Monitoring multiple myeloma

Multiple myeloma (MM) is a B-cell malignancy characterized by the accumulation in bone marrow of terminally differentiated plasma cells. MM is a slowly growing, heterogeneous disease with no known cure. Patients with MM have a median survival of approximately 5 years, during which they may experience significant morbidity. More reliable and rapid determination of changes in the clinical status of patients with MM is becoming increasingly important because of the increasing number of available treatments for these patients. Currently available tests for monitoring patients with MM most often include assessments of monoclonal paraprotein and serum free light chain levels, but the tests have several limitations. Measurement of serum B-cell maturation antigen level may overcome these limitations and improve outcomes for patients with MM. Newer radiologic procedures such as positron emission tomography/computed tomography are superior to plain radiographs, but are costly and inconvenient. Bone marrow examination directly identifies malignant cells, but the heterogeneous nature of the disease makes it problematic to use routinely to follow patients with MM. The development of new markers and approaches to more accurately and quickly assess changes in tumor burden in patients with MM should result in better outcomes for these patients.

Analysis of efficacy and safety of POM as a replacement therapy for lenalidomide for relapsed/refractory multiple myeloma pts refractory to a lenalidomide-containing combination regimen

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Background: Pomalidomide (POM) is a third –generation immunomodulatory drug shown to be safe and effective for the treatment of relapsed/refractory multiple myeloma (RRMM) for patients (pts) previously treated with bortezomib and lenalidomide (LEN) and in combination with dexamethasone it has been shown to overcome resistance in RRMM. In this phase 2 trial, we are evaluating the efficacy, safety and tolerability of POM as a replacement therapy for LEN for pts who have progressed receiving a LEN combination regimen. Methods: This is a phase 2, multicenter, open-label and non-randomized study. Pts who have failed a combination regimen containing LEN were treated with POM along with all of the other drugs previously used in the regimen. POM administered orally (dose is determined based on the previous regimen) on days 1-21 of a 28-day cycle, whereas other drugs are administered using the same schedule(s), dose(s) and drug combination as the last LEN-containing regimen that the patient received and failed. The planned enrollment on the study will be 45 pts. Results: To date, a total of 29 pts have been enrolled, 25 pts are evaluable and 12 pts have discontinued treatment. Of the evaluable pts, 9 (36%) and 16 (64%) received 3mg and 4mg of POM, respectively. The median age of all pts was 72 years (range, 52-81), and 17 (68%) were males. Pts have received a median of 3 prior treatments (range, 1-7). The median follow-up time for all pts is 3.1 months (range, 0.2-8.1). Amongst evaluable pts, 5 (23.8%) pts achieved at least a minimal response, 10 (47.6%) pts showed stable disease while 6 (28.6%) pts exhibited disease progression. At the time of data cutoff, only 17 pts have completed more than 1 full cycle of treatment; and, thus, the overall response and clinical benefit rates are fairly low (14.3% and 23.8%, respectively) but expected to improve with further follow up. The median PFS for the cohort was 7.6 months. Common ≥ Gr3 adverse events were neutropenia (8%), hypomania (4%) and leukopenia (4%). Conclusions: We show thatPOM appears to be promising replacement therapy for LEN in RRMM pts who have progressed within receiving a LEN combination regimen.

Replacement of ixazomib for relapsed/refractory multiple myeloma patients refractory to a bortezomib or carfilzomib-containing combination therapy

