Impact of Implementing a Bendamustine-Based Conditioning Regimen on Outcomes of Autologous Stem Cell Transplantation in Lymphoma while Novel Cellular Therapies Emerge

With the advent of new cellular and targeted therapies, treatment options for relapsed and refractory (r/R) lymphomas have multiplied, and the optimal approach offering the best outcomes remains a matter of passionate debate. High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is still considered a treatment option for patients with chemosensitive lymphoma when cure is the expected goal. The myeloablative conditioning regimen preceding the stem cell infusion is considered the effective component of this approach. Carmustine (BCNU)-based preparative regimens, such as BEAM and BEAC, are considered the standard of care and have shown efficacy and low nonrelapse mortality (NRM). Comparative studies between conditioning regimens have failed to identify a better option. After a BCNU drug shortage in Canada followed by a steep increase in price, we elected to substitute BCNU for bendamustine (benda) in the preparative regimen. The purpose of this substitution was to improve response while preserving safety and controlling costs. From May 2015 to May 2018, a total of 131 consecutive lymphoma patients received benda-EAM conditioning. These patients were compared with 96 consecutive patients who received BCNU-based conditioning from January 2012 to May 2015. Apart from conditioning, supportive care measures were the same in the 2 groups. Patients receiving benda were older (55.7 years versus 51.1 years; P = .002). The development of grade ≥3 mucositis was more frequent with benda conditioning (39.5% versus 7.8%; P < .001) leading to a greater requirement for parenteral nutrition (48.9% versus 21.9%; P < .001). A transient creatinine increase >1.5 times the upper limit of normal (15.3% versus 4.2%; P < .008) and intensive care unit admission (6.9% versus 1.1%; P < .029) were more frequent with benda; however, there were no between-group differences in cardiac, pulmonary, or liver toxicity and NRM. With a median follow-up of 48 months for the benda group and 60 months for the BCNU group, benda was associated with significantly better progression-free survival (71% versus 61%; P = .040; hazard ratio [HR], 1.6; 95% confidence interval [CI], 1.0 to 2.7) and overall survival (86% vs 71%; P = .0066; HR, 2.6; 95% CI, 1.3 to 5.4) compared with BCNU-based conditioning regimens. While novel therapies emerge, our study demonstrates that benda-EAM is safe and effective and should be considered a valid alternative to BCNU conditioning to improve outcomes of patients with chemosensitive r/R lymphomas undergoing ASCT.

Real-world outcomes of autologous and allogeneic hematopoietic stem cell transplantation for relapsed/refractory Hodgkin lymphoma in the era of novel therapies: a Canadian perspective

BACKGROUND

Despite high cure rates with frontline therapy for Hodgkin lymphoma (HL), about 30% of patients will relapse or have primary refractory disease (R/r). Autologous hematopoietic stem cell transplantation (AHSCT) is the standard of care for R/r disease and alloHSCT is a curative option for patients in second relapse. Novel agents are being incorporated for the treatment of R/r HL, such that the optimal timing of transplant is currently being challenged. Additionally, because access to these new agents varies amongst transplant centers, we sought to offer a Canadian perspective to the treatment of R/r HL and demonstrate the utility and effectiveness of both AHSCT and alloHSCT for the treatment of R/r HL.

METHODS

This single-center retrospective study examined outcomes in 89 consecutive patients with R/r HL treated with AHSCT between January 2007 and December 2019. A total of 17 patients underwent alloHSCT either as a tandem auto-allo approach or as salvage therapy.

RESULTS

With a median follow-up of 5.0 years, the estimated 5-year PFS and OS for patients undergoing AHSCT were 57.5% (95% CI 45.2-68.0) and 81.3% (95% CI 70.0-88.8), respectively. Corresponding figures for patients who underwent alloHSCT were 76.5% (95% CI 48.8-90.4) and 82.4% (95% CI 54.7-93.9). NRM at 100 days and 5 years was 0% and 9.4% post AHSCT and 0% and 5.9% post alloHSCT. Cumulative incidence (CI) of acute GVHD at day +100 was 35.3% (95% CI 17.7 - 62.3) and CI of chronic GVHD at 1 year was 23.5% (95% CI 6.9 - 45.8).

CONCLUSIONS

AHSCT and alloHSCT can both provide robust and prolonged disease control and new agents should be used as a bridge to improve the curative potential of these definitive cellular therapies.

