Multiple myeloma: improved outcomes with new therapeutic approaches

Isatuximab plus carfilzomib/dexamethasone versus carfilzomib/dexamethasone in patients with relapsed/refractory multiple myeloma: IKEMA Phase III study design

Although the treatment of relapsed/refractory multiple myeloma has improved dramatically over the past decade, the disease remains incurable; therefore, additional therapies are needed. Novel combination therapies incorporating monoclonal antibodies have shown significant promise. Here we describe the design of a Phase III study (NCT03275285, IKEMA), which is evaluating isatuximab plus carfilzomib and low-dose dexamethasone, versus carfilzomib/dexamethasone in relapsed/refractory multiple myeloma. The primary end point is progression-free survival. Responses are being determined by an independent review committee using 2016 International Myeloma Working Group criteria, and safety will be assessed throughout. The first patient was recruited in November 2017, and the last patient was recruited in March 2019; 302 patients have been randomized, and the study is ongoing. Clinical trial registration: NCT03275285.

Phase I trial of isatuximab monotherapy in the treatment of refractory multiple myeloma

This phase I dose-escalation/expansion study evaluated isatuximab (anti-CD38 monoclonal antibody) monotherapy in patients with relapsed/refractory multiple myeloma (RRMM). Patients progressing on or after standard therapy received intravenous isatuximab (weekly [QW] or every 2 weeks [Q2W]). The primary objective was to determine the maximum tolerated dose (MTD) of isatuximab. Overall, 84 patients received ≥ 1 dose of isatuximab. The MTD was not reached; no cumulative adverse reactions were noted. The most frequent adverse events were infusion reactions (IRs), occurring in 37/73 patients (51%) following introduction of mandatory prophylaxis. IRs were mostly grade 1/2, occurred predominantly during Cycle 1, and led to treatment discontinuation in two patients. CD38 receptor occupancy reached a plateau of 80% with isatuximab 20 mg/kg (highest dose tested) and was associated with clinical response. In patients receiving isatuximab ≥ 10 mg/kg, overall response rate (ORR) was 23.8% (15/63), including one complete response. In high-risk patients treated with isatuximab 10 mg/kg (QW or Q2W), ORR was 16.7% (3/18). Median (range) duration of response at doses ≥ 10 mg/kg was 25 (8–30) weeks among high-risk patients versus 36 (6–85) weeks for other patients. In conclusion, isatuximab demonstrated a manageable safety profile and clinical activity in patients with RRMM.

Isatuximab plus pomalidomide/dexamethasone versus pomalidomide/dexamethasone in relapsed/refractory multiple myeloma: ICARIA Phase III study design

Treatment for relapsed/refractory multiple myeloma (RRMM) remains an unmet need. Isatuximab, an anti-CD38 monoclonal antibody has shown efficacy and tolerability as a monotherapy and combination therapy in Phase I/II studies in RRMM. Here, we describe the design of the Phase III ICARIA-MM study (NCT02990338) which will evaluate isatuximab in combination with pomalidomide (Pom) and low-dose dexamethasone (dex) (Pom/dex) versus Pom/dex alone in RRMM. Patients will be randomized in a 1:1 ratio. The primary endpoint is progression-free survival. Response will be determined by an independent response review committee using IMWG criteria (2016) and safety will be assessed throughout. Approximately 300 patients (150 in each arm) are expected to enroll. The first patient was recruited in January 2017 and accrual is ongoing.

Genetic deletion of Sost or pharmacological inhibition of sclerostin prevent multiple myeloma-induced bone disease without affecting tumor growth

Multiple myeloma (MM) causes lytic bone lesions due to increased bone resorption and concomitant marked suppression of bone formation. Sclerostin (Scl) levels, an osteocyte-derived inhibitor of Wnt/β-catenin signaling, are elevated in MM patient sera and are increased in osteocytes in MM-bearing mice. We show here that genetic deletion of Sost, the gene encoding Scl, prevented MM-induced bone disease in an immune-deficient mouse model of early MM, and that administration of anti-Scl antibody (Scl-Ab) increased bone mass and decreases osteolysis in immune-competent mice with established MM. Sost/Scl inhibition increased osteoblast numbers, stimulated new bone formation and decreased osteoclast number in MM-colonized bone. Further, Sost/Scl inhibition did not affect tumor growth in vivo or anti-myeloma drug efficacy in vitro. These results identify the osteocyte as a major contributor to the deleterious effects of MM in bone and osteocyte-derived Scl as a promising target for the treatment of established MM-induced bone disease. Further, Scl did not interfere with efficacy of chemotherapy for MM suggesting that combined treatment with anti-myeloma drugs and Scl-Ab should effectively control MM growth and bone disease, providing new avenues to effectively control MM and bone disease in patients with active MM.

