Functional Precision Medicine Provides Clinical Benefit in Advanced Aggressive Hematologic Cancers and Identifies Exceptional Responders.

Personalized medicine aims to match the right drug with the right patient by using specific features of the individual patient's tumor. However, current strategies of personalized therapy matching provide treatment opportunities for less than 10% of patients with cancer. A promising method may be drug profiling of patient biopsy specimens with single-cell resolution to directly quantify drug effects. We prospectively tested an image-based single-cell functional precision medicine (scFPM) approach to guide treatments in 143 patients with advanced aggressive hematologic cancers. Fifty-six patients (39%) were treated according to scFPM results. At a median follow-up of 23.9 months, 30 patients (54%) demonstrated a clinical benefit of more than 1.3-fold enhanced progression-free survival compared with their previous therapy. Twelve patients (40% of responders) experienced exceptional responses lasting three times longer than expected for their respective disease. We conclude that therapy matching by scFPM is clinically feasible and effective in advanced aggressive hematologic cancers. SIGNIFICANCE: This is the first precision medicine trial using a functional assay to instruct n-of-one therapies in oncology. It illustrates that for patients lacking standard therapies, high-content assay-based scFPM can have a significant value in clinical therapy guidance based on functional dependencies of each patient's cancer.See related commentary by Letai, p. 290.This article is highlighted in the In This Issue feature, p. 275.

Recommendations for ibrutinib treatment in patients with atrial fibrillation and/or elevated cardiovascular risk.

Ibrutinib is the first clinically approved inhibitor of Bruton's tyrosine kinase, an enzyme that is essential for survival and proliferation of B­cells by activating the B­cell receptor signalling pathway. Ibrutinib has been shown to be highly effective in B­cell malignancies in clinical trials and is recommended in current international guidelines as a first and/or second line treatment of chronic lymphocytic leukemia. The drug has a favorable tolerability and safety profile but the occurrence of specific side effects (e.g. atrial fibrillation, bleeding and hypertension) may complicate or be of concern for doctors and patients considering the use of this treatment. In many cases, however, it is not necessary to withhold this effective therapy. In contrast, ibrutinib treatment can be initiated or continued, if certain recommendations are followed. The possibilities of prevention, diagnosis and management of specific clinical situations are discussed in detail and recommendations are derived, which should facilitate ibrutinib use.

IKAROS expression in distinct bone marrow cell populations as a candidate biomarker for outcome with lenalidomide-dexamethasone therapy in multiple myeloma.

Immunomodulatory drugs (IMiDs) are a cornerstone in the treatment of multiple myeloma (MM), but specific markers to predict outcome are still missing. Recent work pointed to a prognostic role for IMiD target genes (e.g. CRBN). Moreover, indirect activity of IMiDs on immune cells correlated with outcome, raising the possibility that cell populations in the bone marrow (BM) microenvironment could serve as biomarkers. We therefore analysed gene expression levels of six IMiD target genes in whole BM samples of 44 myeloma patients treated with lenalidomide-dexamethasone. Expression of CRBN (R = 0.30, P = .05), IKZF1 (R = 0.31, P = .04), IRF4 (R = 0.38, P = .01), MCT-1 (R = 0.30, P = .05), and CD147 (R = 0.38, P = .01), but not IKZF3 (R = -0.15, P = .34), was significantly associated with response. Interestingly, IKZF1 expression was elevated in BM environmental cells and thus selected for further investigation by multicolor flow cytometry. High IKAROS protein levels in total BM mononuclear cells (median OS 83.4 vs. 32.2 months, P = .02), CD19+ B cells (median OS 71.1 vs. 32.2 months, P = .05), CD3+ CD8+ T cells (median OS 83.4 vs 19.0 months, P = .008) as well as monocytes (median OS 53.9 vs 18.0 months, P = .009) were associated with superior overall survival (OS). In contrast, IKAROS protein expression in MM cells was not predictive for OS. Our data therefore corroborate the central role of immune cells for the clinical activity of IMiDs and built the groundwork for prospective analysis of IKAROS protein levels in distinct cell populations as a potential biomarker for IMiD based therapies.

