Venetoclax and Cobimetinib in Relapsed/Refractory AML: A Phase 1b Trial.

BACKGROUND: Therapies for relapsed/refractory acute myeloid leukemia remain limited and outcomes poor, especially amongst patients who are ineligible for cytotoxic chemotherapy or targeted therapies. PATIENTS AND METHODS: This phase 1b trial evaluated venetoclax, a B-cell lymphoma-2 (BCL-2) inhibitor, plus cobimetinib, a MEK1/2 inhibitor, in patients with relapsed/refractory acute myeloid leukemia, ineligible for cytotoxic chemotherapy. Two-dimensional dose-escalation was performed for venetoclax dosed daily, and for cobimetinib dosed on days 1-21 of each 28-day cycle. RESULTS: Thirty patients (median [range] age: 71.5 years [60-84]) received venetoclax-cobimetinib. The most common adverse events (AEs; in ≥40.0% of patients) were diarrhea (80.0%), nausea (60.0%), vomiting (40.0%), febrile neutropenia (40.0%), and fatigue (40.0%). Overall, 66.7% and 23.3% of patients experienced AEs leading to dose modification/interruption or treatment withdrawal, respectively. The composite complete remission (CRc) rate (complete remission [CR] + CR with incomplete blood count recovery + CR with incomplete platelet recovery) was 15.6%; antileukemic response rate (CRc + morphologic leukemia-free state/partial remission) was 18.8%. For the recommended phase 2 dose (venetoclax: 600 mg; cobimetinib: 40 mg), CRc and antileukemic response rates were both 12.5%. Failure to achieve an antileukemic response was associated with elevated baseline phosphorylated ERK and MCL-1 levels, but not BCL-xL. Baseline mutations in ≥1 signaling gene or TP53 were noted in nonresponders and emerged on treatment. Pharmacodynamic biomarkers revealed inconsistent, transient inhibition of the mitogen-activated protein kinase (MAPK) pathway. CONCLUSION: Venetoclax-cobimetinib showed limited preliminary efficacy similar to single-agent venetoclax, but with added toxicity. Our findings will inform future trials of BCL-2/MAPK pathway inhibitor combinations.

Venetoclax and idasanutlin in relapsed/refractory AML: a nonrandomized, open-label phase 1b trial.

This phase 1b trial (NCT02670044) evaluated venetoclax-idasanutlin in patients with relapsed/refractory (R/R) acute myeloid leukemia (AML) ineligible for cytotoxic chemotherapy. Two-dimensional dose escalation (DE, n = 50) was performed for venetoclax daily with idasanutlin on days 1 to 5 in 28-day cycles, followed by dosing schedule optimization (n = 6) to evaluate reduced venetoclax schedules (21-/14-day dosing). Common adverse events (occurring in ≥40% of patients) included diarrhea (87.3% of patients), nausea (74.5%), vomiting (52.7%), hypokalemia (50.9%), and febrile neutropenia (45.5%). During DE, across all doses, composite complete remission (CRc; CR + CR with incomplete blood count recovery + CR with incomplete platelet count recovery) rate was 26.0% and morphologic leukemia-free state (MLFS) rate was 12%. For anticipated recommended phase 2 doses (venetoclax 600 mg + idasanutlin 150 mg; venetoclax 600 mg + idasanutlin 200 mg), the combined CRc rate was 34.3% and the MLFS rate was 14.3%. Pretreatment IDH1/2 and RUNX1 mutations were associated with higher CRc rates (50.0% and 45.0%, respectively). CRc rate in patients with TP53 mutations was 20.0%, with responses noted among those with co-occurring IDH and RUNX1 mutations. In 12 out of 36 evaluable patients, 25 emergent TP53 mutations were observed; 22 were present at baseline with low TP53 variant allele frequency (median 0.0095% [range, 0.0006-0.4]). Venetoclax-idasanutlin showed manageable safety and encouraging efficacy in unfit patients with R/R AML. IDH1/2 and RUNX1 mutations were associated with venetoclax-idasanutlin sensitivity, even in some patients with co-occurring TP53 mutations; most emergent TP53 clones were preexisting. Our findings will aid ongoing/future trials of BCL-2/MDM2 inhibitor combinations. This trial was registered at www.clinicaltrials.gov as #NCT02670044.

