We present the results of a phase 2 study using thalidomide, dexamethasone, and pegylated liposomal doxorubicin (ThaDD) in the treatment of 50 patients older than 65 years with newly diagnosed multiple myeloma. Thalidomide 100 mg was administered orally at bedtime continuously, dexamethasone 40 mg was administered orally on days 1 to 4 and 9 to 12, and pegylated liposomal doxorubicin 40 mg/m² was administered intravenously on day 1 over the 28-day cycle. Response was assessed according to the EBMT criteria. Seventeen (34%) patients achieved CR, 7 (14%) nCR, 5 (10%) VGPR, 15 (30%) PR, and 5 (10%) MR, resulting in an ORR of 98%. Only 1 patient (2%) presented progressive disease. Time to progression (TTP), event-free survival (EFS), and overall survival (OS) projected at 3 years were 60%, 57%, and 74%, respectively, and these parameters were significantly higher in those patients achieving a response of at least VGPR versus those who did not. Grade 3 and 4 nonhematologic adverse events were constipation (10%), fatigue (6%), tremors (4%), mucositis (4%), and palmar-plantar erythrodysesthesia (2%). Grade 3 and 4 neutropenia occurred in 12% of patients. Grade 3 and 4 infections and thromboembolic accidents were observed in 22% and 14% of patients, respectively. In the treatment of elderly patients with newly diagnosed multiple myeloma, ThaDD is a very effective regimen with manageable toxicity.

Antimicrobial peptides play an important role in host defense against pathogens. Recently, phenol-soluble modulins (PSMs) from Staphylococcus epidermidis (S. epidermidis) were shown to interact with lipid membranes, form complexes, and exert antimicrobial activity. Based on the abundance and innocuity of the cutaneous resident S. epidermidis, we hypothesized that their PSMs contribute to host defense. Here we show that S. epidermidis δ-toxin (PSMγ) is normally present in the epidermis and sparsely in the dermis of human skin using immunohistochemistry. Synthetic δ-toxin interacted with neutrophil extracellular traps (NETs) and colocalized with cathelicidin while also inducing NET formation in human neutrophils. In antimicrobial assays against Group A Streptococcus (GAS), δ-toxin cooperated with CRAMP, hBD2, and hBD3. In whole blood, addition of δ-toxin exerted a bacteriostatic effect on GAS, and in NETs, δ-toxin increased their killing capacity against this pathogen. Coimmunoprecipitation and tryptophan spectroscopy demonstrated direct binding of δ-toxin to host antimicrobial peptides LL-37, CRAMP, hBD2, and hBD3. Finally, in a mouse wound model, GAS survival was reduced (along with Mip-2 cytokine levels) when the wounds were pretreated with δ-toxin. Thus, these data suggest that S. epidermidis–derived δ-toxin cooperates with the host-derived antimicrobial peptides in the innate immune system to reduce survival of an important human bacterial pathogen.

Significance: The expression of hypoxia-inducible factor (HIF)-2α in pulmonary endothelium of mice influences pulmonary vascular resistance and development of hypoxic pulmonary hypertension (PH) via an arginase-1–dependent mechanism. The HIF-2α:arginase-1 axis influences the homeostatic regulation of nitric oxide synthesis in the lung. Impaired generation of this vasoactive agent contributes to the initial development and vascular remodeling process of PH.