Medication adherence with denosumab in patients with bone metastases from solid tumors treated in routine clinical settings: a retrospective study.

PURPOSE: To describe (non)adherence with denosumab among patients with solid tumors and bone metastases. METHODS: This retrospective, observational study pooled data from two completed prospective, multicenter cohort studies (X-TREME; Study 240) in adult patients with bone metastases from primary breast, prostate, lung, kidney, or other solid cancer types and administered denosumab 120 mg in routine clinical practice in Germany and Central and Eastern Europe. The studies were conducted between May 2012 and May 2017; pooled analysis was completed in August 2021. Medication adherence was described according to a three-component consensus taxonomy: initiation (first-ever administration ≤ 90 days from bone metastasis diagnosis), implementation (actual vs prescribed dosing; optimal implementation = regular/consistent dosing), and persistence (≤ 60-day gap between administrations at 3, 6, 9, and 12 months). Descriptive analyses were conducted for each cancer type. RESULTS: The analysis included 1748 patients with solid tumors and bone metastases. Adherence with denosumab was generally high across the initiation, implementation, and persistence phases. Most patients experienced timely initiation (from 64.4% [kidney cancer] to 81.2% [breast cancer]) and optimal implementation (from 62.4% [lung cancer] to 72.5% [breast cancer]). The proportion of patients who were persistent with treatment at 6 months ranged from 41.4% (lung cancer) to 77.8% (prostate cancer). CONCLUSIONS: This study revealed variations by cancer type in the initiation, implementation, and persistence of denosumab in patients with solid tumors and bone metastases in routine clinical practice. Further cancer-specific studies are warranted to examine the determinants of (non)adherence with denosumab, and potential ways to improve medication adherence.

Effectiveness and safety of romiplostim among patients with newly diagnosed, persistent and chronic ITP in routine clinical practice in central and Eastern Europe: an analysis of the PLATON study.

OBJECTIVES: The objective of this analysis was to assess the effectiveness and safety of romiplostim in the real-world by duration of primary immune thrombocytopenia (ITP): <3 ('newly diagnosed'), 3-12 ('persistent'), and >12 ('chronic') months. METHODS: This was a post-hoc analysis of the PLATON single-arm, observational cohort study of adults from five Central and Eastern European countries receiving ≥1 romiplostim dose as second-line therapy, or where surgery was contraindicated. Durable (≥75% of measurements with ≥50 × 109 platelets/L during weeks 14-24) and overall platelet response (≥30 or ≥50 × 109 platelets/L at least once), rescue therapy, bleeding, discontinuation of other ITP medications, and adverse drug reactions (ADRs) were assessed. RESULTS: Of 100 participants, 22.0% had newly diagnosed, 17.0% had persistent, and 61.0% had chronic ITP. Prior splenectomy was most frequently reported in chronic ITP (32.8%), prior bleeding was predominant in newly diagnosed patients (68.2%). Durable platelet response was achieved in 50.0% (95% confidence interval [CI]: 28.2-71.8%) of newly diagnosed, 35.3% (95% CI: 14.2-61.7%) of persistent, and 31.1% (95% CI: 19.9-44.3%) of chronic ITP patients. Overall platelet response was achieved in >80% across all strata. Safety was comparable across groups, with a low incidence of thrombotic ADRs and no bone marrow ADRs. DISCUSSION: In this real-world study, platelet response to romiplostim was consistent across all strata of ITP duration. ADRs were infrequent and similar across ITP settings. CONCLUSION: These findings support the utilization of romiplostim in patients with newly diagnosed and persistent ITP in accordance with recent guidelines and the recent romiplostim label extension.

Prospective observational study to evaluate the persistence of treatment with denosumab in patients with bone metastases from solid tumors in routine clinical practice: final analysis.

