Clarithromycin (Biaxin)-lenalidomide-low-dose dexamethasone (BiRd) versus lenalidomide-low-dose dexamethasone (Rd) for newly diagnosed myeloma

Lenalidomide‐induced autoimmune enteropathy complicating treatment of multiple myeloma with concurrent systemic mastocytosis

Lenalidomide is an IMiD drug which has been associated with a variety of potential immune related complications. We describe the case of a patient with newly diagnosed multiple myeloma along with a history of systemic mastocytosis who developed evidence of an autoimmune enteropathy shortly after initiating lenalidomide based therapy.

Lenalidomide and dexamethasone with or without clarithromycin in patients with multiple myeloma ineligible for autologous transplant: a randomized trial

Although case-control analyses have suggested an additive value with the association of clarithromycin to continuous lenalidomide and dexamethasone (Rd), there are not phase III trials confirming these results. In this phase III trial, 286 patients with MM ineligible for ASCT received Rd with or without clarithromycin until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). With a median follow-up of 19 months (range, 0–54), no significant differences in the median PFS were observed between the two arms (C-Rd 23 months, Rd 29 months; HR 0.783, p = 0.14), despite a higher rate of complete response (CR) or better in the C-Rd group (22.6% vs 14.4%, p = 0.048). The most common G3–4 adverse events were neutropenia [12% vs 19%] and infections [30% vs 25%], similar between the two arms; however, the percentage of toxic deaths was higher in the C-Rd group (36/50 [72%] vs 22/40 [55%], p = 0.09). The addition of clarithromycin to Rd in untreated transplant ineligible MM patients does not improve PFS despite increasing the ≥CR rate due to the higher number of toxic deaths in the C-Rd arm. Side effects related to overexposure to steroids due to its delayed clearance induced by clarithromycin in this elderly population could explain these results. The trial was registered in clinicaltrials.gov with the name GEM-CLARIDEX: Ld vs BiRd and with the following identifier NCT02575144. The full trial protocol can be accessed from ClinicalTrials.gov. This study received financial support from BMS/Celgene.

Drug Repositioning for the Treatment of Hematologic Disease: Limits, Challenges and Future Perspectives

Drug repositioning is a strategy to identify new uses for approved or investigational drugs that are used off-label outside the scope of the original medical indication. In this review, we report the most relevant studies about drug repositioning in hematology, reporting the signalling pathways and molecular targets of these drugs, and describing the biological mechanisms which are responsible for their anticancer effects. Although the majority of studies on drug repositioning in hematology concern acute myeloid leukemia and multiple myeloma, numerous studies are present in the literature on the possibility of using these drugs also in other hematological diseases, such as acute lymphoblastic leukemia, chronic myeloid leukemia, and lymphomas. Numerous anti-infectious drugs and chemical entities used for the therapy of neurological or endocrine diseases, oral antidiabetics, statins and medications used to treat high blood pressure and heart failure, bisphosphonate and natural substance such as artemisin and curcumin, have found a place in the treatment of hematological diseases. Moreover, several molecules drastically reversed the resistance of the tumor cells to the chemotherapeutic drugs both in vitro and in vivo.

Possible mechanisms of action of clarithromycin and its clinical application as a repurposing drug for treating multiple myeloma

Clarithromycin (CAM), a semisynthetic macrolide antibiotic, is a widely used antibacterial drug. Recently, the efficacy of CAM as an add-on drug for treating multiple myeloma (MM) has been noted. Its effect on treating MM has been confirmed in combination chemotherapies that include CAM. However, a single treatment of CAM has no efficacy for treating MM. Many myeloma growth factors (MGFs) including interleukin (IL)-6 are known to be closely involved in the development of MM. CAM has been shown to suppress many MGFs, particularly IL-6. The possible mechanisms of action of CAM in treating MM have been suggested to include its immunomodulatory effect, autophagy inhibition, reversibility of drug resistance, steroid-sparing/enhancing effect and suppression of MGFs. In addition, MM is characterised by uncontrolled cell growth of monoclonal immunoglobulin (Ig)-producing neoplastic plasma cells. Large quantities of unfolded or misfolded Ig production may trigger considerable endoplasmic reticulum stress. Thus, MM is originally a fragile neoplasm particularly susceptible to autophagy-, proteasome- and histone deacetylase 6-inhibitors. Taken together, CAM plays an important role in MM treatments through its synergistic mechanisms. In addition, CAM with its pleiotropic effects on cytokines including IL-6 and indirect antiviral effects might be worth a try for treating COVID-19.

Phase 2 study of clarithromycin, pomalidomide, and dexamethasone in relapsed or refractory multiple myeloma

The addition of clarithromycin enhances the efficacy of lenalidomide plus dexamethasone in treatment-naive multiple myeloma (MM). We conducted a phase 2 trial to evaluate the safety and efficacy of clarithromycin, pomalidomide, and dexamethasone (ClaPd) in relapsed or refractory multiple myeloma (RRMM) with prior lenalidomide exposure. One hundred twenty patients with a median of 5 prior lines of therapy received clarithromycin 500 mg orally twice daily, pomalidomide 4 mg orally on days 1 to 21, and dexamethasone 40 mg orally on days 1, 8, 15, and 22 of a 28-day cycle. The overall response rate (ORR) was 60% with 23% achieving at least a very good partial response. There was no statistical difference in response rates for patients who were refractory to lenalidomide (ORR, 58%), bortezomib (ORR, 55%), or both lenalidomide and bortezomib (ORR, 54%). Median progression-free survival (PFS) for the cohort was 7.7 months and median overall survival (OS) was 19.2 months. A history of dual-refractoriness to lenalidomide and bortezomib did not significantly impact either PFS or OS. The most common toxicities were neutropenia (83%), lymphopenia (74%), and thrombocytopenia (71%). The most common grade ≥3 toxicities included neutropenia (58%), thrombocytopenia (31%), and anemia (28%). ClaPd is an effective combination in RRMM with response and survival outcomes that are independent of lenalidomide- or bortezomib-refractory status. Toxicities are manageable with low rates of nonhematologic or high-grade events. ClaPd is a convenient, all-oral option in RRMM with comparable efficacy to other highly active, 3-drug, pomalidomide-based combinations. This trial was registered at www.clinicaltrials.gov as #NCT01159574.