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Background: The proteasome inhibitor (PI) ixazomib (Ixz) is the first orally administered PI approved for treating multiple myeloma (MM). It has shown clinical activity as a single agent and when used in other combinations. In this phase 1/2 trial, we evaluated Ixz as a replacement therapy for bortezomib or carfilzomib for MM patients who were refractory to a bortezomib- or carfilzomib-containing combination regimen. Methods: This was a phase 1/2, intra-patient, multicenter, open-label trial evaluating the replacement of ixazomib for bortezomib or carfilzomib for MM patients who were refractory in combination with the other agents that the patients had received and failed. Patients received Ixz on days 1, 8 and 15 on a 28-day schedule and the other drugs were administered using the same doses and schedules as they were receiving during their prior regimen. If the Ixz maximum tolerated dose (MTD) for a particular combination regimen was previously determined, then patients were enrolled directly into Phase 2 (PhII). If not, MTD was determined during the Phase 1 (PhI) portion of the trial. Results: To date, a total of 40 patients have been enrolled; 37 patients (21 were enrolled in PhI and 16 in PhII) had completed at least one cycle of this treatment. Patients received a median of 5 prior treatments (range, 1-22). The median follow-up time for all patients was 1.6 months (range, 0.1-10.7 months), whereas that of PhII was 2.2 months (range, 0.2-10.7 months). There was no clinical benefit (CBR; 0%) nor any overall response rate (ORR; 0%) for patients receiving Ixz 3 mg (PhI). Nine patients (43%) showed stable disease (SD) while 12 (57%) exhibited disease progression (PD). In PhII (4mg Ixz) portion of the trial, ORR and CBR were both 18.7% with 16 (43.2%) patients showing SD, and 18 (48.6%) patients displaying PD. Common ≥ Gr3 adverse events were anemia (11%), thrombocytopenia (5.4%), hyponatremia (5.4%), dehydration (5.4%) and neutropenia (2.7%). Conclusions: Replacement of bortezomib or carfilzomib with Ixz infrequently leads to responses among RRMM patient who have progressed while on proteasome inhibitor -containing combination regimens. Clinical trial information: NCT02206425.

Serum B-cell maturation antigen: a novel biomarker to predict outcomes for multiple myeloma patients

B-cell maturation antigen is expressed on plasma cells. In this study, we have identified serum B-cell maturation antigen as a novel biomarker that can monitor and predict outcomes for multiple myeloma patients. Compared to healthy donors, patients with multiple myeloma showed elevated serum B-cell maturation antigen levels (P<0.0001). Serum B-cell maturation antigen levels correlated with the proportion of plasma cells in bone marrow biopsies (Spearman's rho = 0.710; P<0.001), clinical status (complete response vs partial response, P=0.0374; complete response vs progressive disease, P<0.0001), and tracked with changes in M-protein levels. Among patients with non-secretory disease, serum B-cell maturation antigen levels correlated with bone marrow plasma cell levels and findings from positron emission tomography scans. Kaplan-Meier analysis demonstrated that serum B-cell maturation antigen levels above the median levels were predictive of a shorter progression-free survival (P=0.0006) and overall survival (P=0.0108) among multiple myeloma patients (n=243). Specifically, patients with serum B-cell maturation antigen levels above the median level at the time of starting front-line (P=0.0043) or a new salvage therapy (P=0.0044) were found to have shorter progression-free survival. Importantly, serum B-cell maturation antigen levels did not show any dependence on renal function and maintained independent significance when tested against other known prognostic markers for multiple myeloma such as age, serum β2 microglobulin, hemoglobin, and bone disease. These data identify serum B-cell maturation antigen as a new biomarker to manage multiple myeloma patients.

Outcomes of multiple myeloma patients receiving bortezomib, lenalidomide, and carfilzomib

New classes of drugs including the proteasome inhibitors (PI) bortezomib and, more recently, carfilzomib and the immunomodulatory agent lenalidomide have shown improved outcomes for multiple myeloma (MM) patients during the past decade. However, most of the studies reporting outcomes for patients receiving these drugs have relied on older data sets derived from large institutions that included patients not receiving their treatment at those facilities and represented only those eligible for clinical trials or were from sites where treatment options were limited. We have analyzed data from 258 MM patients who have received treatment with at least one of three agents: bortezomib, carfilzomib, and lenalidomide in a single clinic specializing in MM with respect to their responses and other outcomes to treatment regimens including these agents. Response rates were similar between these three drugs when used for the first time and again during subsequent treatment regimens. As expected, the clinical benefit rates (CBRs) were better for patients receiving their first treatment when compared to their use in subsequent treatment regimens. The CBRs were similar during their 2nd, 3rd, and 4th treatments containing these agents. Many patients refractory to these agents showed responses to regimens containing these same drugs when used in different combinations. In addition, patients refractory to one PI often responded to the other PI. The results of this study demonstrate that novel agents can be used repeatedly in novel combinations with significant clinical benefit for patients with MM.

