Resolution of human ribosomal DNA occurs in anaphase, dependent on tankyrase 1, condensin II, and topoisomerase IIα.

Formation of individualized sister chromatids is essential for their accurate segregation. In budding yeast, while most of the genome segregates at the metaphase to anaphase transition, resolution of the ribosomal DNA (rDNA) repeats is delayed. The timing and mechanism in human cells is unknown. Here we show that resolution of human rDNA occurs in anaphase after the bulk of the genome, dependent on tankyrase 1, condensin II, and topoisomerase IIα. Defective resolution leads to rDNA bridges, rDNA damage, and aneuploidy of an rDNA-containing acrocentric chromosome. Thus, temporal regulation of rDNA segregation is conserved between yeast and man and is essential for genome integrity.

Isatuximab in combination with carfilzomib and dexamethasone in 1q21+ patients with relapsed/refractory multiple myeloma: Long-term outcomes in the Phase 3 IKEMA study.

Gain/amplification of 1q21 (≥3 copies), a chromosomal abnormality frequently observed in multiple myeloma, can negatively affect prognosis, due to its involvement in resistance to anti-myeloma therapy and disease progression. In this updated subgroup analysis of the randomized, Phase 3 IKEMA study (NCT03275285) in relapsed/refractory multiple myeloma (RRMM), we evaluated progression-free survival (PFS) and depth of response with the anti-CD38 antibody isatuximab plus carfilzomib-dexamethasone (Isa-Kd) versus Kd, in 1q21+ patients and related subgroups, at long-term follow-up (44.2 months). Our analysis included patients with 1q21+ (≥3 copies, with/without high-risk chromosomal abnormality [HRCA]), isolated 1q21+ (≥3 copies, without HRCA), gain(1q21) (3 copies, with/without HRCA), and amp(1q21) (≥4 copies, with/without HRCA). PFS benefit was achieved with Isa-Kd versus Kd in patients with 1q21+ (HR 0.58, 95% CI: 0.37-0.92), with isolated 1q21+ (HR 0.49, 95% CI: 0.27-0.92), with gain(1q21), or amp(1q21), consistent with the overall population and prior interim 1q21+ subgroup analyses. Median PFS with Isa-Kd versus Kd was 25.8 versus 16.2 months in 1q21+ patients and 38.2 versus 16.2 months in patients with isolated 1q21+. Clinically meaningful, higher rates of very good partial response or better, complete response or better (≥CR), minimal residual disease (MRD) negativity, and MRD negativity and ≥CR were reached with Isa-Kd versus Kd in patients with 1q21+, isolated 1q21+, gain(1q21), or amp(1q21). In Isa-Kd and Kd, the MRD negativity and ≥CR rate was 29.3% versus 15.4% in 1q21+ patients, 36.2% versus 12.9% in patients with isolated 1q21+, 27.9% versus 13.5% in patients with gain(1q21), and 31.3% versus 20.0% in patients with amp(1q21), respectively. In conclusion, addition of Isa to Kd in triplet combination therapy has shown PFS benefit and deeper responses, compared with Kd, in 1q21+ patients at higher risk of progression, including patients with isolated 1q21+, gain(1q21), and amp(1q21), thus supporting Isa-Kd an effective treatment option for patients with RRMM.

Hoyeraal-Hreidarsson syndrome caused by a germline mutation in the TEL patch of the telomere protein TPP1.

Germline mutations in telomere biology genes cause dyskeratosis congenita (DC), an inherited bone marrow failure and cancer predisposition syndrome. DC is a clinically heterogeneous disorder diagnosed by the triad of dysplastic nails, abnormal skin pigmentation, and oral leukoplakia; Hoyeraal-Hreidarsson syndrome (HH), a clinically severe variant of DC, also includes cerebellar hypoplasia, immunodeficiency, and intrauterine growth retardation. Approximately 70% of DC cases are associated with a germline mutation in one of nine genes, the products of which are all involved in telomere biology. Using exome sequencing, we identified mutations in Adrenocortical Dysplasia Homolog (ACD) (encoding TPP1), a component of the telomeric shelterin complex, in one family affected by HH. The proband inherited a deletion from his father and a missense mutation from his mother, resulting in extremely short telomeres and a severe clinical phenotype. Characterization of the mutations revealed that the single-amino-acid deletion affecting the TEL patch surface of the TPP1 protein significantly compromises both telomerase recruitment and processivity, while the missense mutation in the TIN2-binding region of TPP1 is not as clearly deleterious to TPP1 function. Our results emphasize the critical roles of the TEL patch in proper stem cell function and demonstrate that TPP1 is the second shelterin component (in addition to TIN2) to be implicated in DC.