Dasatinib dose optimisation based on therapeutic drug monitoring reduces pleural effusion rates in chronic myeloid leukaemia patients

Dasatinib is a second-generation BCR-ABL1 tyrosine kinase inhibitor approved for patients with chronic myeloid leukaemia (CML). Dasatinib 100 mg per day is associated with an increased risk of pleural effusion (PlEff). We randomly evaluated whether therapeutic drug monitoring (TDM) may reduce dasatinib-associated significant adverse events (AEs) by 12 months (primary endpoint). Eligible patients started dasatinib at 100 mg per day followed by dasatinib (C)min assessment. Patients considered overdosed [(C)min ≥ 3 nmol/l) were randomised between a dose-reduction strategy (TDM arm) and standard of care (control arm). Out of 287 evaluable patients, 80 patients were randomised. The primary endpoint was not met due to early haematological AEs occurring before effective dose reduction. However, a major reduction in the cumulative incidence of PlEff was observed in the TDM arm compared to the control arm (4% vs. 15%; 11% vs. 35% and 12% vs. 39% at one, two and three years, respectively (P = 0·0094)). Molecular responses were superimposable in all arms. Dasatinib TDM during treatment initiation was feasible and resulted in a significant reduction of the incidence of PlEff in the long run, without impairing molecular responses. (NCT01916785; https://clinicaltrials.gov).

Long-term safety and efficacy of the PI3K inhibitor copanlisib in patients with relapsed or refractory indolent lymphoma: 2-year follow-up of the CHRONOS-1 study

Safety profiles of oral PI3K inhibitors have resulted in US FDA black box warnings regarding fatal/serious toxicities. The approved intravenous PI3K inhibitor copanlisib has low incidence of severe toxicities and no black box warnings, but chronic treatment effects were unknown. We provide an update on safety and efficacy of copanlisib with a minimum 2-year follow-up of the CHRONOS-1 study. A total of 142 patients with histologically confirmed indolent B-cell lymphoma who had relapsed after or were refractory to ≥2 prior treatments received intravenous copanlisib 60 mg on days 1, 8, and 15 (28-day cycle). The primary efficacy endpoint was objective response rate (ORR) after ≥4 cycles (independent assessment). The predominant histology was follicular lymphoma (n = 104). The ORR was 60.6% (seven additional complete responses since primary analysis). Secondary endpoints of median duration of response, progression-free survival, and overall survival were 14.1 months (median follow-up, 16.1 months), 12.5 months (median follow-up, 14.0 months), and 42.6 months (median follow-up, 31.5 months), respectively. Median safety follow-up was 6.7 months; 26% of patients received treatment for >1 year. Common treatment-emergent adverse events (TEAEs) (all grade/grade 3/grade 4) were transient hyperglycemia (50.0%/33.1%/7.0%), diarrhea (35.2%/8.5%/0%), transient hypertension (29.6%/23.9%/0%), and neutropenia (28.9%/9.2%/14.8%). Serious AEs were largely unchanged, with no new cases of pneumonitis (4.2%), diarrhea (2.8%), or grade 5 events. Note, TEAEs showed no evidence for increased incidence or worsening following longer exposure in patients treated >1 year. Long-term follow-up of patients with relapsed/refractory indolent B-cell lymphoma treated with intravenous copanlisib demonstrated durable, enhanced responses without evidence of worsening TEAEs, as reported for orally administered PI3K inhibitors.

Evaluation of the Impact of Autologous Hematopoietic Stem Cell Transplantation on the Quality of Life of Older Patients with Lymphoma

High-dose chemotherapy (HDT) followed by autologous hematopoietic stem cell transplantation (AHSCT) improves survival in patients with chemosensitive non-Hodgkin lymphoma (NHL). Determination of the Hematopoietic Cell Transplantation Comorbidity Index (HCT-CI) has contributed to improve patient selection while allowing for prediction of nonrelapse mortality. We previously demonstrated the efficacy and safety of AHSCT in a cohort of older patients with chemosensitive NHL. Quality of life following AHSCT still has not been widely evaluated. The goal of this study was to assess the long-term quality of life of elderly patients surviving AHSCT. This single-center, Research and Ethics Committee-approved study investigated QoL in survivors of AHSCT for the treatment of NHL in a cohort of older patients. Inclusion criteria were defined as patients age ≥60 years who underwent AHSCT for NHL between January 1, 2008, and January 1, 2015, at our center. Fifty-nine patients from the original cohort of 90 survived at a median of 50 months post-AHSCT. Forty-seven (79.7%) of those patients agreed to complete the QoL assessment questionnaires after the transplantation and are included in this report. All patients provided signed informed consent. We used the EQ-5D instrument to assess mobility, self-care, usual activities, pain/discomfort, and anxiety/depression and the Functional Assessment of Cancer Therapy-Bone Marrow Transplant (FACT-BMT) questionnaire to assess physical, social/family, emotional, and functional well-being and BMT-specific concerns. With both tools, a higher score indicates better QoL. Fifteen percent of patients were in relapse at the time of the QoL assessment. In the EQ-5D, few patients (9%) reported severe impairment, which requires significant negative effects in 4 or 5 domains. Lower Karnofsky Performance Status (KPS) score at the time of transplantation was negatively correlated with mobility (P= .001), self-care (P= .001), and usual activities (P= .007) dysfunction. Anxiety was significant for patients in relapsed after transplantation (P= .002). FACT-BMT questionnaire results demonstrated that physical, social, and emotional well-being were all well preserved after the transplantation, whereas functional well-being was more variable among patients. Relapse was associated with impaired functional well-being (P= .007) and lower total FACT-BMT score (P= .014). Other comparators, including the conditioning regimen, sex, age subgroups (<65 or ≥65 years), HCT-CI score, and disease status at transplantation, did not impact any of these outcomes. This study demonstrates that physical, social, and functional well-being are preserved in older patients following AHSCT. Low KPS score before AHSCT is a predictor of disability at distance from AHSCT. Relapse following AHSCT remains the most significant impediment to maintaining a good QoL. Innovative interventions to improve performance status before transplantation and measures to prevent relapse thereafter should be investigated to improve survival and QoL.