PURPOSE: In the integrated analysis of phase III head-to-head trials in patients with advanced solid tumors, denosumab demonstrated superiority over zoledronic acid in preventing skeletal-related events (SREs). Regular and continued drug use (persistence) is a precondition of clinical efficacy; persistence in real-life is yet undetermined for denosumab. METHODS: This was a single-arm, prospective, observational, non-interventional study in 598 patients with bone metastases from breast, prostate, lung, or other solid tumors treated with denosumab every four weeks in real-world clinical practice in Austria, Czech Republic, Hungary, Slovakia, and Bulgaria. Persistence was defined as denosumab administration at ≤ 35-day intervals over 24 or 48 weeks, respectively. RESULTS: Previous SREs were found in 10.9% of patients. 62.6% were persistent over 24 weeks and 40.1% over 48 weeks. The Kaplan-Meier median (95% CI) time to non-persistence was 274.0 days (232.0, 316.0). The most frequent reason for non-persistence was delayed administration. There was a trend towards weaker analgesics over time, with approximately 60% of patients not requiring any analgesics. Serum calcium remained within the normal range throughout the study. Adjudicated osteonecrosis of the jaw was documented in three patients with an incidence per patient-year (95% CI) of 0.012 (0.004, 0.029). CONCLUSIONS: Most patients received denosumab regularly once every four weeks over 24 weeks of treatment. Non-persistence was mainly due to delayed administration. The incidence of adverse drug reactions, especially of osteonecrosis of the jaw, was in line with expectations from previous studies.

Prospective Observational Cohort Study to Describe the Use of Panitumumab in Combination with Chemotherapy in Real-World Clinical Practice for Patients with Wild-Type RAS mCRC.

INTRODUCTION: This study aimed to better understand panitumumab use in real-life clinical practice in first- and second-line treatment of metastatic colorectal cancer in five European countries. METHODS: This is a combined analysis of two observational, non-interventional prospective cohort studies, one of which was conducted in Germany and France, the other in Bulgaria, Czech Republic, and Hungary. The studies observed patients with wild-type [Kirsten] rat sarcoma viral oncogene homolog ([K]RAS/RAS) metastatic colorectal cancer (mCRC), who had been treated with panitumumab in combination with fluorouracil, leucovorin, and oxaliplatin (FOLFOX) in the first line or with panitumumab combined with fluorouracil, leucovorin, and irinotecan (FOLFIRI) in the second line following fluoropyrimidine-based chemotherapy. The planned duration of observation was 12 months from the first dose of panitumumab. RESULTS: A total of 332 patients treated with panitumumab + FOLFOX in the first line and 94 patients treated with panitumumab + FOLFIRI in the second line were analyzed. The median number of panitumumab infusions was 10.0 in first-line FOLFOX patients and 11.5 in second-line FOLFIRI patients; the median duration of panitumumab exposure was 5.7 and 6.9 months, respectively. The unadjusted overall response rate (complete or partial response) in patients with available post-baseline response assessment (n = 290) was 51.7% in first-line FOLFOX and 44.9% in second-line FOLFIRI patients. In the first-line setting, resectability was achieved in 9.3%. Reported hospitalizations were mostly cancer-related visits such as scheduled anticancer treatment administrations, tumor assessment visits, or interventions. The majority of adverse drug reactions were skin disorders, with 75.3% in first-line FOLFOX patients and 72.3% in second-line FOLFIRI patients. CONCLUSION: Overall, the study results show that treatment patterns, clinical efficacy, and the safety profile of panitumumab in routine clinical practice were comparable to those in randomized controlled trials. The relatively low skin toxicity rate could be attributed to increasing experience in managing panitumumab-associated rash and some degree of underreporting. FUNDING: Amgen.

Real­world multiple myeloma management practice patterns and outcomes in selected Central and Eastern European countries.

Introduction Multiple myeloma (MM) treatment has evolved substantially in recent years. Solid data on the impact of treatment strategies on patient outcomes beyond clinical trials are scarce, especially in budget­restricted environments with limited access to new treatments. Objectives This study investigated treatment practices, patterns, and outcomes in real­world clinical practice in Bulgaria, Croatia, Czech Republic, Poland, Romania, and Slovakia. Patients and methods This was a noninterventional, observational chart review comprising a cross­sectional and a retrospective longitudinal phase observing adult patients with symptomatic MM at all stages of therapy. Results The study revealed structural differences in clinical practice compared with a similarly designed study previously conducted in 7 Western European countries. Stem cell transplantation was performed in less than half of newly diagnosed eligible patients. The most frequently used first­line regimens were bortezomib based, with frequent bortezomib retreatment after the first relapse. Lenalidomide­based regimens were predominant in the third and subsequent lines of therapy. Depth of response decreased with each treatment line, with half of patients achieving at least very good partial response (≥VGPR) in the first line, while only one­fourth achieved ≥VGPR in the third or subsequent lines. Time to progression was longer in patients with better response levels. Conclusions Inadequate access to advanced antimyeloma regimens and-in some countries-stem cell transplantation highlights the challenges of MM treatment in the region. Information on real­world patient management and its outcomes can provide valuable input for decision makers to effectively allocate limited resources.