Improved clinical outcomes for multiple myeloma patients treated at a single specialty clinic

Despite recent advances made in its treatment, multiple myeloma (MM) remains an incurable B cell malignancy. Thus, the objective for treating these patients is to prolong overall survival (OS) and preserve patients' quality of life. We have analyzed data from 264 consecutive MM patients who had their initial visit between July 1, 2004 and December 1, 2014 and have received treatment in a single clinic specializing in MM. We determined their progression-free survival (PFS, OS, and 5-year OS). The PFS for frontline (n = 165 treatments), salvage (n = 980), and all treatments (n = 1145) were 13.9, 4.6, and 5.5 months, respectively. The median OS of all patients was 98 months with a 5-year survival of 74%. The results of this study show a marked improvement in OS for unselected MM patients compared with historical data. There were no significant differences in OS between patients with different International Staging System (ISS) stages. Younger patients (<65 years old) showed a longer OS. The results of this study should help physicians predict outcomes for MM patients and be encouraging for patients with this B cell malignancy.

Abstract 1339: Effects of INCB052793, a selective JAK1 inhibitor, in combination with standard of care agents in human multiple myeloma (MM) cell lines and xenograft models

Several studies have demonstrated constitutive activation of the JAK-STAT pathway in MM through dysregulated signaling of cytokines such as IL-6. In addition to its crucial role in promoting the growth, proliferation and survival of myeloma cells, IL-6 is also a potent stimulator of osteoclastogenesis and influences the tumor microenvironment in the bone marrow of myeloma patients by promoting an immunosuppressive milieu. Since JAK1 has been shown to be important for IL-6 signaling, studies to assess the effect of JAK1 inhibition alone and in combination with other anti-MM agents were undertaken. The human MM cell lines, RPMI8226 or U266, were cultured in the presence of the JAK1 selective inhibitor INCB052793 plus a panel of anti-MM agents including the alkylating agents, cyclophosphamide (CY), melphalan (MEL), and bendamustine, the proteasome inhibitor, carfilzomib, the corticosteroid, dexamethasone (DEX) or the immunomodulatory agents lenalidomide (LEN) and pomalidomide (POM). After 48 hours, cell viability was assessed. Combinations of INCB052793 plus the three alkylating agents or carfilzomib synergistically inhibited the viability of both cell lines in vitro. INCB052793 plus CY or MEL also significantly decreased the viability of the MM1S MM cell line. In vivo, mice bearing the human patient derived MM tumor LAGκ-1A had significantly smaller tumors when treated with INCB052793 alone when compared to vehicle control at Day 35 post implantation. This was in contrast to mice treated with single agent DEX, LEN or POM. Although the combination of INCB052793 with DEX, LEN or POM did not synergistically inhibit MM cell line growth in vitro, mice receiving the doublets of INCB052793 and DEX, LEN or POM demonstrated an effect on tumor growth that was superior to the doublets of DEX with LEN or POM. Mice receiving the triple combination of INCB052793 + DEX with LEN or POM demonstrated the most significant effect on tumor growth compared to all other combinations tested. The inhibition of tumor growth with these combinations was observed throughout the study (through Day 70) and all combinations were well tolerated. Concomitant with effects on tumor growth, a significant reduction in serum human IgG levels was also observed. Studies to further understand the mechanistic effects of these combinations on myeloma signaling and the tumor microenvironment are ongoing. In conclusion, these in vitro and in vivo studies demonstrate that the combination of INCB052793 with a broad spectrum of anti-MM agents is effective, and provide further support for the clinical evaluation of these drug combinations in MM patients.

Citation Format: Eric Sanchez, Mingjie Li, Cathy Wang, Puja Mehta, George Tang, Haiming Chen, James R. Berenson. Effects of INCB052793, a selective JAK1 inhibitor, in combination with standard of care agents in human multiple myeloma (MM) cell lines and xenograft models. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1339.

Reduced serum BCMA levels distinguish patients with primary antibody deficiency

B-cell maturation antigen (BCMA) is a TNF family receptor that binds a proliferation inducing ligand (APRIL) and B cell activating factor (BAFF). BCMA is expressed by immunoglobulin secreting cells, but not other B cells, and supports their survival. Primary antibody deficiency (PAD) is the most common primary immunodeficiency and may lead to infection and complications including autoimmunity, enteropathy, lung disease, and malignancy. PAD patients with these complications have reduced survival, yet there are no validated tests to predict those at risk. We previously demonstrated that BCMA is present in the serum and its levels are elevated in patients with multiple myeloma. As BCMA is expressed by both normal and malignant antibody-producing cells, we examined serum levels of BCMA in PAD. Patients with PAD (n=68) had markedly reduced BCMA levels (median, 7.30) compared with healthy donors (n=119; median, 35.20; P &lt; 0.0001). When subgrouped based upon PAD diagnosis, serum BCMA was reduced compared to controls among those with common variable immunodeficiency (CVID) (n=48; median, 7.16; P &lt;0.0001) and X-linked agammaglobulinemia (n=8; median, 2.30; P &lt;0.0001), but not among those with selective IgA deficiency or hyper IgM syndrome. CVID patients with any inflammatory complication, or enteropathy specifically, had significantly lower serum BCMA than CVID patients without complications (P &lt; 0.01 for both). Serum BCMA moderately correlated with isotype-switched memory B cells (r = 0.473), but poorly correlated with IgA, IgG, or IgM levels or total B cell levels. These results demonstrate that reduced serum BCMA levels are found in PAD patients, distinguish types of PAD, and are associated with the development of complications in CVID.

