Beyond first-line non-anthracycline-based chemotherapy for extranodal NK/T-cell lymphoma: clinical outcome and current perspectives on salvage therapy for patients after first relapse and progression of disease

Background

Current standard treatment, including non-anthracycline-based chemotherapy and optimal combining of radiotherapy, has dramatically improved outcomes of patients with extranodal natural killer/T-cell lymphoma (ENKTL) during the last decade. This study was conducted to investigate the clinical outcome of ENKTL patients with relapsed or progressive disease after initial current standard therapy.

Patients and methods

We retrospectively reviewed patients diagnosed with ENKTL at six centers in four countries (China, France, Singapore, and South Korea) from 1997 to 2015 and analyzed 179 patients who had relapsed or progressed after initial current standard therapy.

Results

After a median follow-up of 58.6 months (range 27.9-89.2), the median second progression-free survival (PFS) was 4.1 months [95% confidence interval (CI) 3.04-5.16] and overall survival (OS) was 6.4 months (95% CI 4.36-8.51). Multivariate Cox-regression analysis revealed that elevated lactate dehydrogenase, multiple extranodal sites (≥2), and presence of B symptoms were associated with inferior OS (P < 0.05). OS and PFS were significantly different according to both prognostic index of natural killer lymphoma (PINK) and PINK-E (Epstein-Barr virus) models. Salvage chemotherapy with l-asparaginase (l-Asp)-based regimens showed a significantly better clinical benefit to response rate and PFS, although it did not lead to OS improvement. First use of l-Asp in the salvage setting and l-Asp rechallenge at least 6 months after initial treatment were the best candidates for salvage l-Asp containing chemotherapy.

Conclusions

Most patients with relapsed or refractory ENKTL had poor prognosis with short survival. Further studies are warranted to determine the optimal treatment of patients with relapsed or refractory ENKTL.

Management of hepatitis B reactivation in lymphoma patients on rituximab with past hepatitis B exposure: An observational study

BACKGROUND

Currently, a standardized approach to prevent and manage hepatitis B reactivation in lymphoma patients with past hepatitis exposure receiving rituximab in Singapore is lacking. This study is designed to report the current management approach and outcomes associated with hepatitis B reactivation.

OBJECTIVES

The primary objective was to report 6-, 12-, 24-month cumulative hepatitis B reactivation-related outcomes. Secondary objectives were to report monitoring frequencies of hepatitis B DNA and liver function tests performed in lymphoma patients with resolved hepatitis B receiving rituximab, and anti-viral prophylaxis use.

METHODOLOGY

This was a single centre, retrospective observational study. Patients with resolved hepatitis B initiated on rituximab from January 2011 to December 2015 were identified and reviewed over a two-year period starting from the date of rituximab initiation. Relevant parameters were obtained from electronic medical records. Hepatitis B reactivation was defined by hepatitis B DNA levels 20 IU/ml (1.30 log/ml) and above. Data were analysed using descriptive statistics.

RESULTS

Seventy-five patients were retrospectively reviewed over a two-year period. Hepatitis B reactivation was defined as hepatitis B DNA levels ≥20 IU/ml (1.30 log/ml). The 24-month cumulative hepatitis B reactivation rate was 4.0%. The median (interquartile range) number of hepatitis B DNA tests performed during treatment, initial six-month follow-up, and subsequent follow-up were 1.0 (0.0-2.6), 1.0 (0.0-2.0), and 1.0 (0.0-3.1), respectively.

CONCLUSION

Large variations in hepatitis B reactivation monitoring and management strategies were observed. Further studies are required to develop and determine a standardised protocol that could contribute to safer and more cost-effective care for lymphoma patients with resolved hepatitis B on rituximab.

Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma

Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

Novel findings from the Asian Lymphoma Study Group: focus on T and NK-cell lymphomas

T and NK-cell lymphomas are aggressive neoplasms with a unique epidemiological distribution, demonstrating higher prevalence in Asian countries compared to the West. Through the efforts of international collaboration, significant progress has been made especially on the biological understanding and clinical management of rare lymphoma subtypes including NK/T-cell lymphomas and monomorphic epitheliotropic intestinal T-cell lymphoma. In this review, we summarize the current status of lymphoma research conducted by the Asian Lymphoma Study Group and highlight key updates on the advancement of T and NK-cell lymphoma research.

