A phase 1 study of ruxolitinib, steroids and lenalidomide for relapsed/refractory multiple myeloma patients.

Ruxolitinib with lenalidomide and dexamethasone shows anti-myeloma effects in vitro and in vivo. MUC1 leads to lenalidomide resistance in multiple myeloma (MM) cells, and ruxolitinib blocks its expression. Thus, ruxolitinib may restore sensitivity to lenalidomide. A phase I trial was conducted to determine the safety and efficacy of ruxolitinib with lenalidomide and methylprednisolone for patients with relapsed/refractory (RR)MM who had been treated with lenalidomide, steroids and a proteasome inhibitor and showed progressive disease at study entry. A traditional 3 + 3 dose escalation design was used to enroll subjects in four cohorts. Subjects received ruxolitinib twice daily, lenalidomide daily on days 1-21 of a 28 day cycle and methylprednisolone orally every other day. Primary endpoints were safety, clinical benefit rate (CBR) and overall response rate (ORR). Forty-nine patients were enrolled. The median age was 64 years and they had received a median of six prior treatments including lenalidomide and steroids to which 94% were refractory. No dose limiting toxicities occurred. The CBR and ORR were 49% and 36%, respectively. All responding patients were refractory to lenalidomide. Grade 3 or 4 adverse events (AEs) included anemia (17%), decreased lymphocyte count (15%), and hypophosphatemia (10%). Most common serious AEs included sepsis (9.8%) and pneumonia (7.8%). This Phase I trial demonstrates that a JAK inhibitor, ruxolitinib, can overcome refractoriness to lenalidomide and steroids for patients with RRMM. These results represent a promising novel therapeutic approach for treating MM. NCT03110822.

The role of JAK inhibitors in multiple myeloma.

Multiple myeloma (MM) is the most common primary malignancy of the bone marrow. No established curative treatment is currently available for patients diagnosed with MM. In recent years, new and more effective drugs have become available for the treatment of MM. Many newer drugs have been evaluated together and in combination with older agents. However, even in combination with other active MM agents, the responses are transient, and; thus, therapeutic approaches to help overcome resistance to these drugs are necessary. Recently, the Janus kinase (JAK) family of tyrosine kinases, including JAK1 and JAK2, has been shown to play a role in the pathogenesis of MM. Preclinical studies have demonstrated that the JAK1/2 inhibitor ruxolitinib, in combination with lenalidomide and dexamethasone, reduces proliferation of the MM cell lines and primary tumor cells derived from MM patients, and this inhibition is greater when these drugs are combined than with single agents. Clinically, early results from the oral treatment regimen of ruxolitinib, corticosteroids (methylprednisolone), and lenalidomide for patients with relapsed/refractory disease are encouraging in terms of safety and efficacy, and additional studies will provide further support for this promising new therapeutic approach for patients with MM.

Serum B-Cell maturation antigen is an independent prognostic marker in previously untreated chronic lymphocytic leukemia.

B-Cell maturation antigen (BCMA) is a cell membrane receptor expressed on mature B lymphocytes, with elevated serum levels found among patients with B-cell malignancies, including chronic lymphocytic leukemia (CLL). Serum BCMA (sBCMA) levels were measured in 331 untreated, newly diagnosed CLL patients using an enzyme-linked immunosorbent assay with a polyclonal anti-BCMA antibody. Elevated sBCMA levels were found among patients with CLL compared with age- and sex-matched healthy controls and those with more active CLL based on prognostic factors. The relationships between sBCMA, time to first treatment (TTFT), overall survival (OS) and multiple prognostic factors were compared using Mann-Whitney and Kruskal-Wallis tests. The median sBCMA level in the CLL cohort (48.6 ng/mL) was significantly higher (p < 0.001) compared with those of age- and sex-matched healthy subjects (n = 100; 37.8 ng/mL). Serum BCMA correlated with TTFT (hazard ratio [HR] = 2.9, 95% confidence interval 2.0-4.2, p < 0.001) and OS (HR = 2.5, 95% confidence interval: 1.5-4.0, p < 0.001). Multiple models were used to test the predictive effects of sBCMA, sex, CLL International Prognostic Index (CLL-IPI) and International Prognostic Score for early-stage CLL (IPS-E) on TTFT and OS. The addition of sBCMA to CLL-IPI and IPS-E improved their prognostic ability to predict TTFT and OS. Thus, sBCMA is a new promising prognostic biomarker for CLL.

A phase 2 trial of the efficacy and safety of elotuzumab in combination with pomalidomide, carfilzomib and dexamethasone for high-risk relapsed/refractory multiple myeloma.

