Advances in the molecular characterization of multiple myeloma and mechanism of therapeutic resistance.

Recent insight in the genomic landscape of newly diagnosed multiple myeloma (NDMM) and its precursor conditions, monoclonal gammopathy of uncertain significance (MGUS), and smoldering myeloma have allowed the identification of patients with precursor conditions with a high risk of progression. These cases with "progressor" MGUS/SMM have a higher average mutation burden, have higher rates of mutations in specific genes such as MAPK, DNA repair, MYC, DIS3, and are enriched for specific mutational signatures when compared to non-progressors and are comparable to those found in NDMM. The highly preserved clonal heterogeneity seen upon progression of SMM, combined with the importance of these early variables, suggests that the identification of progressors based on these findings could complement and enhance the currently available clinical models based on tumor burden. Mechanisms leading to relapse/refractory multiple myeloma (RRMM) are of clinical interest given worse overall survival in this population. An Increased mutational burden is seen in patients with RRMM when compared to NDMM, however, there is evidence of branching evolution with many of these mutations being present at the subclonal level. Likewise, alterations in proteins associated with proteosome inhibitor and immunomodulatory drugs activity could partially explain clinical resistance to these agents. Evidence of chromosomal events leading to copy number changes is seen, with the presence of TP53 deletion, mutation, or a combination of both being present in many cases. Additional chromosomal events such as 1q gain and amplification may also interact and lead to resistance.

Carfilzomib and dexamethasone induction with lenalidomide, clarithromycin and dexamethasone consolidation and lenalidomide maintenance for newly diagnosed multiple myeloma.

Combination treatment regimens including a proteasome inhibitor (PI), an immunomodulatory agent (IMiD) and a corticosteroid are standards of care for initial treatment of multiple myeloma (MM). We aimed to evaluate if a sequential treatment program using PI induction followed by IMiD based consolidation and maintenance could achieve similar outcomes with reduced toxicities. This phase 2 study was designed to assess the safety and efficacy of the Car-BiRd regimen: carfilzomib and dexamethasone (Kd) induction until maximum response, followed by lenalidomide, clarithromycin and dexamethasone (BiRd) consolidation until next maximum response, then lenalidomide maintenance in patients with newly diagnosed MM. Seventy-two patients, including both transplant eligible and ineligible patients, were enrolled and evaluated for response. The overall response rate to the Car-BiRd regimen was 94% with 83% of patients achieving a ≥ VGPR and 35% achieving a CR/sCR. The rate of CR/sCR increased from 7% with Kd induction to 21% with BiRd consolidation and 35% with lenalidomide maintenance. These results did not meet the study's target endpoint of a CR rate of 55%. The median PFS using this deferred transplant approach was 37.3 months (95% CI 27.9, 52.7) and median OS was not reached with a median follow-up of 60 months. Toxicities were primarily low grade and manageable. Hematologic toxicities were lower than those expected with a combination PI/IMiD protocol. The sequential Car-BiRd regimen is an effective and safe approach for the upfront treatment of MM including patients unfit for transplant.

Plasma Cell Myeloma Presenting With Amyloid-Laden Crystal-Negative Histiocytosis.

OBJECTIVES: Crystal-storing histiocytosis (CSH) is rare in plasma cell dyscrasias, with only 3 cases reported in the setting of amyloid. No cases of crystal-negative histiocytosis coincident with multiple myeloma and amyloidosis have been reported previously. METHODS: A 58-year-old woman presented with pain due to destructive bone lesions and was found to have plasma cell myeloma (PCM) and marrow amyloid deposition associated with crystal-negative histiocytosis. Differential diagnoses included Langerhans cell histiocytosis, Erdheim-Chester disease, and Rosai Dorfman disease. BRAF mutations were negative, and there was no evidence of paraprotein crystals, arguing against typical CSH. RESULTS: The patient was treated with bortezomib, cyclophosphamide, and dexamethasone, and she subsequently underwent autologous stem cell transplant and ixazomib maintenance. She achieved complete remission with improvement of her symptoms and preserved remission after following up at 60 months. CONCLUSIONS: We describe a case of crystal-negative histiocytosis associated with PCM. CSH is a rare disorder associated with paraprotein-producing conditions in which immunoglobulins aggregate as intracellular crystals in the lysosomes of organ-specific phagocytic macrophages. Light chain tropism in PCM can also lead to the development of amyloid deposition in organs and, in rare cases, is associated with light chain aggregation as intracellular crystals in macrophages.

