Karin Fahl Wader

Activin A inhibits BMP-signaling by binding ACVR2A and ACVR2B.

BackgroundActivins are members of the TGF-β family of ligands that have multiple biological functions in embryonic stem cells as well as in differentiated tissue. Serum levels of activin A were found to be elevated in pathological conditions such as cachexia, osteoporosis and cancer. Signaling by activin A through canonical ALK4-ACVR2 receptor complexes activates the transcription factors SMAD2 and SMAD3. Activin A has a strong affinity to type 2 receptors, a feature that they share with some of the bone morphogenetic proteins (BMPs). Activin A is also elevated in myeloma patients with advanced disease and is involved in myeloma bone disease.ResultsIn this study we investigated effects of activin A binding to receptors that are shared with BMPs using myeloma cell lines with well-characterized BMP-receptor expression and responses. Activin A antagonized BMP-6 and BMP-9, but not BMP-2 and BMP-4. Activin A was able to counteract BMPs that signal through the type 2 receptors ACVR2A and ACVR2B in combination with ALK2, but not BMPs that signal through BMPR2 in combination with ALK3 and ALK6.ConclusionsWe propose that one important way that activin A regulates cell behavior is by antagonizing BMP-ACVR2A/ACVR2B/ALK2 signaling.

Elevated serum concentrations of activated hepatocyte growth factor activator in patients with multiple myeloma

Objectives:  Hepatocyte growth factor (HGF) is a potential key factor in multiple myeloma. Conversion of pro‐HGF to its active form is a critical limiting step for its biological effects. We aimed to examine the levels of the most potent activator, the hepatocyte growth factor activator (HGFA), in serum and bone marrow plasma of patients with multiple myeloma.

Bone morphogenetic protein-9 suppresses growth of myeloma cells by signaling through ALK2 but is inhibited by endoglin.

Multiple myeloma is a malignancy of plasma cells predominantly located in the bone marrow. A number of bone morphogenetic proteins (BMPs) induce apoptosis in myeloma cells in vitro, and with this study we add BMP-9 to the list. BMP-9 has been found in human serum at concentrations that inhibit cancer cell growth in vitro. We here show that the level of BMP-9 in serum was elevated in myeloma patients (median 176 pg/ml, range 8–809) compared with healthy controls (median 110 pg/ml, range 8–359). BMP-9 was also present in the bone marrow and was able to induce apoptosis in 4 out of 11 primary myeloma cell samples by signaling through ALK2. BMP-9-induced apoptosis in myeloma cells was associated with c-MYC downregulation. The effects of BMP-9 were counteracted by membrane-bound (CD105) or soluble endoglin present in the bone marrow microenvironment, suggesting a mechanism for how myeloma cells can evade the tumor suppressing activity of BMP-9 in multiple myeloma.

BRAF V600E mutation in early-stage multiple myeloma: good response to broad acting drugs and no relation to prognosis.

In this study, we analyzed the prevalence and clone size of BRAF V600E mutation in 209 patients with multiple myeloma and related the results to clinical phenotype, response and survival. Biopsies were screened for BRAF V600E by allele-specific real-time PCR (AS-PCR). Positive results were confirmed by immunohistochemistry, Sanger sequencing and, in three patients from whom we had stored purified myeloma cells, whole-exome sequencing. Eleven patients (5.3%) were BRAF V600E mutation positive by AS-PCR and at least one other method. The fraction of mutated cells varied from 4 to 100%. BRAF V600E-positive patients had no characteristic clinical phenotype except for significantly higher levels of serum creatinine (125 versus 86 μmol/l) Seven of eleven patients responded with at least very good partial response to alkylators, immunomodulatory agents or proteasome inhibitors. Progression-free and overall survival were similar in patients with and without the mutation. By this integrated approach, we found that patients with BRAF V600E mutation responded very well to broad acting drugs and there was no relation to prognosis in early-stage myeloma. In particular, a large mutated cell fraction did not correlate with aggressive disease.

