Arsenic trioxide and all-trans retinoic acid treatment for acute promyelocytic leukaemia in all risk groups (AML17): results of a randomised, controlled, phase 3 trial

The History of the Chemo-Free Model in the Treatment of Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) has become a highly curable disease after four decades of endeavors. Thanks to the efforts of investigators throughout the world, the chemo-free concept has become a reality for both low- and high-risk patients. All-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) without chemotherapy has become a first-line treatment for newly diagnosed APL and has been adopted in guidelines or expert recommendations from the NCCN and ELN and in China. Though the regimen has achieved great success, challenges still exist. The rate of early death still has not diminished significantly and is a major obstacle to curing all patients. Leukocytosis is the most important factor for ED, and completely abandoning chemotherapy is dangerous for certain patients in practice. To narrow the gap between guidelines and practice, this review aims to examine the history of the chemo-free model for the treatment of APL in the arsenic-alone era (1974–2002) and the arsenic plus ATRA era (2002–present) and provide practical considerations regarding early death.

Role of cofilin‑1 in arsenic trioxide‑induced apoptosis of NB4‑R1 cells

All-trans retinoic acid (ATRA) and arsenic trioxide (As₂O₃) are currently first-line treatments for acute promyelocytic leukemia (APL). However, a number of patients with APL are resistant to ATRA but still sensitive to As₂O₃, and the underlying mechanisms of this remain unclear. In the present study, two-dimensional gel electrophoresis, mass spectrometry and other proteomic methods were applied to screen and identify the differentially expressed proteins between the retinoic acid-sensitive cell lines and drug-resistant cell lines. The results demonstrated that in retinoic acid-resistant NB4-R1 cells, the protein expression of cofilin-1 was markedly increased compared with that in the drug-sensitive NB4 cells. Subsequently, the effects of cofilin-1 on As₂O₃-induced apoptosis in NB4-R1 cells were further investigated. The results revealed that cell viability was markedly suppressed and apoptosis was increased in the As₂O₃-treated NB4-R1 cells, with increased expression levels of cleaved-poly (ADP-ribose) polymerase and cleaved-caspase 12. Cofilin-1 expression was significantly decreased at both the mRNA and protein levels in the As₂O₃-treated group compared with the control. Western blotting further revealed that As₂O₃ treatment decreased the cytoplasmic cofilin-1 level but increased its expression in the mitochondrion. However, the opposite effects of As₂O₃ on the cytochrome C distribution were found in NB4-R1 cells. This suggested that As₂O₃ can induce the transfer of cofilin-1 from the cytoplasm to mitochondria and trigger the release of mitochondrial cytochrome C in NB4-R1 cells. Moreover, cofilin-1 knockdown by its specific short hairpin RNA significantly suppressed As₂O₃-induced NB4-R1 cell apoptosis and inhibited the release of mitochondrial cytochrome C. Whereas, overexpression of cofilin-1 using a plasmid vector carrying cofilin-1 increased the release of cytochrome C into the cytoplasm from the mitochondria in As₂O₃-treated NB4-R1 cells. In conclusion, cofilin-1 played a role in As₂O₃-induced NB4-R1 cell apoptosis and it might be a novel target for APL treatment.

Successful treatment of relapsed acute promyelocytic leukemia with arsenic trioxide in a hemodialysis-dependent patient: A case report

BACKGROUND

Arsenic trioxide (ATO) is recommended for patients who do not achieve molecular remission or who have molecular or morphologic relapse. However, there are no guidelines for adjusting ATO dosage in patients with severe renal failure or on dialysis. Herein, we report the successful treatment of relapsed acute promyelocytic leukemia (APL) in a patient on hemodialysis with ATO single agent and review the cases in literature.

CASE SUMMARY

A 46-year-old woman who has been on hemodialysis to chronic glomerulone-phritis for 15 years visited our hospital for pancytopenia. She had been seen for pancytopenia 3 years ago and had been diagnosed with APL. She also received chemotherapy for APL but unfortunately was lost to follow-up after her second consolidation chemotherapy. She was noted to have pancytopenia by her nephrologist during hemodialysis 1 mo ago. Bone marrow biopsy and reverse transcriptase-polymerase chain reaction (RT-PCR) tests revealed a diagnosis of relapsed APL. Treatment for relapsed APL with ATO single agent was started and she achieved molecular remission after administering 24 doses of ATO. Thus far, four consolidation therapies have been performed with the ATO single agent, and, to date, the molecular remission has been maintained as negative promyelocytic leukemia/retinoic acid receptor-α fusion gene as confirmed by RT-PCR testing for two years.

CONCLUSION

This is a rare case of relapsed APL successfully treated with the single agent ATO in a patient on hemodialysis.

The genomics of acute myeloid leukemia in children

Acute myeloid leukemia (AML) is a clinically, morphologically, and genetically heterogeneous disorder. Like many malignancies, the genomic landscape of pediatric AML has been mapped recently through sequencing of large cohorts of patients. Much has been learned about the biology of AML through studies of specific recurrent genetic lesions. Further, genetic lesions have been linked to specific clinical features, response to therapy, and outcome, leading to improvements in risk stratification. Lastly, targeted therapeutic approaches have been developed for the treatment of specific genetic lesions, some of which are already having a positive impact on outcomes. While the advances made based on the discoveries of sequencing studies are significant, much work is left. The biologic, clinical, and prognostic impact of a number of genetic lesions, including several seemingly unique to pediatric patients, remains undefined. While targeted approaches are being explored, for most, the efficacy and tolerability when incorporated into standard therapy is yet to be determined. Furthermore, the challenge of how to study small subpopulations with rare genetic lesions in an already rare disease will have to be considered. In all, while questions and challenges remain, precisely defining the genomic landscape of AML, holds great promise for ultimately leading to improved outcomes for affected patients.

Acute myeloid leukaemia therapeutic innovation and clinical trials: past, present and future

Outcomes in acute myeloid leukaemia have improved steadily over the last six decades thanks to advances in disease classification, risk stratification and the advent of new drug and transplant therapies. Over this period the UK has made a major contribution to this international effort, both through its delivery of large prospective randomised trials with integrated genomic and measurable residual disease assessments and its pioneering role in the development of allogeneic stem cell transplantation as a potent anti-leukaemic therapy.

Comanagement Strategy Between Academic Institutions and Community Practices to Reduce Induction Mortality in Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is a curable leukemia with > 90% survival in clinical trials. Population-based studies from Sweden and US SEER data have shown long-term survival rates of 62% and 65.7%, with the lower rate being from a higher percentage of early deaths.

