Cluster 2 comprised both MGUS and WM patients with upregulation of inflammatory response, senescence and glycolysis signatures, increased activated T follicular helper and T regulatory cells, and indolent clinical behavior. Cluster 3 also included both MGUS and WM patients and exhibited intermediate features, including proliferative and inflammatory signaling, as well as glycolysis and mitochondrial metabolism. CONCLUSIONS: We have identified three distinct molecular clusters, suggesting a potential biologic classification that may have therapeutic implications.

Impact of Benzodiazepine Use on Length of Stay and 30-Day ED Visits among Hospitalized Hematopoietic Stem Cell Transplant Recipients.

OBJECTIVES: This study assesses the impact of benzodiazepine (BNZ) use on length of stay (LOS) and 30-day emergency department (ED) visits after hematopoietic stem cell transplant (HSCT). METHODS: Adult patients (18 years and older) who underwent an allogeneic or an autologous HSCT from 2015 to 2018 at the study site were included. Five multivariable models were used for both allogeneic and autologous HSCT: BNZ-naïve status, diazepam equivalent daily dosage (DEDD; 0 vs any), DEDD (excluding 0), ED visits, and LOS. RESULTS: BNZ-naïve autologous HSCT recipients were less likely to use any BNZs in the hospital (odds ratio [OR] 0.07, P < 0.001). If prescribed BNZs, then they used a lesser amount (incidence rate ratio 0.39, P < 0.001). BNZ-naïve autologous HSCT recipients were less likely to experience a 30-day ED visit (OR 0.17, P = 0.009). BNZ-naïve allogeneic HSCT recipients were also less likely to use any BNZ than previous users (OR 0.11, P = 0.014). Patient characteristics influenced BNZ naïvety, DEDD usage, LOS for autologous patients, and BNZ naïvety and DEDD for allogeneic patients. CONCLUSIONS: BNZ use resulted in increased 30-day ED visits after autologous HSCT. BNZ-naïve recipients were less likely to use BNZs during hospital stays; if they required BNZs, then it was in lower dosages.

Lisaftoclax (APG-2575) Is a Novel BCL-2 Inhibitor with Robust Antitumor Activity in Preclinical Models of Hematologic Malignancy.

PURPOSE: Development of B-cell lymphoma 2 (BCL-2)-specific inhibitors poses unique challenges in drug design because of BCL-2 homology domain 3 (BH3) shared homology between BCL-2 family members and the shallow surface of their protein-protein interactions. We report herein discovery and extensive preclinical investigation of lisaftoclax (APG-2575). EXPERIMENTAL DESIGN: Computational modeling was used to design "lead" compounds. Biochemical binding, mitochondrial BH3 profiling, and cell-based viability or apoptosis assays were used to determine the selectivity and potency of BCL-2 inhibitor lisaftoclax. The antitumor effects of lisaftoclax were also evaluated in several xenograft models. RESULTS: Lisaftoclax selectively binds BCL-2 (Ki < 0.1 nmol/L), disrupts BCL-2:BIM complexes, and compromises mitochondrial outer membrane potential, culminating in BAX/BAK-dependent, caspase-mediated apoptosis. Lisaftoclax exerted strong antitumor activity in hematologic cancer cell lines and tumor cells from patients with chronic lymphocytic leukemia, multiple myeloma, or Waldenström macroglobulinemia. After lisaftoclax treatment, prodeath proteins BCL-2‒like protein 11 (BIM) and Noxa increased, and BIM translocated from cytosol to mitochondria. Consistent with these apoptotic activities, lisaftoclax entered malignant cells rapidly, reached plateau in 2 hours, and significantly downregulated mitochondrial respiratory function and ATP production. Furthermore, lisaftoclax inhibited tumor growth in xenograft models, correlating with caspase activation, poly (ADP-ribose) polymerase 1 cleavage, and pharmacokinetics of the compound. Lisaftoclax combined with rituximab or bendamustine/rituximab enhanced antitumor activity in vivo. CONCLUSIONS: These findings demonstrate that lisaftoclax is a novel, orally bioavailable BH3 mimetic BCL-2-selective inhibitor with considerable potential for the treatment of certain hematologic malignancies.