Insulin like growth factor binding protein 7 (IGFBP7) expression is linked to poor prognosis but may protect from bone disease in multiple myeloma.

BACKGROUND: Insulin like growth factor binding protein 7 (IGFBP7) is a secreted protein binding insulin like growth factor 1 (IGF-1), insulin, vascular endothelial growth factor A (VEGFA), and activin A. It antagonizes bone morphogenetic proteins and is involved in the tumour propagation of solid as well as haematological malignancies. Its role in multiple myeloma (MM) is not defined so far. We therefore aim here to investigate its prognostic and pathophysiological role in MM. METHODS: The clinical significance of IGFBP7 gene expression was investigated by gene expression profiling in two independent cohorts (n = 948) of newly-diagnosed MM patients. Methylation of the IGFBP7 promoter was analysed by pyrosequencing and treatment of MM cell lines with 5-aza-2-deoxycytidine. The impact of IGFBP7 on MM cells was studied by CCK-8 assay, BrdU assay and flow cytometry, respectively. IGFBP7 expression in bone marrow stromal cells (BMSCs) was studied by quantitative RT-PCR. For osteoblast development, immortalized and primary human BMSCs were cultured in osteogenic differentiation medium for 7-14 days in the presence of recombinant human IGFBP7 and/or activin A. RESULTS: Median IGFBP7 expression is significantly lower in CD138-purified plasma cells from individuals with MGUS and MM, compared to normal bone marrow plasma cells. IGFBP7 gene expression in MM cells is regulated by methylation, shown by pyrosequencing and exposure to demethylating agents (5-aza-2-deoxycytidine). High expression of IGFBP7 in MM cells is associated with adverse survival in two independent cohorts of 247 and 701 newly-diagnosed MM patients treated with high-dose therapy and autologous stem cell transplantation. IGFBP7 is associated with prognostically adverse chromosomal aberrations (t(4;14) and gain of 1q21), MMSET expression, and higher myeloma cell proliferation. In vitro, IGFBP7 overcomes activin A induced osteoblast suppression and promotes osteogenesis. MM cells downregulate IGFBP7 in stromal cells, possibly contributing to the osteoblast suppression found in MM. Conversely, higher IGFBP7 expression is associated with a lower probability of myeloma bone disease. CONCLUSIONS: Our data indicate that IGFBP7 expression is a marker for a specific methylation pattern in myeloma, linked to translocation t(4;14) associated MMSET expression, showing clinical features of adverse prognosis with absence of myeloma bone disease.

Lenalidomide and dexamethasone for acute light chain-induced renal failure: a phase II study.

We prospectively evaluated the activity and tolerance of lenalidomide-dexamethasone in 35 patients with acute light chain-induced renal failure. The lenalidomide dose was adapted to the estimated glomerular filtration rate and dexamethasone was given at high dose in cycle one and at low dose thereafter. Four patients died within the first two cycles, and five discontinued therapy leaving 26 patients for the per-protocol analysis. Responses were observed in 24/35 (68.6%) patients of the intent-to-treat population. Complete response was noted in seven patients (20%), very good partial response in three patients (8.6%), partial response in 14 patients (40%), and minimal response in one patient (2.9%). Renal response was observed in 16 (45.7%) patients: five (14.2%) achieved complete, four (11.4%) partial and seven (20%) minor renal responses. Five of 13 patients who were dialysis dependent at baseline became dialysis independent. The median time to myeloma and to renal response was 28 days for both parameters, while the median time to best myeloma and best renal response was 92 and 157 days, respectively. The median estimated glomerular filtration rate increased significantly in patients with partial response or better from 17.1 mL/min at baseline to 39.1 mL/min at best response (P=0.001). The median progression-free and overall survival was 5.5 and 21.8 months, respectively, in the intent-to-treat population and 12.1 and 31.4 months, respectively, in the per-protocol group. Infections, cardiotoxicity, anemia and thrombocytopenia were the most frequent toxicities. In conclusion, the lenalidomide-dexamethasone regimen achieved rapid and substantial myeloma and renal responses. The trial was registered under EUDRACT number 2008-006497-15.