Low serum vitamin D occurs commonly among multiple myeloma patients treated with bortezomib and/or thalidomide and is associated with severe neuropathy

PURPOSE

Previous studies have shown that low serum vitamin D levels have been associated with many skeletal and non-skeletal disorders. We studied the relationship between 25-hydroxyvitamin D (25D) levels and motor and sensory peripheral neuropathy (PN) among multiple myeloma (MM) patients who have been treated with bortezomib and/or thalidomide.

METHODS

We performed a study of 111 MM patients who had received at least one of these two agents for at least 12 weeks by correlating physical exam/neurologic assessment findings with patient self-assessment responses.

RESULTS

The median age of study patients was 66 years (range 42-89 years) and 54 % were males. 25D levels were determined, and complete history and physical and neurologic examinations were performed at the same study visit. In addition, study subjects completed questionnaires regarding symptoms related to motor and sensory PN. Overall, patients had a median serum 25D level of only 32 ng/ml; 42 % of patients were considered either 25D-deficient (<20.0 ng/mL; 16 % of patients) or 25D-insufficient (20.0-29.9 ng/mL; 26 %). Notably, we found that 25D-deficient MM patients were more likely to have severe PN (>grade 2) of both motor (p = 0.0415) and sensory (p = 0.0086) types although the overall incidence of PN was not higher in this patient population.

CONCLUSION

These results show that the severity of peripheral neuropathy is associated with lower vitamin D levels and provides the rationale for monitoring vitamin D for myeloma patients especially those receiving drugs associated with the development of peripheral neuropathy.

Maintenance Therapy With Immunomodulatory Drugs in Multiple Myeloma: A Meta-Analysis and Systematic Review

BACKGROUND

Immunomodulatory drugs (IMiDs) and proteasome inhibitors have dramatically changed management of multiple myeloma (MM). While MM remains incurable, consolidation and maintenance therapy aimed at improving duration of response can potentially improve survival outcomes. A majority of randomized controlled trials (RCTs) have demonstrated benefit of IMiD-based maintenance therapy in delaying disease progression; however, whether this therapy can lead to improved survival remains controversial.

METHODS

PubMed and abstract databases of major hematology and/or oncology meetings were searched for RCTs that studied maintenance therapy with IMiDs in MM. A meta-analysis was conducted to systematically evaluate the impact of IMiD-based maintenance therapy on survival outcomes and serious adverse events associated with the therapy. All statistical tests were two-sided.

RESULTS

Eighteen phase 3 RCTs enrolling 7730 patients were included. IMiD-based maintenance therapy statistically significantly prolonged progression-free survival (PFS; hazard ratio (HR) = 0.62, 95% confidence interval (CI) = 0.57 to 0.67, P < .001) but failed to improve overall survival (OS; HR = 0.93, 95% CI = 0.85 to 1.01, P = .082). Stratified analyses demonstrated that both thalidomide and lenalidomide provided PFS but not OS benefit in transplantation as well as nontransplantation settings. IMiD-based maintenance therapy in MM led to a higher risk of grade 3-4 thromboembolism (risk ratio = 2.52, 95% CI = 1.41 to 4.52, P = .002). Thalidomide maintenance therapy increased the risk of peripheral neuropathy; lenalidomide maintenance therapy increased the risks of myelosuppression and second primary hematological malignancies.

CONCLUSIONS

Thalidomide- or lenalidomide-based maintenance therapy improves PFS but not OS in MM and increases risks of grade 3-4 adverse events, including thromboembolism, peripheral neuropathy, neutropenia, and infection.

