Different treatment strategies versus a common standard arm (CSA) in patients with newly diagnosed AML over the age of 60 years: a randomized German inter-group study

The CDK4/6 Inhibitor Palbociclib Synergizes with ATRA to Induce Differentiation in AML

Differentiation therapy based on ATRA almost cured acute promyelocytic leukemia (APL). However, it is disappointing that ATRA is not effective against other acute myeloid leukemia (AML) subtypes. Developing new and effective anti-AML therapies that promote leukemia differentiation is necessary. The CDK4/6-cyclin D pathway is a key initiator of the G1-S phase transition, which determines cell fate. Herein, we investigated whether the CDK4/6 inhibitor palbociclib would synergize with ATRA to promote leukemia differentiation in vitro and in vivo. Our findings revealed that CDK4/6-cyclin D pathway genes were aberrantly expressed in AML, and we observed that palbociclib sensitized AML cells to ATRA-induced morphologic, biochemical, and functional changes indicative of myeloid differentiation. The combination of palbociclib and ATRA attenuated AML cell expansion in vivo. These enhanced differentiation effects may be associated with the regulation of transcription factors, including RARα, E2F1, and STAT1. Overall, our findings demonstrate that CDK4/6 inhibition sensitizes AML cells to ATRA and could guide the development of novel therapeutic strategies for patients with AML.

Improving long-term outcomes with intensive induction chemotherapy for patients with AML

Intensive chemotherapy in combination with allogeneic hematopoietic cell transplantation and supportive care can induce long-term remissions in around 50% of acute myeloid leukemia patients eligible for intensive treatment. Several treatment optimization trials helped to refine schedule and dosing of the historic "7 + 3" combination. Together with the addition of novel agents, increased efficacy and tolerability led to improved long-term outcomes. Unsatisfactory outcomes in fit elderly patients and unfavorable genetic subgroups have raised the question of whether less-intensive venetoclax-based approaches may be beneficial as an alternative. Although tempting and worth exploring, this issue will remain controversial until the results of randomized comparisons appear. To date, intensive chemotherapy remains the only evident curative treatment option for long-term disease eradication in a fixed treatment time. With the advent of more novel agents and advances in minimal residual disease (MRD) detection and maintenance approaches, the face of intensive treatment could change in many ways. Several are being explored in clinical trials, such as (1) combinations of more than 1 novel agent with the intensive backbone, (2) head-to-head comparisons of novel agents, (3) replacement or dose reduction of cytotoxic components such as anthracyclines, and (4) MRD-guided escalation and de-escalation strategies. The combination of intensive treatment with individualized tailored innovative strategies will most certainly reduce treatment-related toxicities and increase the chances for long-term remission in the future.

Ubiquitin-proteasome system as a target for anticancer treatment-an update

As the ubiquitin-proteasome system (UPS) regulates almost every biological process, the dysregulation or aberrant expression of the UPS components causes many pathological disorders, including cancers. To find a novel target for anticancer therapy, the UPS has been an active area of research since the FDA's first approval of a proteasome inhibitor bortezomib in 2003 for treating multiple myeloma (MM). Here, we summarize newly described UPS components, including E3 ubiquitin ligases, deubiquitinases (DUBs), and immunoproteasome, whose malfunction leads to tumorigenesis and whose inhibitors have been investigated in clinical trials as anticancer therapy since 2020. We explain the mechanism and effects of several inhibitors in depth to better comprehend the advantages of targeting UPS components for cancer treatment. In addition, we describe attempts to overcome resistance and limited efficacy of some launched proteasome inhibitors, as well as an emerging PROTAC-based tool targeting UPS components for anticancer therapy.