Idasanutlin plus cytarabine in relapsed or refractory acute myeloid leukemia: results of the MIRROS trial.

The phase 3 MIRROS (MDM2 antagonist Idasanutlin in Relapsed or Refractory acute myeloid leukemia [AML] for Overall Survival) trial (NCT02545283) evaluated the efficacy and safety of the small-molecule MDM2 antagonist idasanutlin plus cytarabine in patients with relapsed/refractory (R/R) AML. Adults (n = 447) with R/R AML whose disease relapsed or was refractory after ≤2 prior induction regimens as initial treatment or following salvage chemotherapy regimen, with Eastern Cooperative Oncology Group performance status ≤2 were enrolled regardless of TP53 mutation status and randomly assigned 2:1 to idasanutlin 300 mg or placebo orally twice daily plus cytarabine 1 g/m2 IV on days 1 to 5 of 28-day cycles. At primary analysis (cutoff, November 2019), 436 patients were enrolled, including 355 in the TP53 wild-type intention-to-treat (TP53WT-ITT) population. The primary endpoint, overall survival in the TP53WT-ITT population, was not met (median, 8.3 vs 9.1 months with idasanutlin-cytarabine vs placebo-cytarabine; stratified hazard ratio [HR], 1.08; 95% confidence interval [CI], 0.81-1.45; P = .58). The complete remission (CR) rate, a key secondary endpoint, was 20.3% vs 17.1% (odds ratio [OR], 1.23; 95% CI, 0.70-2.18). The overall response rate (ORR) was 38.8% vs 22.0% (OR, 2.25; 95% CI, 1.36-3.72). Common any-grade adverse events (≥10% incidence in any arm) were diarrhea (87.0% vs 32.9%), febrile neutropenia (52.8% vs 49.3%), and nausea (52.5% vs 31.5%). In summary, despite improved ORR, adding idasanutlin to cytarabine did not improve overall survival or CR rates in patients with R/R AML.

Impact of time pressure on software quality: A laboratory experiment on a game-theoretical model.

Research suggests the relationship between time pressure and software quality to be more complex than presumed. While software developers can adjust their output to improve observed performance at the expense of software quality, the latter has been found to increase with time pressure in case of work-pace dependent incentives. An untested, but widely disseminated game-theoretical model seeks to resolve this contradiction and hypothesizes that high rates of time pressure avoid so-called 'shortcuts', which occur in the form of imperfections induced by developers to meet unrealistically tight deadlines. We conduct two laboratory experiments to empirically test this model for the first time. Our results corroborate the model with regard to its suggestion that shortcuts can be reduced if developers perceive unrealistic deadlines as ever-present. However, we also show that the actual critical probability of unrealistic deadlines-the point at which shortcut taking is drastically reduced-is above the theoretical one. Although final conclusions on the impact of time pressure on software quality remain to be drawn, our results suggest that-considering the contingencies of our study-time pressure helps in striving for quality in software projects.

Murine double minute 2 inhibition alone or with cytarabine in acute myeloid leukemia: Results from an idasanutlin phase 1/1b study⋆.

The prognosis remains poor for patients with relapsed or refractory (r/r) acute myeloid leukemia; thus, novel therapies are needed. We evaluated idasanutlin-a new, potent murine double minute 2 antagonist-alone or with cytarabine in patients with r/r acute myeloid leukemia, de novo untreated acute myeloid leukemia unsuitable for standard treatment or with adverse features, or secondary acute myeloid leukemia in a multicenter, open-label, phase 1/1b trial. Primary objectives were to determine the maximum tolerated dose (MTD) and recommended dose for expansion (RDE) and characterize the safety profile of idasanutlin monotherapy and combination therapy. Clinical activity and pharmacokinetics were secondary objectives. Two idasanutlin formulations were investigated: a microprecipitate bulk powder (MBP) and optimized spray-dried powder (SDP). Following dose escalation, patients (N = 122) received idasanutlin at the RDE in the extension cohorts. No formal MTD was identified. Idasanutlin was tolerable alone and in combination with cytarabine. The RDE was determined as 600 mg twice a day for the MBP formulation and 300 mg twice a day for the SDP formulation. Adverse events were mostly grade 1/2 (76.2 %). The most common any-grade adverse events were gastrointestinal (including diarrhea [90.2 %]). The early death rate across all patients was 14.8 %. Plasma idasanutlin exposure was dose related. In TP53 wild-type patients, composite complete remission rates were 18.9 % with monotherapy and 35.6 % with combination therapy. Based on these results, idasanutlin development continued with further investigation in the treatment of acute myeloid leukemia. ClinicalTrials.gov: NCT01773408.

