Use of Proteasome Inhibition in the Treatment of Lung Cancer

Proteasome inhibitors in the treatment of nonsmall cell lung cancer: A systematic review of clinical evidence

Background and Aims

Nonsmall cell lung cancer accounts for over 85% of lung cancer incidences worldwide, and often has a poor prognosis. Proteasome inhibitors, such as bortezomib, have previously demonstrated evidence in preclinical and clinical models in the treatment of NSCLC both alone and as part of chemotherapeutic regimens.

Methods

Five databases were searched from inception to February 2023 to identify published clinical trial data and ongoing clinical trials on the use of proteasome inhibitors in treatment of NSCLC with a comprehensive search strategy.

Results

This review examines the clinical evidence from 21 completed and published phase I and II trials studying the use of bortezomib monotherapy and combination therapy in the treatment of NSCLC. Bortezomib/docetaxel combination resulted in longer median time-to-progression (TTP), median duration of response, median duration of disease control and median progression-free survival (PFS) than bortezomib monotherapy, with concurrent administration having greater 6-month PFS and median overall survival (OS) than sequential administration. Bortezomib/vorinostat with chemotherapy was well tolerated and effective. Bortezomib/gemcitabine/carboplatin, bortezomib/bevacizumab/carboplatin and bortezomib/paclitaxel/carboplatin combinations showed promising results and were of further investigational value.

Conclusion

Bortezomib showed some clinical promise in combination therapy but not monotherapy. It also demonstrated a manageable side effect profile. Combination regimens are of further investigation value in Phase II trials.

Phase 1b trial of proteasome inhibitor carfilzomib with irinotecan in lung cancer and other irinotecan-sensitive malignancies that have progressed on prior therapy (Onyx IST reference number: CAR-IST-553)

Introduction Proteasome inhibition is an established therapy for many malignancies. Carfilzomib, a novel proteasome inhibitor, was combined with irinotecan to provide a synergistic approach in relapsed, irinotecan-sensitive cancers. Materials and Methods Patients with relapsed irinotecan-sensitive cancers received carfilzomib (Day 1, 2, 8, 9, 15, and 16) at three dose levels (20/27 mg/m2, 20/36 mg/m2 and 20/45 mg/m2/day) in combination with irinotecan (Days 1, 8 and 15) at 125 mg/m2/day. Key eligibility criteria included measurable disease, a Zubrod PS of 0 or 1, and acceptable organ function. Patients with stable asymptomatic brain metastases were eligible. Dose escalation utilized a standard 3 + 3 design. Results Overall, 16 patients were enrolled to three dose levels, with four patients replaced. Three patients experienced dose limiting toxicity (DLT) and the maximum tolerated dose (MTD) was exceeded in Cohort 3. The RP2 dose was carfilzomib 20/36 mg/m² (given on Days 1, 2, 8, 9, 15, and 16) and irinotecan 125 mg/m2 (Days 1, 8 and 15). Common Grade (Gr) 3 and 4 toxicities included fatigue (19%), thrombocytopenia (19%), and diarrhea (13%). Conclusions Irinotecan and carfilzomib were well tolerated, with common toxicities of fatigue, thrombocytopenia and neutropenic fever. Objective clinical response was 19% (one confirmed partial response (PR) in small cell lung cancer (SCLC) and two unconfirmed); stable disease (SD) was 6% for a disease control rate (DCR) of 25%. The recommended phase II dose was carfilzomib 20/36 mg/m² and irinotecan125 mg/m2. The phase II evaluation is ongoing in relapsed small cell lung cancer.

A phase II, open-label trial of bortezomib (VELCADE(®)) in combination with gemcitabine and cisplatin in patients with locally advanced or metastatic non-small cell lung cancer

BACKGROUND

Bortezomib is a selective reversible proteasome inhibitor with proapoptotic effects. Preclinical and phase I clinical data suggest activity of bortezomib in NSCLC, either as monotherapy or in combination with chemotherapeutic agents including gemcitabine and cisplatin.