A phase 1b study of isatuximab plus lenalidomide and dexamethasone for relapsed/refractory multiple myeloma

This phase 1b, open-label, dose-escalation study assessed the safety, efficacy, and pharmacokinetics of anti-CD38 monoclonal antibody isatuximab given in 2 schedules (3, 5, or 10 mg/kg every other week [Q2W] or 10 or 20 mg/kg weekly [QW] for 4 weeks and then Q2W thereafter [QW/Q2W]), in combination with lenalidomide 25 mg (days 1-21) and dexamethasone 40 mg (QW), in patients with relapsed/refractory multiple myeloma (RRMM). Patients received 28-day treatment cycles; the primary objective was to determine the maximum tolerated dose (MTD) of isatuximab with lenalidomide and dexamethasone. Fifty-seven patients (median 5 [range 1-12] prior regimens; 83% refractory to previous lenalidomide therapy) were treated. Median duration of dosing was 36.4 weeks; 15 patients remained on treatment at data cutoff. Isatuximab-lenalidomide-dexamethasone was generally well tolerated with only 1 dose-limiting toxicity reported (grade 3 pneumonia at 20 mg/kg QW/Q2W); the MTD was not reached. The most common isatuximab-related adverse events were infusion-associated reactions (IARs) (56%), which were grade 1/2 in 84% of patients who had an IAR and predominantly occurred during the first infusion. In the efficacy-evaluable population, the overall response rate (ORR) was 56% (29/52) and was similar between the 10 mg/kg Q2W and 10 and 20 mg/kg QW/Q2W cohorts. The ORR was 52% in 42 evaluable lenalidomide-refractory patients. Overall median progression-free survival was 8.5 months. Isatuximab exposure increased in a greater than dose-proportional manner; isatuximab and lenalidomide pharmacokinetic parameters appeared independent. These data suggest that isatuximab combined with lenalidomide and dexamethasone is active and tolerated in heavily pretreated patients with RRMM. This trial was registered at www.clinicaltrials.gov as #NCT01749969.

Epigenetic Activity of Peroxisome Proliferator-Activated Receptor Gamma Agonists Increases the Anticancer Effect of Histone Deacetylase Inhibitors on Multiple Myeloma Cells

Epigenetic modifications play a major role in the development of multiple myeloma. We have previously reported that the PPARγ agonist pioglitazone (PIO) enhances, in-vitro, the cytotoxic effect of the Histone deacetylase inhibitor (HDACi), valproic acid (VPA), on multiple myeloma cells. Here, we described the development of a new multiple myeloma mouse model using MOLP8 cells, in order to evaluate the effect of VPA/PIO combination on the progression of myeloma cells, by analyzing the proliferation of bone marrow plasma cells. We showed that VPA/PIO delays the progression of the disease and the invasion of myeloma cells in the bone marrow. Mechanistically, we demonstrated that VPA/PIO increases the cleavage of caspase 3 and PARP, and induces the acetylation of Histone 3 (H3). Furthermore, we provided evidence that PPARγ agonist is able to enhance the action of other HDACi such as Vorinostat or Mocetinostat. Using PPARγ antagonist or siPPARγ, we strongly suggest that, as described during adipogenesis, PIO behaves as an epigenetic regulator by improving the activity of HDACi. This study highlights the therapeutic benefit of PIO/VPA combination, compared to VPA treatment as a single-arm therapy on multiple myeloma and further highlights that such combination may constitute a new promising treatment strategy which should be supported by clinical trials.

Racial/ethnic disparities in inflammatory gene single-nucleotide polymorphisms as predictors of a high risk for symptom burden in patients with multiple myeloma 1 year after diagnosis

BACKGROUND

This study was conducted to determine whether any regulatory single-nucleotide polymorphism (SNP) in an inflammatory gene was associated with a high symptom burden in patients 1 year after the diagnosis of multiple myeloma (MM).