High expression of cereblon (CRBN) is associated with improved clinical response in patients with multiple myeloma treated with lenalidomide and dexamethasone.

Cereblon (CRBN) has recently been identified as a target for immunomodulatory drugs (IMiDs) and its downregulation has been linked to resistance to lenalidomide. Here, we studied CRBN expression by real time polymerase chain reaction in 49 bone marrow samples of newly diagnosed patients with multiple myeloma treated with lenalidomide and dexamethasone. Median CRBN expression was 3·45 in patients who achieved complete response, and 3·75, 2·01, 0·78, and 0·70 in those with very good partial response, partial response, stable disease and progressive disease respectively. CRBN expression levels correlated significantly with response to lenalidomide treatment (r = 0·48; P < 0·001). Among established prognostic parameters, only beta-2-microglobulin correlated with cereblon (r = 0·66; P < 0·001). A close association of CRBN with interferon regulatory factor 4 (IRF4) (P < 0·001) and with CTNNB1 (P < 0·001) was found. Overall, a statistically significant association between baseline CRBN expression and response in MM patients treated with lenalidomide is shown. CRBN expression is closely associated with IRF4, which is an important target of IMiD therapy.

Lipoprotein lipase in chronic lymphocytic leukaemia - strong biomarker with lack of functional significance.

In chronic lymphocytic leukaemia (CLL), lipoprotein lipase (LPL) mRNA overexpression is an established poor prognostic marker, its function, however, is poorly understood. Measuring extracellular LPL enzymatic activity and protein, we found no difference between levels in CLL patients and those of controls, both before and after heparin treatment in vivo and in vitro. Investigating LPL knock down effects, we determined five potential downstream targets, of which one gene, STXBP3, reportedly is involved in fatty acid metabolism. While possibly reflecting an epigenetic switch towards an incorrect transcriptional program, LPL overexpression by itself does not appear to significantly influence CLL cell survival.

Rituximab serum concentrations during immuno-chemotherapy of follicular lymphoma correlate with patient gender, bone marrow infiltration and clinical response.

BACKGROUND: Treatment of follicular lymphoma with rituximab is currently recommended at a dose of 375 mg/m(2). We aimed to provide a rationale for optimal dosing and scheduling of this anti-CD20 antibody based on pharmacokinetics. DESIGN AND METHODS: Clinical efficacy of immunochemotherapy with rituximab, fludarabine and mitoxantrone followed by 2-monthly rituximab maintenance was evaluated in 29 patients with previously untreated follicular lymphoma in a prospective phase II trial (AGMT-NHL9). Pharmacokinetic analysis was assessed in 17 patients. RESULTS: Induction treatment resulted in high clinical response rates (complete remission 66%; ORR 100%). Significantly higher complete remission rates were observed in female patients (86 vs. 47%; Odds Ratio 6.8, 95% CI: 1.12; 41.82; P=0.05). Rituximab pharmacokinetic analysis showed a high variability ranging over almost 1 order of magnitude at maintenance cycle 1 (area under the curve 1,540-12,025 g/L*days). Median area under the curve was lower in men (81%) and in patients with initial bone marrow infiltration (76%). Higher rituximab serum concentrations before next therapy (C(trough)) were associated with female sex (P=0.04) as well as with absence of initial bone marrow infiltration (P=0.001). C(trough) correlated with remission quality (complete vs. partial remission; P=0.005) and progression-free survival (P=0.03). A decline in rituximab C(trough) below 25,000 ng/mL was observed 9.5 to 62 months before clinical relapse (P=0.008). CONCLUSIONS: The results of this pilot trial suggest that more differentiated dosing schedules based on gender and bone marrow infiltration should be explored for rituximab therapy for lymphoma. This study was registered in ClinicalTrials.gov (Identifier: NCT01560117).

