Association of response endpoints with survival outcomes in multiple myeloma

Since the introduction of the proteasome inhibitor bortezomib and the immunomodulatory drugs (IMiDs) thalidomide and lenalidomide, more patients with multiple myeloma are achieving deep, durable responses and disease control, and are living longer. These improvements have afforded more robust analyses of the relationship between response and survival. Generally, these studies have demonstrated that improvements in the quality of response across all stages of treatment are associated with better disease control and longer survival. Thus, achievement of maximal response should be strongly considered, particularly in the frontline setting, but must also be balanced with tolerability, quality of life and patient preferences. In select patients, achievement of a lesser response may be adequate to prolong survival, and attempts to treat these patients to a deeper response may place them at unnecessary risk without significant benefit. Maintenance therapy has been shown to improve the quality of response and disease control and, in some studies, survival. Studies support maintenance therapy for high-risk patients as a standard of care, and there are emerging data supporting maintenance therapy in standard-risk patients to improve progression-free and possibly overall survival. Multidrug regimens combining a proteasome inhibitor and an IMiD have shown exceptional response outcomes with acceptable increases in toxicity in both the frontline and salvage settings, and are becoming a standard treatment approach. Moving forward, the use of immunophenotypic and molecular response criteria will be essential in better understanding the impact of highly active and continuous treatment regimens across myeloma patient populations. Future translational studies will help to develop antimyeloma agents to their fullest potential. The introduction of novel targeted therapies, including the IMiD pomalidomide and the proteasome inhibitors carfilzomib and ixazomib (MLN9708), will provide greater options to individualize treatment and help patients achieve a clinically meaningful response

Lenalidomide and dexamethasone in patients with relapsed multiple myeloma and impaired renal function: PrE1003, a PrECOG study

Renal insufficiency is common in patients with relapsed multiple myeloma and can often limit choice of therapy. Lenalidomide, a critical agent in the treatment of relapsed multiple myeloma, is renally cleared., This phase I/II trial evaluated the efficacy and safety of lenalidomide with dexamethasone in patients with relapsed multiple myeloma and renal insufficiency. Three groups were treated, with creatinine clearance 30–60 cc/hr (group A), CrCl \u3c 30 not on dialysis (group B), and patients on dialysis (group C) at escalating doses of lenalidomide. A total of 63 patients were treated and no DLTs were observed in phase I. All three groups were able to escalate to full dose lenalidomide 25 mg daily 21/28 days, although due to reduced accrual the phase II component was not entirely completed for groups B and C. Adverse events were as expected, including anemia, diarrhea and fatigue. Ten patients experienced grade 3–4 pneumonia. Overall response rate was 54% across all groups. PFS was 7.5 months and OS was 19.7 months. Lenalidomide can be given at full dose 25 mg daily 21/28 in patients with a CrCl \u3e 30, and can be given daily to those with CrCl \u3c 30, even when on dialysis, at doses of at least 15 mg daily

New drugs and novel mechanisms of action in multiple myeloma in 2013: a report from the International Myeloma Working Group (IMWG)

Treatment in medical oncology is gradually shifting from the use of nonspecific chemotherapeutic agents toward an era of novel targeted therapy in which drugs and their combinations target specific aspects of the biology of tumor cells. Multiple myeloma (MM) has become one of the best examples in this regard, reflected in the identification of new pathogenic mechanisms, together with the development of novel drugs that are being explored from the preclinical setting to the early phases of clinical development. We review the biological rationale for the use of the most important new agents for treating MM and summarize their clinical activity in an increasingly busy field. First, we discuss data from already approved and active agents (including second- and third-generation proteasome inhibitors (PIs), immunomodulatory agents and alkylators). Next, we focus on agents with novel mechanisms of action, such as monoclonal antibodies (MoAbs), cell cycle-specific drugs, deacetylase inhibitors, agents acting on the unfolded protein response, signaling transduction pathway inhibitors and kinase inhibitors. Among this plethora of new agents or mechanisms, some are specially promising: anti-CD38 MoAb, such as daratumumab, are the first antibodies with clinical activity as single agents in MM. Moreover, the kinesin spindle protein inhibitor Arry-520 is effective in monotherapy as well as in combination with dexamethasone in heavily pretreated patients. Immunotherapy against MM is also being explored, and probably the most attractive example of this approach is the combination of the anti-CS1 MoAb elotuzumab with lenalidomide and dexamethasone, which has produced exciting results in the relapsed/refractory setting.Peer Reviewe

FGFR3 Activates RSK2 to Mediate Hematopoietic Transformation through Tyrosine Phosphorylation of RSK2 and Activation of the MEK/ERK Pathway

SummaryTo better understand the signaling properties of oncogenic FGFR3, we performed phospho-proteomics studies to identify potential downstream signaling effectors that are tyrosine phosphorylated in hematopoietic cells expressing constitutively activated leukemogenic FGFR3 mutants. We found that FGFR3 directly tyrosine phosphorylates the serine/threonine kinase p90RSK2 at Y529, which consequently regulates RSK2 activation by facilitating inactive ERK binding to RSK2 that is required for ERK-dependent phosphorylation and activation of RSK2. Moreover, inhibition of RSK2 by siRNA or a specific RSK inhibitor fmk effectively induced apoptosis in FGFR3-expressing human t(4;14)-positive myeloma cells. Our findings suggest that FGFR3 mediates hematopoietic transformation by activating RSK2 in a two-step fashion, promoting both the ERK-RSK2 interaction and subsequent phosphorylation of RSK2 by ERK

Combining carfilzomib and panobinostat to treat relapsed/refractory multiple myeloma: results of a Multiple Myeloma Research Consortium Phase I Study

Key points CarPan is a highly active, steroid-sparing regimen, effective in both bortezomib-sensitive and refractory patients.The safety profile of CarPan, particularly thrombocytopenia and gastrointestinal adverse events, compares favorably with that of panobinostat and bortezomib