Vector and rodent surveillance for Orientia tsutsugamushi in north India.

BACKGROUND & OBJECTIVES: Scrub typhus or chigger borne typhus, caused by Orientia tsutsugamushi is an emerging vector-borne disease as large numbers of cases have been reported in various tropical countries. It is transmitted to humans through bites of infected chiggers (larval mites). The knowledge about the vector, its distribution, density and habitat are important so as to understand the epidemiology of scrub typhus in a given area. To control rickettsial infections, regular rodent-vector surveillance should be planned in areas where the disease transmission is occurring and it will also help to strengthen the existing entomological data related to the vector of scrub typhus in northern India. METHODS: In the present study, rodent-vector surveillance was planned for one whole year, covering both mite active and non-active seasons (October 2019-December 2020) in selected areas of Chandigarh and Punjab in north India. Rodent tissues and mites were also examined for the presence of O. tsutsugamushi by nested PCR for 56 kDa gene and real-time PCR for 47 kDa outer membrane protein gene. 18S gene PCR was performed for molecular identification of mites. RESULTS: In the surveillance, three types of ectoparasite, viz. mites, fleas and ticks were obtained in rodents. All mites found were of Laelapidae family. None of the pooled rodent tissue samples as well as mite samples were found positive for O. tsutsugamushi by nested PCR for rickettsial DNA. INTERPRETATION & CONCLUSION: In the present study, we did not get any evidence of carriage of O. tsutsugamushi in either mites or rodents collected and sampled in selected regions in Chandigarh and Punjab. We need to strengthen the entomological surveillance over a broader region and increase the frequency of trapping rodents to increase clarity on vector-reservoir dynamics in this geographical region.

Role of Cdc23/Mcm10 in generating the ribonucleotide imprint at the mat1 locus in fission yeast.

The developmental asymmetry of fission yeast daughter cells derives from inheriting 'older Watson' versus 'older Crick' DNA strand from the parental cell, strands that are complementary but not identical with each other. A novel DNA strand-specific 'imprint', installed during DNA replication at the mating-type locus (mat1), imparts competence for cell type inter-conversion to one of the two chromosome replicas. The catalytic subunit of DNA Polymerase α (Polα) has been implicated in the imprinting process. Based on its known biochemical function, Polα might install the mat1 imprint during lagging strand synthesis. The nature of the imprint is not clear: it is either a nick or a ribonucleotide insertion. Our investigations do not support a direct role of Polα in nicking through putative endonuclease domains but confirm its indirect role in installing an alkali-labile moiety as the imprint. While ruling out the role of the primase subunit of Polα holoenzyme, we find that mutations in the Polα-recruitment and putative primase homology domain in Mcm10/Cdc23 abrogate the ribonucleotide imprint formation. These results, while confirming the ribonucleotide nature of the imprint suggest the possibility of a direct role of Mcm10/Cdc23 in installing it in cooperation with Polα and Swi1.

Structural and functional consequences of a disease mutation in the telomere protein TPP1.

Telomerase replicates chromosome ends to facilitate continued cell division. Mutations that compromise telomerase function result in stem cell failure diseases, such as dyskeratosis congenita (DC). One such mutation (K170Δ), residing in the telomerase-recruitment factor TPP1, provides an excellent opportunity to structurally, biochemically, and genetically dissect the mechanism of such diseases. We show through site-directed mutagenesis and X-ray crystallography that this TPP1 disease mutation deforms the conformation of two critical amino acids of the TEL [TPP1's glutamate (E) and leucine-rich (L)] patch, the surface of TPP1 that binds telomerase. Using CRISPR-Cas9 technology, we demonstrate that introduction of this mutation in a heterozygous manner is sufficient to shorten telomeres in human cells. Our findings rule out dominant-negative effects of the mutation. Instead, these findings implicate reduced TEL patch dosage in causing telomere shortening. Our studies provide mechanistic insight into telomerase-deficiency diseases and encourage the development of gene therapies to counter such diseases.

A lentivirus-free inducible CRISPR-Cas9 system for efficient targeting of human genes.

