Opposite activation of the Hedgehog pathway in CD138+ plasma cells and CD138-CD19+ B cells identifies two subgroups of patients with multiple myeloma and different prognosis

Hyperactivation of the Hedgehog (Hh) pathway, which controls refueling of multiple myeloma (MM) clones, might be critical to disease recurrence. Although several studies suggest the Hh pathway is activated in CD138- immature cells, differentiated CD138+ plasma cells might also be able to self-renew by producing themselves the Hh ligands. We studied the gene expression profiles of 126 newly diagnosed MM patients analyzed in both the CD138+ plasma cell fraction and CD138-CD19+ B-cell compartment. Results demonstrated that an Hh-gene signature was able to cluster patients in two subgroups characterized by the opposite Hh pathway expression in mature plasma cells and their precursors. Strikingly, patients characterized by Hh hyperactivation in plasma cells, but not in their B cells, displayed high genomic instability and an unfavorable outcome in terms of shorter progression-free survival (hazard ratio: 1.92; 95% confidence interval: 1.19-3.07) and overall survival (hazard ratio: 2.61; 95% confidence interval: 1.26-5.38). These results suggest that the mechanisms triggered by the Hh pathway ultimately led to identify a more indolent vs a more aggressive biological and clinical subtype of MM. Therefore, patient stratification according to their molecular background might help the fine-tuning of future clinical and therapeutic studies.

Current and emerging triplet combination therapies for relapsed and refractory multiple myeloma

Despite significant improvement in outcomes have been observed for multiple myeloma (MM) patients over the past 10-15 years, mainly due to the introduction of novel agents targeting the tumor clone and the bone marrow microenvironment, treatment of refractory and/or relapsed (RR) disease remains a challenge, particularly for patients who have failed prior bortezomib- and lenalidomide-based therapies. More recently, new drugs with different mechanisms of action, including second generation proteasome inhibitors, third generation immunomodulatory drugs, histone deacetylase inhibitors and monoclonal antibodies, have been developed and are under investigation, further increasing treatment options for RRMM patients. Overall, novel agent-based triplet combinations demonstrated superior response rates and prolonged disease control when compared with two-drug regimens in several randomized clinical trials, without adding any relevant additional toxicity. Salvage triplet therapies are likely to play a key role in overcoming drug-resistance and hold promise to further improve long-term outcomes of RRMM patients.

Role of consolidation therapy in transplant eligible multiple myeloma patients

The role of high-dose therapy and autologous stem-cell transplantation (ASCT) in the treatment of multiple myeloma (MM) has continued to evolve in recent years. The novel agents thalidomide, bortezomib, and lenalidomide have been successfully incorporated into induction therapy in preparation for ASCT and are currently being investigated also as post-ASCT consolidation and maintenance therapy. Consolidation treatment is generally short term and aims to increase the frequency and depth of response obtained with the previous treatment phases, including novel agent-based induction therapy and ASCT. This review will focus on recent trials of novel agents as post-ASCT consolidation therapy, offering an overview of pros and cons of this new treatment strategy in the ASCT sequence for MM patients.

Neuropathy in multiple myeloma treated with thalidomide: a prospective study

BACKGROUND

Thalidomide is effective as a first-line therapy for the treatment of multiple myeloma (MM), but its use is limited by peripheral neurotoxicity.

OBJECTIVE

To study the occurrence of both myeloma-related neuropathy and thalidomide-induced neuropathy in 31 patients with newly diagnosed MM.

METHODS

Clinical and electrophysiologic examinations were performed in 31 patients with newly diagnosed MM before and after 4 months of therapy with thalidomide (200 mg/day, total dose: 21 g) aimed at debulking MM, before autologous transplantation. After transplantation, the patients took thalidomide, 200 mg/day for another 3 months (total dose over three months: 18 g) and then underwent a final clinical and electrophysiologic checkup.

RESULTS

At baseline, four patients presented a mild sensorimotor peripheral neuropathy related to MM, which tended to worsen slightly during treatment with thalidomide. At the end of treatment, 83% of the patients had clinical and electrophysiologic evidence of a mild sensory rather than motor, axonal, length-dependent polyneuropathy, whereas 100% of the patients showed improvement to the basic pathology (>or=partial response).

CONCLUSIONS

Peripheral neuropathy, sometimes subclinical, and mild in our patients, is a common, early side effect of thalidomide therapy. The high doses (21 g) used in all patients for a relatively short time (4 months) rule out any correlations between neuropathy, total dose, and duration of treatment.