Role of Procalcitonin in Differentiating between Infectious and Noninfectious Fevers among Patients with Lymphoma

OBJECTIVE

The primary objective of this study is to prospectively evaluate the role of procalcitonin (PCT) in distinguishing infectious fever from noninfectious fever (NIF) among febrile lymphoma patients. The secondary objective is to evaluate the usefulness of PCT in distinguishing among bloodstream infections (BSI), local infections and unidentified infections (LIUI), and NIF.

METHODS

Patients with lymphoma and fever were prospectively recruited between August 2014 and November 2015. PCT was measured within 24 hours of fever onset (PCT1) and 24-72 hours thereafter (PCT2). The higher PCT value between PCT1 and PCT2 was also documented (PCT_max ). PCT levels (PCT1, PCT2, and PCT_max ) were compared for BSI, LIUI, and NIF. In addition, the difference between PCT1 and PCT2 was evaluated in patients with complete data on both PCT1 and PCT2.

RESULTS

Of 108 eligible patients, 12 were diagnosed with BSI, 83 with LIUI, and 13 with NIF. PCT_max was statistically different between the infectious fever (BSI and LIUI combined) and NIF groups (median PCT_max : 0.44 ng/ml vs 0.19 ng/ml; p=0.026). PCT1 was not statistically different for patients with BSI, LIUI, and NIF (p=0.217). However, PCT2 and PCT_max were significantly higher in patients with BSI compared to those with NIF (p=0.026 and 0.002, respectively). Meanwhile, patients with BSI have significantly higher PCT_max values than those with LIUI (p=0.034). Among 90 cases with complete data on both PCT1 and PCT2, PCT2 was significantly higher than PCT1 in patients with BSI (median PCT: 0.98 ng/ml vs 0.47 ng/ml; p=0.045) and patients with LIUI (median PCT: 0.43 ng/ml vs 0.24 ng/ml; p=0.004), while not significant in patients with NIF (p=0.374).

CONCLUSION

Two separate PCT measurements can differentiate between infectious fever and NIF and predict for BSI in lymphoma patients with fever.

Stenosis detection and quantification on cardiac CTCA using panoramic MIP of coronary arteries

In this work, we proposed to demonstrate the entire 3D coronary tree using panoramic maximum intensity projection (MIP) of coronary arteries, and to detect and quantify coronary stenosis from computed tomography coronary angiography (CTCA). The performance of the proposed method was assessed in comparison with invasive coronary angiography (ICA) as reference standard. Six anonymized CTCA datasets were tested. MIP method achieved a sensitivity of 82% and a specificity of 95% for the stenosis detection with a good reproducibility (i.e. Cohen's kappa coefficient of 0.74 for the intra-rater agreement, and 0.45 for the inter-raters agreement). In stenosis quantification, three image options are provided. The original density images resulted in an accuracy of 0.85. The edge map images resulted in an accuracy of 0.79. The image combination had a better accuracy of 0.89 than any single image option. In conclusion, the panoramic MIP provided fast and accurate way for the stenosis detection and quantification. It may be helpful to assist the radiologist in identifying the location of the greatest narrowing in clinical practice.

Oncogenic activation of STAT3 pathway drives PD-L1 expression in natural killer/T cell lymphoma

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Background: Natural killer/T-cell lymphoma (NKTL) is a rare type of non-Hodgkin lymphoma that occurs more frequently in East Asia and Latin America and is associated with Epstein–Barr virus infection. Recent whole-exome sequencing studies in NKTL have reported recurrent somatic mutations in genes associated with JAK-STAT pathway, however the role of aberrant JAK-STAT signaling in tumor immune escape through PD-L1 regulation is unclear. Methods: To determine the prevalence of JAK-STAT pathway alteration in NKTL, we performed targeted sequencing of 188 genes associated with JAK-STAT pathway in 109 NKTL (22 Singapore cases, 79 China cases and 8 cell lines). Single nucleotide variants and micro-indels were called using Freebayes and candidate variants annotated using ANNOVAR. Ba/F3 model system was used to test the transformation capacity of identified variants. Cell lines were evaluated for PD-L1 expression by immunoblotting and flow cytometry. Tissue microarrays were examined for p-STAT3 and PD-L1 expression by immunohistochemistry. Results: We identified a total of 284 non-synonymous somatic mutations candidates in 114 genes, including 243 missense, 10 nonsense, 4 splice-site and 27 indel mutations. Recurrent mutations were most frequently located in STAT3 (25/109 cases, 23%) followed by TP53 (16/109 cases, 16%) and JAK3 (8/109 cases, 7%). A total of 18 STAT3 variants were identified including known hotspot mutations and novel mutations in the SH2, coiled coil and DNA-binding domains. Characterization of novel E616K mutant residing in the SH2 domain showed that E616K conferred IL3 independent growth to Ba/F3 cells, increased STAT3 phosphorylation and PD-L1 expression. Consistent with these findings, PD-L1 was over expressed in cell lines harboring STAT3 mutations. A positive correlation between PD-L1 and p-STAT3 expression was also observed in tumor tissue (R = 0.51, P = 0.02). Conclusions: We characterized a novel activating STAT3 mutant and demonstrated its ability to drive PD-L1 expression, which may promote tumor evasion from the antitumor immune response. The combination of PD-1/PD-L1 antibodies and STAT3 inhibitors might be a promising and novel therapeutic approach for NKTL in the future.

