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CLINICAL NEWS Written in Blood Continued from page 28 95 percent and 100 percent, respectively. This included complete response (CR) or CR with incomplete marrow recovery rates of 37 percent and 78 percent, respectively ( TABLE 1 ). Responses were similar among patients in the different cytogenetic sub- groups, the authors reported. Three months following the last dose of obinutuzumab, the rates of undetectable MRD (sensitivity of <10 -4 ) were 64 percent and 91 percent in the relapsed/refractory and firstline cohorts, respectively. The re- searchers noted high concordance between MRD-negative levels in peripheral blood and bone marrow samples. Several other therapeutic combina- tions are being tested, all of which include venetoclax plus a Bruton tyrosine kinase inhibitor (e.g., ibrutinib or acalabrutinib with or without obinutuzumab). “Of the agents currently being evaluated, the best two- or three-drug combination remains unknown,” commented Dr. Flinn. “We know that the combination of veneto- clax and an anti-CD20 antibody such as obinutuzumab appears synergistic, but the addition of obinutuzumab to ibruti- nib does not produce the same depth of (PR),” said Dr. Flinn. “This finding is prob- ably due to response criteria classifying patients with small residual lymph nodes seen on CT scans as PR, when, in reality, [these measurable lymph nodes] may be of no consequence.” The authors report relationships with Genentech and AbbVie, which provided support for this study. remission that is seen with obinutuzumab plus venetoclax.” Ultimately, he added, these findings need to be confirmed in larger, randomized clinical trials. Limitations of this early- phase study include the small number of enrolled patients, the lack of a randomized design, and the single-arm design. “While the number of patients is small, this combination appeared to work well in both high- and low-risk groups, and MRD-negativity rates were equal in patients who achieved CR compared with those who achieved partial response REFERENCES Flinn IW, Gribben JG, Dyer MJS, et al. Phase 1b study of venetoclax- obinutuzumab in previously untreated and relapsed/refractory chronic lymphocytic leukemia. Blood. 2019 March 12. [Epub ahead of print] Evaluating Thalidomide-Cyclophosphamide-Prednisone for Idiopathic Multicentric Castleman Disease An oral combination of thalidomide, cyclophosphamide, and prednisone (TCP) induced durable tumor and symptomatic response rates in nearly half of patients with newly diagnosed idiopathic multicentric Castleman disease (iMCD), according to a small phase II study published in Blood. The researchers also found that the TCP regimen was relatively safe, with no patients experiencing grade ≥3 adverse events (AEs). “Although the anti-IL6 therapy siltuximab has been recommended as firstline therapy for all patients with iMCD – according to the first-ever expert consensus [for iMCD treat- ment] – this drug is not effective for more than half of patients and is not available everywhere,” said co-author Jian Li, MD, from the Peking Union Medical College Hospital in Beijing. Its high price and the requirement for repeated intravenous administration also limit its use as firstline therapy in lower-income countries. In this single-center trial, Chinese researchers evaluated the safety and efficacy of TCP as an alternative treat- ment for patients with newly diag- nosed iMCD who do not respond to or do not have access to siltuximab. A total of 25 patients (median age = 40 years; range not reported) were enrolled between June 2015 and June TABLE 2. 2018. All participants had histopatho- logic lymph node features consistent with iMCD. TCP was administered for two years or until treatment failure in the following treatment schedule: • thalidomide 100 mg/day at bedtime for years 1-2 • cyclophosphamide 300 mg/m 2 weekly on days 1, 8, 15, and 22 of a 4-week cycle for year 1 • prednisone 1 mg/kg on days 1-2, 8-9, 15-16, and 22-23 of a 4-week cycle for year 1 The primary endpoint was the incidence of durable tumor and symptomatic response sustained for at least 24 weeks. Responses were defined as: • complete response (CR), or complete disappearance of measurable and evaluable disease as well as a resolution of iMCD- associated baseline symptoms • partial response, or ≥50% reduction in the sum of the product of diameters of measurable lesions, with at least stable disease in the absence of treatment failure (defined as sustained increase in disease- related symptoms, initiating a new iMCD treatment, or death) After administration of TCP, 12 patients (48%) met the primary end- point for response, seven of whom had achieved CR. Three patients (12%) had stable disease, and the remaining 10 patients (40%) experi- enced treatment failure. The authors observed that responders were more likely to have fever (p=0.008) and less likely to have pulmonary involvement (p=0.039) at baseline, compared with nonresponders. Treatment with TCP also was associated with significant improve- ments in symptom score, IL-6 level, hemoglobin, erythrocyte sedimenta- tion rate, albumin, and immunoglobin G from baseline (all p<0.05; TABLE 2 ). During follow-up, one patient died from pulmonary infection and one patient had a grade 3 AE; another patient died from disease progression. The most common grade 1-2 AEs included: constipation (40%), pruritus (20%), rash (16%), peripheral sensory neuropathy (16%), and nausea (16%). During the median follow-up of 14 months (range = 6-36 months), estimated progression-free and overall survival rates were 60 percent and 88 percent, respectively. However, the actual survival data were not reported, which limits the applicability of these findings. “As a single-arm study without a control group, it is difficult to perform a rigorous comparison between the TCP regimen and other treatment options, and further study is needed,” Dr. Li explained. “However, accord- ing to our clinical experience with CHOP (cyclophosphamide, doxo- rubicin, vincristine, prednisone) or CHOP-like regimens – which were the most widely used therapies for Chinese patients when siltuximab was unavailable – oral TCP represented an economical and convenient treatment option with good safety profiles and acceptable response rates.” Dr. Li noted that investigators are continuing to collect data on the long-term efficacy and safety of this regimen. “Moreover, a well-designed multicenter trial that employs the new consensus response criteria is needed,” he added. “Hopefully, a controlled study with siltuximab will be carried out in the future.” ● The authors report relationships with Janssen Pharmaceuticals. REFERENCE Zhang L, Zhao AL, Duan MH, et al. Phase 2 study using oral thalidomide-cyclophosphamide-prednisone for idiopathic Multicentric Castleman disease. Blood. 2019 February 13. [Epub ahead of print] Improvements in iMCD Characteristics From Baseline Characteristics Symptom score IL-6 (pg/mL) Hemoglobin (g/L) C-reactive protein (mg/L) Baseline, Median (Range) Week 24, Median (Range) p Value Last Follow-up, Median (Range) p Value 16 (7-38) 1 (0-6) 28.6 (7.4-865) 10.0 (2-23.5) 0.003 0.5 (0-6) 0.002 0.012 3.7 (2-25.1) 0.002 98 (76-133) 125.5 (93-150) 0.093 132 (93-177) 0.013 41.6 (0.2-185.6) 12.4 (0.8-54.8) 0.028 3.2 (0.7-53.0) 0.005 ESR (mm/h) 90 (6-115) 31 (5-125) 0.042 16 (1-125) 0.013 Albumin (g/L), median (range) 32 (26-43) 37 (36.7-56) 0.018 39.5 (36-56) 0.007 21.7 (14.4-43.8) 12.4 (7.3-20.3) 0.012 14.5 (7.9-24.6) 0.002 IgG (g/L), median (range) ESR = erythrocyte sedimentation rate; IgG = immunoglobin G 30 ASH Clinical News May 2019