Soluble c-Met in serum of patients with multiple myeloma: correlation with clinical parameters

Objectives: The receptor tyrosine kinase c‐Met and its ligand, hepatocyte growth factor (HGF), play key roles in tumour genesis and metastasis and contribute in multiple myeloma pathogenesis. Substantial data support that a soluble extracellular fragment of c‐Met may function as a decoy receptor that downregulates the biological effects of HGF and c‐Met. We examined serum levels of soluble c‐Met in patients with myeloma and healthy individuals and investigated a possible relationship with clinical disease parameters and survival. Methods: The concentration of c‐Met and HGF was measured by enzyme‐linked immunosorbent assay in serum (n = 49) and bone marrow plasma (n = 16) from patients with multiple myeloma and in serum from healthy controls (n = 26). Results: The median serum concentration of soluble c‐Met was 186 ng/mL (range 22–562) in patients with multiple myeloma and 189 ng/mL (range 124–397) in healthy individuals. There was a significant negative correlation between serum c‐Met levels and disease stage, bone marrow plasma cell percentage and serum concentration of M‐protein. Conclusion: We have for the first time examined the concentration of soluble c‐Met in serum from patients with myeloma and found equal median levels in patients with myeloma as a group and healthy individuals. Still, serum levels of soluble c‐Met correlated negatively with parameters of disease burden in patients with myeloma. We suggest that a possible role for the c‐Met ectodomain as a negative regulator of HGF/c‐Met activity should be examined in multiple myeloma.

Proteasome inhibitors and IMiDs can overcome some high-risk cytogenetics in multiple myeloma but not gain 1q21.

Chromosomal aberrations have significant prognostic importance in multiple myeloma (MM). However, proteasome inhibitors (PI) and IMiDs may partly overcome the poor prognostic impact of some of them. In this study, we investigated a population‐based consecutive cohort newly diagnosed patients with MM admitted during a defined time period to hospitals in Denmark, Norway, and Sweden. The impact of treatment modality on the prognostic importance of specific chromosomal aberration was investigated, with special reference to gain 1q21. The median follow‐up of patients still alive at analysis was 40 months for the high‐dose (HDT)‐treated ones and 29 months for the whole population. Three hundred forty‐seven patients with a known 1q21 status were included in this study. The 347 patients were divided into three groups, that is, 119 patients with the 1q21 gain, 105 patients with other aberrations (OA), that is, del(13q), del(17p), t(4,14), and/or (14;16), and 123 patients with no aberrations (NA). The groups were compared in terms of overall survival (OS), time to progression (TTP), and response. The 3‐yr OS for patients with gain 1q21 was 60% compared to patients with OA 74% and NO 82% (gain 1q21 vs. NO P < 0.001; gain 1q21 vs. OA P = 0.095). If treated with PI or IMiDs, the 3‐yr OS was 58% for patients with gain 1q21 compared to patients with OA 78% and NO 78%, respectively (P = 0.041, P = 0.140). In HDT patients, the 3‐yr OS was 69% for patients with gain 1q21 compared to patients with OA 84% and NO 88%, respectively (P < 0.008, P = 0.600). Thus, neither HDT nor using PI or IMiDs could overcome the poor prognostic impact of gain 1q21, while these drugs and HDT seemed to improve OS in patients with OA, approaching the survival in NO. Further, gain 1q21 appears to be one of the most important poor prognostic chromosomal aberrations in multiple myeloma with current treatments. Trials using new drugs or allogeneic transplantation are warranted.

Two courses of four weekly infusions of rituximab with or without interferon-α2a: Final results from a randomized phase III study in symptomatic indolent B-cell lymphomas

Patients with advanced CD20 + indolent lymphoma, requiring therapy, were randomized to rituximab (four weekly infusions of 375 mg/m2) or to rituximab combined with 5 weeks of interferon-α2a (IFN-α2a) (3–4.5 MIU daily) as priming. Responding patients were eligible for a second cycle with the same allocated treatment. In total, 156 patients were randomized to rituximab and 157 to rituximab + IFN-α2a. In the intention-to treat (ITT) population, 244 patients (78%) responded to cycle 1. After a second cycle the complete remission/complete remission unconfirmed (CR/CRu) rate was 41% with the combination versus 24% with monotherapy (p = 0.005). The median time to treatment failure (primary endpoint) in ITT patients was 28 vs. 21.5 months, respectively (p = 0.302). After a long median follow-up (61 months), 33% (42% of patients responding to cycle 1) were still failure-free with an overall survival rate of 88% and with no difference between the treatment groups. The trial was registered at ClinicalTrials.gov Identifier: NCT01609010.

Immunohistochemical analysis of hepatocyte growth factor and c-Met in plasma cell disease.