Long-term follow-up of patients (pts) with relapsed or refractory (r/r) follicular lymphoma (FL) treated with copanlisib

7553

Background: The pan-class I phosphatidylinositol 3-kinase inhibitor copanlisib was approved by the FDA in September 2017 for treatment of relapsed FL based on results from the CHRONOS-1 study in pts with indolent non-Hodgkin lymphoma. We report efficacy and safety results of a 2-year (yr) follow-up of FL pts. Methods: Pts with indolent FL (grade [G] 1-3a) r/r to ≥2 prior lines of treatment received copanlisib (60 mg i.v. infusion) on days 1, 8, and 15 of a 28-day cycle. The primary endpoint was objective tumor response rate (ORR) per independent radiologic review (Cheson et al. 2007). Adverse events were reported using MedDRA (v20.1). Data cut-off: February 20, 2018. Results: 104 FL pts were enrolled. Median age was 62 yr (39% >65 yr), the median number of prior lines of anti-cancer therapy was 3 (range 2-8), and 27 pts (26%) were classified as having G3a disease. The ORR was 59%, with complete responses (CR) in 20% ( n=21); 14 pts had a CR at the primary analysis in June 2016. The median duration of response (mDoR) was 12.2 months (mo) (range 0.03-43 mo). Stable disease (SD) was observed in 33% of pts; median duration of SD was 7.8 mo (range 1.3-23 mo). Median progression-free survival (mPFS) was 11.2 mo (range 0.03-44 mo) with 33% alive and progression-free at 2 yrs. Median overall survival (mOS) was 3.2 yr (range 0.06-4.2 yr) with 67% alive at 2 yrs. Median duration of treatment was 26 weeks (wk) (range 1-192 wk); median duration of safety follow-up was 29 wk. In the G3a subset, the ORR was 67% (26% CR), mDoR was 10.9 mo, mPFS was 12.5 mo, and mOS was 2.5 yr. The most common treatment-emergent adverse events occurring in >25% of pts included (all grade/G3+): diarrhea (37%/9%), neutropenia (26%/23%), and pyrexia (28%/5%). Hyperglycemia (49%/40%) and hypertension (29%/23%) were transient. Incidences of pneumonitis (6.7%/1.9%) and colitis (1.0% G4) were low. Conclusions: Long-term follow-up of r/r FL pts treated with copanlisib revealed robust and durable responses with CRs exceeding 20%, including in pts with higher grade disease. The safety profile continues to be both manageable and favorable, with no evidence of late-onset severe toxicities. Clinical trial information: NCT01660451.

Molecular monitoring of therapeutic milestones and clinical outcomes in patients with chronic myeloid leukemia

BACKGROUND

In the current study, the authors determined whether adhering to molecular monitoring guidelines in patients with chronic myeloid leukemia (CML) is associated with major molecular response (MMR) and assessed barriers to adherent monitoring.

METHODS

Newly treated patients with CML from the Quebec province-wide CML registry from 2005 to 2016 were included. Timely polymerase chain reaction (tPCR) was defined as the molecular assessment of BCR-ABL1 at the 3-month, 12-month, and 18-month time points from the initiation of tyrosine kinase inhibitor (TKI) therapy. The cohort was analyzed as a nested case-control study. Cases with a first-ever MMR (BCR-ABL1 ≤0.1%, assessed at any time during follow-up) were matched to up to 5 controls by duration of TKI therapy, volume of patients with CML at the treatment center, year of cohort entry, and age. Odds ratios (ORs) for the performance of tPCR and MMR were adjusted for sex, comorbidities, type of TKI, and other important covariates.

RESULTS

The cohort included 496 patients. Of 392 MMR events, 67.9% occurred before 18 months. The performance of tPCR was associated with a doubling of the MMR rate (OR, 2.23; 95% confidence interval [95% CI], 1.56-3.21) and was similar with 1 to 3 tPCRs performed (P = .67). Furthermore, tPCRs at 3 months (OR, 2.77; 95% CI, 1.81-4.23) and 12 months (OR, 3.00; 95% CI, 1.64-5.49) were associated with achieving early MMR, whereas tPCRs at 18 months were not (OR, 1.23; 95% CI, 0.80-1.89). Low-volume centers were found to have lower adherence to tPCR (OR, 0.60; 95% CI, 0.40-0.89).

