oprozomib (ONX 0912)

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.

Using the selective reaction monitoring (SRM) method, the measurement was finished with the ion transitions of m/z 533.18 ⟶ 199.01 for oprozomib and m/z 493.03 ⟶ 112.03 for tepotinib (internal standard, IS), respectively. Moreover, the recovery was determined to be from 85.1% to 96.1%, and the values of matrix effect were no more than 110.4%. The optimized UPLC-MS/MS method was also suitable for the pharmacokinetic study of rats after a single oral administration of 21 mg/kg oprozomib.

We performed an extensive search for relevant data sources, including full-published articles in international online databases (PubMed, Web of Science, Scopus), preliminary reports in selected international meeting abstract repositories, and short articles published as supplements of international meetings, by using the following terms: medullary thyroid carcinoma, proteasome inhibitors, bortezomib, carfilzomib, ixazomib, delanzomib, marizomib, oprozomib, and MG132. We might speculate that difficulties in enrolling patients, as happens in other rare diseases, may have discouraged trials' implementation in favor of drugs already approved for MTC. However, given the concrete improvement in the comprehension of the molecular basis of PrIn effects in MTC, new clinical trials with accurate inclusion criteria of enrollment might be warranted, in order to ascertain whether this treatment, alone or in combination with other drugs, could indeed represent an option to enhance the therapeutic response, and to ultimately improve patients' outcome and survival.

Moreover, OPZ promoted the phosphorylation of the apoptosis signaling pathway JNK that was activated by cisplatin, thereby inducing tumor cell apoptosis. These findings provide a theoretical basis for the clinical use of OPZ alone and in combination with cisplatin in the treatment of cervical cancer.

On the basis of ADMET profile, compound (PubChem ID: 102173753) could be a potent drug for MCL treatment. Similar to the established SB-3CT, the compound was also found to be non-toxic with LD50 values for both the compounds lying in the same range.

The destruction of proteins via the ubiquitin-proteasome system is a multi-step, complex process involving polyubiquitination of substrate proteins, followed by proteolytic degradation by the macromolecular 26S proteasome complex. Moreover, OPZ was capable of sensitizing lung cancer cells to the conventional chemotherapeutic drug cisplatin. Our study provides preclinical data and sheds light on the potential applications of proteasome inhibitor OPZ in lung cancer treatment.

Cells were treated with CFZ and the PIs Bortezomib (Bz), Carfilzomib (Cz), Ixazomib (Ix) and Oprozomib (Opz) as single agents or in combination and in vitro cytotoxicity was determined using CellTiter-Glo assay. Based on these results, we propose that CFZ may have strong potential to increase the therapeutic efficacy of PIs when used in combination by specifically targeting MM-CSCs sub cellular population in MM – which we are investigating further. Currently, we are: 1) validating the potency of CFZ (alone or CFZ+PI combination therapy) in primary myeloma cells/PMCs from newly diagnosed patients, followed by 2) bulk mRNA sequencing and 3) single-cell transcriptomic analysis of MM-CSCs in HMCLs and PMCs to evaluate molecular pathways involved in stem-cell based PI-resistance and to characterize PI-resistant sub-cellular stem cell populations based on gene expression signatures using our prediction analysis software SCATTome.