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Background: Although expanded access is an increasingly used pathway for patients to access investigational medicine, little is known on the magnitude and content of published scientific research collected via expanded access. Methods: We performed a review of all peer-reviewed expanded access publications between January 1, 2000 and January 1, 2022. We analyzed the publications for drugs, diseases, disease area, patient numbers, time, geographical location, subject, and research methodology (single center/multicenter, international/national, prospective/retrospective). We additionally analyzed endpoints reported in all COVID-19-related expanded access publications. Results: We screened 3810 articles and included 1231, describing 523 drugs for 354 diseases for 507,481 patients. The number of publications significantly increased over time (p< 0.001). Large geographical disparities existed as Europe and the Americas accounted for 87.4% of all publications, whereas Africa only accounted for 0.6%. Oncology and hematology accounted for 53% of all publications. Twenty-nine percent of all expanded access patients (N = 197,187) reported on in 2020 and 2021 were treated in the context of COVID-19. Conclusions: By summarizing characteristics of patients, diseases, and research methods described in all scientific literature published on expanded access, we provide a unique dataset for future research. We show that published scientific research on expanded access has surged over the past decades, partly due to COVID-19. However, international collaboration and equity in geographic access remain an issue of concern. Lastly, we stress the need for harmonization of research legislation and guidance on the value of expanded access data within real-world data frameworks to improve equity in patient access and streamline future expanded access research.

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Precision medicine is gaining importance in the treatment of acute myeloid leukemia (AML). Objectively reviewing past and current knowledge aids guiding future research. Therefore, we provide a complete overview of all phase II and phase III trials investigating targeted therapies in AML and their primary endpoints over the past two decades in perspective of their clinical benefit. We assessed whether drugs were primarily designed to treat AML or were repurposed and how successful they were based on progression of distinct drugs from phase II to phase III to FDA-approval. Between January 2000 and September 2020, 167 agents with 96 targets were investigated in 397 phase II trials. Twenty-eight agents were steered towards phase III, after three phase II trials on average. Repurposed drugs less often advanced in clinical development than drugs primarily developed for AML. Composite responses were the most prevalent primary endpoints in phase II. Of the eight FDA-approved drugs, none investigated quality of life at time of approval, and three out of eight have yet to show benefit in overall survival. Returns on targeted therapy research remain lean for AML patients. Future trials should not overlook non-targeted agents and foremost study endpoints proven to predict patient well-being.

Most patients with myelodysplastic syndromes (MDS) require therapeutic intervention. However, there are few approved treatments for MDS. To explore reasons, we searched clinicaltrials.gov and clinicaltrialsregister.eu for MDS trials from 2000 to 2020. We assessed which agents were under investigation and analysed clinical trial characteristics and continuation rates from phase I to II to III to approval. As such, we identified 384 unique agents in 426 phase I, 430 phase II and 48 phase III trials. Success rates for phase III trials and agents were low, and MDS trials took markedly longer to complete than the average clinical trial. Although success rates were higher when MDS-specific phase I trials were conducted, 52% of the agents had not been evaluated in a phase I trial for MDS. MDS trials often failed to include quality of life, an especially important outcome for older MDS patients. Our work identifies factors potentially contributing to the paucity of available agents for MDS. We suggest a framework to improve clinical research in MDS that might ultimately augment the number of available agents.

Expanded access is a pathway to access unregistered medicines if there are no registered treatments available and patients cannot enroll in clinical trials. Expanded access may serve as a last resort for patients who are in dire need of treatment options and cannot await the completion of drug development and for patients who may benefit from treatments that are not (or not anymore) registered in their jurisdiction. Unregistered medicine can be acquired via named-patient pathways ('Leveren op Artsenverklaring') or via group programs ('Compassionate Use Programma's). We describe the origins of expanded access and its daily practice in the Netherlands. We observe an increasing trend in expanded access requests. The potential risks these treatments provide, the possibility of ceasing further treatment and the preferences of individual patients should all inform the decision whether or not to pursue expanded access.

New treatment options of acute myeloid leukemia (AML) are rapidly emerging. Pre-clinical models such as ex vivo cultures are extensively used towards the development of novel drugs and to study synergistic drug combinations, as well as to discover biomarkers for both drug response and anti-cancer drug resistance. Although these approaches empower efficient investigation of multiple drugs in a multitude of primary AML samples, their translational value and reproducibility are hampered by the lack of standardized methodologies and by culture system-specific behavior of AML cells and chemotherapeutic drugs. Moreover, distinct research questions require specific methods which rely on specific technical knowledge and skills. To address these aspects, we herein review commonly used culture techniques in light of diverse research questions. In addition, culture-dependent effects on drug resistance towards commonly used drugs in the treatment of AML are summarized including several pitfalls that may arise because of culture technique artifacts. The primary aim of the current review is to provide practical guidelines for ex vivo primary AML culture experimental design.