Therapeutic Approaches for Acute Promyelocytic Leukaemia: Moving Towards an Orally Chemotherapy-Free Era

The treatment of acute promyelocytic leukaemia (APL) has evolved dramatically over the past several decades, making the disease a highly curable form of acute leukaemia. The discoveries of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) were landmark events, leading to historic revolutions in the treatment of APL. One major change was from chemotherapy-based to chemotherapy-free treatment regimens, and the combination of ATRA plus ATO without chemotherapy has been recommended as the standard therapy for non-high-risk APL. The other major change was from the intravenous administration of medicine in the hospital to a largely home-based oral approach, which is a more cost-effective and convenient treatment model. In this review, we focus on the evolution of therapeutic approaches for APL, as well as the challenges that remain with the current approaches.

Incidence of Differentiation Syndrome Associated with Treatment Regimens in Acute Myeloid Leukemia: A Systematic Review of the Literature

Differentiation syndrome (DS) is a potentially fatal adverse drug reaction caused by the so-called differentiating agents such as all-trans retinoic acid (ATRA) and arsenic trioxide (ATO), used for remission induction in the treatment of the M3 subtype of acute myeloid leukemia (AML), acute promyelocytic leukemia (APL). However, recent DS reports in trials of isocitrate dehydrogenase (IDH)-inhibitor drugs in patients with IDH-mutated AML have raised concerns. Given the limited knowledge of the incidence of DS with differentiating agents, we conducted a systematic literature review of clinical trials with reports of DS to provide a comprehensive overview of the medications associated with DS. In particular, we focused on the incidence of DS reported among the IDH-inhibitors, compared to existing ATRA and ATO therapies. We identified 44 published articles, encompassing 39 clinical trials, including 6949 patients. Overall, the cumulative incidence of DS across all treatment regimens was 17.7%. Incidence of DS was notably lower in trials with IDH-inhibitors (10.4%) compared to other regimens, including ATRA and/or ATO (15.4-20.6%). Compared to other therapies, the median time to onset was four times longer with IDH-inhibitors (48 vs. 11 days). Treating oncologists should be mindful of this potentially fatal adverse drug reaction, as we expect the current trials represent an underestimation of the actual incidence.

Gemtuzumab ozogamicin for the treatment of acute myeloid leukemia in adults

INTRODUCTION

Treatment of acute myeloid leukemia (AML) has changed dramatically in the past ten years with the approval of targeted agents, the first of which was the anti-CD33 antibody-drug conjugate gemtuzumab ozogamicin (GO). Despite withdrawal from the market after accelerated approval, GO was reapproved and now has a well-established role in treating select AML patients. CD33 has proven to be an important target for drug development in AML as evidenced by the improvement in survival with GO treatment.

AREAS COVERED

The review summarizes the development of GO, its mechanism of action, initial studies and approval, withdrawal from the market, and subsequent reapproval after the results of several large randomized studies became available. We also provide an overview of its current role in the treatment landscape of AML.

EXPERT OPINION

Multiple phase 3 trials with GO have established a significant benefit with GO in induction therapy for favorable risk AML. Additional studies support the use of GO in relapsed/refractory AML and APL. Despite the withdrawal of GO from the market after initial approval, GO has proven to improve survival of select AML patients when added to induction chemotherapy and in relapsed disease.

Retrospective analysis of data from 73 patients with childhood acute promyelocytic leukaemia receiving modified chemotherapy: a single-centre study

PURPOSE

Early death (ED) and treatment-related toxicity emerge as two major barriers for curing paediatric acute promyelocytic leukaemia (APL) patients. This study aims to investigate the effect of idarubicin on controlling hyperleukocytosis in induction therapy and the efficacy and safety of a risk-adapted attenuated consolidation chemotherapy.

METHODS

We summarised the characteristics and long-term outcomes of 73 paediatric APL patients treated at our institution from February 2002 to October 2018, during which treatment protocols evolved over three periods and were defined as protocol A, B and C chronologically. All of the patients received an all-trans retinoic acid (ATRA)-arsenic trioxide (ATO) combination remission induction therapy, with hydroxyurea (group A) or idarubicin (group B and C) to control hyperleukocytosis. Consolidation chemotherapy was modified with risk-adapted attenuated intensity and minimised cumulative doses of anthracyclines for group C (144 mg/m² and 288 mg/m² of daunorubicin equivalents for standard- and high-risk patients, respectively).

RESULTS

The median initial WBC, platelet count, and fibrinogen were 2.9 × 10⁹/L (range 0.9-158.3 × 10⁹/L), 32 × 10⁹/L (range 4-226 × 10⁹/L), and 160 mg/dL (range 53-549 mg/dL), respectively. High-risk and standard-risk were seen in 20.5% and 79.5% of patients, respectively. Three patients (4.1%) suffered early haemorrhagic death. At the end of induction therapy, 68 (93.2%) patients achieved haematologic complete remission (HCR). At a median follow-up of 91.97 months, the estimated 5-year overall survival (OS) and event-free survival (EFS) rates for the whole cohort were 95.9 ± 2.3% and 88.7 ± 3.8%, respectively. A comparison of HCR rates and documented instances of toxicity between groups A and B + C showed no significant differences. However, idarubicin significantly reduced the peak WBC count (Z = - 3.292, P = 0.001) and duration of hyperleukocytosis (Z = - 2.827, P = 0.005). Estimated 3-year EFS (91.7 ± 8.0%) and OS (100%) rates for group C were not significantly different from those for group B, whereas the risk of treatment-related infections was significantly reduced (χ² = 5.515, P = 0.019).

CONCLUSIONS

Idarubicin (8-10 mg/m²/day for 2 days) for hyperleukocytosis control in induction therapy is safe and effective for paediatric APL. Risk-adapted attenuated consolidation chemotherapy is advocated.

Gemtuzumab ozogamicin in acute myeloid leukemia: past, present and future

After being in the therapeutic wilderness for several decades, acute myeloid leukemia has been recently thrust into the limelight with a series of drug approvals. Technical refinements in production, genetic manipulation and chemical modification of monoclonal antibodies led to growing interest in antibodies-based treatment strategies. Much of the focus of these efforts in acute myeloid leukemia has been on CD33 as a target. On September 2, 2017, the U.S. Food and Drug Administration approved gemtuzumab ozogamicin for treatment of relapsed or refractory CD33⁺ acute myeloid leukemia. This signals a new chapter in the long and unusual story of gemtuzumab ozogamicin, which was the first antibody-drug conjugate approved for human use by the Food and Drug Administration. In this review we have analyzed the history of this drug which, among several mishaps, is experiencing a second youth and still represents a field to be further explored.

Advancing leukemia diagnostics: Role of Next Generation Sequencing (NGS) in acute myeloid leukemia

AML diagnostics, initially based solely on morphological evaluation, now relies on multiple disciplines to reach its full potential. Only by integrating the results of cytomorphology, cytochemistry, immunophenotyping, cytogenetics and molecular genetics it is possible to fulfil WHO classification and ELN prognostication systems. Especially molecular genetics has gained a lot of interest over the last decade, mainly through the introduction of next generation sequencing (NGS). NGS application ranges from the investigation of single genes and panels to even whole exomes, transcriptomes and genomes. In routine AML diagnostics panels are the preferred NGS methodology. Here, we will review the power and limitations of NGS in the context of diagnosis, prognosis and precision medicine. Due to high dimensionality, NGS data interpretation is challenging but it also offers a unique investigatory chance and the opportunity to apply data mining techniques such as artificial intelligence. We will also reflect on how the incorporation of the improved knowledge base into routine diagnostics can pave the way for better treatment and more cure in AML.