CRISPR-Cas9 is a cutting-edge tool for modifying genomes. The efficacy with which Cas9 recognizes its target has revolutionized the engineering of knockouts. However this efficacy complicates the knocking out of important genes in cultured cells. Unedited cells holding a survival advantage within an edited population can confound the knockout phenotype. Here we develop a HeLa-based system that overcomes this limitation, incorporating several attractive features. First, we use Flp-recombinase to generate clones stably integrated for Cas9 and guide RNAs, eliminating the possibility of unedited cells. Second, Cas9 can be induced uniformly in the clonal cultures using doxycycline to measure the knockout phenotype. Third, two genes can be simultaneously knocked out using this approach. Finally, by not involving lentiviruses, our method is appealing to a broad research audience. Using this methodology we generated an inducible AGO2-knockout cell line showing normal RNA interference in the absence of doxycycline. Upon induction of Cas9, the AGO2 locus was cleaved, the AGO2 protein was depleted, and RNA interference was compromised. In addition to generating inducible knockouts, our technology can be adapted to improve other applications of Cas9, including transcriptional/epigenetic modulation and visualization of cellular DNA loci.

SA1 binds directly to DNA through its unique AT-hook to promote sister chromatid cohesion at telomeres.

Sister chromatid cohesion relies on cohesin, a complex comprising a tri-partite ring and a peripheral subunit Scc3, which is found as two related isoforms SA1 and SA2 in vertebrates. There is a division of labor between the vertebrate cohesin complexes; SA1-cohesin is required at telomeres and SA2-cohesin at centromeres. Depletion of SA1 has dramatic consequences for telomere function and genome integrity, but the mechanism by which SA1-cohesin mediates cohesion at telomeres is not well understood. Here we dissect the individual contribution of SA1 and the ring subunits to telomere cohesion and show that telomeres rely heavily on SA1 and to a lesser extent on the ring for cohesion. Using chromatin immunoprecipitation we show that SA1 is highly enriched at telomeres, is decreased at mitosis when cohesion is resolved, and is increased when cohesion persists. Overexpression of SA1 alone was sufficient to induce cohesion at telomeres, independent of the cohesin ring and dependent on its unique (not found in SA2) N-terminal domain, which we show binds to telomeric DNA through an AT-hook motif. We suggest that a specialized cohesion mechanism may be required to accommodate the high level of DNA replication-associated repair at telomeres.

Pre-Clinical Assessment of SAR442257, a CD38/CD3xCD28 Trispecific T Cell Engager in Treatment of Relapsed/Refractory Multiple Myeloma.

Current treatment strategies for multiple myeloma (MM) are highly effective, but most patients develop relapsed/refractory disease (RRMM). The anti-CD38/CD3xCD28 trispecific antibody SAR442257 targets CD38 and CD28 on MM cells and co-stimulates CD3 and CD28 on T cells (TCs). We evaluated different key aspects such as MM cells and T cells avidity interaction, tumor killing, and biomarkers for drug potency in three distinct cohorts of RRMM patients. We found that a significantly higher proportion of RRMM patients (86%) exhibited aberrant co-expression of CD28 compared to newly diagnosed MM (NDMM) patients (19%). Furthermore, SAR442257 mediated significantly higher TC activation, resulting in enhanced MM killing compared to bispecific functional knockout controls for all relapse cohorts (Pearson's r = 0.7). Finally, patients refractory to anti-CD38 therapy had higher levels of TGF-ß (up to 20-fold) compared to other cohorts. This can limit the activity of SAR442257. Vactoserib, a TGF-ß inhibitor, was able to mitigate this effect and restore sensitivity to SAR442257 in these experiments. In conclusion, SAR442257 has high potential for enhancing TC cytotoxicity by co-targeting CD38 and CD28 on MM and CD3/CD28 on T cells.

Ex Vivo Efficacy of SAR442257 Anti-CD38 Trispecific T-cell Engager in Multiple Myeloma Relapsed After Daratumumab and BCMA-targeted Therapies.