A randomized placebo-controlled phase II study of clarithromycin or placebo combined with VCD induction therapy prior to high-dose melphalan with stem cell support in patients with newly diagnosed multiple myeloma

Background

The objective of this randomized placebo-controlled study was to investigate the efficacy and safety of clarithromycin in combination with bortezomib-cyclophosphamide-dexamethasone (VCD) in patients with newly diagnosed multiple myeloma eligible for high-dose therapy.

Methods

Patients were randomized to receive tablet clarithromycin 500 mg or matching placebo tablet twice daily during the first 3 cycles of VCD induction therapy. Primary endpoint was to compare the rate of very good partial response (VGPR) or better response after three cycles of VCD combined with clarithromycin or placebo.

Results

The study was prematurely stopped for safety reasons after the inclusion of 58 patients (36% of the planned study population). The patients were randomly assigned to clarithromycin (n = 27) or placebo (n = 31). VGPR or better response after the VCD induction therapy was obtained in 12 patients (44.4%, 95% CI 25.5-64.7) and in 16 patients (51.6%, 33.1-69.8) (p = 0.59) in the clarithromycin group and the placebo group, respectively. Seven patients (25.9%) in the clarithromycin group developed severe gastrointestinal complications (≥ grade 3) comprising pain, neutropenic enterocolitis, paralytic ileus or peptic ulcer. These complications occurred in only one patient in the placebo group. Septicemia with Gram negative bacteria was observed in 5 patients in the clarithromycin group in contrast to one case of pneumococcal septicemia in the placebo group. Patient-reported QoL were negatively affected in the clarithromycin group compared to the placebo group.

Conclusion

The study was prematurely stopped due to serious adverse events, in particular serious gastrointestinal complications and septicemia. The response data do not suggest any effect of clarithromycin when added to the VCD regimen. The combination of clarithromycin and bortezomib containing regimens is toxic and do not seem to offer extra anti-myeloma efficacy.Trial registration EudraCT (no. 2014-002187-32, registered 7 October 2014, https://www.clinicaltrialsregister.eu/ctr-search/trial/2014-002187-32/DK) and ClinicalTrials.gov (no NCT02573935, retrospectively registered 12 October 2015, https://www.clinicaltrials.gov/ct2/show/NCT02573935?term=Gregersen&cntry=DK&rank=9).

Glucocorticoids in multiple myeloma: past, present, and future

Glucocorticoids are a backbone of treatment for multiple myeloma in both the upfront and relapsed/refractory setting. While glucocorticoids have single agent activity in multiple myeloma, in the modern era, they are paired with novel agents to induce high clinical response rates. On the other hand, toxicities of steroid therapy limit high dose delivery and impact patient quality of life. We provide a history of steroid use in multiple myeloma with the aim to understand how steroids have emerged and persisted in the treatment of multiple myeloma. We review mechanisms of glucocorticoid sensitivity and resistance and highlight potential future directions to evaluate steroid responsiveness. Further research in this area will aid in optimizing steroid utilization and help determine when glucocorticoid therapy may no longer benefit patients.

Roxithromycin monotherapy inducing a partial response in a patient with myeloma: a case report

Background

Clarithromycin is an efficacious treatment for myeloma in combination with other anti-myeloma therapy but not as monotherapy. To date, all studies have focused on a clarithromycin-specific effect rather than a class effect (macrolide) and there is no information on the activity of roxithromycin in myeloma.

Case presentation

Here we report an untreated 86-year-old New Zealand European white man with IgA myeloma whose paraprotein decreased by 57%, consistent with a partial response, after a course of roxithromycin for pneumonia. His paraprotein reduced from 46 to 20 g/L while his hemoglobin improved from 97 to 123 g/L after 1 month.

Conclusion

Additional investigations should be considered to elucidate the therapeutic effect of roxithromycin in myeloma.

A novel combination of bortezomib, lenalidomide, and clarithromycin produced stringent complete response in refractory multiple myeloma complicated with diabetes mellitus - clinical significance and possible mechanisms: a case report

BACKGROUND

In general, dexamethasone is a required component drug in various combination chemotherapies for treating multiple myeloma, and its efficacy has been widely recognized. However, administration of dexamethasone is known to cause various adverse effects including hyperglycemia which requires insulin therapy. During the course of treatment, we developed a novel effective dexamethasone-free combination regimen and evaluated it for its effect in multiple myeloma.

CASE PRESENTATION

We report a case of 68-year-old Japanese woman with refractory advanced Bence-Jones-λ type multiple myeloma associated with diabetes mellitus. Various combination regimens were carried out, but the response to some regimens was insufficient or others containing dexamethasone, although effective, were inappropriate to continue due to aggravation of diabetes mellitus. Thus, we developed a dexamethasone-free, short dosing-period regimen consisting of bortezomib, lenalidomide, and clarithromycin. This regimen was found to be highly effective and succeeded in achieving stringent complete response.