MDM2 inhibition: an important step forward in cancer therapy.

Targeting the interaction between tumor suppressor p53 and the E3 ligase MDM2 represents an attractive treatment approach for cancers with wild-type or functional TP53. Indeed, several small molecules have been developed and evaluated in various malignancies. We provide an overview of MDM2 inhibitors under preclinical and clinical investigation, with a focus on molecules with ongoing clinical trials, as indicated by ClinicalTrials.gov . Because preclinical and clinical exploration of combination strategies is underway, data supporting these combinations are also described. We identified the following molecules for inclusion in this review: RG7112 (RO5045337), idasanutlin (RG7388), AMG-232 (KRT-232), APG-115, BI-907828, CGM097, siremadlin (HDM201), and milademetan (DS-3032b). Information about each MDM2 inhibitor was collected from major congress records and PubMed using the following search terms: each molecule name, "MDM2"and "HDM2." Only congress records were limited by date (January 1, 2012-March 6, 2020). Special attention was given to available data in hematologic malignancies; however, available safety data in any indication are reported. Overall, targeting MDM2 is a promising treatment strategy, as evidenced by the increasing number of MDM2 inhibitors entering the clinic. Additional clinical investigation is needed to further elucidate the role of MDM2 inhibitors in the treatment of human cancers.

Open-label, multicentre expansion cohort to evaluate imgatuzumab in pre-treated patients with KRAS-mutant advanced colorectal carcinoma.

AIM: Imgatuzumab (GA201) is a novel anti-epidermal growth factor receptor (anti-EGFR) antibody glycoengineered for enhanced antibody-dependent cell-mediated cytotoxicity (ADCC). We investigated the efficacy of imgatuzumab in patients with EGFR-positive, KRAS-mutant advanced colorectal cancer. METHODS: Patients received single-agent imgatuzumab (1400mg on day 1 and 8 followed by q2W) as third line therapy in an open-label, multicentre, non-randomised, expansion study. The primary end-point was tumour response. Pre- and on-treatment biopsies and blood samples were investigated for biomarkers related to imgatuzumab's believed mechanism of action (MoA). RESULTS: 25 patients were treated and the best overall response was stable disease occurring in 40% of patients at 8weeks, 24% at 16weeks and 8% (two patients) at 32weeks. Median overall survival was 9.3months (95% confidence interval (CI): 5.1-12.3). Treatment-related rash, hypomagnesaemia and infusion-related reactions were the most common adverse events. Comparison of pre- and post-treatment biopsies revealed that the number of tumour-infiltrating immune cells increased notably after one cycle of therapy (median compound immune reactive score of 1491 versus 898 cells/mm(3) at baseline), whereas the number of peripheral natural killer cells decreased. A potential association between baseline tumour immune infiltration and clinical efficacy was seen. CONCLUSIONS: These data may suggest that the MoA of imgatuzumab involves ADCC-related immune effects in the tumour and is not limited to simple receptor blockade.

Humoral response to catumaxomab correlates with clinical outcome: results of the pivotal phase II/III study in patients with malignant ascites.