COVID-19 infections and outcomes in patients with multiple myeloma in New York City: a cohort study from five academic centers.

Importance: New York City is a global epicenter for the SARS-CoV-2 outbreak with a significant number of individuals infected by the virus. Patients with multiple myeloma have a compromised immune system, due to both the disease and anti-myeloma therapies, and may therefore be particularly susceptible to coronavirus disease 2019 (COVID-19); however, there is limited information to guide clinical management. Objective: To assess risk factors and outcomes of COVID-19 in patients with multiple myeloma. Design: Case-series. Setting: Five large academic centers in New York City. Participants: Patients with multiple myeloma and related plasma cell disorders who were diagnosed with COVID-19 between March 10th, 2020 and April 30th, 2020. Exposures: Clinical features and risk factors were analyzed in relation to severity of COVID-19. Main Outcomes and Measures: Descriptive statistics as well as logistic regression were used to estimate disease severity reflected in hospital admissions, intensive care unit (ICU) admission, need for mechanical ventilation, or death. Results: Of 100 multiple myeloma patients (male 58%; median age 68, range 41-91) diagnosed with COVID-19, 74 (74%) were admitted; of these 13 (18%) patients were placed on mechanical ventilation, and 18 patients (24%) expired. None of the studied risk factors were significantly associated (P>0.05) with adverse outcomes (ICU-admission, mechanical ventilation, or death): hypertension (N=56) odds ratio (OR) 2.3 (95% confidence interval [CI] 0.9-5.9); diabetes (N=18) OR 1.1 (95% CI 0.3-3.2); age >65 years (N=63) OR 2.0 (95% CI 0.8-5.3); high dose melphalan with autologous stem cell transplant <12 months (N=7) OR 1.2 (95% CI 0.2-7.4), IgG<650 mg/dL (N=42) OR=1.2 (95% CI 0.4-3.1). In the entire series of 127 patients with plasma cell disorders, hypertension was significantly associated with the combined end-point (OR 3.4, 95% CI 1.5-8.1). Conclusions and Relevance: Although multiple myeloma patients have a compromised immune system due to both the disease and therapy; in this largest disease specific cohort to date of patients with multiple myeloma and COVID-19, compared to the general population, we found risk factors for adverse outcome to be shared and mortality rates to be within the higher range of officially reported mortality rates.

COVID-19 Infections and Clinical Outcomes in Patients with Multiple Myeloma in New York City: A Cohort Study from Five Academic Centers.

Patients with multiple myeloma have a compromised immune system, due to both the disease and antimyeloma therapies, and may therefore be particularly susceptible to COVID-19. Here, we report outcomes and risk factors for serious disease in patients with multiple myeloma treated at five large academic centers in New York City in the spring of 2020, during which it was a global epicenter of the SARS-CoV-2 pandemic. Of 100 patients with multiple myeloma (male 58%; median age 68) diagnosed with COVID-19, 75 were admitted; of these, 13 patients (17%) were placed on invasive mechanical ventilation, and 22 patients (29%) expired. Of the 25 nonadmitted patients, 4 were asymptomatic. There was a higher risk of adverse outcome (intensive care unit admission, mechanical ventilation, or death) in Hispanics/Latinos (n = 21), OR = 4.7 (95% confidence interval, 1.3-16.7), and African American Blacks (n = 33), OR = 3.5 (1.1-11.5), as compared with White patients (n = 36). Patients who met the adverse combined endpoint had overall higher levels of inflammatory markers and cytokine activation. None of the other studied risk factors were significantly associated (P > 0.05) with adverse outcome: hypertension (n = 56), OR = 2.2 (0.9-5.4); diabetes (n = 18), OR = 0.9 (0.3-2.9); age >65 years (n = 63), OR = 1.8 (0.7-4.6); high-dose melphalan with autologous stem cell transplant <12 months (n = 7), OR = 0.9 (0.2-5.4); and immunoglobulin G <650 mg/dL (n = 42), OR = 0.9 (0.3-2.2). In this largest cohort to date of patients with multiple myeloma and COVID-19, we found the case fatality rate to be 29% among hospitalized patients and that race/ethnicity was the most significant risk factor for adverse outcome. Significance: Patients with multiple myeloma are immunocompromised, raising the question whether they are at higher risk of severe COVID-19 disease. In this large case series on COVID-19 in patients with multiple myeloma, we report 29% mortality rates among hospitalized patients and identify race/ethnicity as the most significant risk factor for severe outcome.See related commentary by Munshi and Anderson, p. 218. This article is highlighted in the In This Issue feature, p. 215.