CONCLUSIONS

The successful dexamethasone-free regimen clearly shows that dexamethasone is not a requisite component in treating multiple myeloma, and it can be substituted with clarithromycin. This regimen is particularly useful for treating patients with multiple myeloma associated with diabetes mellitus.

Effects of Strong CYP3A Inhibition and Induction on the Pharmacokinetics of Ixazomib, an Oral Proteasome Inhibitor: Results of Drug-Drug Interaction Studies in Patients With Advanced Solid Tumors or Lymphoma and a Physiologically Based Pharmacokinetic Analysis

At clinically relevant ixazomib concentrations, in vitro studies demonstrated that no specific cytochrome P450 (CYP) enzyme predominantly contributes to ixazomib metabolism. However, at higher than clinical concentrations, ixazomib was metabolized by multiple CYP isoforms, with the estimated relative contribution being highest for CYP3A at 42%. This multiarm phase 1 study (Clinicaltrials.gov identifier: NCT01454076) investigated the effect of the strong CYP3A inhibitors ketoconazole and clarithromycin and the strong CYP3A inducer rifampin on the pharmacokinetics of ixazomib. Eighty-eight patients were enrolled across the 3 drug-drug interaction studies; the ixazomib toxicity profile was consistent with previous studies. Ketoconazole and clarithromycin had no clinically meaningful effects on the pharmacokinetics of ixazomib. The geometric least-squares mean area under the plasma concentration-time curve from 0 to 264 hours postdose ratio (90%CI) with vs without ketoconazole coadministration was 1.09 (0.91-1.31) and was 1.11 (0.86-1.43) with vs without clarithromycin coadministration. Reduced plasma exposures of ixazomib were observed following coadministration with rifampin. Ixazomib area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration was reduced by 74% (geometric least-squares mean ratio of 0.26 [90%CI 0.18-0.37]), and maximum observed plasma concentration was reduced by 54% (geometric least-squares mean ratio of 0.46 [90%CI 0.29-0.73]) in the presence of rifampin. The clinical drug-drug interaction study results were reconciled well by a physiologically based pharmacokinetic model that incorporated a minor contribution of CYP3A to overall ixazomib clearance and quantitatively considered the strength of induction of CYP3A and intestinal P-glycoprotein by rifampin. On the basis of these study results, the ixazomib prescribing information recommends that patients should avoid concomitant administration of strong CYP3A inducers with ixazomib.

Results from Two Consecutive Studies of Consolidation Therapy after Autologous Transplant for Multiple Myeloma: Thalidomide, Dexamethasone, and Clarithromycin or Lenalidomide, Dexamethasone, and Clarithromycin

BACKGROUND

In multiple myeloma (MM), relapse is a problem after autologous hematopoietic stem cell transplantation (ASCT). In the nontransplant setting, thalidomide/dexamethasone/clarithromycin (BLT-D) and lenalidomide/dexamethasone/clarithromycin (BiRd) achieve responses with acceptable toxicity. Both regimens are reasonable objects of study in the post-ASCT setting.

PATIENTS AND METHODS

We report on BLT-D and BiRd given post-ASCT. Studies were conducted consecutively. After recovery from ASCT, therapy was started. All 3 drugs were given for 1 year, and then immunomodulatory drugs alone were given as long as tolerated or until disease progression.

RESULTS

For BLT-D, the most common toxicity was peripheral neuropathy (PN). For BiRd, infection, PN, and neutropenia were the most common adverse events. BiRd was associated with a higher frequency of secondary cancers. The median follow-up for BLT-D was 10.2 years (range 8.6-10.7) and for BiRd it was 7.5 years (range 6.4-8.4). After BLT-D, 18 patients (67%) were alive and 10 (37%) were alive without disease progression, and after BiRd, 18 patients (58%) were alive and 10 (32%) were alive without disease progression.

CONCLUSIONS

BLT-D and BiRd can be given post-ASCT with different toxicity profiles and comparable disease-free and overall survival rates. A randomized study comparing these regimens to single-agent lenalidomide is needed to determine which approach is superior. Key Message: Relapse of MM is a major problem after ASCT. Strategies are needed post-ASCT to improve outcomes. In the nontransplant setting, thalidomide or lenalidomide/dexamethasone/clarithromycin treat MM with acceptable toxicity. We, thus, studied both regimens post- ASCT. They can be given with different toxicity profiles and result in good disease control.

Progressive refractory light chain amyloidosis and multiple myeloma patients are responsive to the addition of clarithromycin to IMiD based therapy

Multiple myeloma (MM) and primary systemic light chain amyloidosis (AL) are both chronic plasma cell dyscrasias with different clinical expression but limited treatment options for relapsed refractory disease. We report the effect of the addition of clarithromycin on 31 MM and 17 AL with relapsed or refractory disease who had an insufficient response or disease progression while on an IMiD based therapy. In this high risk population, hematological response was reported in 48% of MM patients and 94% of AL patients. Responses were reported early in both groups (median 35 days) and were more sustained in AL patients. Adverse events were common and included mostly grade 1-2 fatigue, infections and abdominal discomfort. Cytopenias were common and cardiac complications were rare in both MM and AL patients. Clarithromycin-IMiD combination therapy appears to be both effective and safe in progressive MM and primarily in AL patients, although a prospective clinical trial is warranted to validate these results. Am. J. Hematol. 92:131-135, 2017. © 2016 Wiley Periodicals, Inc.