The trifunctional antibody catumaxomab is a targeted immunotherapy for the intraperitoneal treatment of malignant ascites. In a Phase II/III trial in cancer patients (n = 258) with malignant ascites, catumaxomab showed a clear clinical benefit vs. paracentesis and had an acceptable safety profile. Human antimouse antibodies (HAMAs), which could be associated with beneficial humoral effects and prolonged survival, may develop against catumaxomab as it is a mouse/rat antibody. This post hoc analysis investigated whether there was a correlation between the detection of HAMAs 8 days after the fourth catumaxomab infusion and clinical outcome. HAMA-positive and HAMA-negative patients in the catumaxomab group and patients in the control group were analyzed separately for all three clinical outcome measures (puncture-free survival, time to next puncture and overall survival) and compared to each other. There was a strong correlation between humoral response and clinical outcome: patients who developed HAMAs after catumaxomab showed significant improvement in all three clinical outcome measures vs. HAMA-negative patients. In the overall population in HAMA-positive vs. HAMA-negative patients, median puncture-free survival was 64 vs. 27 days (p < 0.0001; HR 0.330), median time to next therapeutic puncture was 104 vs. 46 days (p = 0.0002; HR 0.307) and median overall survival was 129 vs. 64 days (p = 0.0003; HR 0.433). Similar differences between HAMA-positive and HAMA-negative patients were seen in the ovarian, nonovarian and gastric cancer subgroups. In conclusion, HAMA development may be a biomarker for catumaxomab response and patients who developed HAMAs sooner derived greater benefit from catumaxomab treatment.

Insertion sites in engrafted cells cluster within a limited repertoire of genomic areas after gammaretroviral vector gene therapy.

Vector-associated side effects in clinical gene therapy have provided insights into the molecular mechanisms of hematopoietic regulation in vivo. Surprisingly, many retrovirus insertion sites (RIS) present in engrafted cells have been found to cluster nonrandomly in close association with specific genes. Our data demonstrate that these genes directly influence the in vivo fate of hematopoietic cell clones. Analysis of insertions thus far has been limited to individual clinical studies. Here, we studied >7,000 insertions retrieved from various studies. More than 40% of all insertions found in engrafted gene-modified cells were clustered in the same genomic areas covering only 0.36% of the genome. Gene classification analyses displayed significant overrepresentation of genes associated with hematopoietic functions and relevance for cell growth and survival in vivo. The similarity of insertion distributions indicates that vector insertions in repopulating cells cluster in predictable patterns. Thus, insertion analyses of preclinical in vitro and murine in vivo studies as well as vector insertion repertoires in clinical trials yielded concerted results and mark a small number of interesting genomic loci and genes that warrants further investigation of the biological consequences of vector insertions.

Genomic instability and myelodysplasia with monosomy 7 consequent to EVI1 activation after gene therapy for chronic granulomatous disease.

Gene-modified autologous hematopoietic stem cells (HSC) can provide ample clinical benefits to subjects suffering from X-linked chronic granulomatous disease (X-CGD), a rare inherited immunodeficiency characterized by recurrent, often life-threatening bacterial and fungal infections. Here we report on the molecular and cellular events observed in two young adults with X-CGD treated by gene therapy in 2004. After the initial resolution of bacterial and fungal infections, both subjects showed silencing of transgene expression due to methylation of the viral promoter, and myelodysplasia with monosomy 7 as a result of insertional activation of ecotropic viral integration site 1 (EVI1). One subject died from overwhelming sepsis 27 months after gene therapy, whereas a second subject underwent an allogeneic HSC transplantation. Our data show that forced overexpression of EVI1 in human cells disrupts normal centrosome duplication, linking EVI1 activation to the development of genomic instability, monosomy 7 and clonal progression toward myelodysplasia.

Advances in the treatment of Chronic Granulomatous Disease by gene therapy.

