Ibrutinib in previously treated Waldenström's macroglobulinemia.

BACKGROUND: MYD88(L265P) and CXCR4(WHIM) mutations are highly prevalent in Waldenström's macroglobulinemia. MYD88(L265P) triggers tumor-cell growth through Bruton's tyrosine kinase, a target of ibrutinib. CXCR4(WHIM) mutations confer in vitro resistance to ibrutinib. METHODS: We performed a prospective study of ibrutinib in 63 symptomatic patients with Waldenström's macroglobulinemia who had received at least one previous treatment, and we investigated the effect of MYD88 and CXCR4 mutations on outcomes. Ibrutinib at a daily dose of 420 mg was administered orally until disease progression or the development of unacceptable toxic effects. RESULTS: After the patients received ibrutinib, median serum IgM levels decreased from 3520 mg per deciliter to 880 mg per deciliter, median hemoglobin levels increased from 10.5 g per deciliter to 13.8 g per deciliter, and bone marrow involvement decreased from 60% to 25% (P<0.01 for all comparisons). The median time to at least a minor response was 4 weeks. The overall response rate was 90.5%, and the major response rate was 73.0%; these rates were highest among patients with MYD88(L265P)CXCR4(WT) (with WT indicating wild-type) (100% overall response rate and 91.2% major response rate), followed by patients with MYD88(L265P)CXCR4(WHIM) (85.7% and 61.9%, respectively) and patients with MYD88(WT)CXCR4(WT) (71.4% and 28.6%). The estimated 2-year progression-free and overall survival rates among all patients were 69.1% and 95.2%, respectively. Treatment-related toxic effects of grade 2 or higher included neutropenia (in 22% of the patients) and thrombocytopenia (in 14%), which were more common in heavily pretreated patients; postprocedural bleeding (in 3%); epistaxis associated with the use of fish-oil supplements (in 3%); and atrial fibrillation associated with a history of arrhythmia (5%). CONCLUSIONS: Ibrutinib was highly active, associated with durable responses, and safe in pretreated patients with Waldenström's macroglobulinemia. MYD88 and CXCR4 mutation status affected responses to this drug. (Funded by Pharmacyclics and others; ClinicalTrials.gov number, NCT01614821.).

Carfilzomib, rituximab, and dexamethasone (CaRD) treatment offers a neuropathy-sparing approach for treating Waldenström's macroglobulinemia.

Bortezomib frequently produces severe treatment-related peripheral neuropathy (PN) in Waldenström's macroglobulinemia (WM). Carfilzomib is a neuropathy-sparing proteasome inhibitor. We examined carfilzomib, rituximab, and dexamethasone (CaRD) in symptomatic WM patients naïve to bortezomib and rituximab. Protocol therapy consisted of intravenous carfilzomib, 20 mg/m2 (cycle 1) and 36 mg/m(2) (cycles 2-6), with intravenous dexamethasone, 20 mg, on days 1, 2, 8, and 9, and rituximab, 375 mg/m(2), on days 2 and 9 every 21 days. Maintenance therapy followed 8 weeks later with intravenous carfilzomib, 36 mg/m(2), and intravenous dexamethasone, 20 mg, on days 1 and 2, and rituximab, 375 mg/m(2), on day 2 every 8 weeks for 8 cycles. Overall response rate was 87.1% (1 complete response, 10 very good partial responses, 10 partial responses, and 6 minimal responses) and was not impacted by MYD88(L265P) or CXCR4(WHIM) mutation status. With a median follow-up of 15.4 months, 20 patients remain progression free. Grade ≥2 toxicities included asymptomatic hyperlipasemia (41.9%), reversible neutropenia (12.9%), and cardiomyopathy in 1 patient (3.2%) with multiple risk factors, and PN in 1 patient (3.2%) which was grade 2. Declines in serum IgA and IgG were common. CaRD offers a neuropathy-sparing approach for proteasome inhibitor-based therapy in WM. This trial is registered at www.clinicaltrials.gov as #NCT01470196.