T cell-engaging antibodies (TCEs) are showing promising efficacy in relapsed/refractory multiple myeloma, even in patients that relapsed after B-cell maturation antigen (BCMA)-targeted therapy. Patients with multiple myeloma may have compromised T-cell health unaccounted for by preclinical models. Here, we use Myeloma Drug Sensitivity Testing (My-DST) for ex vivo measurement of anti-multiple myeloma cytotoxicity for the trispecific CD38/CD28xCD3 TCE SAR442257 through activation of the patients' own endogenous T cells to inform clinical development of the compound in multiple myeloma. My-DST incubates primary mononuclear cells in humanized media for 48 hours followed by flow cytometry for multiple myeloma cell viability with or without drug treatment. SAR442257 was tested on 34 samples from patients with multiple myeloma across disease settings. Potential biomarkers, T-cell dependence, and degranulation were assessed. SAR442257 was effective at low dose in My-DST cultures. High ex vivo response rates were observed in primary aspirates taken from patients with multiple myeloma at diagnosis, with modestly reduced response in multiple myeloma recently treated with anti-CD38 mAbs. SAR442257 was highly effective in patients relapsing after BCMA therapy. The CD38/CD28xCD3 trispecific format was substantially more effective than a conventional bispecific CD38/CD3 antibody format and CD38 mAbs. Anti-multiple myeloma cell cytotoxicity was dependent on the presence of endogenous T cells. Surface CD38 expression was the strongest biomarker of TCE response. My-DST is capable of measuring T cell-dependent killing using the multiple myeloma patient's own bone marrow-derived T cells. SAR442257 shows promise for multiple myeloma and may be best suited for patients declared resistant to both CD38 mAbs and BCMA-targeted therapy. SIGNIFICANCE: This study introduces the use of My-DST to measure and characterize sensitivity to anti-CD38 T-cell engager SAR442257 in primary samples using matched endogenous T cells. Preclinical testing in samples from patients with diverse treatment history supports further testing in post-chimeric antigen receptor T-cell multiple myeloma.

A Review of Rickettsial Diseases Other Than Scrub Typhus in India.

Rickettsial diseases (RD) are widely reported all over the world. Scrub typhus (ST) is a major tropical infection which is well documented all over India. Therefore, the index of suspicion of scrub typhus is high among physicians with regard to patients presenting with acute febrile illness (AFI) and acute undifferentiated febrile illness (AUFI) in India. Rickettsial diseases other than ST (non-ST RDs), which include spotted fever group (SFG) rickettsioses and typhus group (TG) rickettsioses are not uncommon in India, but the index of suspicion is not as high as ST unless there is a history of the presence of fever with rashes and/or recent arthropod bites. This review aims to look into the Indian scenario on the epidemiology of non-ST RDs, especially the SFG and TG rickettsioses based on various investigations, spectrum of clinical presentation, challenges and gaps in knowledge to suspect and diagnose these infections.

Epidemiology of scrub typhus in a tertiary care hospital of Southern Odisha: a cross sectional study.

PURPOSE: Scrub typhus, is a mite-borne disease caused by bacteria named Orientia tsutsugamushi. In recent years the incidence of scrub typhus is increasing day by day. The disease is easily missed because of low sensitization among clinicians and non-specific clinical manifestation. The disease can be fatal in untreated cases. With the availability of testing methods, it can be easily diagnosed and treated. This study aims to depict the epidemiology of scrub typhus in southern Odisha. METHODS: A total of 170 blood samples were collected from clinically suspected acute undifferentiated febrile illness (AUFI) cases. Samples were tested serologically for antibodies against Orientia tsutsugamushi by commercially available Immunochromatography test (ICT) and enzyme-linked immunosorbent assay (ELISA) kit as per the manufacturer's instruction. Molecular diagnosis was done by nested polymerase chain reaction (N-PCR) and Sanger sequencing was done to know the circulating strains. RESULTS: Out of 170 cases of AUFI, 74 cases were diagnosed scrub typhus by IgM ELISA and 67 were positive by ICT. Males were affected more and cases were more clustered in the Ganjam district. The disease followed a typical seasonal i.e. more cases were seen in cooler months of the year. Sequencing revealed the strains were Gilliam and Karp like. CONCLUSIONS: The burden of scrub typhus was 43.5% among the study population. Determining the serotypes in endemic areas is important for basic research on the classification of Orientia tsutsugamushi, the development of vaccines, and the definitive diagnosis of scrub typhus. Expanding the panel of antigens used to test scrub typhus and to take into account of local antigenic diversity would improve the sensitivity of serological diagnosis.

Molecular characterization of Orientia tsutsugamushi causing fatal scrub typhus in a young male affected by so-called "mystery fever" in North India.