Precision medicine is gaining importance in the treatment of acute myeloid leukemia (AML). Objectively reviewing past and current knowledge aids guiding future research. Therefore, we provide a complete overview of all phase II and phase III trials investigating targeted therapies in AML and their primary endpoints over the past two decades in perspective of their clinical benefit. We assessed whether drugs were primarily designed to treat AML or were repurposed and how successful they were based on progression of distinct drugs from phase II to phase III to FDA-approval. Between January 2000 and September 2020, 167 agents with 96 targets were investigated in 397 phase II trials. Twenty-eight agents were steered towards phase III, after three phase II trials on average. Repurposed drugs less often advanced in clinical development than drugs primarily developed for AML. Composite responses were the most prevalent primary endpoints in phase II. Of the eight FDA-approved drugs, none investigated quality of life at time of approval, and three out of eight have yet to show benefit in overall survival. Returns on targeted therapy research remain lean for AML patients. Future trials should not overlook non-targeted agents and foremost study endpoints proven to predict patient well-being.

Mass-spectrometry (MS) based phosphoproteomics is increasingly used to explore aberrant cellular signaling and kinase driver activity, aiming to improve kinase inhibitor (KI) treatment selection in malignancies. Phosphorylation is a dynamic, highly regulated post-translational modification that may be affected by variation in pre-analytical sample handling, hampering the translational value of phosphoproteomics-based analyses. Here, we investigate the effect of delay in mononuclear cell isolation on acute myeloid leukemia (AML) phosphorylation profiles. We performed MS on immuno-precipitated phosphotyrosine (pY)-containing peptides isolated from AML samples after seven pre-defined delays before sample processing (direct processing, thirty minutes, one hour, two hours, three hours, four hours and 24 h delay). Up to four hours, pY phosphoproteomics profiles show limited variation. However, in samples processed with a delay of 24 h, we observed significant change in these phosphorylation profiles, with differential phosphorylation of 22 pY phosphopeptides (p < 0.01). This includes increased phosphorylation of pY phosphopeptides of JNK and p38 kinases indicative of stress response activation. Based on these results, we conclude that processing of AML samples should be standardized at all times and should occur within four hours after sample collection. Significance: Our study provides a practical time-frame in which fresh peripheral blood samples from acute myeloid patients should be processed for phosphoproteomics, in order to warrant correct interpretation of in vivo biology. We show that up to four hours of delayed processing after sample collection, pY phosphoproteomic profiles remain stable. Extended delays are associated with perturbation of phosphorylation profiles. After a delay of 24 h, JNK activation loop phosphorylation is markedly increased and may serve as a biomarker for delayed processing. These findings are relevant for biomedical acute myeloid leukemia research, as phosphoproteomic techniques are of particular interest to investigate aberrant kinase signaling in relation to disease emergence and kinase inhibitor response. With these data, we aim to contribute to reproducible research with meaningful outcomes.

Contains fulltext : 220824.pdf (Publisher’s version ) (Open Access) Acute myeloid leukemia (AML) is a clonal disorder arising from hematopoietic myeloid progenitors. Aberrantly activated tyrosine kinases (TK) are involved in leukemogenesis and are associated with poor treatment outcome. Kinase inhibitor (KI) treatment has shown promise in improving patient outcome in AML. However, inhibitor selection for patients is suboptimal. In a preclinical effort to address KI selection, we analyzed a panel of 16 AML cell lines using phosphotyrosine (pY) enrichment-based, label-free phosphoproteomics. The Integrative Inferred Kinase Activity (INKA) algorithm was used to identify hyperphosphorylated, active kinases as candidate for KI treatment, and efficacy of selected KIs was tested. Heterogeneous signaling was observed with between 241 and 2764 phosphopeptides detected per cell line. Of 4853 identified phosphopeptides with 4229 phosphosites, 4459 phosphopeptides (4430 pY) were linked to 3605 class I sites (3525 pY). INKA analysis in single cell lines successfully pinpointed driver kinases (PDGFRA, JAK2, KIT and FLT3) corresponding with activating mutations present in these cell lines. Furthermore, potential receptor tyrosine kinase (RTK) drivers, undetected by standard molecular analyses, were identified in four cell lines (FGFR1 in KG-1 and KG-1a, PDGFRA in Kasumi-3, and FLT3 in MM6). These cell lines proved highly sensitive to specific KIs. Six AML cell lines without a clear RTK driver showed evidence of MAPK1/3 activation, indicative of the presence of activating upstream RAS mutations. Importantly, FLT3 phosphorylation was demonstrated in two clinical AML samples with a FLT3 internal tandem duplication (ITD) mutation. Our data show the potential of pY-phosphoproteomics and INKA analysis to provide insight in AML TK signaling and identify hyperactive kinases as potential targets for treatment in AML cell lines. These results warrant future investigation of clinical samples to further our understanding of TK phosphorylation in relation to clinical response in the individual patient.