Safety and efficacy of abexinostat, a pan-histone deacetylase inhibitor, in non-Hodgkin lymphoma and chronic lymphocytic leukemia: results of a phase II study

Histone deacetylase inhibitors are members of a class of epigenetic drugs that have proven activity in T-cell malignancies, but little is known about their efficacy in B-cell lymphomas. Abexinostat is an orally available hydroxamate-containing histone deacetylase inhibitor that differs from approved inhibitors; its unique pharmacokinetic profile and oral dosing schedule, twice daily four hours apart, allows for continuous exposure at concentrations required to efficiently kill tumor cells. In this phase II study, patients with relapsed/refractory non-Hodgkin lymphoma or chronic lymphocytic leukemia received oral abexinostat at 80 mg BID for 14 days of a 21-day cycle and continued until progressive disease or unacceptable toxicity. A total of 100 patients with B-cell malignancies and T-cell lymphomas were enrolled between October 2011 and July 2014. All patients received at least one dose of study drug. Primary reasons for discontinuation included progressive disease (56%) and adverse events (25%). Grade 3 or over adverse events and any serious adverse events were reported in 88% and 73% of patients, respectively. The most frequently reported grade 3 or over treatment-emergent related adverse events were thrombocytopenia (80%), neutropenia (27%), and anemia (12%). Among the 87 patients evaluable for efficacy, overall response rate was 28% (complete response 5%), with highest responses observed in patients with follicular lymphoma (overall response rate 56%), T-cell lymphoma (overall response rate 40%), and diffuse large B-cell lymphoma (overall response rate 31%). Further investigation of the safety and efficacy of abexinostat in follicular lymphoma, T-cell lymphoma, and diffuse large B-cell lymphoma implementing a less dose-intense week-on-week-off schedule is warranted. (Trial registered at: EudraCT-2009-013691-47)

Simultaneous Inhibition of PI3Kδ and PI3Kα Induces ABC-DLBCL Regression by Blocking BCR-Dependent and -Independent Activation of NF-κB and AKT

Compared with follicular lymphoma, high PI3Kα expression was more prevalent in diffuse large B cell lymphoma (DLBCL), although both tumor types expressed substantial PI3Kδ. Simultaneous inhibition of PI3Kα and PI3Kδ dramatically enhanced the anti-tumor profile in ABC-DLBCL models compared with selective inhibition of PI3Kδ, PI3Kα, or BTK. The anti-tumor activity was associated with suppression of p-AKT and a mechanism of blocking nuclear factor-κB activation driven by CD79^mut, CARD11^mut, TNFAIP3^mut, or MYD88^mut. Inhibition of PI3Kα/δ resulted in tumor regression in an ibrutinib-resistant CD79B^WT/MYD88^mut patient-derived ABC-DLBCL model. Furthermore, rebound activation of BTK and AKT was identified as a mechanism limiting CD79B^mut-ABC-DLBCL to show a robust response to PI3K and BTK inhibitor monotherapies. A combination of ibrutinib with the PI3Kα/δ inhibitor copanlisib produced a sustained complete response in vivo in CD79B^mut/MYD88^mut ABC-DLBCL models.

Genetic risk of extranodal natural killer T-cell lymphoma: a genome-wide association study

BACKGROUND

Extranodal natural killer T-cell lymphoma (NKTCL), nasal type, is a rare and aggressive malignancy that occurs predominantly in Asian and Latin American populations. Although Epstein-Barr virus infection is a known risk factor, other risk factors and the pathogenesis of NKTCL are not well understood. We aimed to identify common genetic variants affecting individual risk of NKTCL.

