marizomib (NPI-0052)

After 96 h from inhibitor removal, the G361 line presented signs of senescence (increased level of SA-β-galactosidase, IL-8, P-P53, G2/M and S phases of cell cycle, decreased lamin B1 and cleaved lamin B1), while the A375 line demonstrated more signs of apoptosis (increased subG1 phase, P-P53, cleaved lamin B1). The gathered findings suggest that MZB resulted in the induction of cellular senescence (line G361) or enhanced apoptosis (line A375) in the melanoma cell lines tested here and could be a promising therapeutic factor in malignant melanoma treatment.

On the contrary, overproduction of ROS or increased expressions of ERO1α, LC3 II, Beclin 1, and ATG5 were not detected, suggesting that neither oxidative stress nor autophagy were involved in the process of MZB-induced cell death. Thus, marizomib represents a potentially promising compound for facilitating further progress in brain cancer therapy.

A Western blot analysis presented an increase in the expression of proteins related to endoplasmic reticulum (ER) stress as well as markers of the apoptosis. The gathered findings suggest that marizomib induced the ER stress in the examined melanoma cancer cells and directed them towards the apoptosis pathway.

P2, N=0, Withdrawn, Dana-Farber Cancer Institute | N=30 --> 0 | Not yet recruiting --> Withdrawn

Adding marizomib to standard temozolomide-based radiochemotherapy resulted in more toxicity, but did not improve OS or PFS in patients with newly diagnosed glioblastoma.

P1, N=4, Terminated, Dana-Farber Cancer Institute | N=45 --> 4 | Trial completion date: Dec 2024 --> Feb 2024 | Active, not recruiting --> Terminated | Trial primary completion date: Jun 2024 --> Feb 2024; Withdrawal of support from BMS

P3, N=749, Completed, European Organisation for Research and Treatment of Cancer - EORTC | Active, not recruiting --> Completed

P1, N=45, Active, not recruiting, Dana-Farber Cancer Institute | Trial primary completion date: Dec 2023 --> Jun 2024

The accumulation of cell cycle inhibitors p21 and p27, and decreased levels of prosurvival molecules NFKB, survivin, and MGMT, underlie proteasome inhibitors' cytotoxicity when used alone or in combination with the anti-GBM cytostatic drug temozolomide (TMZ). The evidence gathered in preclinical studies substantiated the design of clinical trials that employed the two most promising proteasome inhibitors, bortezomib and marizomib...The data from this phase III study indicate that marizomib does not improve the PFS and OS of GBM patients; however, further analysis of the genetic and epigenetic background of each patient tumor may shed some light on the sensitivity of individual patients to proteasome inhibition. The mutational and epigenetic makeup of GBM cells, like genetic alterations to TP53 and PTEN, or MGMT promoter methylation levels may actually determine the response to proteasome inhibition.

The addition of marizomib to standard temozolomide-based radiochemotherapy was associated with more toxicity but did not confer a survival benefit in glioblastoma patients, independent of the MGMT promoter methylation status.

In this paper we briefly highlight essential clinical elements relating to proteasome inhibitors, such as bortezomib, carfilzomib and ixazomib. A high number of patients develop PI resistance. Thus, we also review new generation PIs, such as marizomib, oprozomib (ONX0912) and delanzomib (CEP-18770) and their combinations with immunotherapies.