Challenges with serum protein electrophoresis in assessing progression and clinical response in patients with Waldenström macroglobulinemia.

Accurate determination of the immunoglobulin (Ig) M paraprotein concentration is crucial to evaluating response in patients with Waldenström macroglobulinemia (WM). In most clinical laboratories, M-spike quantitation is performed by serum protein electrophoresis, which is the same method used to quantitate IgG and IgA paraproteins in patients with multiple myeloma (MM). However, the migration pattern and propensity of IgM paraproteins to form higher-order complexes in serum makes laboratory evaluation of samples from patients with WM especially challenging. We review examples of patients whose IgM paraprotein is particularly ill-suited to M-spike quantitation by serum protein electrophoresis: a case of "sticky M," a case of IgM multimers that cannot be resolved, and a case of an IgM in the ß region. In these and similar cases, a method other than M-spike quantitation, such as IgM heavy chain nephelometry, should be considered in laboratory evaluation of paraprotein concentration.

Comparative response assessment by serum immunoglobulin M M-protein and total serum immunoglobulin M after treatment of patients with Waldenström macroglobulinemia.

Serum immunoglobulin (Ig) M monoclonal protein determined by electrophoresis (sIgM-MP) and total serum IgM (sIgM) by nephelometry are widely used for response assessment in Waldenström macroglobulinemia (WM), although have not been compared for predicting changes in underlying disease burden. We, therefore, compared these serum markers with changes in bone marrow (BM) and extramedullary disease for 73 patients who were rituximab naive and treated with a rituximab-containing regimen. By linear regression analysis, reductions in sIgM-MP and sIgM showed moderate correlation with BM disease involvement (r = 0.4051 and r = 0.4490, respectively), and did not differ from one another as estimators of BM disease response (P = .3745). Neither sIgM-MP nor sIgM showed a strong correlation with BM disease response in patients with low (<1000 mg/dL) or high (>5000 mg/dL) IgM levels and extramedullary disease response. sIgM-MP and sIgM, therefore, are comparable response markers in WM. Development of newer, more accurate surrogate response markers are needed to better delineate treatment outcomes in patients with WM and with low or high IgM levels, and extramedullary disease.

Patients with Waldenström macroglobulinemia commonly present with iron deficiency and those with severely depressed transferrin saturation levels show response to parenteral iron administration.

Anemia often prompts therapy in Waldenström macroglobulinemia (WM), although is not fully explained by bone marrow disease involvement in many patients. Hepcidin regulates gut absorption and distribution of iron and is elevated and associated with anemia in WM. Since hepcidin evaluation remains experimental, we initiated an American Board of Internal Medicine (ABIM) practice improvement project to determine baseline transferrin saturation (TSAT) levels in untreated anemic patients with WM. Among 108 patients with WM evaluated, 56 (52%) had a TSAT level ≤ 20%, which included 25 (23%) patients with severely depressed TSAT levels (≤ 10%). Sixteen patients with TSAT levels ≤ 10% received parenteral iron, and 14 of these patients showed improved hematocrit values (28.75% to 32.75%; P < .0001), mean corpuscular volume (MCV) (84.7 to 89.9; P = .006), and TSAT levels (8.1% to 21.2%; P < .0001). Anemia in 8 of these patients was previously refractory to oral iron therapy. Routine screening of iron saturation levels may therefore identify patients with WM and severe iron deficiency who may be candidates for parenteral iron therapy.

MYD88 L265P in Waldenström macroglobulinemia, immunoglobulin M monoclonal gammopathy, and other B-cell lymphoproliferative disorders using conventional and quantitative allele-specific polymerase chain reaction.