Novel treatment strategies are of paramount importance to improve clinical outcomes in pediatric AML. Since chemotherapy is likely to remain the cornerstone of curative treatment of AML, insights in the molecular mechanisms that determine its cytotoxic effects could aid further treatment optimization. To assess which genes and pathways are implicated in tumor drug resistance, we correlated ex vivo drug response data to genome-wide gene expression profiles of 73 primary pediatric AML samples obtained at initial diagnosis. Ex vivo response of primary AML blasts towards cytarabine (Ara C), daunorubicin (DNR), etoposide (VP16), and cladribine (2-CdA) was associated with the expression of 101, 345, 206, and 599 genes, respectively (p &lt, 0.001, FDR 0.004&ndash, 0.416). Microarray based expression of multiple genes was technically validated using qRT-PCR for a selection of genes. Moreover, expression levels of BRE, HIF1A, and CLEC7A were confirmed to be significantly (p &lt, 0.05) associated with ex vivo drug response in an independent set of 48 primary pediatric AML patients. We present unique data that addresses transcriptomic analyses of the mechanisms underlying ex vivo drug response of primary tumor samples. Our data suggest that distinct gene expression profiles are associated with ex vivo drug response, and may confer a priori drug resistance in leukemic cells. The described associations represent a fundament for the development of interventions to overcome drug resistance in AML, and maximize the benefits of current chemotherapy for sensitive patients.

Controversy exists whether internal tandem duplication of FMS-like tyrosine kinase 3 (FLT3-internal tandem duplication [ITD]) allelic ratio (AR) and/or length of the ITD should be taken into account for risk stratification of pediatric acute myeloid leukemia (AML) and whether it should be measured on RNA or DNA. Moreover, the ITD status may be of relevance for selecting patients eligible for FLT3 inhibitors. Here, we included 172 pediatric AML patients, of whom 36 (21%) harbored FLT3-ITD as determined on both RNA and DNA. Although there was a good correlation between both parameters AR(spearman) = 0.62 (95% confidence interval, 0.22-0.87) and ITDlength(spearman) = 0.98 (95% confidence interval, 0.90-1.00), only AR >= 0.5 and length >= 48 base pairs (bps) based on RNA measurements were significantly associated with overall survival (AR: P-logrank = .008; ITDlength: P-logrank = .011). In large ITDs (>156 bp on DNA) a remarkable 90-bp difference exists between DNA and RNA, including intron 14, which is spliced out in RNA. Ex vivo exposure (n = 30) to FLT3 inhibitors, in particular to the FLT3-specific inhibitor gilteritinib, showed that colony-forming capacity was significantly more reduced in FLT3-ITD-AR >= 0.5 compared with ITD-AR-low and ITD2 patient samples (P