CD38 as a multifaceted immunotherapeutic target in CLL.

CD38 is a glycoprotein expressed on chronic lymphocytic leukemia (CLL) cells, which functions to amplify B-cell receptor signaling and regulate nicotinamide adenine dinucleotide metabolism. Increased CD38 expression on CLL cells is associated with an unfavorable disease course, resulting in shorter overall survival. While the role of CD38 as a negative prognostic marker in CLL has been established for over two decades, the therapeutic benefit to be derived by patients from its inhibition has, till date remained an unresolved subject. With the development of high-affinity anti-CD38 targeting drugs, tremendous insight has been gained on which functions of CD38 are detrimental to CLL cell survival as well as the mechanisms of leukemic cell death engaged by these anti-CD38 agents. The current review attempts to resolve how the enzyamtic and receptorial functions of CD38 contribute to CLL pathogenesis, our ability to exploit these functions for immunotherapeutic effect and development of novel strategies targeting CD38.

Updates in the Use of BCL-2-Family Small Molecule Inhibitors for the Treatment of Relapsed/Refractory Multiple Myeloma.

Despite considerable advances in the treatment of multiple myeloma over the past decade, progression of disease is inevitable, and patients ultimately succumb to relapsed and refractory disease. Efficacious therapeutic regimens that target the key biological pathways that are essential for malignant plasma cell survival are necessary in the efforts to improve patient survival outcomes. The Bcl-2 family of proteins comprise oncogenes that promote myeloma cell survival by conferring resistance to apoptosis. These proteins are frequently upregulated in myeloma cells, thus making them attractive therapeutic targets. Several small molecule inhibitors of Bcl-2-family proteins are currently in clinical development for the treatment of relapsed/refractory multiple myeloma. Venetoclax, a Bcl-2-specific inhibitor, has generated the most clinical data and has shown promising results in patients with multiple myeloma harboring the t (11;14) translocation. Venetoclax has shown efficacy when combined with anti-CD38 monoclonal antibodies, immunomodulatory drugs, and proteasome inhibitors. Several other Bcl-2 inhibitors are in clinical development, as are inhibitors of Mcl-1, a Bcl-2-family oncoprotein that is perhaps more critical for myeloma cell survival than Bcl-2. This review will summarize the latest clinical data regarding the clinical development of Bcl-2-family protein inhibitors in the treatment of relapsed/refractory multiple myeloma.

Insurance-based disparities impact survival outcomes in Waldenström macroglobulinemia within the United States.

Considerable healthcare resource utilization and financial burden have been associated with the treatment of WM; however, the impact of health insurance status on outcomes has not been previously reported. We conducted a National Cancer Database analysis of newly diagnosed cases of active WM between 2004 and 2017 to evaluate the impact of insurance status on outcomes. For patients <65 years old (n = 1249, male sex: 62.4%, median age: 58 years), significant insurance-based survival differences were observed on multivariable analysis; patients who were uninsured [n = 63; HR 3.11 (95%CI, 1.77-5.45), p < 0.001], on Medicaid [n = 87; HR 1.88 (95% CI, 1.01-3.48), p = 0.045], or on Medicare [n = 122; HR 2.78 (95%CI, 1.76-4.38), p < 0.001], had inferior survival compared to patients with private insurance (n = 977; reference). In patients ≥65 years, no insurance-based survival differences were found (p = 0.10). Overall, significant insurance-based outcome disparities exist in WM. Further work is desperately needed to systematically uncover and address these disparities.

Ibrutinib, lenalidomide and dexamethasone in patients with relapsed and/or refractory multiple myeloma: Phase I trial results.