Human bone marrow niche chemoprotection mediated by cytochrome P450 enzymes

Substantial evidence now demonstrates that interactions between the tumor microenvironment and malignant cells are a critical component of clinical drug resistance. However, the mechanisms responsible for microenvironment-mediated chemoprotection remain unclear. We showed that bone marrow (BM) stromal cytochrome P450 (CYP)26 enzymes protect normal hematopoietic stem cells (HSCs) from the pro-differentiation effects of retinoic acid. Here, we investigated if stromal expression of CYPs is a general mechanism of chemoprotection. We found that similar to human hepatocytes, human BM-derived stromal cells expressed a variety of drug-metabolizing enzymes. CYP3A4, the liver's major drug-metabolizing enzyme, was at least partially responsible for BM stroma's ability to protect multiple myeloma (MM) and leukemia cells from bortezomib and etoposide, respectively, both in vitro and in vivo. Moreover, clarithromycin overcame stromal-mediated MM resistance to dexamethasone, suggesting that CYP3A4 inhibition plays a role in its ability to augment the activity of lenalidomide and dexamethasone as part of the BiRd regimen. We uncovered a novel mechanism of microenvironment-mediated drug resistance, whereby the BM niche creates a sanctuary site from drugs. Targeting these sanctuaries holds promise for eliminating minimal residual tumor and improving cancer outcomes.

Clarithromycin Synergistically Enhances Thalidomide Cytotoxicity in Myeloma Cells

Clarithromycin (CAM) is a macrolide antibiotic that is widely used in the treatment of respiratory tract infections, sexually transmitted diseases and infections caused by the Helicobacter pylori and Mycobacterium avium complex. Recent studies showed that CAM was highly effective against multiple myeloma (MM) when used in combination with immunomodulatory drugs and dexamethasone. However, the related mechanism is still unknown. As 3 immunomodulatory agents are all effective in the respective regimen, we postulated that CAM might enhance the effect of immunomodulatory drugs. We evaluated the interaction effects of CAM and thalidomide on myeloma cells. Taking into consideration that thalidomide did not affect the proliferation of myeloma cells in vitro, we cocultured myeloma cells with peripheral blood monocytes and evaluated the effects of CAM and thalidomide on the cocultured cell model. Data showed that thalidomide and CAM synergistically inhibited the proliferation of the cells. On this same model, we also found that thalidomide and CAM synergistically decreased the secretion of tumor necrosis factor-α and interleukin-6. This might be caused by the effect of the 2 drugs on inhibiting the activation of ERK1/2 and AKT. These data suggest that the efficacy of CAM against MM was partly due to its synergistic action with the immunomodulatory agents.

Front-line lenalidomide therapy in patients with newly diagnosed multiple myeloma

The availability of novel drugs with different and innovative mechanisms of action such as proteasome inhibitors such as bortezomib and immunomdulatory agents as thalidomide and lenalidomide have changed the landscape of the treatment of patients with newly diagnosed multiple myeloma, allowing the development of several new therapeutic regimens both for transplant-eligible and -ineligible patients. Among these new agents, lenalidomide has become one of the most commonly used in these patients. In this article, we review the current state-of-the-art of different induction and maintenance lenalidomide-containing regimens administered in transplant-eligible and -ineligible patients with newly diagnosed multiple myeloma. We also discuss the safety profile and potential long-term side effects of this drug and analyze its utility in certain subgroups of patients like those with high-risk disease or different degrees of renal impairment.

Repurposing Drugs in Oncology (ReDO)-clarithromycin as an anti-cancer agent

Clarithromycin (CAM) is a well-known macrolide antibiotic available as a generic drug. CAM is traditionally used for many types of bacterial infections, treatment of Lyme disease and eradication of gastric infection with Helicobacter pylori. Extensive preclinical and clinical data demonstrate a potential role for CAM to treat various tumours in combination with conventional treatment. The mechanisms of action underlying the anti-tumour activity of CAM are multiple and include prolonged reduction of pro-inflammatory cytokines, autophagy inhibition, and anti-angiogenesis. Here, we present an overview of the current preclinical (in vitro and in vivo) and clinical evidence supporting the role of CAM in cancer. Overall these findings justify further research with CAM in many tumour types, with multiple myeloma, lymphoma, chronic myeloid leukaemia (CML), and lung cancer having the highest level of evidence. Finally, a series of proposals are being made to further investigate the use of CAM in clinical trials which offer the greatest prospect of clinical benefit to patients.

Ectopic microRNA-150-5p transcription sensitizes glucocorticoid therapy response in MM1S multiple myeloma cells but fails to overcome hormone therapy resistance in MM1R cells

Glucocorticoids (GCs) selectively trigger cell death in the multiple myeloma cell line MM1S which express NR3C1/Glucocorticoid Receptor (GR) protein, but fail to kill MM1R cells which lack GR protein. Given recent demonstrations of altered microRNA profiles in a diverse range of haematological malignancies and drug resistance, we characterized GC inducible mRNA and microRNA transcription profiles in GC sensitive MM1S as compared to GC resistant MM1R cells. Transcriptome analysis revealed that GCs regulate expression of multiple genes involved in cell cycle control, cell organization, cell death and immunological disease in MM1S cells, which remain unaffected in MM1R cells. With respect to microRNAs, mir-150-5p was identified as the most time persistent GC regulated microRNA, out of 5 QPCR validated microRNAs (mir-26b, mir-125a-5p, mir-146-5p, mir-150-5p, and mir-184), which are GC inducible in MM1S but not in MM1R cells. Functional studies further revealed that ectopic transfection of a synthetic mir-150-5p mimics GR dependent gene expression changes involved in cell death and cell proliferation pathways. Remarkably, despite the gene expression changes observed, overexpression of mir-150-5p in absence of GCs did not trigger significant cytotoxicity in MM1S or MM1R cells. This suggests the requirement of additional steps in GC induced cell death, which can not be mimicked by mir-150-5p overexpression alone. Interestingly, a combination of mir-150-5p transfection with low doses GC in MM1S cells was found to sensitize therapy response, whereas opposite effects could be observed with a mir-150-5p specific antagomir. Although mir-150-5p overexpression did not substantially change GR expression levels, it was found that mir-150-5p evokes GR specific effects through indirect mRNA regulation of GR interacting transcription factors and hormone receptors, GR chaperones, as well as various effectors of unfolded protein stress and chemokine signalling. Altogether GC-inducible mir-150-5p adds another level of regulation to GC specific therapeutic responses in multiple myeloma.