The potential of panobinostat as a treatment option in patients with relapsed and refractory multiple myeloma

Panobinostat is an investigational and potent histone deacetylase inhibitor (HDACi) that has shown promise as an antimultiple myeloma agent in the preclinical setting. In this review, we discuss the rationale for the use of panobinostat as a combination therapy for multiple myeloma and provide an overview of recent and ongoing clinical trials testing the safety and efficacy of panobinostat for the treatment of the disease.

A phase 3 trial of armodafinil for the treatment of cancer-related fatigue for patients with multiple myeloma

PURPOSE

Fatigue is a common problem among multiple myeloma (MM) patients. Armodafinil is a drug known to promote wakefulness, which is related to modafinil, a compound that improves fatigue in some cancer patients treated with chemotherapeutic agents. We investigated whether armodafinil could reduce cancer-related fatigue in MM patients.

METHODS

This double-blind, placebo-controlled phase 3 trial evaluated the efficacy of armodafinil in MM patients with evidence of moderate fatigue. Patients were randomized to one of two arms: treatment-only, with armodafinil given at 150 mg/daily for 56 days, or placebo-first, with placebo given on days 1-28, followed by armodafinil administered at 150 mg daily on days 29-56. Fatigue was measured on days 1 (pre-dose: baseline), 15, 28, 43, and 56 using seven separate assessments, including four patient-reported outcomes of fatigue and related quality of life measures, as well as three objective measures of cognitive function.

RESULTS

Overall toxicities were similar between treatment groups. No significant differences were observed between the placebo-first and the treatment-only arms after 28 days. Treatment with armodafinil for 28 additional days did not produce responses. Both placebo-first and treatment-only patients showed similar significant improvements in three patient-reported measures and one objective task at day 28 compared to baseline. Placebo-first patients improved on eight additional measures (one patient-reported measure, six subscales, and one objective task), suggesting a strong placebo effect in this patient population.

CONCLUSIONS

Evaluation and treatment of cancer-related fatigue continues to be challenging; a clear definition of this symptom and better assessment tools are needed.

Treatment strategies for skeletal complications of cancer

Skeletal complications are a common result of many cancers, particularly of multiple myeloma and bone metastases of solid tumors originating in the breast, prostate or lung. A number of treatment options are available, including radiotherapy, radiopharmaceuticals, surgery and chemotherapy. Recently, bisphosphonates have emerged as a promising new treatment option for bone complications of cancer. These agents are potent inhibitors of osteoclast activity that bind to the bone matrix, are released during bone resorption, and are subsequently internalized by osteoclasts, where they interfere with biochemical pathways and induce osteoclast apoptosis. Bisphosphonates also antagonize osteoclastogenesis and promote the differentiation of osteoblasts. As a result, bisphosphonates inhibit tumor-induced osteolysis and reduce skeletal morbidity. Bisphosphonates are generally well tolerated, although they have recently been associated with osteonecrosis of the jaw, a painful and debilitating side effect that is only beginning to be understood. Despite this concern, bisphosphonates are an important tool in the management of skeletal complications of cancer, providing benefits for the treatment of hypercalcemia, osteolytic lesions and fractures, as well as offering amelioration of pain and improvement in quality of life.

Carfilzomib in multiple myeloma

INTRODUCTION

Advances in drug therapy for multiple myeloma (MM) during the previous decade have improved survival outcomes; however, the disease remains incurable as patients eventually relapse or become refractory to all available therapies. Therefore, there is a clear need for more effective and well-tolerated treatments.

AREAS COVERED

We review preclinical and clinical data regarding the use of carfilzomib , a proteasome inhibitor that is structurally and mechanistically distinct from bortezomib, for the treatment of MM patients. Carfilzomib pharmacokinetics, pharmacodynamics, efficacy, safety and tolerability are summarized, based on Phase I/II trial data.

EXPERT OPINION

Carfilzomib represents a significant advance in the management of relapsed and/or refractory MM patients, including those intolerant or resistant to bortezomib. High response rates have been demonstrated with carfilzomib as a single agent or in combination with alkylating agents, immunomodulators and corticosteroids, even among patients who have failed multiple prior therapies. Carfilzomib also has significant potential in the frontline setting, with encouraging response and survival rates observed for combination regimens. Further evaluation of carfilzomib-containing regimens is ongoing in Phase III trials and investigator-sponsored studies, which include combinations with novel investigational agents. These findings will shape the future role of carfilzomib for MM patients across multiple settings.