METHODS

Chemotherapy-naïve patients with inoperable stage IIIB or IV NSCLC were administered bortezomib 1 mg/m(2) i.v. on days 1 and 8, and starting on day 21 (cycle 2), bortezomib (days 1 and 8) in combination with gemcitabine 1000 mg/m(2), (days 1 and 8), and cisplatin 70 mg/m(2) (day 1) in cycles of 21 days. Up to 8 cycles of combination therapy could be administered; single-agent bortezomib was continued until disease progression or unacceptable toxicity.

RESULTS

Fifty-three patients [median age 66 years; 79.2 % male; 96.2 % stage IV; performance status (ECOG) 0/1 73.6/26.4 %; adenocarcinoma 45.3 %, squamous cell carcinoma 41.5 %] were enrolled. All patients were evaluable for toxicity and 43 for efficacy. Grade 3-4 hematologic toxicity consisted of neutropenia (22.6 %) and thrombocytopenia (17 %). Grade 2-4 non-hematologic adverse events were fever (9.4 %), fatigue (20.8 %), infection (18.9 %), and dyspnea (15.1 %). There was no >grade 2 neurotoxicity. Febrile neutropenia occurred in two (1.9 %) patients, and there were three possibly treatment-related deaths (5.4 %). In the intention-to-treat population, the objective response rate was 17 % (95 % CI 6.9-27.1 %). No difference in response rate was observed for squamous versus other histology (18.2 vs. 16.1 %, p = 0.845). The median progression-free survival was 2.5 months, the median overall survival 10.6 months and the 1-year survival rate 38.1 %.

CONCLUSION

The incorporation of bortezomib into the gemcitabine/cisplatin regimen, in the dose and schedule used in this study, could not improve the efficacy of the chemotherapy regimen and has not to be further investigated.

Dithiocarbamate-based coordination compounds as potent proteasome inhibitors in human cancer cells

Dithiocarbamates are a class of metal-chelating compounds with various applications in medicine. They have been used for the treatment of bacterial and fungal infections, possible treatment of AIDS, and most recently cancer. Their anti-tumor effects can in part be attributed to their ability to complex tumor cellular copper, leading to binding to and inhibition of the proteasome and in turn initiating tumor cell-specific apoptosis. Current chemotherapeutic agents are highly toxic and therefore their efficacy in the eradication of tumors is greatly limited. As a result many scientists have joined the quest for novel targeted therapies in hopes of reducing toxicity while maximizing potency and proteasome inhibition has become an attractive therapy in this regard. Here we discuss the origins, mechanism, and evolution of dithiocarbamates as potent proteasome inhibitors and therefore anti-cancer agents.

The role of proteasome inhibition in nonsmall cell lung cancer

Lung cancer therapy with current available chemotherapeutic agents is mainly palliative. For these and other reasons there is now a great interest to find targeted therapies that can be effective not only palliating lung cancer or decreasing treatment-related toxicity, but also giving hope to cure these patients. It is already well known that the ubiquitin-proteasome system like other cellular pathways is critical for the proliferation and survival of cancer cells; thus, proteosome inhibition has become a very attractive anticancer therapy. There are several phase I and phase II clinical trials now in non-small cell lung cancer and small cell lung cancer using this potential target. Most of the trials use bortezomib in combination with chemotherapeutic agents. This paper tends to make a state-of-the-art review based on the available literature regarding the use of bortezomib as a single agent or in combination with chemotherapy in patients with lung cancer.

The proteasome inhibitor Velcade enhances rather than reduces disease in mouse hepatitis coronavirus-infected mice

Many viruses, including coronaviruses (CoVs), depend on a functional cellular proteasome for efficient infection in vitro. Hence, the proteasome inhibitor Velcade (bortezomib), a clinically approved anticancer drug, shown in an accompanying study (M. Raaben et al., J. Virol. 84:7869-7879, 2010) to strongly inhibit mouse hepatitis CoV (MHV) infection in cultured cells, seemed an attractive candidate for testing its antiviral properties in vivo. Surprisingly, however, the drug did not reduce replication of the virus in mice. Rather, inhibition of the proteasome caused enhanced infection with lethal outcome, calling for caution when using this type of drug during infection.