Effect of levofloxacin prophylaxis for prevention of severe infections in multiple myeloma patients receiving bortezomib-containing regimens

Fluoroquinolone is recommended as a prophylactic antibiotic for high-risk patients with profound neutropenia. We previously reported that multiple myeloma (MM) patients who received bortezomib-based regimens were at higher risk of severe infections (30.9%) associated with lymphocytopenia. In the study, we evaluated whether severe infectious complications can be prevented by prophylactic administration of oral levofloxacin in MM patients treated with bortezomib-based regimens. A total of 80 patients received oral levofloxacin 500 mg daily during the median four cycles of treatment. The prophylactic group (n = 80) with levofloxacin showed significantly decreased severe infections compared to a historical control group (n = 139) without levofloxacin prophylaxis during treatment of bortezomib-based regimens (17.5 vs. 30.9%, P = 0.037). In the prophylactic group, two patients (2.5%) died of pneumonia and septic shock. Four patients (5%) stopped levofloxacin due to side effects that consisted of gastrointestinal discomfort (2.5%), itching sense (1.25%), and QTc prolongation (1.25%). In conclusion, prophylaxis with levofloxacin may be effective in the prevention of severe infection in MM patients receiving bortezomib-based regimens. A prospective randomized study is needed to test the prophylactic effect of levofloxacin in MM patients treated with bortezomib-based regimens.

Carfilzomib in multiple myeloma

INTRODUCTION

Advances in drug therapy for multiple myeloma (MM) during the previous decade have improved survival outcomes; however, the disease remains incurable as patients eventually relapse or become refractory to all available therapies. Therefore, there is a clear need for more effective and well-tolerated treatments.

AREAS COVERED

We review preclinical and clinical data regarding the use of carfilzomib , a proteasome inhibitor that is structurally and mechanistically distinct from bortezomib, for the treatment of MM patients. Carfilzomib pharmacokinetics, pharmacodynamics, efficacy, safety and tolerability are summarized, based on Phase I/II trial data.

EXPERT OPINION

Carfilzomib represents a significant advance in the management of relapsed and/or refractory MM patients, including those intolerant or resistant to bortezomib. High response rates have been demonstrated with carfilzomib as a single agent or in combination with alkylating agents, immunomodulators and corticosteroids, even among patients who have failed multiple prior therapies. Carfilzomib also has significant potential in the frontline setting, with encouraging response and survival rates observed for combination regimens. Further evaluation of carfilzomib-containing regimens is ongoing in Phase III trials and investigator-sponsored studies, which include combinations with novel investigational agents. These findings will shape the future role of carfilzomib for MM patients across multiple settings.

Clarithromycin overcomes resistance to lenalidomide and dexamethasone in multiple myeloma

The combination of clarithromycin, lenalidomide and dexamethasone (BiRd) has led to highly durable responses in newly diagnosed myeloma. However, the ability of clarithromycin to overcome resistance to lenalidomide and dexamethasone (Rd) is not known. To study this, we performed a retrospective analysis of 24 patients with myeloma for which clarithromycin was added to Rd at the time of progression on Rd. The median number of prior therapies was 3 (range 1-8). The best response was complete response (CR) in one (4.2%), very good partial response (VGPR) in one (4.2%) and partial response in eight (33.3%) patients. Ten patients, 41.7% (95% CI: 22.1, 63.4), achieved ≥PR. The median time to response was 4.4 months (range 1-13.6 months) and the median duration of response was 6.9 months (range 3-52.2 months). The clinical benefit rate (CR + VGPR + PR + MR) was 45.8% (95% CI 25.6, 67.2). The median progression-free survival was 4 months. Median overall survival was 25 months with a median follow-up of 27.5 months. The regimen was well tolerated and only 2 patients needed a clarithromycin dose reduction. Addition of clarithromycin to Rd can overcome resistance to Rd in a subset of patients and lead to durable clinical responses.

Improvement in daytime sleepiness with clarithromycin in patients with GABA-related hypersomnia: Clinical experience

The macrolide antibiotic clarithromycin can enhance central nervous system excitability, possibly by antagonism of GABA-A receptors. Enhancement of GABA signaling has recently been demonstrated in a significant proportion of patients with central nervous system hypersomnias, so we sought to determine whether clarithromycin might provide symptomatic benefit in these patients. We performed a retrospective review of all patients treated with clarithromycin for hypersomnia, in whom cerebrospinal fluid enhanced GABA-A receptor activity in vitro in excess of controls, excluding those with hypocretin deficiency or definite cataplexy. Subjective reports of benefit and objective measures of psychomotor vigilance were collected to assess clarithromycin's effects. Clinical and demographic characteristics were compared in responders and non-responders. In total, 53 patients (38 women, mean age 35.2 (SD 12.8 years)) were prescribed clarithromycin. Of these, 34 (64%) reported improvement in daytime sleepiness, while 10 (19%) did not tolerate its side effects, and nine (17%) found it tolerable but without symptomatic benefit. In those who reported subjective benefit, objective corroboration of improved vigilance was evident on the psychomotor vigilance task. Twenty patients (38%) elected to continue clarithromycin therapy. Clarithromycin responders were significantly younger than non-responders. Clarithromycin may be useful in the treatment of hypersomnia associated with enhancement of GABA-A receptor function. Further evaluation of this novel therapy is needed.