Lenalidomide downregulates the cell survival factor, interferon regulatory factor-4, providing a potential mechanistic link for predicting response.

Overexpression of the transcription factor interferon regulatory factor-4 (IRF4), which is common in multiple myeloma (MM), is associated with poor prognosis. Patients with higher IRF4 expression have significantly poorer overall survival than those with low IRF4 expression. Lenalidomide is an IMiD immunomodulatory compound that has both tumouricidal and immunomodulatory activity in MM. This study showed that lenalidomide downregulated IRF4 levels in MM cell lines and bone marrow samples within 8 h of drug exposure. This was associated with a decrease in MYC levels, as well as an initial G1 cell cycle arrest, decreased cell proliferation, and cell death by day 5 of treatment. In eight MM cell lines, high IRF4 levels correlated with increased lenalidomide sensitivity. The clinical significance of this observation was investigated in 154 patients with MM. Among MM patients with high levels of IRF4 expression, treatment with lenalidomide led to a significantly longer overall survival than other therapies in a retrospective analysis. These data confirm the central role of IRF4 in MM pathogenesis; indicate that this is an important mechanism by which lenalidomide exerts its antitumour effects; and may provide a mechanistic biomarker to predict response to lenalidomide.

Prolonged progression-free survival in patients with chronic lymphocytic leukemia receiving granulocyte colony-stimulating factor during treatment with fludarabine, cyclophosphamide, and rituximab.

The clinical benefit of the addition of granulocyte colony-stimulating factor (G-CSF) to standard immunochemotherapy of chronic lymphocytic leukemia (CLL) with fludarabine, cyclophosphamide, and rituximab (FCR) is still unclear. In this retrospective study we analyzed the outcome of 32 consecutive patients with CLL during treatment with FCR. Sixteen patients received G-CSF for treatment of CTC grade 3 or 4 neutropenia or febrile neutropenia at some point during therapy and 16 did not. Both groups were well balanced for clinical and biological risk factors. Overall response rates were not significantly different (94% vs. 75%; p=0.144). Interestingly, a significantly better progression-free survival (100% vs. 35.4% at 24 months; p<0.001) and even overall survival (100% vs. 77.8% at 24 months; p=0.022) was observed in patients receiving G-CSF. While the underlying cause remains to be elucidated, these data strongly suggest an association of the addition of G-CSF to FCR therapy with final patient outcome.

Nonpegylated liposomal doxorubicin is highly active in patients with B and T/NK cell lymphomas with cardiac comorbidity or higher age.

We used nonpegylated liposomal doxorubicin (NPLD) in cytostatic drug combinations to treat 37 patients with non-Hodgkin's lymphoma and pre-existing cardiac disorder or elderly patients with reduced physical state who were ineligible for conventional anthracycline-containing therapy. High remission rates were observed in this poor-risk population: Complete remission rates were 75% for diffuse large B cell lymphoma (DLBCL) and 55% for T/NK cell neoplasm (overall response rate of 80% and 89%, respectively). Twenty-seven patients (73%) are still alive after a median observation time of 14 months. No major cardiac or gastrointestinal toxicity was observed. Extravasation of NPLD in two patients resulted in mild inflammation without tissue damage. Hematologic toxicity was comparable to that of conventional anthracycline-containing regimens. We conclude that NPLD is highly active in combination chemotherapy for lymphoma with low cardiac toxicity in patients with pre-existing cardiac disorders or higher age. Moreover, we also observed remarkable efficacy in T/NK cell lymphomas.

Overexpression of the paternally expressed gene 10 (PEG10) from the imprinted locus on chromosome 7q21 in high-risk B-cell chronic lymphocytic leukemia.