Bortezomib plus gemcitabine/carboplatin as first-line treatment of advanced non-small cell lung cancer: a phase II Southwest Oncology Group Study (S0339)

INTRODUCTION

Bortezomib is a small-molecule proteasome inhibitor with single-agent activity in patients with non-small cell lung carcinoma (NSCLC) and synergy with gemcitabine in preclinical studies. This phase II study of bortezomib in combination with gemcitabine/carboplatin was conducted in chemotherapy-naive advanced NSCLC patients to assess efficacy and safety.

METHODS

Patients with selected stage IIIB/IV NSCLC, performance status 0-1, and no history of brain metastasis received up to six 21-day cycles of gemcitabine 1000 mg/m, days 1 and 8, carboplatin area under curve 5.0, day 1, and bortezomib 1.0 mg/m, days 1, 4, 8, and 11.

RESULTS

One-hundred-fourteen patients (52% adenocarcinoma, 85% stage IV) received a median of 3.6 treatment cycles. Median follow-up was >3 years. Median overall survival was 11 months; 1-year and 2-year survival rates were 47% and 19%, respectively. Median progression-free survival was 5 months; 1-year progression-free survival rate was 7%. Response rate was 23%, and disease control rate (responses + stable disease) was 68%. The most common grade 3/4 toxicities were thrombocytopenia (63%) and neutropenia (52%). One patient experienced febrile neutropenia. Grade 3/4 neuropathy occurred in 4%, and a further 6% experienced grade 2 sensory neuropathy.

CONCLUSIONS

Bortezomib plus gemcitabine/carboplatin resulted in a notable survival benefit in patients with advanced NSCLC, with the anticipated primary toxicity of myelosuppression. Further studies designed to investigate the role of bortezomib in advanced NSCLC are warranted.

Bortezomib induces caspase-dependent apoptosis in Hodgkin lymphoma cell lines and is associated with reduced c-FLIP expression: A gene expression profiling study with implications for potential combination therapies

The Hodgkin cells and Reed-Sternberg cells (HRS) of classical Hodgkin lymphoma (CHL) are derived from germinal center B cells. The pathogenesis of CHL is unclear but constitutive activation of NFkappaB may contribute. Proteasome inhibition aimed at inhibiting NFkappaB has been shown to result in apoptosis in HRS cells. Here we investigated the effects of bortezomib, a proteasome inhibitor, in HRS cells with a combination of functional assays and gene expression profiling (GEP). Exposure of KMH2 and L428 cells to bortezomib resulted in inhibition of proliferation and induction of apoptosis. Gene expression analysis of KMH2 cells by oligonucleotide cDNA microarrays showed that a limited set of genes were differentially expressed involving several key cellular pathways including cell cycle and apoptosis. Among them, the caspase 8 inhibitor cFLIP was down-regulated and confirmed by Q-PCR. Given the evidence that cFLIP in HRS cells contribute to cells' insensitive to death receptor-mediated apoptosis, we combined bortezomib and TRAIL. This combination caused further down-regulation of cFLIP protein and increased apoptosis in CHL cells demonstrated by PARP p85 immunohistochemistry and immunoblotting. Such apoptotic effects were inhibited by caspase inhibitor z-VAD-FMK, confirming the pro-apoptotic effects of bortezomib and TRAIL are caspase-dependent. Bortezomib has no detectable effect on expression of TRAIL receptor DR4/DR5 in these two cell lines. Tissue microarray analysis of primary Hodgkin lymphomas displayed that 82% cases (95/116) expressed cFLIP in Reed-Sternberg cells. The discovery of apoptotic pathways that can be manipulated by proteasome inhibition provides rationale for the combination of bortezomib and agents such as TRAIL in CHL treatment.