Salvage therapy of multiple myeloma: the new generation drugs

During the past decade, overall results of treatment of multiple myeloma (MM) have been improved and survival curves are now significantly better with respect to those obtained with historical treatment. These improvements are linked to a deeper knowledge of the biology of disease and to the introduction in clinical practice of drugs with different mechanism of action such as proteasome inhibitors and immunomodulatory drugs (IMiDs). However, MM remains in most cases an incurable disease. For patients who relapse after treatment with novel agents, the prognosis is dismal and new drugs and therapeutic strategies are required for continued disease control. In this review, we summarize new insights in salvage therapy for relapsed/refractory MM as emerging from recent clinical trials exploring the activity of bendamustine, new generation proteasome inhibitors, novel IMiDs, monoclonal antibodies, and drugs interfering with growth pathways.

Thalidomide, clarithromycin, lenalidomide and dexamethasone therapy in newly diagnosed, symptomatic multiple myeloma

We studied T-BiRD (thalidomide [Thalomid(®)], clarithromycin [Biaxin(®)], lenalidomide [Revlimid(®)] and dexamethasone) in symptomatic, newly diagnosed multiple myeloma. In 28-day cycles, patients received dexamethasone 40 mg/day on days 1, 8, 15, 22, clarithromycin 500 mg twice daily on days 1-28; lenalidomide 25 mg/day on days 1-21; and thalidomide 100 mg/day (50 mg/day on days 1-7 of cycle 1 only) on days 1-28. Twenty-six patients received a median of 6 cycles (range 0-41). Overall response rate (ORR) was 80% for the group and 100% in 11 patients who underwent autologous stem cell transplantation as part of first-line therapy. The 4-year overall survival rate was 74.9%, and the median progression-free survival was 35.6 months. Eight patients discontinued due to regimen toxicity. Grade 3 non hematologic toxicity affected 12 patients (46.2%). T-BiRD is a highly active regimen with potential toxicity limitations. ClinicalTrials.gov identifier: NCT00538733.

Preclinical and clinical results with pomalidomide in the treatment of relapsed/refractory multiple myeloma

Despite the evolution of effective frontline treatment strategies, many patients with myeloma inevitably relapse. Treatment can be complicated by the interplay of disease-, treatment-, and patient-related factors. Unfortunately, many patients eventually develop disease that is refractory to lenalidomide and bortezomib and have few treatment options. Pomalidomide is a distinct IMiD agent recently approved in the US and Europe. We review the pomalidomide mechanism of action, summarizing its direct antimyeloma, immunomodulatory, and stromal-support inhibitory activities. We also detail its clinical development, including establishment of the approved dose/schedule, phase 2 and 3 trials in relapsed and refractory patients, and novel pomalidomide-based combinations.

Clarithromycin in rheumatoid arthritis: the addition to methotrexate and low-dose methylprednisolone induces a significant additive value--a 24-month single-blind pilot study

To compare the efficacy of the addition of clarithromycin (CM) to methotrexate (MTX) and methylprednisolone (MP) in active rheumatoid arthritis (RA). 32 patients with RA consecutively randomized.

CONTROL GROUP

sixteen patients treated for 24 months with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily. CM group: sixteen patients treated with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily for 24 months; CM therapy added in the first month (500 mg twice a day for the first 15 days followed by 500 mg a day for the remaining 15 days). Evaluation of the improvement following ACR criteria was performed at months 1 (primary endpoint), 3 and 6. Patients were furthermore observed after 12, 18 and 24 months from the study beginning. At month 1, following ACR70 improvement criteria, we found a significant additive value in CM group (10/16 = 63% vs 4/16 = 25%, p = 0.033--chi-square test). After discontinuation of CM, the difference between groups was anymore evident (month 3: CM group 10/16 = 63% vs control group 9/16 = 56%). At month 24, 7/16 (44%) in control group and 12/16 (75%) in CM group completed the follow-up. The addition of CM to MTX and MP can induce the remission ACR 70 in the majority of RA patients within 4 weeks, while MTX and MP alone need about 3 months to achieve the same result.

Current treatment strategies with lenalidomide in multiple myeloma and future perspectives

Lenalidomide is an immunomodulatory drug derived from thalidomide, developed to maximize its anti-inflammatory and antineoplastic properties while reducing toxicity. Lenalidomide administered orally at 25 mg/d on days 1-21 of 28-day cycles plus dexamethasone is indicated for the treatment of relapsed/refractory multiple myeloma patients, who received at least one prior therapy. In the pivotal MM-009 and MM-010 Phase III registration trials, lenalidomide-dexamethasone, when compared with placebo-dexamethasone, significantly improved response rate (60 vs 20%, respectively), time-to-progression and survival. The most common adverse events included hematologic toxicity and venous thromboembolism. The drug is currently being investigated for the treatment of newly diagnosed myeloma and, in association with chemotherapy drugs (cyclophosphamide and melphalan) or novel agents (bortezomib, carfilzomib and elotuzumab), for the development of highly active combination regimens.

