Cost Estimate of Immune-Related Adverse Reactions Associated with Innovative Treatments of Metastatic Melanoma.

BACKGROUND AND OBJECTIVE: Immuno-oncology therapies represent a new treatment opportunity for patients affected by metastatic melanoma. The purpose of this study was to estimate the costs of immune-related adverse events (irAEs) associated with the new anti-PD1 immuno-oncology therapies, with the anti-CTLA-4 immuno-oncology therapy and with the combined therapy (CTLA4 + anti-PD1) in patients affected by metastatic melanoma. MATERIALS AND METHODS: A probabilistic cost-of-illness (COI) model was developed to estimate the management costs of grade ≥ 3 adverse events associated with the new anti-PD1 therapies (pembrolizumab and nivolumab), the anti-CTLA-4 therapy (ipilimumab) and the combined therapy CTLA4 + anti-PD1 (nivolumab + ipilimumab) for the treatment of patients with metastatic melanoma from the National Health Service (NHS) perspective in Italy. Identification of the epidemiological and cost parameters was carried out through a systematic literature review (SLR). Univariate and probabilistic sensitivity analyses were performed to account for uncertainty and variation in the model results. RESULTS: The model estimated a cost associated with the management of grade ≥ 3 immune-related adverse events in patients with metastatic melanoma equal to €176.2 (95% CI 63.5-335.0) for anti-CTLA-4 therapy, €48.6 (95% CI 40.1-58.5) for the new anti-PDI therapies and €276.8 (95% CI 240.4-316.2) for the combined therapy. Among the innovative therapies for the considered metastatic melanoma, the combined therapy was the most expensive innovative treatment in terms of event management of immune-related grade ≥ 3 adverse events. CONCLUSION: This study may represent a useful tool to understand the economic burden associated with the management of irAEs associated with patients affected by metastatic melanoma.

PrPc activation induces neurite outgrowth and differentiation in PC12 cells: role for caveolin-1 in the signal transduction pathway.

Cellular prion protein (PrP(c)) is a ubiquitous glycoprotein, whose physiological role is poorly characterized. It has been suggested that PrP(c) participates in neuritogenesis, neuroprotection, copper metabolism, and signal transduction. In this study we detailed the intracellular events induced by PrP(c) antibody-mediated cross-linking in PC12 cells. We found a Fyn-dependent activation of the Ras-Raf pathway, which leads to a rapid and transient phosphorylation of extracellular regulated kinases. In addition, this activation cascade relies on the engagement of integrins, and involves focal adhesion kinase activation. We demonstrated the tyrosine phosphorylation of caveolin-1 as a consequence of PrP(c) stimulation, and showed that phosphocaveolin-1 scaffolds and coordinates protein complexes involved in PrP(c)-dependent signaling. Moreover, we found that caveolin-1 phosphorylation, is a mechanism for recruiting the C-terminal Src kinase and inactivating Fyn, so as to terminate cell signaling. Furthermore our data support a significant role for PrP(c) as a response mediator in neuritogenesis and cell differentiation.

Low molecular weight protein tyrosine phosphatase and caveolin-1: interaction and isoenzyme-dependent regulation.

Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are small enzymes that are ubiquitous in many organisms. They are important in biological processes such as cell proliferation, adhesion, migration, and invasiveness. LMW-PTP is expressed in mammalian cells as two isoforms (IF1 and IF2) originating through alternative splicing. We have previously shown that IF2 targets lipid rafts called caveolae and interacts with caveolin-1, their major structural protein. Caveolae are cholesterol- and sphingolipid-rich membrane microdomains that have been implicated in a variety of cellular functions, including signal transduction events. Caveolin-1 contains a scaffolding region that contributes to the binding of the protein to the plasma membrane and mediates protein omo- and etero-oligomerization. Interaction of many signaling molecules with the scaffolding domain sequesters them into caveolae and inhibits or suppresses their activities. Caveolin-interacting proteins usually have a typical sequence motif, also present in all the LMW-PTPs, which is characterized by aromatic or large hydrophobic residues in specific positions. We have examined here the interaction of the LMW-PTP isoforms with caveolin-1 and its molecular mechanism, together with the consequences for their tyrosine phosphatase activities. We found that IF1 and IF2 are both capable of interacting with defined regions of caveolin-1 and that their putative caveolin binding sequence motif is not responsible for the association. The formation of LMW-PTP/caveolin-1 complexes is accompanied by modulation of the enzyme activities, and the inhibitory effect elicited against IF1 is stronger than that against IF2. The caveolin scaffolding domain is directly involved in the observed phenomena.