Antiproliferative activity of bortezomib alone and in combination with cisplatin or docetaxel in head and neck squamous cell carcinoma cell lines

PURPOSE

Proteasome inhibition has been shown to be effective in multiple myeloma and solid tumor models. In this in vitro study, we investigated the antitumor effect of bortezomib (Velcade((R))) in squamous cell carcinoma of the head and neck (SCCHN) cell lines and examined the interaction of the drug with docetaxel (TAX) and cisplatin (CDDP).

METHODS

Dose escalation studies were performed with eight squamous cell carcinoma cell lines using bortezomib alone or in combination with TAX or CDDP. Growth inhibitory and proapoptotic effects were measured quantitatively using cytohistology and western blot analysis.

RESULTS

Bortezomib alone showed a significant antiproliferative activity in all SCCHN cell lines (P = 0.012), and the activity was further enhanced by the addition of TAX or CDDP (P </= 0.036). When the combination of bortezomib and CDDP was used, the dose of the latter could be reduced to yield the same antiproliferative effect as the cytotoxic drug alone (P < 0.012).

CONCLUSIONS

Our results indicate that bortezomib increases the cytotoxic activity of TAX and CDDP in SCCHN cell lines. In vivo and in the clinical setting, the addition of bortezomib may allow to reduce the doses of TAX or CDDP to decrease the systemic toxicity of these drugs.

Recent advances in targeted therapy for non-small cell lung cancer

Non-small-cell lung cancer (NSCLC) is characterized by wide molecular heterogeneity. In recent years, novel agents that target specific, aberrant molecular pathways in NSCLC have been under rigorous evaluation. Erlotinib, an inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, improves survival for advanced NSCLC patients who progressed following one or two prior chemotherapy regimens. Novel molecular predictive markers, such as EGFR mutations and gene amplification, are at present under evaluation to select patients for therapy with erlotinib. Another area of progress is the recent demonstration that bevacizumab, a monoclonal antibody against the vascular endothelial growth factor (VEGF), extended survival when administered in combination with chemotherapy for patients with non-squamous NSCLC. Promising anticancer activity has also been noted with agents that inhibit the VEGF receptor tyrosine kinase in patients with advanced NSCLC. Inhibitors of the proteosomal complex, histone deacetylase, mammalian target of rapamycin pathway, and other growth factor receptor-mediated signaling are under investigation for treatment of NSCLC. These developments have paved the way for a new era of tailor-made therapies based on clinical or molecular/genetic profiles in the treatment of NSCLC. This article reviews the recent advances in targeted therapy of advanced NSCLC.

Randomized phase II study of bortezomib alone and bortezomib in combination with docetaxel in previously treated advanced non-small-cell lung cancer

PURPOSE

To evaluate the efficacy and toxicity of bortezomib +/- docetaxel as second-line therapy in patients with relapsed or refractory advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Patients were randomly assigned to bortezomib 1.5 mg/m2 (arm A) or bortezomib 1.3 mg/m2 plus docetaxel 75 mg/m2 (arm B). A treatment cycle of 21 days comprised four bortezomib doses on days 1, 4, 8, and 11, plus, in arm B, docetaxel on day 1. Patients could receive unlimited cycles. The primary end point was response rate.

RESULTS

A total of 155 patients were treated, 75 in arm A and 80 in arm B. Baseline characteristics were comparable. Investigator-assessed response rates were 8% in arm A and 9% in arm B. Disease control rates were 29% in arm A and 54% in arm B. Median time to progression was 1.5 months in arm A and 4.0 months in arm B. One-year survival was 39% and 33%, and median survival was 7.4 and 7.8 months in arms A and B, respectively. Adverse effect profiles were as expected in both arms, with no significant additivity. The most common grade > or = 3 adverse events were neutropenia, fatigue, and dyspnea (4% and 53%, 19% and 26%, and 17% and 14% of patients in arms A and B, respectively).

