Treatment of newly diagnosed multiple myeloma: advances in current therapy

CD229 interacts with RASAL3 to activate RAS/ERK pathway in multiple myeloma proliferation

Multiple myeloma (MM) is an incurable plasma cell malignancy, while CAR-T therapy offers a new direction for the treatment of MM. Recently, signaling lymphocytic activation molecule family 3 (CD229), a cell surface immune receptor belonging to the signaling lymphocyte activating molecule family (SLAMF), is emerging as a CAR-T therapeutic target in MM. However, a clear role of CD229 in MM remains elusive. In this study, MM patients with elevated CD229 expression achieved poor prognosis by analyzing MM clinical databases. In addition, CD229 promoted MM cell proliferation in vitro as well as in xenograft mouse model in vivo. Mechanism study revealed that CD229 promoted MM cell proliferation by regulating the RAS/ERK signaling pathway. Further exploration employed co-immunoprecipitation coupled with mass spectrometry to identify RASAL3 as an important downstream protein of CD229. Additionally, we developed a co-culture method combined with the immunofluorescence assay to confirm that intercellular tyrosine phosphorylation mediated self-activation of CD229 to activate RAS/ERK signaling pathway via interacting with RASAL3. Taken together, these findings not only demonstrate the oncogenic role of CD229 in MM cell proliferation, but also illustrate the potential of CD229 as a promising therapeutic target for MM treatment.

Bendamustine, lenalidomide, and dexamethasone (BRD) is highly effective with durable responses in relapsed multiple myeloma

Bendamustine is a multifunctional alkylating agent with single agent activity in myeloma. We designed the current phase 1/2 trial to determine the maximum tolerated doses (MTD) of bendamustine that can be safely combined with lenalidomide and dexamethasone and to assess the safety and efficacy of the combination. Patients with relapsed MM following at least 1 prior therapy, but no more than four lines of prior therapy and with measurable disease were enrolled. Bendamustine 75 mg/m(2) given on days 1 and 2, lenalidomide 25 mg given days 1-21 and dexamethasone 40 mg on days 1, 8, 15, and 22, was the recommended Phase 2 dose. Seventy-one patients were accrued: 21 on Phase 1 and 50 on Phase 2. The median age was 62.3 years; patients had a median of three prior lines of therapy (range 1-4), with over 70% of the patients having received prior lenalidomide, bortezomib, and/or peripheral blood stem cell transplant. Thirty-four of 70 (49%) patients had a confirmed partial response or better, including 20 patients (29%) with a very good partial response or better. An additional 4 patients had a minor response, translating to an overall 55% clinical benefit rate. Grade 3 or higher toxicity was seen in 96% of patients, with ≥grade 3 hematologic in 94% and nonhematologic in 50%. The median progression free survival was 11.8 months and the median duration of response was 23 months. The combination of bendamustine, lenalidomide, and dexamethasone is very effective in relapsed multiple myeloma with high response rates and durable responses

BUB1B promotes multiple myeloma cell proliferation through CDC20/CCNB axis

Multiple myeloma (MM) is the second most common hematopoietic malignancy characterized by plasma cell proliferative disorder. In this study, we disclosed that expression of BUB1B significantly increased in high-risk myeloma patients especially in the most aggressive myeloma genetic subgroups of proliferation. Increased BUB1B expression promotes MM cell proliferation. Mechanism study showed that BUB1B expression was highly correlated to CDC20 and CCNB1/2 expression in MM cells, leading to increased MM cell proliferation. Therefore, BUB1B may be a potential target for MM treatment especially for high-risk MM patients.

