Cost-effectiveness analysis of atezolizumab plus bevacizumab compared with sorafenib as first-line treatment in advanced hepatocellular carcinoma in Singapore.

OBJECTIVES: This study aims to explore the cost-effectiveness of atezolizumab plus bevacizumab against sorafenib for first-line treatment of locally advanced or metastatic hepatocellular carcinoma (HCC) in Singapore. METHODS: A partitioned survival model was developed from a healthcare system perspective, with a 10-year lifetime horizon. Clinical inputs and utilities were obtained from the IMbrave150 trial. Healthcare resource use costs were obtained from published local sources; drug costs reflected the most recent public hospital selling prices. Outcomes included life years, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs). Deterministic and probabilistic sensitivity analyses were performed to assess the model's robustness. RESULTS: Atezolizumab plus bevacizumab offered an additional 1.42 life years and 1.09 QALYs, with an additional cost of S$111,847; the ICER was S$102,988/QALY. The World Health Organization considers interventions with ICERs <1 gross domestic product (GDP)/capita to be highly cost-effective. At a willingness-to-pay (WTP) threshold of S$114,165/QALY (Singapore's 2022 GDP/capita), atezolizumab plus bevacizumab is cost-effective compared with sorafenib. The ICER was most sensitive to variations in utilities, but all parameter variations had no significant impact on the model outcomes. CONCLUSION: At a WTP threshold of Singapore's GDP/capita, atezolizumab plus bevacizumab is cost-effective compared with sorafenib.

Cost-effectiveness analysis of add-on pertuzumab to trastuzumab biosimilar and chemotherapy as neoadjuvant treatment for human epidermal growth receptor 2-positive early breast cancer patients in Singapore.

OBJECTIVES: The Asian PEONY trial showed that add-on pertuzumab to trastuzumab and chemotherapy significantly improved pathological complete response in the neoadjuvant treatment of patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (EBC). This study evaluated the cost-effectiveness of pertuzumab as an add-on therapy to trastuzumab and chemotherapy for neoadjuvant treatment of patients with HER2+ EBC in Singapore. METHODS: A six-state Markov model was developed from the Singapore healthcare system perspective, with a lifetime time horizon. Model outputs were: costs; life-years (LYs); quality-adjusted LYs (QALYs); incremental cost-effectiveness ratios (ICERs). Sensitivity/scenario analyses explored model uncertainties. RESULTS: The base case projected the addition of pertuzumab to be associated with improved outcomes by 0.277 LYs and 0.271 QALYs, increased costs by S$1,387, and an ICER of S$5,121/QALY. The ICER was most sensitive to the pCR rate, and the probabilistic sensitivity analysis showed that add-on pertuzumab had an 81.3% probability of being cost-effective at a willingness-to-pay threshold of S$45,000/QALY gained. CONCLUSIONS: This model demonstrated that the long-term clinical impact of early pertuzumab use, particularly the avoidance of metastatic disease and thus avoidance of higher costs and mortality rates, make neoadjuvant pertuzumab a cost-effective option in the management of patients with HER2+ breast cancer in Singapore.

Cleavage of misfolded nuclear receptor corepressor confers resistance to unfolded protein response-induced apoptosis.

We have recently reported that accumulation of misfolded nuclear hormone receptor corepressor (N-CoR) as insoluble protein aggregates in acute promyelocytic leukemia (APL) cells induces endoplasmic reticulum (ER) stress and activates unfolded protein response (UPR). Although accumulation of misfolded proteins is known to trigger UPR-induced cytotoxic cell death in several neurodegenerative disorders, APL cells are notably resistant to UPR-induced apoptosis. The molecular basis for the paradoxical response of APL cells to UPR is not known. Here, we report that a glycoprotease, selectively expressed in APL cells, regulates the response of APL cells to UPR-induced apoptosis through processing of misfolded N-CoR protein. Results show that misfolded N-CoR is cleaved selectively in APL cells, and cellular extracts of APL cells and human primary APL cells contain activity that cleaves N-CoR protein. Purification and spectrometric analysis of N-CoR cleaving activity from an APL cell line reveals that it is a glycoprotein endopeptidase known as OSGEP. Furthermore, the cleavage of N-CoR in APL cells could be blocked by the broad-spectrum protease inhibitor AEBSF and by RNA interference-mediated down-regulation of OSGEP expression. AEBSF selectively inhibits growth and promotes apoptosis of APL cells possibly through a mechanism involving AEBSF-induced accumulation of insoluble N-CoR protein and by triggering ER stress. Taken together, these findings suggest that selective induction of protease activity in APL cells may represent a novel cytoprotective component of UPR, which could be exploited by tumor cells to survive the toxic insult of misfolded protein(s).

Therapeutic targeting of nuclear receptor corepressor misfolding in acute promyelocytic leukemia cells with genistein.

We have recently reported that PML-RAR-induced misfolding of the N-CoR protein could be reversed by retinoic acid (RA), a therapeutic agent that promotes differentiation of acute promyelocytic leukemia (APL) cells. This finding suggests a role of misfolded N-CoR in the differentiation arrest of APL cells and highlights its significance as a potential molecular target in protein conformation-based therapy for APL. Based on this hypothesis, we investigated the therapeutic potential of several protein conformation modifiers on APL-derived cell lines NB4 and NB4-R1. Through a small-scale screening of these selected compounds, we identified genistein as a potent inhibitor of growth of both RA-sensitive and RA-resistant APL cells. Genistein inhibited the growth of NB4 cells through its collective regulatory effects on cell cycle progression, differentiation, and apoptosis. Genistein-induced apoptosis of NB4 cells was mediated by activation of caspase-9 and caspase-3 and was associated with a decrease in mitochondrial transmembrane potential and cytosolic release of cytochrome c. Genistein promoted differentiation of both RA-sensitive and RA-resistant NB4 cells and induced cell cycle arrest by blocking the G(2)-M transition. Genistein up-regulated the expression of PML and N-CoR proteins, promoted degradation of PML-RAR, and reorganized the microspeckled distribution of PML oncogenic domains to a normal dot-like pattern in NB4 cells. Moreover, genistein significantly reversed the PML-RAR-induced misfolding of N-CoR protein by possibly inhibiting the selective phosphorylation-dependent binding of N-CoR to PML-RAR. These findings identify genistein as a potent modifier of N-CoR protein conformation and highlights its therapeutic potential in both RA-sensitive and RA-resistant APL cells.