CONCLUSIONS

Timely molecular assessment at 3 months and 12 months appears to benefit patients with CML. Adherence to timely monitoring should be encouraged, especially in low-volume treatment centers.

Outcome of autologous hematopoietic stem cell transplant in older patients with B cell lymphoma when selected for fitness and chemosensitive disease

BACKGROUND

Autologous hematopoietic stem cell transplantation (AHSCT) in the older population is associated with an increased risk of morbidity and mortality. Determination of the hematopoietic cell transplant comorbidity index (HCT-CI) has contributed to improve patient selection while allowing prediction of their non-relapse mortality (NRM). The goal of this study was to identify factors influencing both safety and efficacy of AHSCT in an older non-Hodgkin lymphoma (NHL) population to better select those who will benefit from this intervention in the Canadian context of a single-payer government healthcare program.

METHODS

This single center, retrospective study, examined clinical outcomes in 90 consecutive older patients (≥60 years old) with B-cell NHL treated with AHSCT between 2008 and 2014.

FINDINGS

Median age was 63 (60-69) at time of transplantation. The HCT-CI risk score was low, intermediate and high in 34%, 40% and 26% of patients, respectively. NRM was 1% at 100 days and one-year post transplant and not influenced by age. At a median follow-up of 52 months, median progression-free survival (PFS) was 56 months while median overall survival (OS) was still not reached. Stable and progressive disease status at time of transplantation were associated with a lower PFS (HR 2.94) and OS (HR 3.91). BEAC conditioning and a graft cell dose  5 × 10⁶ CD34+/kg led to faster recovery, decreased toxicity and resource consumption.

INTERPRETATION

In the older population, AHSCT is safe and optimal when restricted to fit chemosensitive patients.

Concise Review: Age-Related Clonal Hematopoiesis: Stem Cells Tempting the Devil

The recent characterization of clonal hematopoiesis in a large segment of the aging population has raised tremendous interest and concern alike. Mutations have been documented in genes associated with hematological cancers and in non-driver candidates. These mutations are present at low frequency in the majority of individuals after middle-age, and principally affect the epigenetic modifiers DNMT3A and TET2. In 10%-40% of cases, the clone will progress to meet the diagnostic criteria for Clonal Hematopoiesis of Indeterminate Potential, which is associated with an increased risk of hematological cancer and cardiovascular mortality. Blood cell parameters appear unmodified in these individuals, but a minority of them will develop a hematologic malignancy. At this time, the factors put forward as potentially influencing the risk of cancer development are clone size, specific gene, specific mutation, and the number of mutations. Specific stress on hematopoiesis also gives rise to clonal expansion. Genotoxic exposure (such as chemotherapy), or immune attack (as in aplastic anemia) selects/provides a fitness advantage to clones with a context-specific signature. Clonal hematopoiesis offers a new opportunity to understand the biology and adaptation mechanisms of aging hematopoiesis and provides insight into the mechanisms underlying malignant transformation. Furthermore, it might shed light on common denominators of age-associated medical conditions and help devise global strategies that will impact the prevention of hematologic cancers and promote healthy aging. Stem Cells 2018;36:1287-1294.

Phosphatidylinositol 3-Kinase Inhibition by Copanlisib in Relapsed or Refractory Indolent Lymphoma

Purpose

Phosphatidylinositol 3-kinase (PI3K) signaling is critical for the proliferation and survival of malignant B cells. Copanlisib, a pan-class I PI3K inhibitor with predominant activity against PI3K-α and -δ isoforms, has demonstrated efficacy and a manageable safety profile in patients with indolent lymphoma.

Patients and Methods

In this phase II study, 142 patients with relapsed or refractory indolent lymphoma after two or more lines of therapy were enrolled to receive copanlisib 60 mg intravenously on days 1, 8, and 15 of a 28-day cycle. The primary end point was objective response rate; secondary end points included duration of response, progression-free survival, and overall survival. In addition, safety and gene expression were evaluated.

Results

Median age was 63 years (range, 25 to 82 years), and patients had received a median of three (range, two to nine) prior regimens. The objective response rate was 59% (84 of 142 patients); 12% of patients achieved a complete response. Median time to response was 53 days. Median duration of response was 22.6 months, median progression-free survival was 11.2 months, and median overall survival had not yet been reached. The most frequent treatment-emergent adverse events were transient hyperglycemia (all grades, 50%; grade 3 or 4, 41%) and transient hypertension (all grades, 30%; grade 3, 24%). Other grade ≥3 events included decreased neutrophil count (24%) and lung infection (15%). High response rates to copanlisib were associated with high expression of PI3K/B-cell receptor signaling pathway genes.

Conclusion

PI3K-α and -δ inhibition by copanlisib demonstrated significant efficacy and a manageable safety profile in heavily pretreated patients with relapsed or refractory indolent lymphoma.