Dinaciclib, a novel CDK inhibitor, demonstrates encouraging single-agent activity in patients with relapsed multiple myeloma

Dysregulation of cyclin-dependent kinases is a hallmark of myeloma, and specifically, cdk5 inhibition can enhance the activity of proteasome inhibitors in vitro. Dinaciclib is a novel potent small molecule inhibitor of cyclin-dependent kinases (CDK)1, CDK2, CDK5, and CDK9. Patients with relapsed multiple myeloma and ≤5 prior lines of therapy, with measurable disease, were enrolled. Dinaciclib was administered on day 1 of a 21-day cycle at doses of 30 to 50 mg/m(2). Overall, 27 evaluable patients were accrued; the median number of prior therapies was 4. The dose level of 50 mg/m(2) was determined to be the maximally tolerated dose. The overall confirmed partial response rate (PR) was 3 of 27 (11%), including 1 patient at the 30 mg/m(2) dose (1 very good PR [VGPR]) and 2 patients at the 40 mg/m(2) dose (1 VGPR and 1 PR). In addition, 2 patients at the 50 mg/mg(2) dose achieved a minimal response (clinical benefit rate, 19%). Leukopenia, thrombocytopenia, gastrointestinal symptoms, alopecia, and fatigue were the most common adverse events. The current study demonstrates single agent activity of dinaciclib in relapsed myeloma, with 2 patients achieving a deep response (VGPR) and 10 patients obtaining some degree of M protein stabilization or decrease. This trial was registered at www.clinicaltrials.gov as #NCT01096342.

Fifteen years of single center experience with stem cell transplantation for multiple myeloma: a retrospective analysis

INTRODUCTION

Autologous stem cell transplantation (ASCT) became standard of care for patients with multiple myeloma (MM) under the age of 65 years. We routinely perform ASCT for newly diagnosed MM since 1996 in our department.

PATIENTS AND METHODS

We retrospectively analyzed all 285 transplants in 185 patients done for MM from January 1996 till December 2010. We analyzed overall survival (OS) and progression-free survival (PFS) regarding conditioning, stage, complete or very good partial remission (CR, VGPR) achievement, renal impairment, single vs. double transplant.

RESULTS

Estimated 10-years survival of the whole set of patients is 39% (median survival 95 months). Patients with renal impairment show same OS as those without (p = 0.22). Patients show similar overall survival and event free survival regardless of type of transplant. We observed better outcome in terms of overall survival in patients treated with new drugs (p = 0.0014). Reaching CR or VGPR was not translated into better OS (p = 0.30) and EFS (p = 0.10). Also stage of the disease and whether single or double transplant was used did not make any significant difference in the outcome.

CONCLUSION

Stem cell transplantation greatly improved outcome of patients with MM. Poor outcome of allogeneic transplantation in our group of patients is related to high transplant related mortality (20% vs. 0%) and unexpected high relapse rate. There is a trend towards better survival, when new drugs are incorporated at any time in the course of the disease. This fact supports hypothesis that use of these drugs with ASCT should translate into better long-term outcome.

Referrals for suspected hematologic malignancy: a survey of primary care physicians

Little is known about referrals from primary care providers (PCPs) for suspected hematologic malignancies, including their clinical triggers and frequency. A random sample of 190 Massachusetts PCPs were presented with a vignette concerning a patient with a new finding of moderate anemia, asked how they would respond, and then asked what they would do if the patient returned with persistent anemia plus one additional sign or symptom. We also asked about referral behaviors for suspected hematologic malignancies during the prior year. A total of 134 (70.5%) PCPs responded. At first anemia presentation,only 3.8% reported referring to hematology. The development of a second sign or symptom yielded higher referral rates: pancytopenia 588.7%, leukopenia 5 63.9%, thrombocytopenia 5 63.9%, lymphadenopathy 5 42.9%, leukocytosis 5 37.6%, night sweats 5 25.6%, and weight loss 5 23.3%. The median yearly number (interquartile range) of patients PCPs reported suspecting of having hematologic malignancy was 5 (3, 10), and the median formally referred was 5 (3, 10). We conclude that anemia plus signs and symptoms suggestive of myelodysplasia or leukemia (compared with those suggestive of lymphoma) are more likely to prompt hematology referral. In addition, given their rarity,the numbe