Predictors of early death, serious hemorrhage, and differentiation syndrome in Japanese patients with acute promyelocytic leukemia

Significant advancements have been achieved with regard to the outcomes of acute promyelocytic leukemia (APL) patients through the introduction of all-trans retinoic acid; however, early hemorrhagic death and differentiation syndrome remain the major causes of remission induction failure in patients with APL. To investigate early death, serious hemorrhage, and differentiation syndrome during remission induction therapy in terms of incidence, risk factors, influence on outcomes, and prophylactic effects of several new anticoagulants, the results of 344 patients enrolled in the Acute Promyelocytic Leukemia 204 study conducted by the Japan Adult Leukemia Study Group were analyzed. Early death was observed in 16 patients (4.7%), of whom 14 had serious hemorrhage and 2 had differentiation syndrome. Serious hemorrhage and differentiation syndrome of grade 2 or higher were observed in 21 and 54 patients, respectively. Patients who achieved complete remission had a 7-year disease-free survival of 84.8% if they did not experience serious hemorrhage and 40.0% if they experienced serious hemorrhage during remission induction therapy (P = 0.001). Risk factor analyses showed that higher white blood cell count was associated with early death, higher white blood cell count and lower platelet count with serious hemorrhage, and leukocytosis during induction therapy and higher body surface area with differentiation syndrome. In conclusion, these results indicate that patients with such high-risk features may benefit from more intensive supportive care. The hemorrhagic risk was not relieved by the introduction of new anticoagulants. Further studies are required to establish the predictive impact of body surface area on differentiation syndrome. This trial is registered with UMIN-CTR as C000000154 on September 13, 2005.

Severe Peripheral Neuropathy From Treatment With Arsenic Trioxide in a Patient Suffering From Acute Promyelocytic Leukemia

Treatment with arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) is standard treatment for patients suffering from acute promyelocytic leukemia (APL). Peripheral neuropathy is a common sign of arsenic poisoning but reports of peripheral neuropathy from patients treated with ATO for APL are limited. We here present a case of a woman treated with standard regimes of ATRA-ATO for APL, who subsequently developed severe peripheral neuropathy from ATO poisoning.

Advances and challenges in retinoid delivery systems in regenerative and therapeutic medicine

Retinoids regulate a wide spectrum of cellular functions from the embryo throughout adulthood, including cell differentiation, metabolic regulation, and inflammation. These traits make retinoids very attractive molecules for medical purposes. In light of some of the physicochemical limitations of retinoids, the development of drug delivery systems offers several advantages for clinical translation of retinoid-based therapies, including improved solubilization, prolonged circulation, reduced toxicity, sustained release, and improved efficacy. In this Review, we discuss advances in preclinical and clinical tests regarding retinoid formulations, specifically the ones based in natural retinoids, evaluated in the context of regenerative medicine, brain, cancer, skin, and immune diseases. Advantages and limitations of retinoid formulations, as well as prospects to push the field forward, will be presented.

Health-Related Quality of Life and Treatment of Older Adults with Acute Myeloid Leukemia: a Young International Society of Geriatric Oncology Review Paper

PURPOSE OF REVIEW

The treatment landscape for older patients with acute myeloid leukemia (AML) is evolving. Many treatments have comparable efficacy making their impact on quality of life (QoL) an important differentiating factor. In this review, we discuss QoL in older adults with AML, focusing on therapeutic and observational trials that have incorporated QoL assessments.

RECENT FINDINGS

Health-related quality of life (HRQoL) is a multi-dimensional concept incorporating physical, mental, emotional, and social functioning domains. HRQoL components overlap with components of geriatric assessment, a multidisciplinary diagnostic process that identifies underlying vulnerabilities of older adults and guides subsequent management strategies. HRQoL questionnaires may be general, cancer-specific, leukemia-specific, or symptom-focused. Therapeutic and observational cohort studies suggest HRQoL improves, or at least remains stable, during intensive and lower-intensity therapies. Nonetheless, HRQoL is not routinely incorporated in AML therapeutic trials. HRQoL assessments can inform both decision-making and management for older adults with AML.

Biomarkers of Gemtuzumab Ozogamicin Response for Acute Myeloid Leukemia Treatment

Gemtuzumab ozogamicin (GO, Mylotarg®) consists of a humanized CD33-targeted antibody-drug conjugated to a calicheamicin derivative. Growing evidence of GO efficacy in acute myeloid leukemia (AML), demonstrated by improved outcomes in CD33-positive AML patients across phase I to III clinical trials, led to the Food and Drug Administration (FDA) approval on 1 September 2017 in CD33-positive AML patients aged 2 years and older. Discrepancies in GO recipients outcome have raised significant efforts to characterize biomarkers predictive of GO response and have refined the subset of patients that may strongly benefit from GO. Among them, CD33 expression levels, favorable cytogenetics (t(8;21), inv(16)/t(16;16), t(15;17)) and molecular alterations, such as NPM1, FLT3-internal tandem duplications and other signaling mutations, represent well-known candidates. Additionally, in depth analyses including minimal residual disease monitoring, stemness expression (LSC17 score), mutations or single nucleotide polymorphisms in GO pathway genes (CD33, ABCB1) and molecular-derived scores, such as the recently set up CD33_PGx6_Score, represent promising markers to enhance GO response prediction and improve patient management.

Resurrection of Oral Arsenic Trioxide for Treating Acute Promyelocytic Leukaemia: A Historical Account From Bedside to Bench to Bedside

Various forms of arsenic were used in China and elsewhere for over 5,000 years. Following the initial success of intravenous arsenic trioxide (i.v. As₂O₃), we revived an oral formulation of pure As₂O₃ in 1998 for the treatment of acute promyelocytic leukemia (APL). We were the first to produce a 1 mg/ml oral-As₂O₃ solution and showed that it had comparable bioavailability to i.v. As₂O₃. Moreover, we also reported that intracellular arsenic concentrations were considerably higher than the corresponding plasma values. Our oral-As₂O₃ was patented internationally and registered in Hong Kong for the treatment of APL. Safety, tolerability and clinical efficacy was confirmed in long-term follow-up studies. We have extended the use of oral-As₂O₃ to frontline induction of newly diagnosed APL. With these findings, we are moving toward an era of completely oral and chemotherapy-free management of APL.

Population-Level Outcomes of Pediatric Acute Promyelocytic Leukemia in the United States

OBJECTIVE

To determine whether the population level outcomes of pediatric acute promyelocytic leukemia have improved over time.