We report high expression of the maternally imprinted gene PEG10 in high-risk B-CLL defined by high LPL mRNA expression. Differential expression was initially identified by microarray analysis and confirmed by real time PCR in 42 B-CLL patients. mRNA expression ranged from 0.3- to 375.4-fold compared to normal peripheral blood mononuclear cells (PBMNC). Expression levels in CD19+ B-CLL cells were 100-fold higher than in B-cells from healthy donors. PEG10 expression levels in B-CLL patient samples remained stable over time even after chemotherapy. High PEG10 expression correlated with high LPL expression (p=0.001) and a positive Coombs' test (p=0.04). Interestingly, similar expression patterns were observed for the neighbouring imprinted gene sarcoglycan-epsilon (SGCE). Monoallelic expression and maintained imprinting of PEG10 were found by allele- or methylation-specific PCR. The intensity of intracellular staining of PEG10 protein corresponded to mRNA levels as confirmed by immunofluorescence staining. Short term knock-down of PEG10 in B-CLL cells and HepG2 cells was not associated with changes in cell survival but resulted in a significant change in the expression of 80 genes. However, long term inhibition of PEG10 led to induction of apoptosis in B-CLL cells. Our data indicate (i) a prognostic value of PEG10 in B-CLL patients; (ii) specific deregulation of the imprinted locus at 7q21 in high-risk B-CLL; (iii) a potential functional and biological role of PEG10 protein expression. Altogether, PEG10 represents a novel marker in B-CLL.

Burkitt lymphoma following splenic marginal zone lymphoma. evidence for two independent B-cell clones.

We report the progression of splenic marginal zone lymphoma (SMZL) with circulating villous lymphocytes to Burkitt lymphoma with the presence of a t(8;14)(q24;q32) followed by a highly aggressive course. While the initial indolent lymphoma had an IgM lambda immunophenotype the Burkitt lymphoma was IgM kappa-positive. Immunoglobulin heavy chain gene (IGH) sequence analysis showed no identity between the two clones. We conclude that Burkitt lymphoma can occur in patients with SMZL, although not necessarily of identical clonal origin.

Variable prognostic value of FLT3 internal tandem duplications in patients with de novo AML and a normal karyotype, t(15;17), t(8;21) or inv(16).

INTRODUCTION: Internal tandem duplication of the FLT3 gene (FLT3/ITD) has been linked to poor outcome in acute myeloid leukemia (AML). However, the prognostic value of FLT3/ITD in various cytogenetic risk groups is still a matter of debate. The aim of this study was to evaluate the prognostic significance in patients with de novo AML and a normal karyotype or a t(15;17), t(8;21) or inv(16) (good risk group). PATIENTS AND METHODS: Diagnostic samples of 100 patients were investigated by single-step PCR of exons 11 and 12 of the FLT3 gene in a single center retrospective analysis. Subgroups included 53 patients with normal karyotype, 21 patients with t(15;17), 9 patients with t(8;21) and 17 patients with inv(16). RESULTS: FLT3/ITD was found in 26 out of 100 patients: 30% of patients with a normal karyotype and 38% of t(15;17) patients tested positive. The complete remission (CR) rates for the ITD(+) or ITD(-) groups were 50 vs 76% in normal karyotypes, and 100 vs 53% in t(15;17) patients, while the relapse rates were 75 vs 25% in normal karyotypes and 50 vs 42% in t(15;17) patients. Overall survival (OS) and disease free survival (DFS) at 5 years were significantly different in patients with normal cytogenetics: ITD(+) vs ITD(-): OS 6 vs 28% (P<0.003); DFS 13 vs 41% (P<0.02) Interestingly, FLT3/ITD had no significant effect on the outcome of t(15;17) patients: ITD(+) vs ITD(-): OS 85 vs 53% (P=0.056), DFS 45 vs 60% (P=0.6) at 50 months. CONCLUSIONS: These data suggest a high prognostic value of FLT3/ITD in patients with normal cytogenetics. However, we find no evidence that FLT3/ITD is a predictive marker for patients with t(15;17).