High-risk multiple myeloma (MM) continues to have a poor prognosis and remains a therapeutic challenge. This phase 2 study evaluated the efficacy and safety of elotuzumab in combination with pomalidomide, carfilzomib, and low-dose dexamethasone for patients with high-risk relapsed/refractory (RR)MM (NCT03104270). Of 13 enrolled patients, 11 were evaluable for efficacy. Overall response rate and clinical benefit rate were 45.4% and 54.5%, respectively. Deep responses were observed including two complete responses. The novel quadruplet combination was overall well-tolerated, with clinically manageable adverse events. Common adverse events of ≥ grade 3 included lymphopenia (15%), anemia (15%), sepsis (15%), pneumonia (15%), and hypophosphatemia (15%). The novel combination showed promising efficacy and was well tolerated in this heavily pretreated MM population. Even though the study was terminated early prior to completion of enrollment, the results indicate that this may be a promising therapeutic approach for high-risk RRMM patients, which warrants further study.

A Phase I Study of Ruxolitinib, Lenalidomide, and Steroids for Patients with Relapsed/Refractory Multiple Myeloma.

PURPOSE: Ruxolitinib with lenalidomide and dexamethasone shows antimyeloma effects in vitro and in vivo. MUC1 leads to lenalidomide resistance in multiple myeloma cells, and ruxolitinib blocks its expression. Thus, ruxolitinib may restore sensitivity to lenalidomide. Therefore, a phase I trial was conducted to determine the safety and efficacy of ruxolitinib with lenalidomide and methylprednisolone for patients with relapsed/refractory multiple myeloma (RRMM) who had been treated with lenalidomide/steroids and a proteasome inhibitor and showed progressive disease at study entry. PATIENTS AND METHODS: A traditional 3+3 dose escalation design was used to enroll subjects in four cohorts with planned total enrollment of 28 patients. Subjects received ruxolitinib twice daily, lenalidomide daily on days 1-21 of a 28-day cycle, and methylprednisolone orally every other day. Primary endpoints were safety, clinical benefit rate (CBR), and overall response rate (ORR). RESULTS: Twenty-eight patients were enrolled. The median age was 67 years and received a median of six prior treatments including lenalidomide and steroids to which 93% were refractory. No dose-limiting toxicities occurred. The CBR and ORR were 46% and 38%, respectively. All 12 responding patients were refractory to lenalidomide. Grade 3 or grade 4 adverse events (AE) included anemia (18%), thrombocytopenia (14%), and lymphopenia (14%). Most common serious AEs included sepsis (11%) and pneumonia (11%). CONCLUSIONS: This phase I trial demonstrates that a JAK inhibitor, ruxolitinib, can overcome refractoriness to lenalidomide and steroids for patients with RRMM. These results represent a promising novel therapeutic approach for treating multiple myeloma (ClinicalTrials.gov number, NCT03110822).

Plasma B-Cell Maturation Antigen Levels are Elevated and Correlate with Disease Activity in Patients with Chronic Lymphocytic Leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) is a malignancy of late B cells. In another late B-cell malignancy (multiple myeloma), levels of solubilized B-cell maturation antigen (sBCMA) are elevated and predict outcomes. OBJECTIVE: We sought to evaluate sBCMA as a possible prognostic factor and monitoring tool for patients with CLL. PATIENTS AND METHODS: Using an enzyme-linked immunosorbent assay (ELISA), we assessed plasma (p) levels of BCMA in 171 CLL patients and compared them with levels in healthy individuals. RESULTS: pBCMA levels were significantly higher among patients with CLL than those from healthy donors (p < 0.0001). Among patients with aggressive disease, pBCMA was elevated compared with patients with indolent disease (p < 0.001). Those with an initial pBCMA level in the highest quartile had a shorter time to first treatment compared with CLL patients with pBCMA levels in the lowest three quartiles (p < 0.0001). Among those in the highest quartile (pBCMA > 110.9 ng/mL), overall survival was shorter than those in the lowest three quartiles (p = 0.0007). Finally, among those patients who underwent serial pBCMA testing, changes in these levels correlated with changes in their clinical status. CONCLUSIONS: Together, our findings show that pBCMA is a promising new prognostic and predictive indicator for patients with CLL.

Serum B-cell maturation antigen (BCMA) reduces binding of anti-BCMA antibody to multiple myeloma cells.

B-cell maturation antigen (BCMA), a tumor necrosis factor receptor (TNFR) family member, is selectively expressed on terminally differentiated B-lymphocytes including multiple myeloma (MM) tumor cells. We sought to determine whether circulating (c)BCMA in MM serum interferes with antiBCMA antibody binding to MM cells. An enzyme-linked immunosorbent assay (ELISA) was used to determine serum (s) BCMA levels among 379 samples from patients with relapsed/refractory MM (RRMM). Furthermore, flow cytometric and immunofluorescent studies were used to examine if concentrations of BCMA in patients' serum were high enough to interfere with the binding of anti-BCMA antibody to MM tumor cells. We have shown that BCMA is elevated in the serum from MM patients and that the median concentration of sBCMA from RRMM patients was 176 ng/mL (n = 379). Additionally, there was a consistent decrease in the binding of anti-BCMA antibody to MM tumor cells with sBCMA level ≥156 ng/mL. Together, these results demonstrate that circulating BCMA levels in most RRMM patients are high enough to interfere with anti-BCMA antibody binding to MM tumor cells and may interfere with BCMA-targeted immune-based therapies.