Therapeutic strategies that target novel pathways are urgently needed for patients with relapsed/refractory multiple myeloma (RRMM). Ibrutinib is an oral covalent inhibitor of Bruton tyrosine kinase, which is overexpressed in MM cells. This phase 1 dose-escalation study examined various doses of ibrutinib in combination with standard doses of lenalidomide (25 mg) and dexamethasone (40 mg) using a standard 3 + 3 design in RRMM patients. The primary objective was to determine the maximum tolerated dose (MTD) of ibrutinib in combination with lenalidomide and dexamethasone. Patients (n = 15) had received a median of 4 prior regimens, 53% were triple-class exposed, 33% were penta-exposed, and 54% were lenalidomide-refractory. The MTD of ibrutinib was 840 mg (n = 6) and only 1 dose-limiting toxicity; a grade 3 rash possibly related to ibrutinib was noted. The most common ≥ grade 3 adverse events were rash in 2 (13%), lymphopenia in 2 (13%), leukopenia, neutropenia, thrombocytopenia, and anemia all occurring in 3 (20%) patients each. One patient achieved a partial response for an overall response rate of 7%. The clinical benefit rate was 80%. The median time to progression was 3.8 months. Ibrutinib, lenalidomide and dexamethasone appears to be a safe and well-tolerated regimen with reasonable efficacy in heavily pretreated RRMM patients.

Dihydronicotinamide Riboside Is a Potent NAD+ Precursor Promoting a Pro-Inflammatory Phenotype in Macrophages.

Nicotinamide adenine dinucleotide (NAD) metabolism plays an important role in the regulation of immune function. However, a complete picture of how NAD, its metabolites, precursors, and metabolizing enzymes work together in regulating immune function and inflammatory diseases is still not fully understood. Surprisingly, few studies have compared the effect of different forms of vitamin B3 on cellular functions. Therefore, we investigated the role of NAD boosting in the regulation of macrophage activation and function using different NAD precursors supplementation. We compared nicotinamide mononucleotide (NMN), nicotinamide riboside (NR), and nicotinamide (NAM) supplementation, with the recently described potent NAD precursor NRH. Our results show that only NRH supplementation strongly increased NAD+ levels in both bone marrow-derived and THP-1 macrophages. Importantly, NRH supplementation activated a pro-inflammatory phenotype in resting macrophages, inducing gene expression of several cytokines, chemokines, and enzymes. NRH also potentiated the effect of lipopolysaccharide (LPS) on macrophage activation and cytokine gene expression, suggesting that potent NAD+ precursors can promote inflammation in macrophages. The effect of NRH in NAD+ boosting and gene expression was blocked by inhibitors of adenosine kinase, equilibrative nucleoside transporters (ENT), and IκB kinase (IKK). Interestingly, the IKK inhibitor, BMS-345541, blocked the mRNA expression of several enzymes and transporters involved in the NAD boosting effect of NRH, indicating that IKK is also a regulator of NAD metabolism. In conclusion, NAD precursors such as NRH may be important tools to understand the role of NAD and NADH metabolism in the inflammatory process of other immune cells, and to reprogram immune cells to a pro-inflammatory phenotype, such as the M2 to M1 switch in macrophage reprogramming, in the cancer microenvironment.

Awareness of myeloma care and the global impact of treatment: An international internet-based prospective study.

OBJECTIVE: Outcomes in multiple myeloma (MM) have significantly improved necessitating focus on survivorship. METHODS: We undertook a web-based survey in collaboration with International Myeloma Foundation (IMF) to explore patient awareness and psycho-physical impacts of MM. The survey was viewed on the IMF website by 1,324 individuals from 32 countries. RESULTS: The survey responses were available from 959 individuals, with 62% who completed the survey. Treating doctors were the most frequent source of MM-related information. Only 56% patients admitted full compliance with treatment. Treatment side effects bothered 86% responders, including >50% admitting to pain, peripheral neuropathy and asthenia. Majority (57%) reported some degree of depression, 82% had discontent with their quality of life and only 35% reported being satisfied with their coping mechanisms. Patients ≥65 years of age reported more peripheral neuropathy (p = 0.007) and difficulty with ability to work (p = 0.015). CONCLUSIONS: We report the prevalence of psychologic, social and physical domains as well as patient-physician relationship dynamics. This knowledge can help improve MM survivorship.Introduction.