METHODS

We did a genome-wide association study of 189 patients with extranodal NKTCL, nasal type (WHO classification criteria; cases) and 957 controls from Guangdong province, southern China. We validated our findings in four independent case-control series, including 75 cases from Guangdong province and 296 controls from Hong Kong, 65 cases and 983 controls from Guangdong province, 125 cases and 1110 controls from Beijing (northern China), and 60 cases and 2476 controls from Singapore. We used imputation and conditional logistic regression analyses to fine-map the associations. We also did a meta-analysis of the replication series and of the entire dataset.

FINDINGS

Associations exceeding the genome-wide significance threshold (p<5 × 10(-8)) were seen at 51 single-nucleotide polymorphisms (SNPs) mapping to the class II MHC region on chromosome 6, with rs9277378 (located in HLA-DPB1) having the strongest association with NKTCL susceptibility (p=4·21 × 10(-19), odds ratio [OR] 1·84 [95% CI 1·61-2·11] in meta-analysis of entire dataset). Imputation-based fine-mapping across the class II MHC region suggests that four aminoacid residues (Gly84-Gly85-Pro86-Met87) in near-complete linkage disequilibrium at the edge of the peptide-binding groove of HLA-DPB1 could account for most of the association between the rs9277378*A risk allele and NKTCL susceptibility (OR 2·38, p value for haplotype 2·32 × 10(-14)). This association is distinct from MHC associations with Epstein-Barr virus infection.

INTERPRETATION

To our knowledge, this is the first time that a genetic variant conferring an NKTCL risk is noted at genome-wide significance. This finding underlines the importance of HLA-DP antigen presentation in the pathogenesis of NKTCL.

FUNDING

Top-Notch Young Talents Program of China, Special Support Program of Guangdong, Specialized Research Fund for the Doctoral Program of Higher Education (20110171120099), Program for New Century Excellent Talents in University (NCET-11-0529), National Medical Research Council of Singapore (TCR12DEC005), Tanoto Foundation Professorship in Medical Oncology, New Century Foundation Limited, Ling Foundation, Singapore National Cancer Centre Research Fund, and the US National Institutes of Health (1R01AR062886, 5U01GM092691-04, and 1R01AR063759-01A1).

Using Quality Improvement Methods and Time-Driven Activity-Based Costing to Improve Value-Based Cancer Care Delivery at a Cancer Genetics Clinic

Purpose:

To meet increasing demand for cancer genetic testing and improve value-based cancer care delivery, National Cancer Centre Singapore restructured the Cancer Genetics Service in 2014. Care delivery processes were redesigned. We sought to improve access by increasing the clinic capacity of the Cancer Genetics Service by 100% within 1 year without increasing direct personnel costs.

Methods:

Process mapping and plan-do-study-act (PDSA) cycles were used in a quality improvement project for the Cancer Genetics Service clinic. The impact of interventions was evaluated by tracking the weekly number of patient consultations and access times for appointments between April 2014 and May 2015. The cost impact of implemented process changes was calculated using the time-driven activity-based costing method.

Results:

Our study completed two PDSA cycles. An important outcome was achieved after the first cycle: The inclusion of a genetic counselor increased clinic capacity by 350%. The number of patients seen per week increased from two in April 2014 (range, zero to four patients) to seven in November 2014 (range, four to 10 patients). Our second PDSA cycle showed that manual preappointment reminder calls reduced the variation in the nonattendance rate and contributed to a further increase in patients seen per week to 10 in May 2015 (range, seven to 13 patients). There was a concomitant decrease in costs of the patient care cycle by 18% after both PDSA cycles.

Conclusion:

This study shows how quality improvement methods can be combined with time-driven activity-based costing to increase value. In this paper, we demonstrate how we improved access while reducing costs of care delivery.

Routine Primary Prophylaxis for Febrile Neutropenia with Biosimilar Granulocyte Colony-Stimulating Factor (Nivestim) or Pegfilgrastim Is Cost Effective in Non-Hodgkin Lymphoma Patients undergoing Curative-Intent R-CHOP Chemotherapy

OBJECTIVE

This study aims to compare the cost-effectiveness of various strategies of myeloid growth factor prophylaxis for reducing the risk of febrile neutropenia (FN) in patients with non-Hodgkin lymphoma in Singapore who are undergoing R-CHOP chemotherapy with curative intent.