Abstract CT149: Copanlisib in patients with relapsed or refractory indolent B-cell lymphoma: Primary results of the pivotal Chronos-1 study

Introduction: There are limited treatment options for patients with indolent B-cell lymphoma who have relapsed or are refractory to standard therapies. Copanlisib is an intravenously administered pan-Class I phosphatidylinositol 3-kinase (PI3K) inhibitor with predominant activity against PI3K-α and PI3K-δ isoforms. We report here the primary results from a pivotal phase II study (NCT01660451, part B).

Methods: Patients with indolent B-cell non-Hodgkin lymphoma (4 subtypes: follicular [FL], marginal zone [MZL], small lymphocytic [SLL] and lymphoplasmacytoid/Waldenström macroglobulinemia [LPL-WM]) and relapsed after, or refractory to, ≥2 prior lines of treatment were eligible. Previous treatment had to include rituximab and an alkylating agent. Copanlisib (60 mg, I.V.) was intermittently administered on days 1, 8 and 15 of a 28-day cycle. The primary efficacy endpoint was objective tumor response rate (ORR) as assessed per independent radiologic review (Cheson et al., JCO 20:579, 2007).

Results: The full analysis set comprised 142 patients, of which 141 patients had indolent lymphoma (FL/MZL/SLL/LPL-WM: 104/23/8/6). At the time of primary analysis, median duration of treatment was 22 weeks (range 1-105); 46 patients remained on treatment. The most common treatment-related AEs (all grade/grade 3+) were transient hyperglycemia (49%/40%) and hypertension (29%/23%). Other AEs of interest included neutropenia (25%/19%), diarrhea (18%/4%), lung infection (14%/11%), pneumonitis (7%/1.4%), and colitis (0.7%/0.7%). No colonic perforations occurred. There were two non-fatal opportunistic infections. Laboratory toxicities of interest were principally grade-1, including alanine aminotransferase (23% all-grade/19% grade-1) and aspartate aminotransferase (28%/25%). There were 6 deaths, 3 of which were attributed to copanlisib: lung infection, respiratory failure, and a thromboembolic event. The ORR was 59.2%, including 12.0% complete response (CR) and 47.2% partial response (PR), with stable disease in 29.6% of patients and progressive disease in 2.1% of patients. In the FL subset, the ORR was 58.7%, including 14.4% CR and 44.2% PR. In the MZL subset, the ORR was 69.6%, including 8.7% CR and 60.9% PR. The estimated Kaplan-Meier (KM) median duration of response in the full analysis set was 687 days (range 0-687) and 370 days (range 0-687) in the FL subset. The KM-estimate of median PFS was 340 days (range 0-736). Median overall survival had not yet been reached.

Conclusions: Treatment of patients with relapsed or refractory indolent B-cell lymphoma with copanlisib resulted in durable tumor responses. Administration of copanlisib had a manageable safety profile, with low rates of severe hepatic enzymopathy, diarrhea or inflammatory events, as well as low rates of opportunistic infections, fatal infections or other fatal serious adverse events.

Citation Format: Martin Dreyling, Armando Santoro, Luigina Mollica, Sirpa Leppä, George A. Follows, Georg Lenz, Won Seog Kim, Arnon Nagler, Panayiotis Panayiotidis, Judit Demeter, Muhit Özcan, Marina Kosinova, Krimo Bouabdallah, Franck Morschhauser, Don A. Stevens, David Trevarthen, Marius Giurescu, Lisa Kupit, Shuxin Yin, Florian Hiemeyer, Jose Garcia-Vargas, Barrett H. Childs, Pier Luigi Zinzani. Copanlisib in patients with relapsed or refractory indolent B-cell lymphoma: Primary results of the pivotal Chronos-1 study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT149. doi:10.1158/1538-7445.AM2017-CT149