STUDY DESIGN

We conducted a retrospective analysis of the Surveillance Epidemiology and End Results database for patients with acute promyelocytic leukemia, up to 20 years of age, diagnosed between 1976 and 2016 and actively followed. Patients were stratified based on their period of diagnosis (1976-1989, 1990-1999, 2000-2009, 2010-2016) to assess the temporal trends in overall survival and early mortality.

RESULTS

A total of 553 patients with a median age of 15 years (range, 0-20 years) were included. The 5-year overall survival increased significantly over time (by 22.6% from 1976 to 1989; by 59.2% from 1990 to 1999; by 77.7% from 2000 to 2009; and by 88.9% from 2010 to 2016; P < .001). Early mortality showed an improvement over time in the most recent cohort (by 14% from 1976 to 1989; by 13.5% from1990 to 1999; by 13.3% 2000 to 2009; and by 7.2% from 2010 to 2016) after adjusting for other demographic characteristics in a logistic regression model. On multivariate analysis of overall survival, diagnosis in the earlier time periods was associated with higher mortality as compared with the 2010-2016 period. Age, sex, and race/ethnicity were not significant predictors of overall survival.

CONCLUSIONS

Outcomes of pediatric acute promyelocytic leukemia have continued to improve over time at the population level.

A Cereblon Modulator CC-885 Induces CRBN- and p97-Dependent PLK1 Degradation and Synergizes with Volasertib to Suppress Lung Cancer

Therapeutic targeting of advanced or metastatic non-small-cell lung cancer (NSCLC) represents a major goal of clinical treatment. Polo-like kinase 1 (PLK1) is an essential mitotic kinase in cell cycle progression and is associated with oncogenesis in a large spectrum of cancer types, including NSCLC. Volasertib (BI 6727) is a potent, selective, PLK1 inhibitor that is currently under phase 2 clinical trials with modest antitumor activity against solid tumors. As the combination of volasertib with pemetrexed does not improve efficacy for NSCLC treatment, it is crucial to identify compounds that could enhance efficacy with volasertib. Immunomodulatory drugs (IMiDs) bind to E3 ligase CRBN and repurposes it to ubiquitinate other proteins as neo-substrates, representing an effective treatment for hematologic malignancies. In this study, by screening IMiDs, we found that a novel CRBN modulator, CC-885, can synergistically inhibit NSCLC with volasertib both in vitro and in vivo. This synergistic effect overcomes volasertib resistance caused by PLK1 mutations and is compromised in CRBN-or p97-depleted cells. Mechanistically, CC-885 selectively promotes CRBN- and p97-dependent PLK1 ubiquitination and degradation, thereby enhancing the sensitivity of NSCLC to volasertib. In conclusion, our findings reveal that PLK1 is a neo-substrate of CUL4-CRBN induced by CC-885 and represent a combinational approach for treating NSCLC.

Measurable residual disease after the first consolidation predicts the outcomes of patients with acute promyelocytic leukemia treated with all-trans retinoic acid and chemotherapy

We stratified patients with newly diagnosed acute promyelocytic leukemia (APL) according to a white blood cell (WBC) count of ≥ 3 × 10⁹/L (high risk) or < 3 × 10⁹/L (low risk) before administering risk-adapted chemotherapy in combination with all-trans retinoic acid (ATRA). In total, 27 low-risk and 23 high-risk patients were assigned to receive induction and three courses of consolidation with ATRA and anthracycline, followed by 2-year maintenance regimen. High-risk group additionally received cytarabine during 1st consolidation and another one-shot idarubicin treatment during 3rd consolidation. We prospectively monitored measurable residual disease (MRD) after induction and each consolidation. In the low-risk and high-risk groups, 5-year disease-free survival (DFS) rates were 86.5% and 81.2% (p = 0.862), and 5-year overall survival rates were 100% and 84.8% (p = 0.062), respectively. In the MRD-negative and MRD-positive groups, 5-year DFS rates were 91.7% and 78.4% (p = 0.402) and 84.7% and 60.0% (p = 0.102) after induction and 1st consolidation, respectively. Relapse rates were 8.3% and 13.3% (p = 0.570) and 9.0% and 40.0% (p = 0.076) after induction and 1st consolidation, respectively. Achieving MRD-negativity after 1st consolidation, rather than after induction, was a potential predictor of relapse and DFS in patients with APL treated with ATRA + chemotherapy.

When Poisons Cure: The Case of Arsenic in Acute Promyelocytic Leukemia

Arsenic has been known for centuries for its double-edged potential: a poison and at the same time a therapeutic agent. The name "arsenikon," meaning "potent," speaks itself for the pharmaceutical properties of this compound, questioned and analyzed for at least 2000 years. In the last decades, acute promyelocytic leukemia (APL) has evolved from a highly fatal to a curable disease, due to the use of all-trans-retinoic acid and, more recently, arsenic trioxide combinations. The success of these entirely chemo-free regimens increased the awareness of APL and reduced the prevalence of early deaths, which was an impending issue in this disease. Further improvements are expected with the next use of oral arsenic formulations, which will allow a complete outpatient approach, at least in the post-induction settings, further improving patients' quality of life. The wide use of standardized approaches in APL will also help unravel long-standing open questions, including the pathogenesis, prevention, and treatment of the differentiation syndrome and of short-term organ toxicities. In the long term, the study of survivorship issues, such as fertility and organ-related and psychological damages, in the increasing number of survivors will help further improve their life after APL.

Impact of CD56 Continuously Recognizable as Prognostic Value of Acute Promyelocytic Leukemia: Results of Multivariate Analyses in the Japan Adult Leukemia Study Group (JALSG)-APL204 Study and a Review of the Literature

BACKGROUND

After long-term analysis of the JALSG-APL204 study we recently reported that maintenance therapy with tamibarotene was more effective than all-trans retinoic acid (ATRA) by reducing relapse in APL patients. Here, the clinical significance of other important prognostic factors was evaluated with multivariate analyses.

PATIENTS AND METHODS

Newly diagnosed acute promyelocytic leukemia (APL) patients were registered with the study. Induction was composed of ATRA and chemotherapy. Patients who achieved molecular remission after consolidation were randomly assigned to maintenance with tamibarotene or ATRA.

RESULTS

Of the 344 eligible patients, 319 (93%) achieved complete remission (CR). After completing consolidation, 269 patients underwent maintenance random assignment-135 to ATRA, and 134 to tamibarotene. By multivariate analysis, overexpression of CD56 in blast was an independent unfavorable prognostic factor for relapse-free survival (RFS) (p = 0.006) together with more than 10.0 × 10⁹/L WBC counts (p = 0.001) and the ATRA arm in maintenance (p = 0.028). Of all phenotypes, CD56 was related most clearly to an unfavorable prognosis. The CR rate, mortality rate during induction and overall survival of CD56⁺ APL were not significantly different compared with CD56^- APL. CD56 is continuously an independent unfavorable prognostic factor for RFS in APL patients treated with ATRA and chemotherapy followed by ATRA or tamibarotene maintenance therapy.