High-dose bendamustine and melphalan conditioning for autologous stem cell transplantation for patients with multiple myeloma.

High-dose melphalan (MEL200) followed by autologous stem cell transplantation (ASCT) remains a standard of care for multiple myeloma (MM). Bendamustine induces responses in MM resistant to other alkylators. Our prior Phase I trial adding bendamustine to MEL200 transplant conditioning resulted in no additional toxicity. We now report a single-arm, phase II study that evaluated the efficacy of bendamustine 225 mg/m2 with MEL200 conditioning for ASCT in 18 patients with newly diagnosed MM (NDMM) and 17 with relapsed or refractory MM (RRMM). The primary end point was the complete response (CR/sCR) rate at day+ 100. Sample size was determined according to Simon's two-stage design. At stage 1, sixteen patients entered the study. As there were eight patients with CR/sCR, enrollment increased to 28 patients. Sixteen out of the first 28 evaluable patients achieved CR/sCR, meeting the design criteria. Enrollment was then expanded to a total of 35 patients. 51% achieved a CR/sCR. After a median follow-up of 65 months, 21 patients progressed, including 7 deaths. The median PFS for NDMM and RRMM was 48 and 45 months, respectively. Bendamustine/MEL200 conditioning resulted in excellent overall and depth of response as well as PFS, particularly in the RRMM patients, and is worthy of further investigation (NCT00916058).

Phase II study of carfilzomib and dexamethasone therapy for newly diagnosed multiple myeloma.

Carfilzomib and dexamethasone (Kd) has significant activity in relapsed and refractory multiple myeloma. Kd has not previously been evaluated in newly diagnosed multiple myeloma (NDMM). We report a single-arm phase 2 study of 72 patients with NDMM to evaluate the efficacy and tolerability of Kd induction. Carfilzomib was administered in two dosing cohorts with dosing of 20/45 mg/m2 in the first 25 patients and 20/56 mg/m2 in the subsequent 47 patients. Carfilzomib was administered on days 1, 2, 8, 9, 15 and 16 of a 28-day cycle, dexamethasone 20 mg was administered orally on days 1, 2, 8, 9, 15, 16, 22 and 23. Treatment was continued to maximum response, progression of disease, or regimen intolerability. Endpoints included overall response rate (ORR), regimen toxicity and impact of carfilzomib on CD34+ stem cell collection yield. Sixty-five pts achieved at least a partial response (PR) for an ORR of 90%. The maximum response achieved was complete response or better in 5 (7%), very good partial response (VGPR) in 42 (58%), PR in 18 (25%) and stable disease in 7 pts (10%). Toxicities were predominantly low grade with 547 grade 1/2 adverse events and 44 grade ≥3 events. The rate of grade ≥3 cardiovascular adverse events was 11.1% with eight observed events. The activity of Kd described represents the highest rate of overall response and ≥VGPR for any 2-agent combination in NDMM reported to date. Kd demonstrated a safety profile consistent with previously reported carfilzomib studies.

Phase 2 study of clarithromycin, pomalidomide, and dexamethasone in relapsed or refractory multiple myeloma.