By whole-genome and/or Sanger sequencing, we recently identified a somatic mutation (MYD88 L265P) that stimulates nuclear factor κB activity and is present in >90% of Waldenström macroglobulinemia (WM) patients. MYD88 L265P was absent in 90% of immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) patients. We therefore developed conventional and real-time allele-specific polymerase chain reaction (AS-PCR) assays for more sensitive detection and quantification of MYD88 L265P. Using either assay, MYD88 L265P was detected in 97 of 104 (93%) WM and 13 of 24 (54%) IgM MGUS patients and was either absent or rarely expressed in samples from splenic marginal zone lymphoma (2/20; 10%), CLL (1/26; 4%), multiple myeloma (including IgM cases, 0/14), and immunoglobulin G MGUS (0/9) patients as well as healthy donors (0/40; P < 1.5 × 10(-5) for WM vs other cohorts). Real-time AS-PCR identified IgM MGUS patients progressing to WM and showed a high rate of concordance between MYD88 L265P ΔCT and BM disease involvement (r = 0.89, P = .008) in WM patients undergoing treatment. These studies identify MYD88 L265P as a widely present mutation in WM and IgM MGUS patients using highly sensitive and specific AS-PCR assays with potential use in diagnostic discrimination and/or response assessment. The finding of this mutation in many IgM MGUS patients suggests that MYD88 L265P may be an early oncogenic event in WM pathogenesis.

Family history of non-hematologic cancers among Waldenstrom macroglobulinemia patients: a preliminary study.

BACKGROUND: Little is known about the epidemiology and etiology of Waldenstrom macroglobulinemia (WM). Despite several studies of the relation between family history and B-cell disorders and WM, family history of non-hematologic cancers has not been systematically investigated. We thus examined associations of family history of breast, colorectal, lung, ovarian, and prostate cancers with WM. METHODS: All probands aged 20-79 years with bone marrow biopsy-confirmed diagnosis of WM between May 1, 1999 and January 1, 2010 at the Bing Center for Waldenstrom Macroglobulinemia were eligible for inclusion in our analysis. We reviewed medical records for eligible probands to determine family history of cancer (defined as a cancer diagnosis for ≥1 first-degree relative(s) of the proband). Using expected values constructed from the United States National Health Interview Survey, we estimated age- and race-standardized rate ratios (RRs) for family history of breast, colorectal, lung, ovarian, and prostate cancers by WM subtype. RESULTS: Family history of prostate cancer had the largest overall rate ratio (RR=1.4, 95% confidence limits [CL]: 1.1, 1.7), and among sporadic cases, family history of prostate and breast cancer had the largest rate ratios (prostate: RR=1.3, 95% CL: 1.1, 1.7; breast: RR=1.3, 95% CL: 1.2, 1.6). CONCLUSION: Our study suggests that it may be worthwhile to pursue these associations in a case-control study with uniform selection and data collection for cases and controls, and at least some record-based information on family history.

Perceived uncertainty, coping strategies, and adaptation in women with human papillomavirus on pap smear.

OBJECTIVE: To explore, identify, and describe the perception of uncertainty over time in college-aged women experiencing the unexpected event of an abnormal Pap smear with human papillomavirus (HPV). METHODS: Eighty-eight female patients, who had abnormal Pap smear and had indications for colposcopy, were recruited from a Student Health Service and consented for study participation. Uncertainty levels were measured over time. Relationships among uncertainty, knowledge of HPV, body attitude and moods, coping strategies, and follow-up were evaluated. RESULTS: The relationship between uncertainty and coping strategies was supported in the emotion-focused path as predicted but not in the problem-focused path. Evidence of adaptation to uncertainty through emotion-focused coping was found in the significant relationship between emotion-focused coping and body attitude. Similarly, there was a significant relationship between emotion-focused coping and moods in the path analysis and in correlations with the subcategories of positive and negative moods. The problem-focused indirect path from uncertainty to adaptation showed no significant relationship. Likewise, uncertainty also had no significant direct effect on body attitude or promptness of follow-up but did have a direct impact on moods. The direct path from previous knowledge to uncertainty was not supported. CONCLUSIONS: The presence of uncertainty over time was established in this study population. Statistically significant relationships were confirmed among uncertainty, emotion-focused coping strategies, and adaptation in a group of young women experiencing a mildly abnormal Pap smear.