Structure-Activity Relationship Study Enables the Discovery of a Novel Analogue as the RXRα Activator to Inhibit Colon Cancer

We reported recently that berberine (Ber), a traditional oriental medicine to treat gastroenteritis, binds and activates retinoid X receptor α (RXRα) for suppressing the growth of colon cancer cells. Here, we extended our studies based on the binding mode of Ber with RXRα by design, synthesis, and biological evaluation of a focused library of 15 novel Ber analogues. Among them, 3,9-dimethoxy-5,6-dihydroisoquinolino[3,2-a]isoquinolin-7-ium chloride (B-12) was identified as the optimal RXRα activator. More efficiently than Ber, B-12 bound and altered the conformation of RXRα/LBD, thereby suppressing the Wnt/β-catenin pathway and colon cancer cell growth via RXRα mediation. In addition, B-12 not only preserved Ber's tumor selectivity but also greatly improved its bioavailability. Remarkably, in mice, B-12 did not show obvious side effects including hypertriglyceridemia as other RXRα agonists or induce hepatorenal toxicity. Together, our study describes an approach for the rational design of Ber-derived RXRα activators as novel effective antineoplastic agents for colon cancer.

20(S)-ginsenoside Rh2 induces caspase-dependent promyelocytic leukemia-retinoic acid receptor A degradation in NB4 cells via Akt/Bax/caspase9 and TNF-α/caspase8 signaling cascades

Background

Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia–retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear.

Methods

Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α ) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation.

Results

GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-α expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner.

Conclusion

GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.

Hemorrhage in acute promyelocytic leukemia: Can it be predicted and prevented?

Hemorrhagic death is the leading cause of treatment failure in acute promyelocytic leukemia (APL). Our ability to identify patients at greatest risk of hemorrhage, and to actively prevent hemorrhage, remains limited. Nevertheless, some data is available to guide contemporary clinical practice and future investigation. Circulating disease burden, best represented by the peripheral WBC / blast count, is the most consistent predictor of major and fatal bleeding risk. In contrast, laboratory markers of disseminated intravascular coagulation (DIC) appear to be poor predictors. A number of interventions have been posited to reduce bleeding risk. Prompt initiation of all-trans retinoic acid (ATRA), avoidance of invasive procedures, transfusion support, and cytoreduction all have theoretical merit. Though they lack strong evidence to support their benefit with respect to bleeding, they are associated with limited risks, and are therefore advisable. Low-dose therapeutic heparin and antifibrinolytics have not shown the ability to positively modify bleeding risk, and heparin has been associated with harm. Thrombomodulin has shown promise in limited retrospective studies however further prospective data are needed. rFVIIa may have a role in cases of life-threatening bleeding however evidence is largely anecdotal. Additional studies evaluating the above interventions, and investigating other potential interventions are needed.

Treating Leukemia in the Time of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic poses several challenges to the management of patients with leukemia. The biology of each leukemia and its corresponding treatment with conventional intensive chemotherapy, with or without targeted therapies (venetoclax, FLT3 inhibitors, IDH1/2 inhibitors, Bruton's tyrosine kinase inhibitors), introduce additional layers of complexity during COVID-19 high-risk periods. The knowledge about COVID-19 is accumulating rapidly. An important distinction is the prevalence of “exposure” versus “clinical infectivity,” which determine the risk versus benefit of modifying potentially highly curative therapies in leukemia. At present, the rate of clinical infection is <1–2% worldwide. With a mortality rate of 1–5% in CO­VID-19 patients in the general population and potentially of >30% in patients with cancer, careful consideration should be given to the risk of COVID-19 in leukemia. Instead of reducing patient access to specialized cancer centers and modifying therapies to ones with unproven curative benefit, there is more rationale for less intensive, yet effective therapies that may require fewer clinic visits or hospitalizations. Here, we offer recommendations on the optimization of leukemia management during high-risk COVID-19 periods.

Differentiation Syndrome with Ivosidenib and Enasidenib Treatment in Patients with Relapsed or Refractory IDH-Mutated AML: A U.S. Food and Drug Administration Systematic Analysis

PURPOSE

Differentiation syndrome (DS) is a serious adverse reaction of isocitrate dehydrogenase (IDH) inhibitors ivosidenib and enasidenib in patients with (IDH)1- and IDH2-mutated acute myeloid leukemia (AML), respectively.

EXPERIMENTAL DESIGN

During FDA review of marketing applications for ivosidenib and enasidenib, data from pivotal trials were queried to identify cases of DS in patients with relapsed or refractory (R/R) AML. One hundred seventy-nine patients with R/R AML received ivosidenib and 214 received enasidenib. Adverse events, labs, and vital signs in the first 90 days of treatment were screened per diagnostic criteria, and narratives were reviewed to adjudicate DS cases.

RESULTS

We identified 72 of 179 (40%) potential cases for ivosidenib and 86 of 214 (40%) for enasidenib; 34 of 179 (19%) and 41 of 214 (19%) were adjudicated as DS. Leukocytosis was present in 79% and 61% of cases, respectively. Median (range) time to onset was 20 (1-78) and 19 (1-86) days. Grade ≥ 3 adverse reactions occurred in 68% and 66%; 6% and 5% were fatal. Univariate analyses suggested baseline bone marrow blasts ≥ 48% and peripheral blood blasts ≥ 25% and 15% for ivosidenib and enasidenib, respectively, were associated with increased risk of DS. Complete remission (CR) + CR with partial hematologic recovery rates were lower in patients with versus without DS [ivosidenib 18% (95% confidence interval, 7%-35%) vs. 36% (28%-45%); enasidenib 18% (7%-33%) vs. 25% (18%-32%)].

CONCLUSIONS

DS is a common and potentially fatal adverse reaction of IDH inhibitors, and use of standardized diagnostic criteria may aid in earlier diagnosis and treatment.See related commentary by Zeidner, p. 4174.

Sequencing-Based Measurable Residual Disease Testing in Acute Myeloid Leukemia

Next generation sequencing (NGS) methods have allowed for unprecedented genomic characterization of acute myeloid leukemia (AML) over the last several years. Further advances in NGS-based methods including error correction using unique molecular identifiers (UMIs) have more recently enabled the use of NGS-based measurable residual disease (MRD) detection. This review focuses on the use of NGS-based MRD detection in AML, including basic methodologies and clinical applications.

Arsenic trioxide ameliorates experimental autoimmune encephalomyelitis in C57BL/6 mice by inducing CD4+ T cell apoptosis

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system characterized by severe white matter demyelination. Because of its complex pathogenesis, there is no definite cure for MS. Experimental autoimmune encephalomyelitis (EAE) is an ideal animal model for the study of MS. Arsenic trioxide (ATO) is an ancient Chinese medicine used for its therapeutic properties with several autoimmune diseases. It is also used to inhibit acute immune rejection due to its anti-inflammatory and immunosuppressive properties. However, it is unclear whether ATO has a therapeutic effect on EAE, and the underlying mechanisms have not yet been clearly elucidated. In this study, we attempted to assess whether ATO could be used to ameliorate EAE in mice.