The addition of clarithromycin enhances the efficacy of lenalidomide plus dexamethasone in treatment-naive multiple myeloma (MM). We conducted a phase 2 trial to evaluate the safety and efficacy of clarithromycin, pomalidomide, and dexamethasone (ClaPd) in relapsed or refractory multiple myeloma (RRMM) with prior lenalidomide exposure. One hundred twenty patients with a median of 5 prior lines of therapy received clarithromycin 500 mg orally twice daily, pomalidomide 4 mg orally on days 1 to 21, and dexamethasone 40 mg orally on days 1, 8, 15, and 22 of a 28-day cycle. The overall response rate (ORR) was 60% with 23% achieving at least a very good partial response. There was no statistical difference in response rates for patients who were refractory to lenalidomide (ORR, 58%), bortezomib (ORR, 55%), or both lenalidomide and bortezomib (ORR, 54%). Median progression-free survival (PFS) for the cohort was 7.7 months and median overall survival (OS) was 19.2 months. A history of dual-refractoriness to lenalidomide and bortezomib did not significantly impact either PFS or OS. The most common toxicities were neutropenia (83%), lymphopenia (74%), and thrombocytopenia (71%). The most common grade ≥3 toxicities included neutropenia (58%), thrombocytopenia (31%), and anemia (28%). ClaPd is an effective combination in RRMM with response and survival outcomes that are independent of lenalidomide- or bortezomib-refractory status. Toxicities are manageable with low rates of nonhematologic or high-grade events. ClaPd is a convenient, all-oral option in RRMM with comparable efficacy to other highly active, 3-drug, pomalidomide-based combinations. This trial was registered at www.clinicaltrials.gov as #NCT01159574.

Comparison of time to engraftment between autologous patients receiving washed versus non-washed cryopreserved peripheral blood stem cell products.

Washing cryopreserved peripheral blood stem cell (PBSC) products can decrease infusion-related adverse reactions but can also result in cell loss and reduced cell viability. To assess the risk and benefit of washing products, we compared the time to neutrophil and platelet engraftment between autologous patients that received washed products (n = 201) and non-washed products (n = 89). The effect of the other variables, including age, gender, diagnosis, transplant dose, method of stem cell mobilization, and growth factor support regimen post-transplant, was assessed. In multivariate analysis, direct thaw and infusion of non-washed products resulted in significantly faster neutrophil engraftment (p = .003) and platelet engraftment (p = .017) than washed products. The mean neutrophil and platelet engraftment times were 1.07 days faster and 2.27 days faster, respectively. In conclusion, direct thaw and infusion of cryopreserved PBSC without washing results in significantly shorter time to recovery of neutrophils and platelets after autologous transplantation.

Thalidomide, clarithromycin, lenalidomide and dexamethasone therapy in newly diagnosed, symptomatic multiple myeloma.

We studied T-BiRD (thalidomide [Thalomid(®)], clarithromycin [Biaxin(®)], lenalidomide [Revlimid(®)] and dexamethasone) in symptomatic, newly diagnosed multiple myeloma. In 28-day cycles, patients received dexamethasone 40 mg/day on days 1, 8, 15, 22, clarithromycin 500 mg twice daily on days 1-28; lenalidomide 25 mg/day on days 1-21; and thalidomide 100 mg/day (50 mg/day on days 1-7 of cycle 1 only) on days 1-28. Twenty-six patients received a median of 6 cycles (range 0-41). Overall response rate (ORR) was 80% for the group and 100% in 11 patients who underwent autologous stem cell transplantation as part of first-line therapy. The 4-year overall survival rate was 74.9%, and the median progression-free survival was 35.6 months. Eight patients discontinued due to regimen toxicity. Grade 3 non hematologic toxicity affected 12 patients (46.2%). T-BiRD is a highly active regimen with potential toxicity limitations. ClinicalTrials.gov identifier: NCT00538733.

Age matters: Young T lymphocytes offer better protection from myeloma proliferation.