Landmark Cancer Clinical Trials and Real-World Patient Populations: Examining Race and Age Reporting.

BACKGROUND: Concern exists that the clinical trial populations differ from respective cancer populations in terms of their age distribution affecting the generalizability of the results, especially in underrepresented minorities. We hypothesized that the clinical trials that do not report race are likely to suffer from a higher degree of age disparity. METHODS: Food and Drug Administration (FDA) drug approvals from July 2007 to June 2019 were reviewed to identify oncology approvals, and trials with age details were selected. The outcomes studied were the weighted mean difference in age between the clinical trial population and real-world population for various cancers, the prevalence of race reporting and association of age and race reporting with each other. RESULTS: Of the 261 trials, race was reported in 223 (85.4%) of the trials, while 38 trials (14.6%) had no mention of race. Race reporting improved minimally over time: 29 (85.3%) in 2007-2010 vs. 49 (80.3%) in 2011-2014 vs. 145 (85.4%) during the period 2015-2019 (p-value = 0.41). Age discrepancy between the clinical trial population and the real-world population was higher for studies that did not report race (mean difference -8.8 years (95% CI -12.6 to -5.0 years)) vs. studies that did report it (mean difference -5.1 years, (95% CI -6.4 to -3.7 years), p-value = 0.04). CONCLUSION: The study demonstrates that a significant number of clinical trials leading to cancer drug approvals suffer from racial and age disparity when compared to real-world populations, and that the two factors may be interrelated. We recommend continued efforts to recruit diverse populations.

Utilization of radiation therapy in multiple myeloma: trends and changes in practice.

Plasma cell disorders including plasmacytomas and multiple myeloma (MM) are exquisitely radiosensitive, and thus, radiation therapy (XRT) is used effectively in their management. The role of XRT in the setting of novel MM therapeutics has not been explored. The 2016 National Cancer Database (NCDB) for MM with patients diagnosed between 2004 and 2013 was studied. Association between utilization of XRT as part of initial therapy and patient, disease, or treating facility characteristics was studied. A total of 111,281 cases with 91.6% MM, 7% osseous plasmacytoma (PLA-O), and 1.4% extramedullary plasmacytoma (PLA-E) were identified. XRT was utilized as part of initial therapy in 25.4% cases, including 69.3% of PLA-O, 60% of PLA-E, and 21.5% of MM patients. Patients with PLA-E and MM were significantly less likely to receive XRT as compared to PLA-O (p < 0.001). A significantly decreased use of XRT was noted over time (p < 0.001), and for advancing patient age (p < 0.001), women (p < 0.001), and blacks (p < 0.001), and with increasing income (p = 0.015). Patients with Medicare were less likely to receive XRT (OR 0.86, 95% CI 0.78, 0.94) as compared to uninsured as were those with initial treatment at academic or high-volume facilities and facilities performing stem cell transplant. There was overall decreased utilization of XRT in recent years, possibly due to advent of efficacious systemic agents for MM therapy, with a higher XRT utilization for plasmacytomas. Patterns of XRT use need to be explored prospectively, so that uniform standards of healthcare delivery can be maintained and treatment heterogeneity can be minimized.

Trends in Early Mortality From Multiple Myeloma: A Population-Based Analysis.