Copanlisib in patients with relapsed or refractory follicular lymphoma

7535

Background: Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma (iNHL) subtype, yet treatment options in the relapsed/refractory (r/r) setting are limited. Copanlisib is a pan-Class I phosphatidylinositol 3-kinase (PI3K) inhibitor with predominant PI3K-α and PI3K-δ activity. We report results from the FL subset of a large phase II study (n=141) in iNHL patients (pts) (NCT01660451, part B). Methods: A total of 104 pts with indolent FL (grade 1-3a) relapsed/refractory to ≥2 prior lines of treatment were treated with copanlisib (60 mg IV infusion) administered on days 1, 8 and 15 of a 28-day cycle. The primary endpoint was objective tumor response rate (ORR) per independent radiologic review (Cheson et al., JCO 20:579, 2007). Results: Of the 104 pts treated, 62% were refractory; median prior lines 3 (range 2-8), median time from progression 8 wks (range 1-73 wks). 52% were male, 83% white, median age 62 yrs, and 62% ECOG 0. At the time of primary analysis the ORR was 58.7%, comprising 15 pts (14.4%) with complete response (CR) and 46 (44.2%) with partial response. Stable disease was observed in 35 (33.7%) pts and progression of disease as best response in 2 pts. The median duration of response was 370 days (range 0-687), with 43 responders censored at data cut-off. Median duration of treatment was 22 wks (range 1-105); 33 (32%) pts remained on treatment. For all pts, the most common treatment-emergent AEs occurring in >25% of pts included (all grade/grade 3+): diarrhea (34%/5%), reduced neutrophil count (30%/24%), fatigue (30%/2%), and fever (25%/4%). Hyperglycemia (50%/41%) and hypertension (30%/24%) were transient. The incidence of pneumonitis (8%/1.4%), hepatic enzymopathy (AST 28%/1.4%; ALT 23%/1.4%), opportunistic infection (1.4%) and colitis (0.7%) were low. Six deaths were observed, 3 of which were attributed to copanlisib: one lung infection, one respiratory failure, and one thromboembolic event. Conclusions: Copanlisib was highly active as a single agent in heavily pretreated r/r FL pts and resulted in durable responses in the majority of pts. Toxicities were manageable, with a low incidence of severe AEs associated with other PI3K inhibitors, especially hepatic enzymopathy, opportunistic infections, and colitis. Clinical trial information: NCT01660451.

Protein-ligand (un)binding kinetics as a new paradigm for drug discovery at the crossroad between experiments and modelling

In the last three decades, protein and nucleic acid structure determination and comprehension of the mechanisms, leading to their physiological and pathological functions, have become a cornerstone of biomedical sciences. A deep understanding of the principles governing the fates of cells and tissue at the molecular level has been gained over the years, offering a solid basis for the rational design of drugs aimed at the pharmacological treatment of numerous diseases. Historically, affinity indicators (i.e. Kd and IC50/EC50) have been assumed to be valid indicators of the in vivo efficacy of a drug. However, recent studies pointed out that the kinetics of the drug-receptor binding process could be as important or even more important than affinity in determining the drug efficacy. This eventually led to a growing interest in the characterisation and prediction of the rate constants of protein-ligand association and dissociation. For instance, a drug with a longer residence time can kinetically select a given receptor over another, even if the affinity for both receptors is comparable, thus increasing its therapeutic index. Therefore, understanding the molecular features underlying binding and unbinding processes is of central interest towards the rational control of drug binding kinetics. In this review, we report the theoretical framework behind protein-ligand association and highlight the latest advances in the experimental and computational approaches exploited to investigate the binding kinetics.

Human blood cell levels of 5-hydroxymethylcytosine (5hmC) decline with age, partly related to acquired mutations in TET2

Epigenetic alteration may play a role in age-associated dysfunction of stem cells and predispose to the development of hematological cancers. We analyzed global levels of hematopoietic 5-hydroxymethylcytosine (5hmC) and 5-methylcytosine (5mC) in a cross-sectional study comprising 198 unrelated individuals from four age categories (neonates, 25-30, 70-75, and >90 years old) by liquid chromatography-electrospray ionization-tandem mass spectrometry with multiple reaction monitoring. X-chromosome inactivation (XCI) ratios and telomere length (TL) were measured in all individuals by polymerase chain reaction. Sequencing of epigenetic regulator genes (including TET2, DNMT3A, ASXL1, IDH1, IDH2, and WT1) was performed in the two older subcohorts. We found that global 5hmC levels declined with age in human blood cells (27.5% reduction from birth to old age, p < 0.0005). The levels of 5mC underwent a more modest reduction (2.4% drop) between newborns and the elderly (p < 0.0005). Low 5hmC was associated with increased skewing of XCI (age-adjusted p = 0.0304) and reduced TL (age-adjusted p = 0.0354), both surrogate markers of clonal dominance. Of the 100 individuals over the age of 70, 16 had somatic mutations in TET2, 14 in DNMT3A, and none in IDH1, IDH2, or WT1. Individuals with TET2 mutations had significantly lower 5hmC (relative to unmutated individuals), whereas DNMT3A-mutated subjects did not. However, mutations in TET2 cannot account solely for the decline in 5hmC levels observed with aging because unmutated older individuals also had lower 5hmC levels compared with younger individuals. This suggests that the age-associated decline in 5hmC is multifactorial. Larger prospective studies are needed to determine whether 5hmC reduction is a biomarker of hematological cancer development.

Modified Corneosurfametry as a new accelerated high-throughput ex vivo methodology for predicting cleanser effects towards human skin

BACKGROUND

Corneosurfametry (CSM) was originally developed as a tool to predict irritation potential of cleansers. In this method, surface skin stripped using cyanoacrylate is contacted with surfactants/products, rinsed and stained with toluidine blue and basic fuschin dyes. The intensity of staining increases with increases in irritation potential of surfactant. Our objective was to modify the CSM technique to achieve better control of the tape stripping process. Another objective was to correlate the modified CSM (MCSM) with a traditional in-vivo forearm controlled application test (FCAT) for mildness and to explore its utility to assess the state of corneum after a clinical test.

