Purpose: To describe the clinical, radiologic, and pathologic features and risk factors for osteonecrosis of the jaw (ONJ) in multiple myeloma (MM) patients. Patients and Methods: A retrospective review of 90 MM patients who had dental assessments, including 22 patients with ONJ. There were 62 men; the median age was 61 years in ONJ patients and 58 years among the rest. Prior MM therapy included thalidomide (n = 67) and stem-cell transplantation (n = 72). Bisphosphonate therapy included zoledronate (n = 34) or pamidronate (n = 17) and pamidronate followed by zoledronate (n = 33). Twenty-seven patients had recent dental extraction, including 12 patients in the ONJ group. Median time from MM diagnosis to ONJ was 8.4 years for the whole group. Results: Patients usually presented with pain. ONJ occurred posterior to the cuspids (n = 20) mostly in the mandible. Debridement and sequestrectomy with primary closure were performed in 14 patients; of these, four patients had major infections and four patients had recurrent ONJ. Bone histology revealed necrosis and osteomyelitis. Microbiology showed actinomycetes (n = 7) and mixed bacteria (n = 9). More than a third of ONJ patients also suffered from long bone fractures (n = 4) and/or avascular necrosis of the hip (n = 4). The variables predictive of developing ONJ were dental extraction (P = .009), treatment with pamidronate/zoledronate (P = .009), longer follow-up time (P = .03), and older age at diagnosis of MM (P = .006). Conclusion: ONJ appears to be time-dependent with higher risk after long-term use of bisphosphonates in older MM patients often after dental extractions. No satisfactory therapy is currently available. Trials addressing the benefits/risks of continuing bisphosphonate therapy are needed.

Data are presented on 81 multiple myeloma (MM) patients with renal failure (creatinine > 176·8 μmol/l) at the time of autologous stem cell transplantation (auto‐SCT), including 38 patients on dialysis. The median age was 53 years (range: 29–69) and 26% had received more than 12 months of prior chemotherapy. CD34⁺ cells were mobilized with granulocyte colony‐stimulating factor (G‐CSF) alone (n = 51) or chemotherapy plus G‐CSF (n = 27), yielding medians of 10 and 16 × 10⁶ CD34⁺ cells/kg respectively (P = 0·003). Sixty patients (27 on dialysis) received melphalan 200 mg/m² (MEL‐200). Because of excessive toxicity, the subsequent 21 patients (11 on dialysis) received MEL 140 mg/m² (MEL‐140). Thirty‐one patients (38%) completed tandem auto‐SCT, including 11 on dialysis. Treatment‐related mortality (TRM) was 6% and 13% after the first and second auto‐SCT. Median times to absolute neutrophil count (ANC) > 0·5 × 10⁹/l and to platelets > 50 × 10⁹/l were 11 and 41 d respectively. Non‐haematological toxicities included mucositis, pneumonitis, dysrhythmias and encephalopathy. At a median follow up of 31 months, 30 patients have died. Complete remission (CR) was achieved in 21 patients (26%) after first SCT and 31 patients (38%) after tandem SCT. Two patients discontinued dialysis after SCT. Median durations of complete remission (CR) and overall survival (OS) have not been reached; probabilities of event‐free survival (EFS) and OS at 3 years were 48% and 55% respectively. Dialysis dependence and MEL dose did not affect EFS or OS. Sensitive disease prior to SCT, normal albumin level and younger age were independent prognostic factors for better OS. In conclusion, renal failure had no impact on the quality of stem cell collections and did not affect engraftment. MEL‐140 had an acceptable toxicity and appeared equally effective as MEL‐200. In the setting of renal failure, the role of auto‐SCT early in the disease course and benefits of tandem SCT require further evaluation.

Purpose: Vorinostat, a histone deacetylase inhibitor, enhances cell death by the proteasome inhibitor bortezomib in vitro. We sought to test the combination clinically. Experimental Design: A phase I trial evaluated sequential dose escalation of bortezomib at 1 to 1.3 mg/m² i.v. on days 1, 4, 8, and 11 and vorinostat at 100 to 500 mg orally daily for 8 days of each 21-day cycle in relapsed/refractory multiple myeloma patients. Vorinostat pharmacokinetics and dynamics were assessed. Results: Twenty-three patients were treated. Patients had received a median of 7 prior regimens (range, 3-13), including autologous transplantation in 20, thalidomide in all 23, lenalidomide in 17, and bortezomib in 19, 9 of whom were bortezomib-refractory. Two patients receiving 500 mg vorinostat had prolonged QT interval and fatigue as dose-limiting toxicities. The most common grade >3 toxicities were myelo-suppression (n = 13), fatigue (n = 11), and diarrhea (n = 5). There were no drug-related deaths. Overall response rate was 42%, including three partial responses among nine bortezomib refractory patients. Vorinostat pharmacokinetics were nonlinear. Serum C_max reached a plateau above 400 mg. Pharmacodynamic changes in CD-138+ bone marrow cells before and on day 11 showed no correlation between protein levels of NF-κB, IκB, acetylated tubulin, and p21CIP1 and clinical response. Conclusions: The maximum tolerated dose of vorinostat in our study was 400 mg daily for 8 days every 21 days, with bortezomib administered at a dose of 1.3 mg/m² on days 1, 4, 8, and 11. The promising antimyeloma activity of the regimen in refractory patients merits further evaluation. (Clin Cancer Res 2009;15(16):5250–7)

Key Points: This is the first trial to investigate PD-1 inhibitor, pembrolizumab, and an IMiD (pomalidomide) in MM with promising clinical efficacy. PD-L1 expression on myeloma cells and PD-1 on marrow infiltrating T lymphocytes are potential biomarkers for efficacy of PD-1 blockade.

This phase 2 study assessed the safety, pharmacokinetics, pharmacodynamics and efficacy of carfilzomib, a selective proteasome inhibitor, in patients with multiple myeloma and varying degrees of renal impairment, including patients on chronic hemodialysis. Patients were grouped by creatinine clearance: >80 ml/min, 50–80 ml/min, 30–49 ml/min, <30 ml/min and chronic hemodialysis. Carfilzomib was administered on days 1, 2, 8, 9, 15 and 16 in 28-day cycles: 15 mg/m² (Cycle 1), 20 mg/m² (Cycle 2) and 27 mg/m² (Cycles 3+). There were no differences in carfilzomib clearance or exposure among patients with normal renal function and any group with renal impairment. Grade 3/4 adverse events (AEs) included anemia (28.0%), thrombocytopenia (20.0%), lymphopenia (18.0%) and fatigue (14.0%). AEs were similar among groups. At 15 mg/m², proteasome inhibition up to 85% was observed and did not differ among groups. Although nearly 50% of patients were refractory to both bortezomib and lenalidomide, end of study partial response or better (overall response rate) was 25.5% with 7.9 months median duration of response. In conclusion, the pharmacokinetics and safety of carfilzomib were not influenced by the degree of baseline renal impairment, including in patients on dialysis, and carfilzomib was well tolerated and demonstrated promising efficacy.