Scrub typhus is a zoonotic disease caused by Orientia tsutsugamushi. Although the presence of eschar is considered pathognomic, diagnosis of scrub typhus is challenging due to overlapping presentation. The diagnosis is based on the serological and molecular assay. Here, we describe a case of a young male patient who was diagnosed with scrub typhus and developed complications in the course of the disease. We also performed molecular characterization of the strain which revealed a close relatedness to Karp-like Linh.DT strains were previously reported from Vietnam.

First detection and genetic identification of Rickettsia spp. from ticks collected from rodents in north India.

BACKGROUND: Changing climatic conditions and invasion of ticks in urban areas have led to a greater number of cases of tick-borne diseases, thus, becoming a matter of increasing concern. Tick borne rickettsioses are one of the important emerging diseases worldwide. Knowledge of epidemiology of the vector and pathogen in the community is essential in order to understand and prevent the transmission of the disease to healthy population. METHODS: In our present study, we trapped rodents in selected areas of Chandigarh and Punjab in north India. The rodents were screened for the presence of ticks which were further screened for the presence of rickettsial agents. PCRs targeting 17 â€‹kDa and gltA genes were carried out followed by Sanger sequencing of the positive amplicons followed by phylogenetic analysis of the sequences. RESULTS: A total of 17 ticks were collected out of which one (Rhipicephalus sanguineus) was found to be harboring a Rickettsia sp. PCR targeting gltA and 17 â€‹kDa genes of rickettsia were put up and Sanger sequencing was performed. Phylogenetic analysis revealed the sequences to be closely related to Rickettsia rhipicephali. CONCLUSION: The current study establishes the presence of rickettsial agents in the community. Although Rickettsia rhipicephali is a non-pathogenic agent, the study encourages more vigorous community surveillance should be carried out in order to determine the exact burden of rickettsial agents in our community. To our knowledge, this is the first study reporting Rickettsia rhipicephali in India.

Immunomodulatory properties of CD38 antibodies and their effect on anticancer efficacy in multiple myeloma.

BACKGROUND: CD38 has been established as an important therapeutic target for multiple myeloma (MM), for which two CD38 antibodies are currently approved-daratumumab and isatuximab. CD38 is an ectoenzyme that degrades NAD and its precursors and is involved in the production of adenosine and other metabolites. AIM: Among the various mechanisms by which CD38 antibodies can induce MM cell death is immunomodulation, including multiple pathways for CD38-mediated T-cell activation. Patients who respond to anti-CD38 targeting treatment experience more marked changes in T-cell expansion, activity, and clonality than nonresponders. IMPLICATIONS: Resistance mechanisms that undermine the immunomodulatory effects of CD38-targeting therapies can be tumor intrinsic, such as the downregulation of CD38 surface expression and expression of complement inhibitor proteins, and immune microenvironment-related, such as changes to the natural killer (NK) cell numbers and function in the bone marrow niche. There are numerous strategies to overcome this resistance, which include identifying and targeting other therapeutic targets involved in, for example, adenosine production, the activation of NK cells or monocytes through immunomodulatory drugs and their combination with elotuzumab, or with bispecific T-cell engagers.

Leishmania donovani isolates with antimony-resistant but not -sensitive phenotype inhibit sodium antimony gluconate-induced dendritic cell activation.