METHODS

ATO (0.5 mg/kg/day) was administered intraperitoneally to EAE mice 10 days post-immunization for 8 days. On day 22 post-immunization, the spinal cord, spleen, and blood were collected to analyze demyelination, inflammation, microglia activation, and the proportion of CD4+ T cells. In vitro, for mechanistic studies, CD4+ T cells were sorted from the spleen of naïve C57BL/6 mice and treated with ATO and then used for an apoptosis assay, JC-1 staining, imaging under a transmission electron microscope, and western blotting.

RESULTS

ATO delayed the onset of EAE and alleviated the severity of EAE in mice. Treatment with ATO also attenuated demyelination, alleviated inflammation, reduced microglia activation, and decreased the expression levels of IL-2, IFN-γ, IL-1β, IL-6, and TNF-α in EAE mice. Moreover, the number and proportion of CD4+ T cells in the spinal cord, spleen, and peripheral blood were reduced in ATO-treated EAE mice. Finally, ATO induced CD4+ T cell apoptosis via the mitochondrial pathway both in vitro and in vivo. Additionally, the administration of ATO had no adverse effect on the heart, liver, or kidney function, nor did it induce apoptosis in the spinal cord.

CONCLUSIONS

Overall, our findings indicated that ATO plays a protective role in the initiation and progression of EAE and has the potential to be a novel drug in the treatment of MS.

Oral arsenic trioxide, all-trans retinoic acid, and ascorbic acid maintenance after first complete remission in acute promyelocytic leukemia: Long-term results and unique prognostic indicators

BACKGROUND

The role of arsenic trioxide (As₂ O₃ ) in the maintenance of first complete remission (CR1) in acute promyelocytic leukemia (APL) is unclear.

METHODS

A total of 129 consecutive adult patients with APL of all risk categories who achieved CR1 with conventional induction (all-trans retinoic acid [ATRA]/daunorubicin) and consolidation (daunorubicin/cytarabine [induction daunorubicin and consolidation omitted for age ≥70 years]) underwent maintenance comprising ATRA (45 mg/m² /day), oral As₂ O₃ (10 mg/day), and ascorbic acid (1 g/day) (AAA) for 2 weeks every 2 months for 2 years.

RESULTS

Over a 17-year period from August 1, 2002, to July 31, 2019, 63 men and 66 women (median age, 46 years [range, 18-82 years]) received AAA maintenance, which was already completed in 117 patients. At a median follow-up of 100 months (range, 8-215 months), 17 patients (13%) developed first relapse (R1) (hematologic, n = 14; molecular, n = 3) after a median of 19 months (range, 7-96 months) from CR1. Two R1 patients had concomitant central nervous system (CNS) involvement. All patients achieved CR2 with oral As₂ O₃ -based salvage. Five patients had a subsequent relapse and died. Eight patients died of unrelated causes while still in CR1. The 5-year and 10-year rates of relapse-free survival (RFS) were 89% and 85%, respectively. The 5-year and 10-year rates of overall survival (OS) were 94% and 87%, respectively. Multivariate analysis showed that inferior RFS was associated with FLT3-ITD (P = .005) and CNS involvement on presentation (P = .004), and inferior OS was associated with therapy-related APL (P = .03), FLT3-ITD (P = .03), and relapse (P = .03). The safety profile was favorable, with no grade 3/4 organ toxicities.

CONCLUSION

CR1 maintenance with AAA is safe and results in favorable long-term survival in patients with APL.

Improved Outcomes of All-trans-retinoic Acid and Arsenic Trioxide Plus Idarubicin as a Frontline Treatment in Adult Patients With Acute Promyelocytic Leukemia

INTRODUCTION

The purpose of this study was to explore the outcomes of all-trans-retinoic acid (ATRA) and arsenic trioxide (ATO) plus idarubicin (IDA) as a frontline treatment in adult patients with acute promyelocytic leukemia (APL).

PATIENTS AND METHODS

We analyzed the outcomes of ATRA and intravenous ATO plus IDA as a frontline induction therapy in 118 patients with APL with high-risk (HR) and standard-risk (SR) disease from January 2008 to December 2017. The medical records of 118 patients with APL (HR, n = 45; SR, n = 73) who received the frontline triple combination regimen at Henan Provincial People's Hospital and Tongji Hospital were retrospectively reviewed. Consolidation therapy comprised 6 cycles of ATO and ATRA plus IDA, and IDA was administered in 1 to 4 cycles of consolidation therapy based on the comparable clinical efficacy compared with 6 cycles and fewer side effects to myocardium without subsequent maintenance therapy.

RESULTS

Of 118 patients, there were 3 (2.5%) early deaths and 115 (97.5%) hematologic complete remissions; 102 (88.7%) of 115 patients achieved molecular complete remission following induction therapy, and all patients were polymerase chain reaction-negative for promyelocytic leukemia-retinoic acid receptor alpha after the first cycle of consolidation therapy. The 5-year overall survival (OS) and event-free survival (EFS) were 93.0% ± 2.9% and 92.4% ± 3.0%, respectively. Early death, hematologic complete remissions, molecular complete remissions, and toxicities were comparable between the HR and SR groups. The cumulative incidence of relapse in the HR group was 4.7% (n = 2), and the cumulative incidence of relapse in the SR group was 0. The OS and EFS of the SR and HR groups were comparable (92.3% ± 4.5% vs. 92.8% ± 4.0%; X² = 0.263; P = .608; 92.3% ± 4.5% vs. 91.1% ± 4.2%, X² = 0.917; P = .338). The total dosage of IDA was approximately 181 to 258 mg, and no patient experienced cardiotoxicity. OS and EFS were not influenced by fms-related tyrosine kinase 3 internal tandem duplication mutation status (P = .405 and P = .528, respectively).

CONCLUSION

The triple combination of ATRA and ATO plus IDA as both an induction and consolidation therapy for the HR and SR groups attained excellent outcomes, and this regimen was effective, safe, and easy, without maintenance therapy. The triple combination treatment might be a preferred frontline therapy for patients with APL, especially for those with HR or the APL fms-related tyrosine kinase 3 internal tandem duplication mutation.

Classic and Variants APLs, as Viewed from a Therapy Response

Most acute promyelocytic leukemia (APL) are caused by PML-RARA, a translocation-driven fusion oncoprotein discovered three decades ago. Over the years, several other types of rare X-RARA fusions have been described, while recently, oncogenic fusion proteins involving other retinoic acid receptors (RARB or RARG) have been associated to very rare cases of acute promyelocytic leukemia. PML-RARA driven pathogenesis and the molecular basis for therapy response have been the focus of many studies, which have now converged into an integrated physio-pathological model. The latter is well supported by clinical and molecular studies on patients, making APL one of the rare hematological disorder cured by targeted therapies. Here we review recent data on APL-like diseases not driven by the PML-RARA fusion and discuss these in view of current understanding of "classic" APL pathogenesis and therapy response.

