Controversy

Epirubicin and doxorubicin: a comparison of their characteristics, therapeutic activity and toxicity

No standard maintenance treatment has been obtained to prolong the response duration of soft tissue sarcoma (STS) after first-line chemotherapy. In this study, we aimed to evaluate the efficacy and safety of anlotinib as a maintenance treatment after chemotherapy in STS.

In this multicentre, open-label, single-arm phase 2 trial, patients with advanced STS who achieved partial response or stable disease after first-line anthracycline-based chemotherapy were enrolled between April 2019 and January 2022. All patients received anlotinib as a maintenance treatment. The primary endpoint was progression-free survival (PFS) of anlotinib maintenance treatment. Other endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR) and safety. This study is registered with ClinicalTrials.gov, NCT03890068.

At the data cut-off date (August 8, 2022), 49 patients were enrolled, including 17 with liposarcoma (35%) and 15 with leiomyosarcoma (31%). After a median follow-up of 17.1 months (IQR 9.0–27.2), the median PFS from the beginning of maintenance treatment was 9.1 months (95% CI 5.7–12.5), and the median OS was not reached, and the 1-year OS rate for anlotinib maintenance treatment was 98.0%. The best ORR and DCR were 16% (8/49, 95% CI 7–30) and 94% (46/49, 95% CI 83–99), respectively. Most of the treatment-related adverse events were grade 1–2. Of the grade 3–4 adverse events, the most common were hypertension (10%) and hand-foot syndrome reaction (6%).

Postchemotherapy maintenance treatment with anlotinib exhibits promising efficacy and tolerable toxicity in patients with advanced STS.

Chia Tai Tianqing Pharmaceutical Group Co., Ltd., the National Key Research and Development Program of China, and the National Natural Science Foundation of China.

Anthracyclines have been important and effective treatments against a number of cancers since their discovery. However, their use in therapy has been complicated by severe side effects and toxicity that occur during or after treatment, including cardiotoxicity. The mode of action of anthracyclines is complex, with several mechanisms proposed. It is possible that their high toxicity is due to the large set of processes involved in anthracycline action.

The development of resistance is a major barrier to successful treatment when using anthracyclines. This resistance is based on a series of mechanisms that have been studied and addressed in recent years. This work provides an overview of the anthracyclines used in cancer therapy. It discusses their mechanisms of activity, toxicity, and chemoresistance, as well as the approaches used to improve their activity, decrease their toxicity, and overcome resistance.

PSMD10^Gankyrin, a proteasomal chaperone is also an oncoprotein. Overexpression of PSMD10^Gankyrin is associated with poor prognosis and survival in many cancers. Therefore, PSMD10^Gankyrin is a sought-after drug target in many hard-to-treat cancers. However, its surface appears flat and undruggable. Here, we build on our earlier discovery of a common hot spot region that defined the interface of multiple interacting partners of PSMD10^Gankyrin to expose vulnerable spots for a peptide and a small molecule inhibitor.

High throughput virtual screening was used to screen compounds against PSMD10^Gankyrin. Interaction of PSMD10^Gankyrin with the drug or protein (CLIC1) or peptide was studied using any one or more of these techniques; Microscale Thermophoresis, limited trypsinolysis, SPR and ITC. Cytotoxic effect of doxorubicin was evaluated using MTT assay.

We identified doxorubicin as the first-generation small molecule inhibitor of PSMD10^Gankyrin. K116 and to a lesser extent R41 on PSMD10^Gankyrin contribute to the bulk of binding energy for the peptide EEVD, CLIC1 and doxorubicin. We further demonstrate that PSMD10^Gankyrin is an intended target for doxorubicin in cells.

Drug design against protein interactions in general and PSMD10^Gankyrin in particular, remains a challenge. We provide consolidated biophysical evidence for the use of a shared interface motif EEVD as a possible inhibitor of interaction network in cancers driven by PSMD10^Gankyrin. We identify a chemical scaffold for designing novel inhibitors of PSMD10^Gankyrin. These findings will impact the field of protein interactions in the context of disease biology/drug discovery.