The inability of sodium antimony gluconate (SAG)-unresponsive kala-azar patients to clear Leishmania donovani (LD) infection despite SAG therapy is partly due to an ill-defined immune-dysfunction. Since dendritic cells (DCs) typically initiate anti-leishmanial immunity, a role for DCs in aberrant LD clearance was investigated. Accordingly, regulation of SAG-induced activation of murine DCs following infection with LD isolates exhibiting two distinct phenotypes such as antimony-resistant (Sb(R)LD) and antimony-sensitive (Sb(S)LD) was compared in vitro. Unlike Sb(S)LD, infection of DCs with Sb(R)LD induced more IL-10 production and inhibited SAG-induced secretion of proinflammatory cytokines, up-regulation of co-stimulatory molecules and leishmanicidal effects. Sb(R)LD inhibited these effects of SAG by blocking activation of PI3K/AKT and NF-kappaB pathways. In contrast, Sb(S)LD failed to block activation of SAG (20 microg/ml)-induced PI3K/AKT pathway; which continued to stimulate NF-kappaB signaling, induce leishmanicidal effects and promote DC activation. Notably, prolonged incubation of DCs with Sb(S)LD also inhibited SAG (20 microg/ml)-induced activation of PI3K/AKT and NF-kappaB pathways and leishmanicidal effects, which was restored by increasing the dose of SAG to 40 microg/ml. In contrast, Sb(R)LD inhibited these SAG-induced events regardless of duration of DC exposure to Sb(R)LD or dose of SAG. Interestingly, the inhibitory effects of isogenic Sb(S)LD expressing ATP-binding cassette (ABC) transporter MRPA on SAG-induced leishmanicidal effects mimicked that of Sb(R)LD to some extent, although antimony resistance in clinical LD isolates is known to be multifactorial. Furthermore, NF-kappaB was found to transcriptionally regulate expression of murine gammaglutamylcysteine synthetase heavy-chain (mgammaGCS(hc)) gene, presumably an important regulator of antimony resistance. Importantly, Sb(R)LD but not Sb(S)LD blocked SAG-induced mgammaGCS expression in DCs by preventing NF-kappaB binding to the mgammaGCS(hc) promoter. Our findings demonstrate that Sb(R)LD but not Sb(S)LD prevents SAG-induced DC activation by suppressing a PI3K-dependent NF-kappaB pathway and provide the evidence for differential host-pathogen interaction mediated by Sb(R)LD and Sb(S)LD.

Direct diagnosis of scrub typhus by full-length 16S ribosomal RNA gene analysis using Oxford Nanopore sequencing.

Scrub typhus (caused by Orientia tsutsugamushi) is a neglected and underdiagnosed disease due to its non-specific clinical presentation and challenging diagnostics. We document the first study of direct diagnosis of scrub typhus from the blood sample of a patient by full-length 16S ribosomal RNA gene amplicon analysis using Oxford Nanopore sequencing.

Differential impact of a dyskeratosis congenita mutation in TPP1 on mouse hematopoiesis and germline.

Telomerase extends chromosome ends in somatic and germline stem cells to ensure continued proliferation. Mutations in genes critical for telomerase function result in telomeropathies such as dyskeratosis congenita, frequently resulting in spontaneous bone marrow failure. A dyskeratosis congenita mutation in TPP1 (K170∆) that specifically compromises telomerase recruitment to telomeres is a valuable tool to evaluate telomerase-dependent telomere length maintenance in mice. We used CRISPR-Cas9 to generate a mouse knocked in for the equivalent of the TPP1 K170∆ mutation (TPP1 K82∆) and investigated both its hematopoietic and germline compartments in unprecedented detail. TPP1 K82∆ caused progressive telomere erosion with increasing generation number but did not induce steady-state hematopoietic defects. Strikingly, K82∆ caused mouse infertility, consistent with gross morphological defects in the testis and sperm, the appearance of dysfunctional seminiferous tubules, and a decrease in germ cells. Intriguingly, both TPP1 K82∆ mice and previously characterized telomerase knockout mice show no spontaneous bone marrow failure but rather succumb to infertility at steady-state. We speculate that telomere length maintenance contributes differently to the evolutionary fitness of humans and mice.

Chromosomal 1q21 abnormalities in multiple myeloma: a review of translational, clinical research, and therapeutic strategies.

INTRODUCTION: Multiple myeloma (MM) remains an incurable disease with a median overall survival of approximately 5 years. Gain or amplification of 1q21 (1q21+) occurs in around 40% of patients with MM and generally portends a poor prognosis. Patients with MM who harbor 1q21+ are at increased risk of drug resistance, disease progression, and death. New pharmacotherapies with novel modes of action are required to overcome the negative prognostic impact of 1q21+. Areas covered: This review discusses the detection, biology, prognosis, and therapeutic targeting of 1q21+ in newly diagnosed and relapsed MM. Patients with MM and 1q21+ tend to present with higher tumor burden, greater end-organ damage, and more co-occurring high-risk cytogenetic abnormalities than patients without 1q21+. The chromosomal rearrangements associated with 1q21+ result in dysregulation of genes involved in oncogenesis. Identification and characterization of the 1q21+ molecular targets are needed to inform on prognosis and treatment strategy. Clinical trial data are emerging that addition of isatuximab to combination therapies may improve outcomes in patients with 1q21+ MM. Expert opinion: In the next 5 years, the results of ongoing research and trials are likely to focus on the therapeutic impact and treatment decisions associated with 1q21+ in MM.