Challenges in multiple myeloma diagnosis and treatment

Although multiple myeloma (MM) remains an incurable disease, the advent of novel treatment paradigms has improved survival outcomes in the past two decades. This includes widespread use of high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT) and the development of the novel agents thalidomide, lenalidomide and bortezomib. The efficacy and tolerability of these novel agents have allowed for the exploration of continuous therapy approaches. Maintenance therapy after HDT-ASCT, for example, may help prolong progression-free survival by providing sustained control of residual disease. Trials are also under way to evaluate lenalidomide in patients with high-risk smoldering MM, with the aim of delaying progression to symptomatic MM. Other research is focusing on improving HDT-ASCT protocols and integrating novel agents, such as bortezomib, as an induction or consolidation therapy. Despite these advances, more effective strategies are needed, particularly for the management of older, less fit patients who are ineligible for HDT-ASCT. Preliminary results on the use of lenalidomide maintenance therapy in elderly patients are encouraging. Taken together, these observations indicate that in this era of novel agents, optimal treatment of MM requires a long-term perspective that focuses on providing sustained disease control while maintaining quality of life.

Macrolide antibiotics block autophagy flux and sensitize to bortezomib via endoplasmic reticulum stress-mediated CHOP induction in myeloma cells

The specific 26S proteasome inhibitor bortezomib (BZ) potently induces autophagy, endoplasmic reticulum (ER) stress and apoptosis in multiple myeloma (MM) cell lines (U266, IM-9 and RPMI8226). The macrolide antibiotics including concanamycin A, erythromycin (EM), clarithromycin (CAM) and azithromycin (AZM) all blocked autophagy flux, as assessed by intracellular accumulation of LC3B-II and p62. Combined treatment of BZ and CAM or AZM enhanced cytotoxicity in MM cell lines, although treatment with either CAM or AZM alone exhibited almost no cytotoxicity. This combination also substantially enhanced aggresome formation, intracellular ubiquitinated proteins and induced the proapoptotic transcription factor CHOP (CADD153). Expression levels of the proapoptotic genes transcriptionally regulated by CHOP (BIM, BAX, DR5 and TRB3) were all enhanced by combined treatment with BZ plus CAM, compared with treatment with each reagent alone. Like the MM cell lines, the CHOP+/+ murine embryonic fibroblast (MEF) cell line exhibited enhanced cytotoxicity and upregulation of CHOP and its transcriptional targets with a combination of BZ and one of the macrolides. In contrast, CHOP-/- MEF cells exhibited resistance against BZ and almost completely canceled enhanced cytotoxicity with a combination of BZ and a macrolide. These data suggest that ER stress-mediated CHOP induction is involved in pronounced cytotoxicity. Simultaneously targeting two major intracellular protein degradation systems such as the ubiquitin-proteasome system by BZ and the autophagy-lysosome system by a macrolide antibiotic enhances ER stress-mediated apoptosis in MM cells. This result suggests the therapeutic possibility of using a macrolide antibiotic with a proteasome inhibitor for MM therapy.

BiRd (clarithromycin, lenalidomide, dexamethasone): an update on long-term lenalidomide therapy in previously untreated patients with multiple myeloma

The combination of clarithromycin, lenalidomide, and dexamethasone (BiRd) was evaluated as therapy for treatment-naive symptomatic multiple myeloma (MM), with overall response at 2 years of 90%. We reviewed the long-term follow-up of initial BiRd therapy. Seventy-two patients were given dexamethasone 40 mg weekly, clarithromycin 500 mg twice daily, and lenalidomide 25 mg daily on days 1 to 21 of a 28-day cycle. After a median follow-up of 6.6 years, overall response rates were 93%, with a very good partial response or better of 68%. Median progression-free survival was 49 months. Evaluation for the development of second primary malignancies (SPMs) was conducted, and no increase in incidence was noted in our cohort of patients who received frontline immunomodulatory therapy. BiRd remains a highly potent and safe regimen for frontline therapy in patients with MM without apparent increase in risk of SPMs. This trial was registered at www.clinicaltrials.gov as #NCT00151203.

Inhibition of autophagy with clarithromycin: a new strategy to enhance sensitivity of CML stem cells to tyrosine kinase inhibitors

Autophagy inhibition has been shown to sensitize tumor cells to cell death induced by tyrosine kinase inhibitors (TKIs). The remarkable responses obtained in seven patients with the combination of clarithromycin and TKIs support the hypothesis that the inhibition of autophagy may make chronic myeloid leukemia cells sensitive to killing by TKIs.

Biological activity of lenalidomide and its underlying therapeutic effects in multiple myeloma

Lenalidomide is a synthetic compound derived by modifying the chemical structure of thalidomide. It belongs to the second generation of immunomodulatory drugs (IMiDs) and possesses pleiotropic properties. Even if lenalidomide has been shown to be active in the treatment of several hematologic malignancies, this review article is mostly focalized on its mode of action in multiple myeloma. The present paper is about the direct and indirect antitumor effects of lenalidomide on malignant plasmacells, bone marrow microenvironment, bone resorption and host's immune response. The molecular mechanisms and targets of lenalidomide remain largely unknown, but recent evidence shows cereblon (CRBN) as a possible mediator of its therapeutical effects.

Lenalidomide in the treatment of young patients with multiple myeloma: from induction to consolidation/maintenance therapy

Multiple myeloma is the second most common hematologic malignancy. It accounts for 20,580 new cancer cases in the USA in 2009, including 11,680 cases in men, 8,900 cases in women, and 10,580 deaths overall. Although the disease remains still incurable, outcomes have improved substantially over recent years thanks to the use of high-dose therapy and the availability of novel agents, such as the immunomodulatory drugs thalidomide and lenalidomide, and the proteasome inhibitor bortezomib. Various trials have shown the advantages linked to the use of novel agents in the transplant and not-transplant settings. In particular, this paper will present an overview of the results achieved with lenalidomide-containing combinations in patients eligible for high-dose therapies, namely, young patients. The advantages obtained should always be outweighed with the toxicity profile associated with the regimen used. Therefore, here, we will also provide a description of the main adverse events associated with lenalidomide and its combination.