METHODS

Surface skin cells were tape stripped from forearms of volunteers with D-Squame Adhesive Discs. Discs were treated with a 10% solution of the product in a 96-plate well for 10 min, rinsed, dried and treated with basic fuschin-toluidine blue dye solution, rinsed and dried again. Forearm Controlled Application Test (FCAT) was based on a published protocol. Tape strips obtained after product treatment were also analyzed by the MCSM procedure without additional product treatment.

RESULTS

Mildness/barrier damage assessed from in-vivo FCAT showed a similar ranking to the MCSM results. MCSM, TEWL and Erythema analysis of between-treatment differences showed a good correlation indicating that barrier damage seen in in-vivo studies can be predicted from ex-vivo MCSM studies. MCSM analysis of tape strips after the FCAT study showed that the damage decreased with increase in tape strip number. A moisturizing body wash (MBW) with mild surfactants showed the least damage in all layers. In contrast, harsh dish washing liquid showed significantly higher damage down to several layers. Another MBW with petrolatum in a harsher base showed damage almost similar to that of the harsh dish washing liquid in the surface layers. Thus, the MCSM was able to show underlying damage which would have been normally masked by the deposited petrolatum.

CONCLUSION

The MCSM assay was shown to be a valuable tool for accelerated high throughput evaluation of mildness of surfactants and fully formulated products. MCSM can also be used to assess the state of the corneum after a product treatment.

Recurrent somatic TET2 mutations in normal elderly individuals with clonal hematopoiesis

Aging is characterized by clonal expansion of myeloid-biased hematopoietic stem cells and by increased risk of myeloid malignancies. Exome sequencing of three elderly females with clonal hematopoiesis, demonstrated by X-inactivation analysis, identified somatic TET2 mutations. Recurrence testing identified TET2 mutations in 10 out of 182 individuals with X-inactivation skewing. TET2 mutations were specific to individuals with clonal hematopoiesis without hematological malignancies and were associated with alterations in DNA methylation.

Telomere length is severely and similarly reduced in JAK2V617F-positive and -negative myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) are clonal stem cell disorders characterized by chronic proliferation of hematopoietic progenitors. We studied the telomere length (TL) of 335 MPN patients and 93 gender- and age-matched controls using a quantitative PCR method (relative TL calculated as the ratio of the amount of telomere DNA vs single-copy DNA: T/S ratio). TL was markedly reduced in MPN patients compared with controls (T/S 0.561 vs 0.990, P<0.001). In JAK2V617F MPN patients, TL correlated inversely with allelic burden (P<0.001). Patients homozygous for the mutation (allelic burden 90-100%) had the shortest TL, even when compared with patients with lower allele burdens consistent with a dominant heterozygous population (allelic burden 55-65%) (T/S 0.367 vs 0.497, P=0.037). This suggests that the high degree of proliferation of the MPN clone reduces TL and suggests the possibility that TL shortening may be indicative of progressive genomic instability during MPN progression. The TL of JAK2V617F-negative MPN patients was similar to JAK2V617F-positive counterparts (T/S 0.527 vs 0.507, P=0.603), suggesting that the yet-to-be-discovered causative mutation(s) impact the mutated stem cell similarly to JAK2V617F, and that TL measurement may prove useful in the diagnostic workup of JAK2V617F-negative MPN.

Hb Montreal II: a novel elongated beta-globin variant caused by a frameshift mutation [beta142 (-C)]

We report a novel elongated C-terminal beta hemoglobin (Hb) variant caused by a single nucleotide (C) deletion at codon 143 (nucleotide 480 of GenBank entry NM_000518). This deletion leads to the substitution of histidine 143 by threonine, and displaces the beta Hb gene stop codon from codon 147 to codon 157. It was identified in a 30-year-old man from Montreal, and called Hb Montreal II. This Hb variant differs from its normal counterpart by 14 residues, the latter 10 being identical to those observed in Hbs Tak, Cranston, Saverne, Trento, and Florida. The patient did not present thalassemic features but had a compensated chronic hemolysis with splenomegaly, red cell inclusion bodies, and a positive Kleihauer test.

No evidence that skewing of X chromosome inactivation patterns is transmitted to offspring in humans

Skewing of X chromosome inactivation (XCI) can occur in normal females and increases in tissues with age. The mechanisms underlying skewing in normal females, however, remain controversial. To better understand the phenomenon of XCI in nondisease states, we evaluated XCI patterns in epithelial and hematopoietic cells of over 500 healthy female mother-neonate pairs. The incidence of skewing observed in mothers was twice that observed in neonates, and in both cohorts, the incidence of XCI was lower in epithelial cells than hematopoietic cells. These results suggest that XCI incidence varies by tissue type and that age-dependent mechanisms can influence skewing in both epithelial and hematopoietic cells. In both cohorts, a correlation was identified in the direction of skewing in epithelial and hematopoietic cells, suggesting common underlying skewing mechanisms across tissues. However, there was no correlation between the XCI patterns of mothers and their respective neonates, and skewed mothers gave birth to skewed neonates at the same frequency as nonskewed mothers. Taken together, our data suggest that in humans, the XCI pattern observed at birth does not reflect a single heritable genetic locus, but rather corresponds to a complex trait determined, at least in part, by selection biases occurring after XCI.