Reports of "positive" results in early phase trials as presented at ASH presumably herald therapeutic advances, or at a minimum, a larger, potentially confirmatory, randomized trial. However, the predictive value of an ASH abstract reporting positive results in AML for subsequent clinical utility seems low (Estey 2006, ASH). Furthermore, not all results presented at ASH are published in peer-reviewed journals, and selectively publishing positive results leads to publication bias. Moreover, truly negative studies may be scientifically more rigorous and accurate than positive studies given the unequivocal findings. The extent of publication bias is unknown as is the frequency with which positive or negative abstracts lead to subsequent investigation in phase III and the reasons why positive phase II studies might not progress to phase III. We downloaded all 2013 - 2015 ASH abstracts (N = 17,251) and evaluated all abstracts reporting phase II clinical trials (N = 371) of novel drugs and therapeutic regimens presented at ASH in these years, covering investigational treatments of MM, CLL, AML, DLBCL, MDS, NHL, ALL, CML, MCL, SLL, other lymphomas and POEMS. We first scored abstracts "positive", "negative" or "inconclusive". Criteria for a positive abstract were words/phrases such as "encouraging", "promising", "could represent a novel therapeutic option" and "warrants investigation in a randomized trial". Negative abstracts included terms such as "does not support further research" and "demonstrates no clinical activity". The remainder were scored as inconclusive. Using this approach, we scored 296/371 (80%) abstracts as positive, 37/371 (10%) as negative, and 38/371 (10%) as inconclusive. 292/371 abstracts (79%) were published in peer-reviewed journals. The abstract conclusion (positive, negative or inconclusive) was not associated with publication in a peer-reviewed journal. Most frequently, studies were published in Blood (34/292 [11.6%]) and British Journal of Haematology (39/292 [13.4%]) . In Blood, 91% (31/34) of the studies were positive. British Journal of Haematology published significantly more negative studies than Blood (26%, Fisher Exact p = 0.02). Abstracts reporting studies with larger sample sizes tended to be published more often (p = 0.066). Differences exist between the abstract conclusion and later peer-reviewed publications. Of positive ASH abstracts, 6% changed to a negative conclusion in the peer-reviewed publication. Similarly, 6.5% of the initial negative abstract later reversed to a positive conclusion. 53% of positive abstracts did not lead to phase III studies, as registered on clinicaltrials.gov. Subsequently, regimens described in positive peer-reviewed publications did not proceed to phase III research in 48%. To explore why, we sent questionnaires to the first and/or last authors of positive studies not prompting phase III trials. 52% responded. Failure of positive phase II trials to proceed to phase III was due to the decision by the pharmaceutical company to halt clinical investigation (44%), lack of any intent to study the drug in phase III in the first place (40%), insufficient funding (35%), insufficient efficacy (despite the "positive" abstract; 33%) and safety concerns (4%) (Figure). Additional reasons for not proceeding to phase III were the availability of newer regimens, the rarity of the disease, or when regulatory approval had already been obtained after phase II. In conclusion, "positive" and "negative" ASH abstracts are published as full papers equally often, although the positive ones may be published more often in journals with higher "impact factors". More than half of the regimens presented in positive ASH abstracts remain unevaluated in randomized phase III trials. A separate problem is the likely tendency to disproportionately submit (and/or accept) positive, rather than negative, studies to ASH in the first place. We believe our findings raise issues in clinical research that may not be in the best interest of patients. This demands more consideration than it currently receives. Figure 1 Figure 1. Disclosures Ossenkoppele: Astellas: Consultancy, Honoraria; Agios: Consultancy, Honoraria; Abbvie, AGIOS, BMS/Celgene Astellas,AMGEN, Gilead,Servier,JAZZ,Servier Novartis: Consultancy, Honoraria; BMS/Celgene: Consultancy, Honoraria; Jazz: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Gilead: Consultancy, Honoraria. Rowe: Biosight Inc.: Consultancy.

Limited data are available on the incidence and impact of TP53 alterations and TP53 pathway deregulation in paediatric acute myeloid leukaemia (AML). We analysed TP53 alterations in bone marrow samples of 229 patients with de novo paediatric AML, and detected heterozygous missense exon mutations in two patients (1%) and 17p deletions of the TP53 gene in four patients (2%). These patients more frequently had complex karyotype (50% vs. 4%, P = 0·002) or adverse cytogenetic abnormalities, including complex karyotype (67% vs. 17%, P = 0·013), compared to TP53 wild-type. Differential expression of TP53 pathway genes was associated with poor survival, indicating a role for TP53 regulators and effector genes.

Controversy exists whether internal tandem duplication of FMS-like tyrosine kinase 3 (

It has been well established that dysregulated activation of kinases is essential for the development of acute myeloid leukemia(AML). In contrast, little is known about the role of their dephosphorylation counterparts, the tyrosine phosphatases. Here we performed whole tyrosine phosphatome sequencing in 15 pediatric AML samples and found a somatic P394L mutation in the FERM-adjacent region of PTPN4. In the absence of a crystal structure of PTPN4, bioinformatics analysis with the software tool PROVEAN (Protein Variation Effect Analyzer) revealed that this P394L mutation is expected to inflict a deleterious effect on the phosphatase activity of PTNP4. Exploring the frequency of this PTPN4 mutation in 227 acute leukemia samples uncovered an additional silent A364A mutation in exon 13 of PTPN4. No additional mutations were found, which further emphasizes the low mutation burden in pediatric AML. Further functional studies are warranted to explore the actual impact of this P394L mutation on the structure and/or function of PTPN4.

Acute myeloid leukemia is a bone marrow disease characterized by a block in differentiation of the myeloid lineage with a concomitant uncontrolled high proliferation rate. Development of acute myeloid leukemia from stem cells with specific founder mutations, leads to an oligoclonal disease that progresses into a very heterogeneous leukemia at diagnosis. Measurement of leukemic stem cell load and characterization of these cells are essential for prediction of relapse and target identification, respectively. Prediction of relapse by monitoring the disease during minimal residual disease detection is challenged by clonal shifts during therapy. To overcome this, characterization of the potential relapse-initiating cells is required using both flow cytometry and molecular analysis since leukemic stem cells can be targeted both on extracellular features and on stem-cell specific signal transduction pathways.