It's Time to Take Clarithromycin Seriously in Multiple Myeloma

Targeting Reactive Oxygen Species Capacity of Tumor Cells with Repurposed Drug as an Anticancer Therapy

Accumulating evidence shows that elevated levels of reactive oxygen species (ROS) are associated with cancer initiation, growth, and response to therapies. As concentrations increase, ROS influence cancer development in a paradoxical way, either triggering tumorigenesis and supporting the proliferation of cancer cells at moderate levels of ROS or causing cancer cell death at high levels of ROS. Thus, ROS can be considered an attractive target for therapy of cancer and two apparently contradictory but virtually complementary therapeutic strategies for the regulation of ROS to treat cancer. Despite tremendous resources being invested in prevention and treatment for cancer, cancer remains a leading cause of human deaths and brings a heavy burden to humans worldwide. Chemotherapy remains the key treatment for cancer therapy, but it produces harmful side effects. Meanwhile, the process of de novo development of new anticancer drugs generally needs increasing cost, long development cycle, and high risk of failure. The use of ROS-based repurposed drugs may be one of the promising ways to overcome current cancer treatment challenges. In this review, we briefly introduce the source and regulation of ROS and then focus on the status of repurposed drugs based on ROS regulation for cancer therapy and propose the challenges and direction of ROS-mediated cancer treatment.

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.

Successful Clarithromycin Monotherapy in a Patient with Primary Follicular Lymphoma of the Duodenum

Primary follicular lymphoma of the duodenum (FL-D) constitutes a rare subtype of extranodal follicular lymphoma with a usually indolent course. To date, no distinct treatment recommendations have been defined for those patients. We report the case of a 58-year-old male patient presenting with endoscopically assessed, symptomatic FL-D who was treated with clarithromycin monotherapy in analogy to recent data for mucosa-associated lymphoid tissue lymphoma. Each treatment cycle consisted of clarithromycin 500 mg twice daily for 3 weeks followed by a 2-week break. After four cycles of treatment, the patient showed a very good response with normal macroscopic findings confirmed by endosonographic examination and only focal minimal residual disease of lymphoma persisting in the histological assessment. The patient is currently asymptomatic and without treatment for 24+ months. As clarithromycin combines antimicrobial and direct antiproliferative effects mediated through a variety of pleiotropic mechanisms, this appears to be an interesting treatment approach for indolent lymphoma, particularly in those where a chronic infectious background cannot be completely ruled out, i.e., gastrointestinal manifestations. We suggest further investigation of this treatment approach.

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.