Treatment of acute promyelocytic leukemia in older patients: recommendations of an International Society of Geriatric Oncology (SIOG) task force

Approximately one third of patients diagnosed with acute promyelocytic leukemia (APL) are above the age of sixty. It is important to ensure older adults receive optimal diagnosis and management since this subtype of acute myeloid leukemia - given appropriate treatment - is highly curable with lower risk of adverse events compared to other types of leukemia. Historically, older age has been a risk factor for early death and poorer overall survival. However, prospects have changed with the introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO). APL is curable in the majority of patients regardless of age, and the threshold of fitness that makes ATRA/ATO therapy possible is likely to be lower than for cytotoxic chemotherapy. APL frequently presents as a medical emergency and rapid diagnosis and intervention - typically involving referral to a specialist centre - is a major determinant of outcome. After diagnosis, management of APL in older adults presents particular challenges. Geriatric assessment, including evaluation of frailty, comorbidities and polypharmacy can assist in providing optimal supportive care for older adults during remission induction and may help individualize therapy in the post-remission phase. Here, we review the available evidence, highlighting areas of consensus, gaps in evidence and opportunities for research to enhance diagnosis, management and survivorship for older patients.

Anti-PD-L1-modified and ATRA-loaded nanoparticles for immuno-treatment of oral dysplasia and oral squamous cell carcinoma

Aim: To develop nanomedicines for immuno-therapy of oral dysplasia and oral squamous cell carcinoma. Materials & methods: All-trans retinoic acid (ATRA)-poly(lactide-co-glycolide acid) (PLGA)-poly(ethylene glycol) (PEG)-programmed death-ligand 1 (PD-L1) nanomedicines were fabricated by loading ATRA into PLGA-PEG nanocarriers and modification using an anti-PD-L1 antibody. Results: ATRA-PLGA-PEG-PD-L1 nanoparticles showed fast cellular uptake, significantly inhibited proliferation and induced apoptosis in DOK and CAL27 cells. Moreover, in C3H tumor-bearing mice, ATRA-PLGA-PEG-PD-L1 nanoparticles more specifically targeted tumor cells, enhanced anticancer activity and reduced side effects when compared with free ATRA. Furthermore, CD8+ T cells were activated around PD-L1 positive cells in the tumor microenvironment after treatment. Conclusion: ATRA-PLGA-PEG-PD-L1 nanoparticles had low toxicity, high biocompatibility and specifically targeted oral dysplasia and squamous carcinoma cells both in vitro and in vivo.

Acute promyelocytic leukemia (APL): a review of the literature

Acute Promyelocytic Leukemia (APL) is characterized by a block in differentiation where leukemic cells are halted at the promyelocyte stage. A characteristic balanced chromosomal translocation between chromosomes 15 and 17 t (15;17) (q24; q21) is seen in 95% of cases — the translocation results in the formation of the PML-RARA fusion protein. The introduction of retinoic acid (RA) and arsenic trioxide (ATO) has been responsible for initially remarkable cure rates. However, relapsed APL, particularly in the high-risk subset of patients, remains an important clinical problem. In addition, despite the success of ATRA & ATO, many clinicians still elect to use cytotoxic chemotherapy in the treatment of APL. Patients who become resistant to ATO have an increased risk of mortality. The probability of relapse is significantly higher in the high-risk subset of patients undergoing treatment for APL; overall approximately 10-20% of APL patients relapse regardless of their risk stratification. Furthermore, 20-25% of patients undergoing treatment will develop differentiation syndrome, a common side effect of differentiation agents. Recent evidence using in vitro models has shown that mutations in the B2 domain of the PML protein, mediate arsenic resistance. Alternative agents and approaches considering these clinical outcomes are needed to address ATO resistance as well as the relapse rate in high risk APL.

Old dog, new trick: Trivalent arsenic as an immunomodulatory drug

Trivalent arsenic (As(III)) is recently found to be an immunomodulatory agent. As(III) has therapeutic potential in several autoimmune and inflammatory diseases in vivo. In vitro, it selectively induces apoptosis of immune cells due to different sensitivity. At a non-toxic level, As(III) shows its multifaceted nature by inducing either pro- or anti-inflammatory functions of immune subsets. These effects are exerted by either As(III)-protein interactions or as a consequence of As(III)-induced homeostasis imbalance. The immunomodulatory properties also show synergistic effects of As(III) with cancer immunotherapy. In this review, we summarize the immunomodulatory effects of As(III), focusing on the effects of As(III) on immune subsets in vitro, on mouse models of immune-related diseases, and the role of As(III) in cancer immunotherapy. Updates of the mechanisms of action, the pioneer clinical trials, dosing, and adverse events of therapeutic As(III) are also provided.

Therapeutic strategy of arsenic trioxide in the fight against cancers and other diseases

Arsenic trioxide (ATO) has been recognized as a drug for the treatment of various diseases in traditional medicine for more than two thousand years. Although ATO has recently shown excellent efficacy for the treatment of acute promyelocytic leukemia (APL), it could not provide satisfactory outcomes as a single-agent for the management of non-APL leukemia or different solid tumors. Nevertheless, combination treatment strategies, e.g., ATO with other agents, have shown promising results against different diseases. Here, we introduce in depth the latest evidence and detailed insights into ATO-mediated cures for APL by targeting PML/RARα chimeric protein, followed by the preclinical and clinical efficacy of ATO on various non-APL malignancies and solid tumors. Likewise, the antiviral activity of ATO against human immunodeficiency virus (HIV) and hepatitis C virus (HCV) was also discussed briefly. Our review would provide a clear prospect for the combination of ATO with other agents for treatment of numerous neoplastic diseases, and open a new era in the clinically applicable range of arsenicals.

Arsenic Trioxide Treatment during Pregnancy for Acute Promyelocytic Leukemia in a 22-Year-Old Woman

Acute leukemia during pregnancy is rare (1 for 100000 pregnancies). The association of arsenic trioxide (ATO) and all-trans retinoic acid (ATRA) is known as the best therapy in standard-risk acute promyelocytic leukemia (APL). We describe the first case of a pregnancy with ATRA and ATO reported in the literature. In March 2018 at the University Hospital of Besançon, a 22-year-old woman was diagnosed with APL at 14 weeks of gestation (WG). She received a total of 2160 mg of ATRA and 930 mg of ATO between 14 and 35 WG. The mother's cytological remission was very fast. No maternal or fetal complications occurred during pregnancy. The pediatrics outcomes were good. Many case reports about ATRA exposure during the second and third trimesters report no serious adverse effect for pregnancy. ATO is teratogenic, genotoxic, and carcinogenic and passes through the placenta. Fetal exposure seems to be associated with bad pregnancy outcomes (preterm delivery, decreased birth weight, and fetal loss) and with lung diseases in young adults. No clinical trial is obviously possible, and the only data available are environmental exposure or animal studies. This case report may help medical teams to make hard decision for a treatment of APL during pregnancy.