Gene transfer into hematopoietic stem cells has been successfully used to correct immunodeficiencies affecting the lymphoid compartment. However, similar results have not been reported for diseases affecting myeloid cells, mainly due to low engraftment levels of gene-modified cells observed in unconditioned patients. Here we review the developments leading to a gene therapy approach for the treatment of Chronic Granulomatous Disease (CGD), a primary life threatening immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes. Although the disease can be cured by bone marrow transplantation, this treatment is only available to patients with HLA-identical sibling or matched unrelated donors. One therapeutic option for patients without suitable donor is the genetic modification of autologous hematopoietic stem cells. Although early attempts to correct CGD by gene therapy were unsuccessful, these studies demonstrated the safety and limitations of gene transfer into hematopoietic stem cells (HSC) of CGD patients using retroviral vectors. The recent development of advanced gene transduction protocols together with improved retroviral vectors, combined with low intensity chemotherapy conditioning, allowed partial correction of the granulocytic function with a significant clinical benefit in treated patients. These results may have important implications for future applications of gene therapy in myeloid disorders and inherited diseases using hematopoietic stem cells.

Gene therapy for chronic granulomatous disease.

Chronic granuloniatous disease (CGD) is a rare inherited imnunodeficiency characterized by recurrent, often life threatening bacterial and fungal infections due to a functional defect in the microbial-killing activity of phagocytic neutrophils. If regular care and conventional therapy fail, tile disease can be cured by bone marrow transplantation. This treatment is, however, only available to patients with human leukocyte antigen-identical sibling or matched unrelated donors. One therapeutic option for patients lacking suitable donors is the genetic modification of autologous hematopoietic stem cells. This review discusses the developments that have led to the realization of a successful gene therapy protocol for the correction of CGD.

Correction of X-linked chronic granulomatous disease by gene therapy, augmented by insertional activation of MDS1-EVI1, PRDM16 or SETBP1.

Gene transfer into hematopoietic stem cells has been used successfully for correcting lymphoid but not myeloid immunodeficiencies. Here we report on two adults who received gene therapy after nonmyeloablative bone marrow conditioning for the treatment of X-linked chronic granulomatous disease (X-CGD), a primary immunodeficiency caused by a defect in the oxidative antimicrobial activity of phagocytes resulting from mutations in gp91(phox). We detected substantial gene transfer in both individuals' neutrophils that lead to a large number of functionally corrected phagocytes and notable clinical improvement. Large-scale retroviral integration site-distribution analysis showed activating insertions in MDS1-EVI1, PRDM16 or SETBP1 that had influenced regulation of long-term hematopoiesis by expanding gene-corrected myelopoiesis three- to four-fold in both individuals. Although insertional influences have probably reinforced the therapeutic efficacy in this trial, our results suggest that gene therapy in combination with bone marrow conditioning can be successfully used to treat inherited diseases affecting the myeloid compartment such as CGD.

Mobilization and transduction of CD34(+) peripheral blood stem cells in patients with X-linked chronic granulomatous disease.

As a single-gene defect in phagocytes, the X-linked form of chronic granulomatous disease (X-CGD) is a disorder potentially amenable to gene therapy by transfer of a functional copy of the gp91(phox) gene into hematopoietic stem cells (HSC). Although antimicrobial agents and interferon-gamma (IFN-gamma) have significantly improved its prognosis, CGD is still associated with high morbidity and mortality. The disease can be cured by bone marrow transplantation (BMT); however, BMT in CGD has been associated with unacceptably high rates of morbidity, mortality, and graft failure, except in very selected cases in which an HLA-identical donor is available. Prerequisites for a clinical gene therapy of CGD are an efficient mobilization of peripheral blood stem cells (PBSC) as well as the preservation of their viability and hematopoietic potential following transduction and ex vivo culture. We show that (i) mobilization and collection of CD34(+) cells after a 4-week IFN-gamma-free period by G-CSF results in sufficient numbers of cells for transplantation; (ii) the quality of collected stem cells is not altered in comparison to cells obtained from healthy volunteers as assessed by long-term culture initiating cells (LTC-IC) and progenitor cell expansion; (iii) retroviral transfer of the gp91(phox) gene under defined, serum-free conditions leads to high and stable reconstitution of the respiratory burst activity in X-CGD neutrophils derived from transduced CD34(+) progenitor and LTC-IC. Withdrawal of IFN-gamma in CGD patients may improve mobilization of CD34(+) stem cells by G-CSF. The gene transfer conditions established here are applicable to a clinical approach for gene therapy of X-CGD.