Lack of efficacy of clarithromycin in advanced multiple myeloma. Intergroupe Français du Myélome (IFM)

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.

Clarithromycin as the empiric antibiotic therapy for medication-related osteonecrosis of the jaw in multiple myeloma patients

About half of individuals diagnosed with medication-related osteonecrosis of the jaw (MRONJ) are multiple myeloma (MM) patients, and most are treated using antibiotics for long-term courses. The penicillin group is recommended as the empiric drug of choice, and quinolones, metronidazole, clindamycin, doxycycline, and erythromycin as alternatives. This paper suggests the macrolide clarithromycin as the empiric antibiotic therapy of MRONJ in MM patients because of its better pharmacologic properties in comparison to erythromycin, and the beneficial effect of this agent in MM. This empiric antibiotic regimen should be later adjusted according to the response and findings of the microbial cultures.

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.

Inflammatory and Anti-Inflammatory Equilibrium, Proliferative and Antiproliferative Balance: The Role of Cytokines in Multiple Myeloma

Multiple myeloma (MM) is typically exemplified by a desynchronized cytokine system with increased levels of inflammatory cytokines. We focused on the contrast between inflammatory and anti-inflammatory systems by assessing the role of cytokines and their influence on MM. The aim of this review is to summarize the available information to date concerning this equilibrium to provide an overview of the research exploring the roles of serum cytokines in MM. However, the association between MM and inflammatory cytokines appears to be inadequate, and other functions, such as pro-proliferative or antiproliferative effects, can assume the role of cytokines in the genesis and progression of MM. It is possible that inflammation, when guided by cancer-specific Th1 cells, may inhibit tumour onset and progression. In a Th1 microenvironment, proinflammatory cytokines (e.g., IL-6 and IL-1) may contribute to tumour eradication by attracting leucocytes from the circulation and by increasing CD4 ⁺ T cell activity. Hence, caution should be used when considering therapies that target factors with pro- or anti-inflammatory activity. Drugs that may reduce the tumour-suppressive Th1-driven inflammatory immune response should be avoided. A better understanding of the relationship between inflammation and myeloma will ensure more effective therapeutic interventions.

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.

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.

Activity of 129 single-agent drugs in 228 phase I and II clinical trials in multiple myeloma

BACKGROUND

More than 400 preclinical studies report ≥ 1 compound as cytotoxic to multiple myeloma (MM) cells; however, few of these agents became relevant in the clinic. Thus, the utility of such assays in predicting future clinical value is debatable.

PATIENTS AND METHODS

We examined the application of early-phase trial experiences to predict future clinical adoption. We identified 129 drugs explored as single agents in 228 trials involving 7421 patients between 1961 and 2013.

RESULTS

All drugs in common use in MM (melphalan, dexamethasone, prednisone, cyclophosphamide, bendamustine, thalidomide, lenalidomide, pomalidomide, bortezomib, carfilzomib, and doxorubicin) demonstrated a best reported response rate of ≥ 22%. Older agents, including teniposide, fotemustine, paclitaxel, and interferon, also appear active by this criterion; however, if mean response rates from all reported trials for an agent are considered, then only drugs with a mean response rate of 15% partial response are in clinical use.

CONCLUSION

Our analysis suggests that thresholds of 20% for best or 15% for mean response are highly predictive of future clinical success. Below these thresholds, no drug has yet reached regulatory approval or widespread use in the clinic. Thus, this benchmark provides 1 element of the framework for guiding choice of drugs for late-stage clinical testing.

Clarithromycin with low dose dexamethasone and thalidomide is effective therapy in relapsed/refractory myeloma

A combination of clarithromycin, low dose of thalidomide and low dose dexamethasone was used in a phase II study to treat patients with relapsed and refractory myeloma. Thirty patients received clarithromycin 250 mg twice daily and thalidomide 50 mg at night on an ongoing basis with 4-d pulses of 10 mg dexamethasone given monthly. Eight patients had permitted escalation of thalidomide dosage up to 200 mg daily. The combination was well tolerated and could be given to elderly, infirm and severely cytopenic patients. Response rates were high, with 89% achieving at least 50% reduction in paraprotein and a 96% overall response rate. Although clarithromycin has only minimal anti-myeloma properties when used as a single agent, its combination with thalidomide and dexamethasone appears very effective, allowing these to be used in lower and more tolerable doses with good clinical effects.

BiRD (Biaxin [clarithromycin]/Revlimid [lenalidomide]/dexamethasone) combination therapy results in high complete- and overall-response rates in treatment-naive symptomatic multiple myeloma

This trial determined the safety and efficacy of the combination regimen clarithromycin (Biaxin), lenalidomide (Revlimid), and dexamethasone (BiRD) as first-line therapy for multiple myeloma. Patients received BiRD in 28-day cycles. Dexamethasone (40 mg) was given orally once weekly, clarithromycin (500 mg) was given orally twice daily, and lenalidomide (25 mg) was given orally daily on days 1 to 21. Objective response was defined by standard criteria (ie, decrease in serum monoclonal protein [M-protein] by at least 50%, and a decrease in urine M-protein by at least 90%). Of the 72 patients enrolled, 65 had an objective response (90.3%). A combined stringent and conventional complete response rate of 38.9% was achieved, and 73.6% of the patients achieved at least a 90% decrease in M-protein levels. This regimen did not interfere with hematopoietic stem-cell harvest. Fifty-two patients who did not go on to receive transplants received continued therapy (complete response, 37%; very good partial response, 33%). The major adverse events were thromboembolic events, corticosteroid-related morbidity, and cytopenias. BiRD is an effective regimen with manageable side effects in the treatment of symptomatic, newly diagnosed multiple myeloma. This trial was registered at www.clinicaltrials.gov as #NCT00151203.

Treatment of Waldenstrom's macroglobulinemia with single-agent thalidomide or with the combination of clarithromycin, thalidomide and dexamethasone

To evaluate the activity of thalidomide in Waldenstrom's macroglobulinemia (WM), 20 patients were treated on a dose schedule that escalated from 200 mg/d to 600 mg/d. On an intention-to-treat basis, five (25%) patients achieved a partial response, which was noted within 3 months of treatment. Adverse effects were common and prevented dose escalation of thalidomide in 75% of patients and led to premature discontinuation of treatment in 35%. We subsequently evaluated the oral combination of clarithromycin (500 mg twice per day), low-dose thalidomide (200 mg once daily), and dexamethasone (40 mg once per week). Our preliminary analysis on 12 previously treated patients indicate activity of this regimen in WM: three patients achieved a partial response and two patients demonstrated monoclonal protein reduction of greater than 25%. This combination was associated with a variety of side effects due not only to thalidomide, but also to corticosteroids and to clarithromycin. Our preliminary data indicate that this combination may be a useful salvage regimen for some patients with heavily pretreated macroglobulinemia.