Wader K F, Fagerli U‐M, Børset M, Lydersen S, Hov H, Sundan A, Bofin A & Waage A 
(2012) Histopathology60,443–451 
Immunohistochemical analysis of hepatocyte growth factor and c‐Met in plasma cell disease

Ibrutinib, lenalidomide, and rituximab in relapsed or refractory mantle cell lymphoma (PHILEMON): a multicentre, open-label, single-arm, phase 2 trial

BACKGROUND Regimens based on ibrutinib alone and lenalidomide and rituximab in combination show high activity in patients with relapsed or refractory mantle cell lymphoma. We hypothesised that the combination of all three drugs would improve efficacy compared with previously published data on either regimen alone. METHODS In this multicentre, open-label, single-arm, phase 2 trial, we enrolled patients aged 18 years or older with relapsed or refractory mantle cell lymphoma who had previously been treated with at least one rituximab-containing regimen, an Eastern Cooperative Oncology Group performance status score of 0-3, and at least one site of measurable disease, and who met criteria for several laboratory-assessed parameters. Treatment was divided into an induction phase of 12 cycles of 28 days with all three drugs and a maintenance phase with ibrutinib and rituximab only (cycle duration 56 days), given until disease progression or unacceptable toxicity. In the induction phase, patients received intravenous (375 mg/m2) or subcutaneous (1400 mg) rituximab once a week during cycle 1 and then once every 8 weeks. Oral ibrutinib (560 mg once a day) was given to patients every day in the cycle, whereas oral lenalidomide (15 mg once a day) was given on days 1-21. The primary endpoint was overall response assessed in the intention-to-treat population according to Lugano criteria. Safety analysis included all patients who received the treatment, irrespective of eligibility or duration of treatment. The trial is ongoing, but is no longer accruing patients, and is registered with ClinicalTrials.gov, number NCT02460276. FINDINGS Between April 30, 2015, and June 1, 2016, we enrolled 50 patients with relapsed or refractory mantle cell lymphoma at ten centres in Sweden, Finland, Norway, and Denmark. At a median follow-up of 17·8 months (IQR 14·7-20·9), 38 (76%, 95% CI 63-86) patients had an overall response, including 28 (56%, 42-69) patients who had a complete response and ten (20%, 11-33) who had a partial response. The most common grade 3-4 adverse events were neutropenia (in 19 [38%] of 50 patients), infections (in 11 [22%] patients), and cutaneous toxicity (in seven [14%] patients). There were three treatment-related deaths during the study, two due to sepsis and one due to embolic stroke. INTERPRETATION Our results provide preliminary evidence that the triplet combination of ibrutinib, lenalidomide, and rituximab is an active regimen in patients with relapsed or refractory mantle cell lymphoma, and should be evaluated in a prospective randomised controlled trial. FUNDING Janssen and Celgene.

Chemotherapy-Free Initial Treatment of Advanced Indolent Lymphoma Has Durable Effect With Low Toxicity: Results From Two Nordic Lymphoma Group Trials With More Than 10 Years of Follow-Up

PURPOSE For indolent lymphoma, the optimal timing, sequence, and choice of therapeutic regimens remain a matter of debate. In two Nordic Lymphoma Group randomized trials, symptomatic or clearly progressing patients were treated first line with a rituximab-containing regimen without chemotherapy. The purpose of this study was to assess long-term survival, risk of transformation, and need of new therapies. METHODS Data were collected at cross-sectional follow-up for 321 patients with indolent lymphoma (84% with follicular lymphomas [FL]) included in one of two Nordic Lymphoma Group trials (accrual 1998 to 1999 and 2002 to 2008). All patients received first-line therapy with one or two cycles of four weekly infusions of rituximab 375 mg/m2, and 148 were randomly allocated to the addition of interferon alfa-2a. Follow-up data were retrieved from initial trial databases and medical records on repeated clinical evaluations. RESULTS At the end of follow-up, 73% of patients were alive, with a median follow-up after random assignment of 10.6 years. Among all, 36% (38% with FL) had never needed chemotherapy. For patients with FL who required new therapy within 24 months because of early disease progression, the 10-year survival rate was 59% versus 81% for those with longer remission. Interferon was not shown to improve long-term outcome. Transformation was diagnosed in 20% of all patients (2.4% per person-year) and in 18% with FL. An additional malignancy was found in 12%. CONCLUSION Approximately one third of patients with symptomatic indolent lymphoma (30% with FL, 23% without FL) did not need new therapy in the long term after first-line rituximab without chemotherapy. In the entire cohort, 10-year survival was excellent with no major safety issues, which suggests that chemotherapy can be delayed safely in the majority of patients.