METHODS

A Markov model was created to compare seven prophylaxis strategies: 1) primary prophylaxis (PP) with nivestim (biosimilar filgrastim) throughout all cycles of chemotherapy; 2) PP with nivestim during the first two cycles of chemotherapy; 3) secondary prophylaxis (SP) with nivestim; 4) PP with pegfilgrastim throughout all cycles of chemotherapy; 5) PP with pegfilgrastim during the first two cycles of chemotherapy; 6) SP with pegfilgrastim; and 7) no prophylaxis (NP). The perspective of a hospital was taken and cost-effectiveness was expressed as the cost per episode of FN avoided over six cycles of chemotherapy. A probabilistic sensitivity analysis was conducted.

RESULTS

Strategies 3, 6, and 7 were dominated in the base case analysis by strategy 5. The costs associated with strategies 2, 5, 1, and 4 were US$3,813, US$4,056, US$4,545, and US$5,331, respectively. The incremental cost-effectiveness ratios for strategy 5 vs. strategy 2, strategy 1 vs. strategy 5, and strategy 4 vs. strategy 1 were US$13,532, US$22,565, and US$30,452, respectively, per episode of FN avoided. Strategy 2 has the highest probability to be cost-effective (ranged from 48% to 60%) when the willingness to pay (WTP) threshold is lower than US$10,000 per FN episode prevented.

CONCLUSION

In Singapore, routine PP with granulocyte colony-stimulating factor (nivestim or pegfilgrastim) is cost-effective for reducing the risk of FN in patients receiving R-CHOP.

JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma

Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.

Antisense oligonucleotide-mediated MDM4 exon 6 skipping impairs tumor growth

MDM4 is a promising target for cancer therapy, as it is undetectable in most normal adult tissues but often upregulated in cancer cells to dampen p53 tumor-suppressor function. The mechanisms that underlie MDM4 upregulation in cancer cells are largely unknown. Here, we have shown that this key oncogenic event mainly depends on a specific alternative splicing switch. We determined that while a nonsense-mediated, decay-targeted isoform of MDM4 (MDM4-S) is produced in normal adult tissues as a result of exon 6 skipping, enhanced exon 6 inclusion leads to expression of full-length MDM4 in a large number of human cancers. Although this alternative splicing event is likely regulated by multiple splicing factors, we identified the SRSF3 oncoprotein as a key enhancer of exon 6 inclusion. In multiple human melanoma cell lines and in melanoma patient-derived xenograft (PDX) mouse models, antisense oligonucleotide-mediated (ASO-mediated) skipping of exon 6 decreased MDM4 abundance, inhibited melanoma growth, and enhanced sensitivity to MAPK-targeting therapeutics. Additionally, ASO-based MDM4 targeting reduced diffuse large B cell lymphoma PDX growth. As full-length MDM4 is enhanced in multiple human tumors, our data indicate that this strategy is applicable to a wide range of tumor types. We conclude that enhanced MDM4 exon 6 inclusion is a common oncogenic event and has potential as a clinically compatible therapeutic target.

Incidence and Management of Toxicity Associated with LAsparaginase in the Treatment of ALL and NK/TCell Lymphoma: an Observational Study

BACKGROUND

Lasparaginase (ASNase) is commonly used in the treatment of acute lymphoblastic leukemia (ALL) and natural killer (NK)/Tcell lymphoma. This study was designed to describe the incidence of toxicity associated with ASNase in Asian adults. Secondary objectives were to investigate the management and impact of toxicity on subsequent ASNase use, and to compare the actual management against current recommendations.

MATERIALS AND METHODS

In this retrospective, multicenter, observational study, Asian patients ≥ 18 years old who received ≥ 1 dose of the native E. coli ASNase from 2008 to 2013 were included. Patients were excluded if they did not receive ASNase. Endpoints of this study were development of specific toxicities, whether ASNase was discontinued or rechallenged, and developmentg of recurrent toxicity. All data analyses were performed using SPSS version 20.0.

RESULTS

A total of 56 patients were analyzed. Mean (±SD) age was 36.2 (±15.2) years old, with 62.5% being males, 55.4% with ALL and 28.6% with NK/Tcell lymphoma. Hypersensitivity (12.5%) was associated with the highest incidence of toxicity (6 out of 7 patients had Grade 3 and 4 toxicity), followed by 10.7% for hepatic transaminitis, 3.6% for nonCNS thrombosis and 1.8% each for hyperbilirubinemia and pancreatitis. Hypersensitivity recurred in the 3 patients who were rechallenged with E. coli ASNase.

CONCLUSIONS

ASNase is associated with a wide range of toxicities, with hypersensitivity being the most commonly observed among Asian adult patients.