Safety and efficacy outcomes of early cessation of anti-PD1 therapy in patients 80 years or older: A retrospective cohort study.

Older patients have similar immune checkpoint inhibitor efficacy and rates of adverse events as younger patients, but appear to have decreased tolerability, particularly in the oldest patient cohort (>80 years), often leading to early cessation of therapy. We aimed to determine whether early discontinuation impacts efficacy of anti-PD-1 therapy in patients ≥80 years old. In this retrospective, multicenter, international cohort study, we examined 773 patients with 4 tumor types who were at least 80 years old and treated with anti-PD-1 therapy. We determined response rate, overall survival (OS), and progression-free survival (PFS) in patients who discontinued therapy early (<12 months) for reasons other than progression or death. We used descriptive statistics for demographics, response, and toxicity rates. Survival statistics were described using Kaplan Meier curves. Median (range) age at anti-PD-1 initiation was 83.0 (75.8-97.0) years. The cancer types included were melanoma (n = 286), non-small cell lung cancer (NSCLC) (n = 345), urothelial cell carcinoma (UCC) (n = 108), and renal cell carcinoma (RCC) (n = 34). Of these, 102 met the primary endpoint of <12 months to discontinuation for reasons other than death or progression. Median PFS and OS, respectively, for these patients were 34.4 months and 46.6 months for melanoma, 15.8 months and 23.4 months for NSCLC, and 10.4 months and 15.8 months for UCC. This study suggests geriatric patients who have demonstrated therapeutic benefit and discontinued anti-PD-1 therapy at less than 12 months of duration for reasons other than progression may have durable clinical benefit without additional therapy.

Investigational Approaches for Treatment of Melanoma Patients Progressing After Standard of Care.

ABSTRACT: The advent of effective immunotherapy, specifically cytotoxic T-lymphocyte associated protein 4 and programmed cell death 1 inhibitors, as well as targeted therapy including BRAF/MEK inhibitors, has dramatically changed the prognosis for metastatic melanoma patients. Up to 50% of patients may experience long-term survival currently. Despite these advances in melanoma treatment, many patients still progress and die of their disease. As such, there are many studies aimed at providing new treatment options for this population. Therapies currently under investigation include, but are not limited to, novel immunotherapies, targeted therapies, tumor-infiltrating lymphocytes and other cellular therapies, oncolytic viral therapy and other injectables, and fecal microbiota transplant. In this review, we discuss the emerging treatment options for metastatic melanoma patients who have progressed on standard of care treatments.

Iron homeostasis proteins Grx4 and Fra2 control activity of the Schizosaccharomyces pombe iron repressor Fep1 by facilitating [2Fe-2S] cluster removal.

The Bol2 homolog Fra2 and monothiol glutaredoxin Grx4 together play essential roles in regulating iron homeostasis in Schizosaccharomyces pombe. In vivo studies indicate that Grx4 and Fra2 act as coinhibitory partners that inactivate the transcriptional repressor Fep1 in response to iron deficiency. In Saccharomyces cerevisiae, Bol2 is known to form a [2Fe-2S]-bridged heterodimer with the monothiol Grxs Grx3 and Grx4, with the cluster ligands provided by conserved residues in Grx3/4 and Bol2 as well as GSH. In this study, we characterized this analogous [2Fe-2S]-bridged Grx4-Fra2 complex in S. pombe by identifying the specific residues in Fra2 that act as ligands for the Fe-S cluster and are required to regulate Fep1 activity. We present spectroscopic and biochemical evidence confirming the formation of a [2Fe-2S]-bridged Grx4-Fra2 heterodimer with His66 and Cys29 from Fra2 serving as Fe-S cluster ligands in S. pombe. In vivo transcription and growth assays confirm that both His66 and Cys29 are required to fully mediate the response of Fep1 to low iron conditions. Furthermore, we analyzed the interaction between Fep1 and Grx4-Fra2 using CD spectroscopy to monitor changes in Fe-S cluster coordination chemistry. These experiments demonstrate unidirectional [2Fe-2S] cluster transfer from Fep1 to Grx4-Fra2 in the presence of GSH, revealing the Fe-S cluster dependent mechanism of Fep1 inactivation mediated by Grx4 and Fra2 in response to iron deficiency.