CONCLUSION

Bortezomib has modest single-agent activity in patients with relapsed or refractory advanced NSCLC using this schedule, with minor enhancement in combination with docetaxel. Additional investigation of bortezomib in NSCLC is warranted in combination with other drugs known to be active, or using different schedules.

Protein degradation by the 26S proteasome system in the normal and stressed myocardium

The 26S proteasome is a multicatalytic threonine protease complex responsible for degradation of the majority of proteins in eukaryotic cells. In the last two decades, the ubiquitin proteasome system (UPS) has been increasingly recognized as an integral component in numerous biologic processes including cell proliferation, adaptation to stress, and cell death. The turnover of intracellular proteins inevitably affects the contributions of these molecules to cellular networks and pathways in any given tissue or organ, including the myocardium. Perturbations in the protein-degradation process have been shown to affect protein turnover and thereby affect the cardiac cell functions that these molecules are designated to carry out, engendering diseased cardiac phenotypes. Recent studies have implicated the role of proteasomes in stressed cardiac phenotypes including postischemia-reperfusion injury and cardiac remodeling (e.g., heart failure). The 26S proteasomes also appear to be susceptible to modulation by stresses (e.g., reactive oxygen species). This review focuses on roles of the 26S proteasome system in protein degradation; it provides an overview of the progress made in cardiac proteasome research as well as a discussion of recent controversies regarding the UPS system in diseased cardiac phenotypes.

Proteasome inhibition with bortezomib: a new therapeutic strategy for non-Hodgkin's lymphoma

The incidence of non-Hodgkin's lymphoma (NHL) has markedly increased in the US and other westernized countries in recent years and presents a considerable clinical challenge. NHL is divided into subtypes that follow an aggressive or indolent course. Follicular lymphoma (FL), the most common indolent subtype, and mantle cell lymphoma (MCL), an aggressive subtype that accounts for approximately 5% of cases, are generally incurable. MCL has a relatively poor prognosis, with a median survival of 3-4 years. Despite improving response rates with new agents and regimens, the lack of demonstrated improvement in overall survival in many subtypes supports the development of novel approaches, such as proteasome inhibition. Bortezomib is the first proteasome inhibitor to be evaluated in human studies. It has already been approved as second-line treatment in multiple myeloma and is now under active investigation in NHL. The US FDA has granted bortezomib fast-track designation for relapsed and refractory MCL. In vitro and in vivo studies have demonstrated single-agent activity against various lymphoid tumors, and additive or synergistic effects in combination with other agents, including standard chemotherapy drugs employed in NHL. Phase 2 clinical trials indicate that bortezomib is well tolerated and active in several NHL subtypes, with response rates of 18-60% in FL and 39-56% in MCL. A number of combination trials are currently underway with a range of standard agents. Bortezomib has the potential to play a significant role throughout the NHL treatment algorithm in the future.

Other Compounds and Targets in Non–Small Cell Lung Cancer

It has become increasingly apparent in recent years that a therapeutic plateau has been reached for patients with advanced stage non-small cell lung cancer (NSCLC) treated with conventional cytotoxic agents. As a result, investigators have directed their efforts toward the development of treatments encompassing novel targeted agents. Apoptosis is one of many cellular pathways currently under investigation as a therapeutic target for the treatment of NSCLC. Anti-inflammatory agents, including cyclooxygenase inhibitors, have been shown to inhibit apoptosis and appear promising based on preclinical studies. However, several phase II studies indicate that this therapeutic strategy is unlikely to be successful. In contrast, the proteosome inhibitor bortezomib has shown promise in preliminary studies, and further efforts to elucidate the role this agent may play in the treatment of NSCLC are ongoing. Agonists of the tumor necrosis factor-related, apoptosis-inducing ligand have also entered into early clinical studies in patients with NSCLC. Further studies will be needed to fully clarify how agents targeting the apoptotic pathway can be used in the treatment of NSCLC, but the results of current clinical trials suggest that certain agents may be active.