The application and biology of immunomodulatory drugs (IMiDs) in cancer

Immunomodulatory drugs (IMiDs) have been used in hematologic malignancies for the last decade. However, the mechanism of action of IMiDs is largely unknown. Here we provide a comprehensive overview of pivotal studies, recent advances in the application of IMiDs in cancer as well as their effects on hematopoietic stem cells including the risk of secondary malignancies. IMiDs have a well-established role as first-line therapy for patients with newly diagnosed and relapsed/refractory multiple myeloma (MM). Variant combinations of IMiDs with other chemotherapy reagents show promising outcomes in MM. Recent concerns on increased rate of secondary cancer in MM patients treated with maintenance lenalidomide were raised. But analysis of maintenance studies showed that the benefit of maintenance outweighs the risk of secondary cancers in MM. IMiDs also show efficacy in myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML), chronic lymphocytic leukemia (CLL), Non-Hodgkin's lymphoma (NHL) and myelofibrosis (MF), but not in solid tumors. The major adverse effects are venous thromboembolism, neuropathy and cytopenias. IMiDs induce expansion and self-renewal of CD34+ hematopoietic progenitors and inhibit lineage maturation/differentiation by affecting critical transcription factors which might contribute to myelosuppression effect of IMiDs.

Lenalidomide before and after Autologous Hematopoietic Stem Cell Transplantation in Multiple Myeloma

Although multiple myeloma remains incurable outside of allogeneic hematopoietic stem cell transplantation, novel agents made available only in the last few decades have nonetheless tremendously improved the landscape of myeloma treatment. Lenalidomide, of the immunomodulatory class of drugs, is one of those novel agents. In the non-transplant and relapsed/refractory settings, lenalidomide clearly benefits patients in terms of virtually all meaningful outcomes including overall survival. Data supporting the usage of lenalidomide as part of treatment approaches incorporating high-dose chemotherapy with autologous stem cell support (ASCT) are less mature as pertains to such long-term outcomes and toxicity, and lenalidomide is not currently approved by regulatory agencies for use in the context of ASCT in either the United States or Europe. That said, relatively preliminary efficacy data describing lenalidomide as a component of ASCT-based treatment approaches to MM are indeed promising, and consequently lenalidomide's role in ASCT-based treatment strategies is growing. In this review we summarize existing data that pertains to lenalidomide in the specific context of ASCT, and we share our thoughts on how our own group applies these data to approach this complex issue clinically.

Oral antibiotic prophylaxis of early infection in multiple myeloma: a URCC/ECOG randomized phase III study

Multiple myeloma (MM) is a malignancy of clonal plasma cells, resulting in an increased production of ineffective immunoglobulins with suppression of non-involved immunoglobulins. Patients with MM are at increased risk of infectious complications, particularly streptococcal and staphylococcal infections. This study evaluated the impact of prophylactic antibiotics on the incidence of serious bacterial infections (SBIs) during the first 2 months of treatment in patients with newly diagnosed MM. Patients with MM receiving initial chemotherapy were randomized on a 1:1:1 basis to daily ciprofloxacin (C; 500 mg twice daily), trimethoprim-sulfamethoxazole (T; DS twice daily) or observation (O) and evaluated for SBI (Eastern Cooperative Oncology Group ≥grade 3) for the first 2 months of treatment. From July 1998 to January 2008, 212 MM patients were randomized to C (n=69), T (n=76) or O (n=67). The incidence of SBI was comparable among groups: C=12.5%, T=6.8% and O=15.9%; P=0.218. Further, any infection during the first 2 months was also comparable (20% vs 23% vs 22%, respectively, P=0.954). We demonstrate that prophylactic antibiotics did not decrease the incidence of SBI (≥grade 3) within the first 2 months of treatment. We conclude that routine use of prophylactic antibiotics should not be mandated for patients receiving induction chemotherapy.

Clarithromycin enhances bortezomib-induced cytotoxicity via endoplasmic reticulum stress-mediated CHOP (GADD153) induction and autophagy in breast cancer cells

The specific 26S proteasome inhibitor, bortezomib (BZ) potently induces apoptosis as well as autophagy in metastatic breast cancer cell lines such as MDA-MB-231 and MDA-MB-468. The combined treatment of clarithromycin (CAM) and BZ significantly enhances cytotoxicity in these cell lines. Although treatment with up to 100 μg/ml CAM alone had little effect on cell growth inhibition, the accumulation of autophagosomes and p62 was observed after treatment with 25 μg/ml CAM. This result indicated that CAM blocked autophagy flux. However, the combined treatment of BZ and CAM resulted in more pronounced autophagy induction, as assessed by increased expression ratios of LC3B-II to LC3B-I and clearance of intracellular p62, than treatment with BZ alone. This combination further enhanced induction of the pro-apoptotic transcription factor CHOP (CADD153) and the chaperone protein GRP78. Knockdown of CHOP by siRNA attenuated the death-promoting effect of BZ in MDA-MB-231 cells. A wild-type murine embryonic fibroblast (MEF) cell line also exhibited enhanced BZ-induced cytotoxicity with the addition of CAM, whereas a Chop knockout MEF cell line completely abolished this enhancement and exhibited resistance to BZ treatment. These data suggest that endoplasmic reticulum (ER)-stress mediated CHOP induction is involved in pronounced cytotoxicity by combining these reagents. Simultaneously targeting two major intracellular protein degradation pathways such as the ubiquitin-proteasome system by BZ and the autophagy-lysosome pathway by CAM may improve the therapeutic outcome in breast cancer patients via ER-stress mediated apoptosis.