BACKGROUND: The incidence and growth of cancer has been reported to increase with age and/or impaired T lymphocyte function. RESULTS: Consistent with these observations, we found that a monoclonal serum immunoglobulin (mIgG2b), rarely detectable after the injection of 5T33 murine multiple myeloma (MMM) cells into 3-4 month old wild-type C57BL/6 mice was seen more frequently in 18-20 month old wild-type C57BL/6 mice and in 3-4 month old Rag1-deficient C57BL/6 mice. These observations were confirmed and extended using more sensitive assays such as quantitation of splenic mRNA specific for the canonical 5T33 monoclonal IgG2b produced by 5T33 myeloma cells and the most sensitive assay, photon-imaging of mice injected with 5T33 cells, stably transfected with fire-fly luciferase gene (5T33L cells), which emit photons after the injection of luciferin. Furthermore, the proliferation of 5T33L myeloma cells in Rag1-deficient C57BL/6 mice was greater in mice which also received spleen T cells from 18-20 month old C57BL/6 wild-type mice compared to mice which received splenic T cells from 3-4 month old C57BL/6 wild-type mice. Thus, immune reconstitution of C57BL/6 mice with splenic T cells from young wild-type mice offered greater protection from progressive growth of 5T33L myeloma cells than did reconstitution with splenic T cells from old mice. CONCLUSIONS: Our findings support the hypothesis that age-associated changes in splenic T cell function contribute to the increased growth of 5T33 MMM cells in old compared to young C57BL/6 mice. Should similar processes occur in humans, increasing the anti-myeloma activity of T cells in old patients with multiple myeloma or transferring cryopreserved, young, autologous, T cells might benefit elderly patients with multiple myeloma.

Overcoming the response plateau in multiple myeloma: a novel bortezomib-based strategy for secondary induction and high-yield CD34+ stem cell mobilization.

PURPOSE: This phase II study evaluated bortezomib-based secondary induction and stem cell mobilization in 38 transplant-eligible patients with myeloma who had an incomplete and stalled response to, or had relapsed after, previous immunomodulatory drug-based induction. EXPERIMENTAL DESIGN: Patients received up to six 21-day cycles of bortezomib plus dexamethasone, with added liposomal doxorubicin for patients not achieving partial response or better by cycle 2 or very good partial response or better (≥VGPR) by cycle 4 (DoVeD), followed by bortezomib, high-dose cyclophosphamide, and filgrastim mobilization. Gene expression/signaling pathway analyses were conducted in purified CD34+ cells after bortezomib-based mobilization and compared against patients who received only filgrastim ± cyclophosphamide. Plasma samples were similarly analyzed for quantification of associated protein markers. RESULTS: The response rate to DoVeD relative to the pre-DoVeD baseline was 61%, including 39% ≥ VGPR. Deeper responses were achieved in 10 of 27 patients who received bortezomib-based mobilization; postmobilization response rate was 96%, including 48% ≥ VGPR, relative to the pre-DoVeD baseline. Median CD34+ cell yield was 23.2 × 10(6) cells/kg (median of 1 apheresis session). After a median follow-up of 46.6 months, median progression-free survival was 47.1 months from DoVeD initiation; 5-year overall survival rate was 76.4%. Grade ≥ 3 adverse events included thrombocytopenia (13%), hand-foot syndrome (11%), peripheral neuropathy (8%), and neutropenia (5%). Bortezomib-based mobilization was associated with modulated expression of genes involved in stem cell migration. CONCLUSION: Bortezomib-based secondary induction and mobilization could represent an alternative strategy for elimination of tumor burden in immunomodulatory drug-resistant patients that does not impact stem cell yield.

Atypical serum immunofixation patterns frequently emerge in immunomodulatory therapy and are associated with a high degree of response in multiple myeloma.

