Anti-tumor effect of antibody drug conjugate ASP1235 targeting Fms-like tyrosine kinase 3 with venetoclax plus azacitidine in an acute myeloid leukemia xenograft mouse model

CD37 in acute myeloid leukemia: a novel surface target for drug delivery

ABSTRACT

Acute myeloid leukemia (AML) is the most common and lethal leukemia in adults. AML consists of many genetic subtypes, which limits broad applicability of targeted therapy. We discovered that the hematopoiesis-restricted tetraspanin CD37 is expressed on the majority of primary AML blasts and thus may represent a common therapeutic target for AML regardless of subtype. We demonstrate that the internalization properties of CD37 are distinct in AML blasts when compared with normal blood cells, and that CD37 rapidly accumulates inside AML blasts via dynamin-dependent endocytosis. Our work revealed that the clinically relevant anti-CD37 antibody-drug conjugate (ADC) Debio 1562 (αCD37-DM1) is highly cytotoxic to AML blasts, but not normal hematopoietic stem cells. We found that αCD37-DM1 improved clinical outcomes and overall survival in multiple in vivo models of AML. Together, these data demonstrate that targeting CD37 with an ADC such as αCD37-DM1 is a feasible and promising therapeutic option for the treatment of AML.

Venetoclax with low-dose cytarabine, a forgotten combination in patients with acute myeloid leukemia ineligible for intensive chemotherapy: a systematic review

BACKGROUND

Based on the VIALE-A and VIALE-C studies, the Food and Drug Administration approved venetoclax in 2020 in combination with azacitidine or low-dose cytarabine for the treatment of patients with acute myeloid leukemia ineligible for intensive chemotherapy. After the publication of these studies, venetoclax/azacitidine was assumed to be superior to venetoclax/low-dose cytarabine; however, these studies were not designed to demonstrate superiority between these combinations. Therefore, we conducted a systematic review to describe overall survival, complete remission rate, and composite complete remission rate to assess response of these two regimens in patients with newly diagnosed acute myeloid leukemia who are ineligible for intensive chemotherapy.

MATERIALS AND METHODS

The PubMed and Web of Science databases were searched for retrospective studies and complete remission, composite complete remission, and overall survival rates were recorded.

RESULTS

Only 11 of the 815 publications identified were eligible to be included n this review, ten studies evaluated the venetoclax/azacitidine combination and one study evaluated the venetoclax/low-dose cytarabine combination. The median overall survival for venetoclax/azacitidine was 10.75 months, whereas for venetoclax/low-dose cytarabine the median overall survival had not been reached at the time of publication. Composite complete remission was 63.3 % for venetoclax/azacitidine and 90 % for venetoclax/low-dose cytarabine. Adverse events were similar for both combinations.

CONCLUSIONS

A limited number of studies investigating the venetoclax/low-dose cytarabine combination exist. Based on the available data, the superiority of venetoclax/azacitidine over venetoclax/low-dose cytarabine cannot be assumed for all acute myeloid leukemia patients who are ineligible for intensive chemotherapy. Venetoclax/low-dose cytarabine can still be considered as an option for the drug combinations currently under investigation.

Oxime-Linked Peptide-Daunomycin Conjugates as Good Tools for Selection of Suitable Homing Devices in Targeted Tumor Therapy: An Overview

Chemotherapy is still one of the main therapeutic approaches in cancer therapy. Nevertheless, its poor selectivity causes severe toxic side effects that, together with the development of drug resistance in tumor cells, results in a limitation for its application. Tumor-targeted drug delivery is a possible choice to overcome these drawbacks. As well as monoclonal antibodies, peptides are promising targeting moieties for drug delivery. However, the development of peptide-drug conjugates (PDCs) is still a big challenge. The main reason is that the conjugates have to be stable in circulation, but the drug or its active metabolite should be released efficiently in the tumor cells. For this purpose, suitable linker systems are needed that connect the drug molecule with the homing peptide. The applied linker systems are commonly categorized as cleavable and non-cleavable linkers. Both the groups possess advantages and disadvantages that are summarized briefly in this manuscript. Moreover, in this review paper, we highlight the benefit of oxime-linked anthracycline-peptide conjugates in the development of PDCs. For instance, straightforward synthesis as well as a conjugation reaction proceed in excellent yields, and the autofluorescence of anthracyclines provides a good tool to select the appropriate homing peptides. Furthermore, we demonstrate that these conjugates can be used properly in in vivo studies. The results indicate that the oxime-linked PDCs are potential candidates for targeted tumor therapy.