Mesoporous silica nanoparticles (MNs) emerged as new promising drug-delivery platforms capable to overcome resistance in bacteria. Dual loading of drugs on these nanocarriers, exploiting synergistic interactions between the nanoparticles and the drugs, could be considered as a way to increase the efficacy against resistant bacteria with a positive effect even at very low concentrations. Considering that patients with cancer are highly susceptible to almost any type of bacterial infections, in this work, nanocarriers mesoporous silica-based, MNs and MNs@EPI were synthetized and submitted to single and/or dual loading of antibiotics (ofloxacin – OFLO) and anticancer drugs (Doxorubicin – DOX; Epirubicin – EPI), and investigated regarding their antibacterial activity against Escherichia coli, Staphylococcus aureus, methicillin–resistant S. aureus (MRSA), Enterococcus faecalis and Pseudomonas aeruginosa. Formulations containing ofloxacin such as MNs-OFLO, MNs-EPI + OFLO, MNs-DOX + OFLO and MNs@EPI + OFLO, present antibacterial activity in all bacterial strains tested. All these are more effective in E.coli with MIC and MBC values for MNs-OFLO, MNs-EPI + OFLO and MNs-DOX + OFLO of around 1 and 2 µg_nanomaterial/mL, corresponding to ofloxacin concentrations of 0.03, 0.02 and 0.04 µg/mL, respectively. In the cocktail formulations the conjugation of epirubicin with ofloxacin presents a more effective antibacterial activity with more than 3-fold reduction of ofloxacin concentration when comparing to the single ofloxacin system. By far, the most effective synergistic effect was obtained for the system where epirubicin was functionalized at nanoparticles surface (MNs@EPI), where a 40-fold and 33-fold reductions of ofloxacin concentration were obtained, in P. aeruginosa in comparison to the MNs-OFLO and MNs-EPI + OFLO systems, respectively. These effects are shown in all bacterial strains tested, even in strains that have acquired resistance mechanisms, such as MRSA.

Anthracyclines are effective drugs in the treatment of various cancers, but their use comes with severe side effects. The archetypal anthracycline drug, doxorubicin, displays two molecular modes of action: DNA double-strand break formation (through topoisomerase IIα poisoning) and chromatin damage (via eviction of histones). These biological activities can be modulated and toxic side effects can be reduced by separating these two modes of action through alteration of the aminoglycoside moiety of doxorubicin. We herein report on the design, synthesis, and evaluation of a coherent set of configurational doxorubicin analogues featuring all possible stereoisomers of the 1,2-amino-alcohol characteristic for the doxorubicin 3-amino-2,3-dideoxyfucoside, each in nonsubstituted and N,N-dimethylated forms. The set of doxorubicin analogues was synthesized using appropriately protected 2,3,6-dideoxy-3-amino glycosyl donors, equipped with an alkynylbenzoate anomeric leaving group, and the doxorubicin aglycon acceptor. The majority of these glycosylations proceeded in a highly stereoselective manner to provide the desired axial α-linkage. We show that both stereochemistry of the 3-amine carbon and N-substitution state are critical for anthracycline cytotoxicity and generally improve cellular uptake. N,N-Dimethylepirubicin is identified as the most potent anthracycline that does not induce DNA damage while remaining cytotoxic.

Monoclonal antibodies can effectively target to tumors in patients, as validated by antibody–drug conjugates (ADCs). The clinically used ADCs, nevertheless, are restricted to toxins only and suffer from low drug content, excessive use of antibody, and high cost. Here, we report on trastuzumab-decorated disulfide-cross-linked polymersomes (Tra-Ps) for specific delivery of epirubicin hydrochloride (EPI·HCl) to HER2-positive SKOV-3 ovarian tumor. EPI·HCl-loaded Tra-Ps (Tra-Ps-EPI) with a small size of 50–60 nm and varying Tra surface densities (0.5 to 2.4 Tra per Ps) were conveniently obtained via post-conjugation of thiolated trastuzumab onto the surface of maleimide-functionalized Ps-EPI with a drug loading content of 12.7 wt %. Interestingly, Tra-Ps with 1.3 trastuzumab on the surface exhibited a 6-fold higher binding affinity to the HER2 extracellular domain than that of native trastuzumab. In vitro studies revealed that Tra-Ps-EPI with long-term storage stability could rapidly release drugs under a reductive condition and efficiently deliver a large amount of EPI·HCl to HER2-positive SKOV-3 cells, leading to stronger cytotoxicity than the nontargeted Ps-EPI. Moreover, Tra-Ps-EPI displayed a long circulation time (ca. 8 h), deep tumor penetration, and superior tumor growth inhibition in SKOV-3 ovarian tumor-bearing nude mice, which were more effective than free EPI·HCl and nontargeted Ps-EPI. These HER2-specific reduction-sensitive immunopolymersomes with high loading of epirubicin emerge as an attractive treatment for HER2-positive tumors.