METHODS

MM patients rated symptoms with the MD Anderson Symptom Inventory multiple myeloma module (MDASI-MM) and provided buccal-swab DNA samples. SNPs for 4 cytokine genes (interleukin 6 [IL6] -174G>C, IL1β -511C>T, tumor necrosis factor α [TNFα] -308G>A, and IL10 -1082G>A) were tested. Logistic regression models were used to identify SNPs that might predict moderate/severe symptoms (rated ≥ 4 on the MDASI-MM 0-10 scale). For the evaluation of the relationship between SNPs and overall symptom burden, a 2-step cluster analysis was used to divide patients into subgroups with high or low symptom levels.

RESULTS

Forty-one percent of the 344 patients enrolled had a high overall symptom burden. The most prevalent moderate/severe symptoms were fatigue (47%), pain (42%), numbness (38%), and bone aches (32%). For non-Hispanic whites, the IL1β -511 CC genotype was associated with a high overall symptom burden (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.25-4.72; P = .004), whereas the IL6 -174 GG genotype predicted less moderate/severe fatigue (OR, 0.53; 95% CI, 0.29-0.88; P = .013). For other patients, the IL6 -174 GG genotype predicted moderate/severe pain (OR, 3.36; 95% CI, 1.23-13.64; P = .010).

CONCLUSIONS

These results support growing evidence showing that inflammation is associated with cancer-related symptoms, and they suggest that racial/ethnic factors contribute to this association.

Incidence and risk factors for suicide and attempted suicide following a diagnosis of hematological malignancy

Solid tumors are associated with an increased risk of suicide, however, there is limited detailed information on the risk of suicide in patients with hematological malignancies. Therefore, we conducted a population-based study including 47,220 patients with hematological malignancies (diagnosed 1992-2006) and their 235,868 matched controls to define the incidence and risk factors for suicide and suicide attempt. Information on suicides, suicide attempts, and preexisting psychiatric disorders was obtained from Swedish registers and individual medical records. There was a twofold increased (hazard ratio [HR] = 1.9, 95% confidence interval 1.5-2.3, P < 0.0001) risk of suicide/suicide attempt during the first 3 years after diagnosis in patients with hematological malignancies compared to matched controls. Of all hematological malignancies, multiple myeloma was associated with the highest risk (HR = 3.4; 2.3-5.0, P < 0.0001). Patients with a preexisting psychiatric disorder were at a very high risk of suicide and suicide attempt (HR = 23.3; 16.6-32.6, P < 0.0001), regardless of type of hematological malignancy. Among patients who committed suicide, 19% were in a palliative phase and 44% were in remission with no active treatment. In conclusion, the risk of suicide and suicide attempt is elevated in patients with hematological malignancies. Certain high-risk patients may benefit from early detection and preventive measures.

A macromolecular prodrug strategy for combinatorial drug delivery

A novel macromolecular prodrug strategy was developed for the combinatorial delivery of two poorly water-soluble drugs, dexamethasone and doxorubicin. In this work, dexamethasone was firstly conjugated onto a water-soluble modified polysaccharide by an acid-labile hydrazone linkage. The resultant macromolecular prodrug had an amphiphilic character and could self-assemble into spherical polymeric micelles in aqueous system. With these micelles, doxorubicin was then encapsulated into their hydrophobic cores. For the conjugated dexamethasone and encapsulated doxorubicin, they could exhibit independent and acid-sensitive release characteristics. For the doxorubicin-loaded prodrug micelles, they were easily be internalized by living cells and showed obvious antitumor activity.

Liposomal chemotherapeutics

Currently, six liposomal chemotherapeutics have received clinical approval and many more are in clinical trials or undergoing preclinical evaluation. Liposomes exhibit low toxicity and improve the biopharmaceutical features and therapeutic index of drugs, thereby increasing efficacy and reducing side effects. In this review we discuss the advantages of using liposomes for the delivery of chemotherapeutics. Gemcitabine and paclitaxel have been chosen as examples to illustrate how the performance of a metabolically unstable or poorly water-soluble drug can be greatly improved by liposomal incorporation. We look at the beneficial effects of liposomes in a variety of solid and blood-borne tumors, including thyroid cancer, pancreatic cancer, breast cancer and multiple myeloma.