Acute Promyelocytic Leukemia: A Constellation of Molecular Events around a Single PML-RARA Fusion Gene

Although acute promyelocytic leukemia (APL) is one of the most characterized forms of acute myeloid leukemia (AML), the molecular mechanisms involved in the development and progression of this disease are still a matter of study. APL is defined by the PML-RARA rearrangement as a consequence of the translocation t(15;17)(q24;q21). However, this abnormality alone is not able to trigger the whole leukemic phenotype and secondary cooperating events might contribute to APL pathogenesis. Additional somatic mutations are known to occur recurrently in several genes, such as FLT3, WT1, NRAS and KRAS, whereas mutations in other common AML genes are rarely detected, resulting in a different molecular profile compared to other AML subtypes. How this mutational spectrum, including point mutations in the PML-RARA fusion gene, could contribute to the 10%–15% of relapsed or resistant APL patients is still unknown. Moreover, due to the uncertain impact of additional mutations on prognosis, the identification of the APL-specific genetic lesion is still the only method recommended in the routine evaluation/screening at diagnosis and for minimal residual disease (MRD) assessment. However, the gene expression profile of genes, such as ID1, BAALC, ERG, and KMT2E, once combined with the molecular events, might improve future prognostic models, allowing us to predict clinical outcomes and to categorize APL patients in different risk subsets, as recently reported. In this review, we will focus on the molecular characterization of APL patients at diagnosis, relapse and resistance, in both children and adults. We will also describe different standardized molecular approaches to study MRD, including those recently developed. Finally, we will discuss how novel molecular findings can improve the management of this disease.

Patient Experience Captured by Quality-of-Life Measurement in Oncology Clinical Trials

IMPORTANCE

Quality of life (QoL) is an important consideration in cancer medicine, especially because drugs are becoming more costly and may only result in modest gains in overall survival. However, there has been no descriptive analysis for the points at which QoL is measured in cancer trials.

OBJECTIVE

To estimate the prevalence of studies that measure QoL at different points and see how many studies measure QoL for the entirety of a patient's life.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional analysis includes all articles on oncology clinical trials in the 3 highest-impact oncology journals, published between July 2015 and June 2018, that reported QoL outcomes.

MAIN OUTCOMES AND MEASURES

Data were abstracted on when QoL was assessed and the characteristics of these studies.

RESULTS

For all 149 studies that met inclusion criteria, QoL assessment was high during treatment (104 articles [69.8%]), during follow-up (81 articles [54.4%]), and after the end of the intervention (68 articles [45.6%]). In 5 of the 149 studies (3.4%), QoL was assessed until death, including in only 1 of the 74 studies on metastatic or incurable cancers. Among these 5 studies, only 1 (20%) used a drug intervention, 1 (20%) used a behavioral intervention, and 2 (40%) used a radiation intervention; only 1 of 5 was in the metastatic setting. The number of studies that reported a positive QoL outcome (ie, QoL outcome was more favorable in the intervention group than in the control group) was between 42 of 81 articles (51.9%) and 16 of 28 articles (57.1%) for most QoL assessment points but only 1 of 5 articles (20%) for studies measuring QoL until death.

CONCLUSIONS AND RELEVANCE

This study found that most clinical trials assessed QoL during the treatment or intervention and often during a given amount of follow-up but infrequently assessed QoL on disease progression and rarely followed QoL until the end of the patient's life. Most studies reporting QoL until the end of life reported worse QoL outcomes for the intervention group than the control group. Future research and policy recommendations should consider not just short-term QoL outcomes but QoL outcomes throughout the patient's cancer care.

Outcome of older (≥70 years) APL patients frontline treated with or without arsenic trioxide-an International Collaborative Study

Data on outcome in older (≥70 years) patients with acute promyelocytic leukemia after treatment with arsenic trioxide (ATO) compared with standard chemotherapy (CTX) is scarce. We evaluated 433 patients (median age, 73.4 years) treated either with ATO+ all-trans retinoic acid (ATO/ATRA; n = 26), CTX/ATRA + ATO during consolidation (CTX/ATRA/ATO; n = 148), or with CTX/ATRA (n = 259). Median follow-up for overall survival (OS) was 4.8 years. Complete remissions (CR) were achieved in 92% with ATO/ATRA and 82% with CTX/ATRA; induction death rates were 8% and 18%, respectively. For analysis of postremission outcomes we combined the ATO/ATRA and CTX/ATRA/ATO groups (ATO/ATRA ± CTX). Cumulative incidence of relapse (CIR) was significantly lower after ATO/ATRA ± CTX compared with CTX/ATRA (P < 0.001). The same held true when restricting the analysis according to the treatment period after the year 2000. OS of patients in CR1 was not different between ATO/ATRA ± CTX compared with CTX/ATRA (P = 0.20). High (>10 × 10⁹/l) white blood cell (WBC) counts at diagnosis were associated with higher CIR (P < 0.001) compared with lower WBC in the CTX/ATRA group, but not in the ATO/ATRA ± CTX group (P = 0.48). ATO, when added to ATRA or CTX/ATRA is feasible and effective in elderly patients for remission induction and consolidation, particularly in patients with high WBC at diagnosis.

A phase II study evaluating the role of bortezomib in the management of relapsed acute promyelocytic leukemia treated upfront with arsenic trioxide

The standard‐of‐care for patients with acute promyelocytic leukemia (APL) relapsing after upfront arsenic trioxide (ATO) therapy is not defined. The present study was undertaken to evaluate the safety of addition of bortezomib to ATO in the treatment of relapsed APL based on our previously reported preclinical data demonstrating synergy between these agents. This was an open label, nonrandomized, phase II, single‐center study. We enrolled 22 consecutive patients with relapsed APL. The median age was 26.5 years (interquartile range 17.5 to 41.5). The median time from initial diagnosis to relapse was 23.1 months (interquartile range 15.6 to 43.8). All patients achieved hematological remission at a median time of 45 days (range 40‐63). Nineteen patients were in molecular remission at the end of induction. Grade 3 adverse events occurred in eight instances with one patient requiring discontinuation of therapy for grade 3 neuropathy. Twelve (54.5%) patients underwent autologous transplantation (auto‐SCT) in molecular remission while the rest opted for maintenance therapy. The median follow‐up was 48 months (range 28‐56.3). Of the patients undergoing auto‐SCT, all except one was alive and relapse free at last follow‐up. Of the patients who opted for maintenance therapy, three developed a second relapse. For treatment of APL relapsing after upfront ATO therapy, addition of bortezomib to a standard ATO‐based salvage regimen is safe and effective. This trial was registered at http://www.clinicaltrials.gov as NCT01950611.