The M-protein is the major reference measure for response in multiple myeloma (MM) and its correct interpretation is key to clinical management. The emergence of oligoclonal banding is recognized as a benign finding in the postautologous stem cell transplantation setting (ASCT) for MM but its significance during non-myeloablative therapy is unknown. In a study of the immunomodulatory combination BiRD, (lenalidomide and dexamethasone with clarithromycin), we frequently detected the emergence of mono- and oligo-clonal immunoglobulins unrelated to the baseline diagnostic M-protein. The new M-proteins seen on serum immunofixation electrophoresis were clearly different in either heavy or light chain component(s) from the original M-spike protein and were termed atypical serum immunofixation patterns (ASIPs). Overall, 24/72 (33%) patients treated with BiRD developed ASIPs. Patients who developed ASIPs compared with patients treated with BiRD without ASIPs, had a significantly greater overall response (100% vs. 85%) and complete response rates (71% vs. 23%). ASIPs were not associated with new clonal plasma cells or other lymphoproliferative processes, and molecular remissions were documented. This is the first time this phenomenon has been seen with regularity in non-myeloablative therapy for MM. Analogous to the ASCT experience, ASIPs do not signal incipient disease progression, but rather herald robust response.

Stem cell mobilization with cyclophosphamide overcomes the suppressive effect of lenalidomide therapy on stem cell collection in multiple myeloma.

A total of 28 treatment-naïve patients with stage II or III multiple myeloma (MM) were treated with the combination of clarithromycin, lenalidomide, and dexamethasone (BiRD). Stem cells were collected following granulocyte-colony stimulating factor (G-CSF) or cyclophosphamide (Cy) plus G-CSF mobilization at maximum response. Sufficient stem cells for 2 autologous stem cell transplants were collected from all patients mobilized with Cy plus G-CSF, versus 33% mobilized with G-CSF alone (P < .0001). The duration of prior lenalidomide therapy did not correlate with success of stem cell harvests (P = .91). In conclusion, Cy can be added to G-CSF for stem cell mobilization to successfully overcome the suppressive effect of prior treatment with lenalidomide.

BiRD (Biaxin [clarithromycin]/Revlimid [lenalidomide]/dexamethasone) combination therapy results in high complete- and overall-response rates in treatment-naive symptomatic multiple myeloma.

This trial determined the safety and efficacy of the combination regimen clarithromycin (Biaxin), lenalidomide (Revlimid), and dexamethasone (BiRD) as first-line therapy for multiple myeloma. Patients received BiRD in 28-day cycles. Dexamethasone (40 mg) was given orally once weekly, clarithromycin (500 mg) was given orally twice daily, and lenalidomide (25 mg) was given orally daily on days 1 to 21. Objective response was defined by standard criteria (ie, decrease in serum monoclonal protein [M-protein] by at least 50%, and a decrease in urine M-protein by at least 90%). Of the 72 patients enrolled, 65 had an objective response (90.3%). A combined stringent and conventional complete response rate of 38.9% was achieved, and 73.6% of the patients achieved at least a 90% decrease in M-protein levels. This regimen did not interfere with hematopoietic stem-cell harvest. Fifty-two patients who did not go on to receive transplants received continued therapy (complete response, 37%; very good partial response, 33%). The major adverse events were thromboembolic events, corticosteroid-related morbidity, and cytopenias. BiRD is an effective regimen with manageable side effects in the treatment of symptomatic, newly diagnosed multiple myeloma. This trial was registered at www.clinicaltrials.gov as #NCT00151203.

Lenalidomide-induced myelosuppression is associated with renal dysfunction: adverse events evaluation of treatment-naïve patients undergoing front-line lenalidomide and dexamethasone therapy.

Data on 72 patients receiving lenalidomide/dexamethasone for multiple myeloma (MM) was used to determine the factors that are associated with lenalidomide-induced myelosuppression. Eight of 14 patients with grade > or =3 myelosuppression had baseline creatinine clearance (CrCl) < or =0.67 ml/s. Kaplan-Meier analysis by log-rank test demonstrated a significant association (P < 0.0001) between renal insufficiency and time to myelosuppression (hazard ratio = 8.4; 95% confidence interval 2.9-24.7, P = 0.0001). Therefore, CrCl is inversely associated with significant myelosuppression. Caution should be exercised when lenalidomide therapy is commenced and CrCl should be incorporated as a determinant of the initial dosing of lenalidomide in MM patients.