INTRODUCTION: Despite significant improvements in multiple myeloma (MM) treatment modalities, patient mortality early in the course of disease has been identified as a persistent phenomenon with variable reported rates and causes. Trends in early mortality over time have not been clearly defined. PATIENTS AND METHODS: The Surveillance Epidemiology and End Results (SEER) database was used to identify adult patients with MM between 1975 and 2015. Association of available sociodemographic factors with all-cause and MM-specific early mortality (death within 6 months after the diagnosis of MM) was conducted by multivariate analysis. Trends in early mortality were studied by joinpoint regression analysis. RESULTS: Of the 90,975 MM cases included in this analysis, early mortality was noted in 21%. Median age was 68 years overall, and 75 years for the early mortality cohort (P < .01). The most common causes of death for early mortality were MM itself, followed by cardiovascular, infections, and renal failure. Male gender, "other" race/ethnicity group, advancing age, and West, Midwest or South regions (reference Northeast) were associated with increased risk of both all-cause and MM-specific early mortality. Joinpoint regression analysis of trends data resulted in 1 joinpoint for all-cause 6-month mortality (2006-2015), while 2 joinpoints were noticed for myeloma-specific 6-month mortality (1975-1987 and 2003-2015). CONCLUSION: Early mortality remains a significant unmet need for MM patient care, despite improving trends in recent years. Understanding the factors associated with early mortality can help develop individualized plans of patient care and mitigate circumstances that may contribute to early mortality among MM patients.

Treatment facility volume and patient outcomes in Waldenstrom macroglobulinemia.

Waldenstrom macroglobulinemia (WM) has an annual incidence of 3-3.2 cases per million-person/year. National Cancer Data Base was used to identify newly diagnosed WM cases requiring initiation of therapy and their annual facility volume was used to divide the treatment facilities into four quartiles (Qs). Cox regression was used to analyze the association between facility volume and survival, adjusted by demographics, socioeconomic, geographic, comorbidity factors and year of diagnosis. A total of 3064 patients treated in 795 facilities were included. The unadjusted median overall survival (OS) by facility volume was: Q1:6.5 years (5-year OS 55%), Q2:7 years (5-year OS 60%), Q3:8 years (5-year OS 64%), and Q4: NR (5-year OS 71%), p < 0.0001. Our results demonstrated that a volume-outcome relationship exists in WM and is an independent predictor of overall survival in addition to the established risk factors as age and disease severity.

The Circular Life of Human CD38: From Basic Science to Clinics and Back.

Monoclonal antibodies (mAbs) were initially considered as a possible "magic bullet" for in vivo elimination of tumor cells. mAbs represented the first step: however, as they were murine in nature (the earliest experience on the field), they were considered unfit for human applications. This prompted the development of techniques for cloning the variable regions of conventional murine antibodies, genetically mounted on human IgG. The last step in this years-long process was the design for the preparation of fully human reagents. The choice of the target molecule was also problematic, since cancer-specific targets are quite limited in number. To overcome this obstacle in the planning phases of antibody-mediated therapy, attention was focused on a set of normal molecules, whose quantitative distribution may balance a tissue-dependent generalized expression. The results and clinical success obtained with anti-CD20 mAbs revived interest in this type of strategy. Using multiple myeloma (MM) as a tumor model was challenging first of all because the plasma cells and their neoplastic counterpart eluded the efforts of the Workshop on Differentiation Antigens to find a target molecule exclusively expressed by these cells. For this reason, attention was turned to surface molecules which fulfill the requisites of being reasonably good targets, even if not specifically restricted to tumor cells. In 2009, we proposed CD38 as a MM target in virtue of its expression: it is absent on early hematological progenitors, has variable but generalized limited expression by normal cells, but is extremely high in plasma cells and in myeloma. Further, regulation of its expression appeared to be dependent on a variety of factors, including exposure to all-trans retinoic acid (ATRA), a potent and highly specific inducer of CD38 expression in human promyelocytic leukemia cells that are now approved for in vivo use. This review discusses the history of human CD38, from its initial characterization to its targeting in antibody-mediated therapy of human myeloma.