Hypomorphic promoter mutation in PIGM causes inherited glycosylphosphatidylinositol deficiency

Attachment to the plasma membrane by linkage to a glycosylphosphatidylinositol (GPI) anchor is a mode of protein expression highly conserved from protozoa to mammals. As a clinical entity, deficiency of GPI has been recognized as paroxysmal nocturnal hemoglobinuria, an acquired clonal disorder associated with somatic mutations of the X-linked PIGA gene in hematopoietic cells. We have identified a novel disease characterized by a propensity to venous thrombosis and seizures in which deficiency of GPI is inherited in an autosomal recessive manner. In two unrelated kindreds, a point mutation (c --> g) at position -270 from the start codon of PIGM, a mannosyltransferase-encoding gene, disrupts binding of the transcription factor Sp1 to its cognate promoter motif. This mutation substantially reduces transcription of PIGM and blocks mannosylation of GPI, leading to partial but severe deficiency of GPI. These findings indicate that biosynthesis of GPI is essential to maintain homeostasis of blood coagulation and neurological function.

Autoantibodies to thrombin directed against both of its cryptic exosites

Immunoglobulin G (IgG) anti-thrombin autoantibodies (ATA) were purified from the plasma of a patient referred for haematological investigation because of bleeding for 24 h following a dental extraction. The ATA did not inhibit the catalytic activity of thrombin against a chromogenic substrate, suggesting that they did not interact with the active site of thrombin. The ATA did, however, prolong the time required to generate thrombin in plasma, suggesting that they inhibited factor V and factor VIII activation. Surface plasmon resonance (SPR) was used to demonstrate that ATA bound to thrombin with high affinity. Competition of thrombin-ATA binding, using known thrombin exosite I and II ligands (hirudin, thrombomodulin and heparin), demonstrated that ATA bound to both thrombin exosites. Thrombin residues that are important for ATA binding were identified using a library of 53 recombinant thrombin variants encompassing alanine substitutions of 78 surface-exposed residues. They were H66, R68, R70 and Y71 in exosite I, and R89, R93, E94, R98, R245 and K248 in exosite II. ATA bound predominantly to exosite II. They did not bind to prothrombin, illustrating the cryptic nature of both exosites exposed and presented as potential antigens following prothrombin conversion to thrombin.

Blockade of the apoptotic machinery by cyclosporin A redirects cell death toward necrosis in arterial endothelial cells: regulation by reactive oxygen species and cathepsin D

Blockade of the mitochondrial permeability transition pore (mPTP) by cyclosporin A (CsA) inhibits apoptosis in various cell types. However, use of CsA in humans is associated with damage to the arterial endothelium. We evaluated whether inhibition of the apoptotic machinery by CsA promotes other forms of cell death in arterial endothelial cells (EC). Exposure of human umbilical artery EC (HUAEC) to clinically relevant concentrations of CsA for up to 24 h was associated with a significant increase in necrotic features. We detected inhibition of apoptosis and a significant increase in necrosis in HUAEC exposed concomitantly to CsA and mitomycin C, a proapoptotic DNA damaging agent. We found that CsA-induced cell death is independent of caspase activation, p53 induction, and calcineurin inhibition. However, bongkrekic acid, another mPTP blocker, also increased necrosis in HUAEC. Dihydroethidium and acridine orange staining revealed increased intracellular production of reactive oxygen species (ROS) followed by lysosomal damage in HUAEC exposed to CsA. Hydroxyl radical and superoxide scavengers and inhibition of cathepsin D activity significantly attenuated CsA-induced EC death. These results suggest that inhibition of the apoptotic machinery by CsA in arterial EC favors development of a necrotic form of cell death regulated by ROS and secondary lysosomal damage.

Inactivation of tyrosine aminotransferase in neutral homogenates and rat liver slices

Inactivation of tyrosine aminotransferase induced in vivo by triamcinolone was studied in a homogenate incubated at neutral pH values. The integrity and the presence of subcellular particles together with a compartment of acidic pH are necessary for inactivation of tyrosine aminotransferase. It is suggested that tyrosine aminotransferase is inactivated inside lysosomes. The system responsible for inactivation of tyrosine aminotransferase was partially purified and identified with lysosomal cathepsins B and B(1). Inactivation of tyrosine aminotransferase in liver slices is controlled by the amino acid concentration and strongly stimulated by cysteine. 3,3',5-Tri-iodo-l-thyronine reversibly and strongly decreases the rate of inactivation of tyrosine aminotransferase. The effect is not due to an increased rate of tyrosine aminotransferase synthesis.