Integrated safety profile of single-agent carfilzomib: experience from 526 patients enrolled in 4 phase II clinical studies

Carfilzomib, a selective proteasome inhibitor, was approved in 2012 for the treatment of relapsed and refractory multiple myeloma. Safety data for single-agent carfilzomib have been analyzed for 526 patients with advanced multiple myeloma who took part in one of 4 phase II studies (PX-171-003-A0, PX-171-003-A1, PX-171-004, and PX-171-005). Overall analyses of adverse events and treatment modifications are presented, as well as specific analyses of adverse events by organ system. Overall, the most common adverse events of any grade included fatigue (55.5%), anemia (46.8%), and nausea (44.9%). In the grouped analyses, any grade adverse events were reported in 22.1% for any cardiac (7.2% cardiac failure), 69.0% for any respiratory (42.2% dyspnea), and 33.1% for any grouped renal impairment adverse event (24.1% increased serum creatinine). The most common non-hematologic adverse events were generally Grade 1 or 2 in severity, while Grade 3/4 adverse events were primarily hematologic and mostly reversible. There was no evidence of cumulative bone marrow suppression, either neutropenia or thrombocytopenia, and febrile neutropenia occurred infrequently (1.1%). Notably, the incidence of peripheral neuropathy was low overall (13.9%), including patients with baseline peripheral neuropathy (12.7%). Additionally, the incidence of discontinuations or dose reductions attributable to adverse events was low. These data demonstrate that single-agent carfilzomib has an acceptable safety profile in heavily pre-treated patients with relapsed/refractory multiple myeloma. The tolerable safety profile allows for administration of full-dose carfilzomib, both for extended periods and in a wide spectrum of patients with advanced multiple myeloma, including those with pre-existing comorbidities.

Incident hyperglycemia, parenteral nutrition administration and adverse outcomes in patients with myeloma admitted for initial auto-SCT

Parenteral nutrition (PN) exacerbates hyperglycemia, which is associated with increased morbidity and mortality in various cancer populations. By using a retrospective design, we examined incident hyperglycemia in PN and non-PN recipients and the associations with clinical events and 5-year survival in a cohort treated for myeloma with melphalan and auto-SCT (n=112). Clinical comparisons were made at admission, and 'before' and 'after' initiating PN to discern differences and temporality. Actual infusion times were used for PN patients; time frames based on mean PN infusion days were created for the non-PN recipients. Oral intake was lower 'before' in PN vs non-PN patients (P<0.001); however, no differences in mucositis, emesis, infections or transfusions were detected 'before.' Incident hyperglycemia (≥7.0 mmol/L) was significant 'after' PN initiation, and PN recipients experienced delays in WBC (P<0.05) and platelet engraftment (P=0.009), and required significantly greater RBC (P=0.0014) and platelet (P=0.001) support 'after' than non-PN patients. Neutropenic fever and longer hospital stay were more frequent among PN vs non-PN recipients (P<0.001). Differences in 5-year mortality were not apparent. The findings fail to support clinical benefits of PN administration during auto-SCT for myeloma. Further study is needed to discern if hyperglycemia or feeding per se was deleterious in this patient population.

Induction of malignant plasma cell proliferation by eosinophils

The biology of the malignant plasma cells (PCs) in multiple myeloma (MM) is highly influenced by the bone marrow (BM) microenvironment in which they reside. More specifically, BM stromal cells (SCs) are known to interact with MM cells to promote MM cell survival and proliferation. By contrast, it is unclear if innate immune cells within this same space also actively participate in the pathology of MM. Our study shows for the first time that eosinophils (Eos) can contribute to the biology of MM by enhancing the proliferation of some malignant PCs. We first demonstrate that PCs and Eos can be found in close proximity in the BM. In culture, Eos were found to augment MM cell proliferation that is predominantly mediated through a soluble factor(s). Fractionation of cell-free supernatants and neutralization studies demonstrated that this activity is independent of Eos-derived microparticles and a proliferation-inducing ligand (APRIL), respectively. Using a multicellular in vitro system designed to resemble the native MM niche, SCs and Eos were shown to have non-redundant roles in their support of MM cell growth. Whereas SCs induce MM cell proliferation predominantly through the secretion of IL-6, Eos stimulate growth of these malignant cells via an IL-6-independent mechanism. Taken together, our study demonstrates for the first time a role for Eos in the pathology of MM and suggests that therapeutic strategies targeting these cells may be beneficial.