The p110beta isoform of phosphoinositide 3-kinase signals downstream of G protein-coupled receptors and is functionally redundant with p110gamma.

The p110 isoforms of phosphoinositide 3-kinase (PI3K) are acutely regulated by extracellular stimuli. The class IA PI3K catalytic subunits (p110alpha, p110beta, and p110delta) occur in complex with a Src homology 2 (SH2) domain-containing p85 regulatory subunit, which has been shown to link p110alpha and p110delta to Tyr kinase signaling pathways. The p84/p101 regulatory subunits of the p110gamma class IB PI3K lack SH2 domains and instead couple p110gamma to G protein-coupled receptors (GPCRs). Here, we show, using small-molecule inhibitors with selectivity for p110beta and cells derived from a p110beta-deficient mouse line, that p110beta is not a major effector of Tyr kinase signaling but couples to GPCRs. In macrophages, both p110beta and p110gamma contributed to Akt activation induced by the GPCR agonist complement 5a, but not by the Tyr kinase ligand colony-stimulating factor-1. In fibroblasts, which express p110beta but not p110gamma, p110beta mediated Akt activation by the GPCR ligands stromal cell-derived factor, sphingosine-1-phosphate, and lysophosphatidic acid but not by the Tyr kinase ligands PDGF, insulin, and insulin-like growth factor 1. Introduction of p110gamma in these cells reduced the contribution of p110beta to GPCR signaling. Taken together, these data show that p110beta and p110gamma can couple redundantly to the same GPCR agonists. p110beta, which shows a much broader tissue distribution than the leukocyte-restricted p110gamma, could thus provide a conduit for GPCR-linked PI3K signaling in the many cell types where p110gamma expression is low or absent.

Structural determinants involved in the activation and regulation of G protein-coupled receptors: lessons from the alpha1-adrenegic receptor subtypes.

The aim of a large number of studies on G protein-coupled receptors was centered on understanding the structural basis of their main functional properties. Here, we will briefly review the results obtained on the alpha1-adrenergic receptor subtypes belonging to the rhodopsin-like family of receptors. These findings contribute, on the one hand, to further understand the molecular basis of adrenergic transmission and, on the other, to provide some generalities on the structure-functional relationship of G protein-coupled receptors.

The alpha1b-adrenergic receptor subtype: molecular properties and physiological implications.

The aim of this review is to summarize some of the main findings from our laboratory as well as from others concerning the biochemical, molecular, and functional properties of the alpha1b-adrenergic receptor. Experimental and computational mutagenesis of the alpha1b-adrenergic receptor have been instrumental in elucidating some of the molecular mechanisms underlying receptor activation and receptor coupling to Gq. The knockout mouse model lacking the alpha1b-adrenergic receptor has highlighted the potential implication of this receptor subtype in variety of functions including the regulation of blood pressure, glucose homeostasis, and the rewarding response to drugs of abuse.

Co- and posttranslational modification of the alpha(1B)-adrenergic receptor: effects on receptor expression and function.

We have characterized the maturation, co- and posttranslational modifications, and functional properties of the alpha(1B)-adrenergic receptor (AR) expressed in different mammalian cells transfected using conventional approaches or the Semliki Forest virus system. We found that the alpha(1B)-AR undergoes N-linked glycosylation as demonstrated by its sensitivity to endoglycosidases and by the effect of tunicamycin on receptor maturation. Pulse-chase labeling experiments in BHK-21 cells demonstrate that the alpha(1B)-AR is synthesized as a 70 kDa core glycosylated precursor that is converted to the 90 kDa mature form of the receptor with a half-time of approximately 2 h. N-Linked glycosylation of the alpha(1B)-AR occurs at four asparagines on the N-terminus of the receptor. Mutations of the N-linked glycosylation sites did not have a significant effect on receptor function or expression. Surprisingly, receptor mutants lacking N-linked glycosylation migrated as heterogeneous bands in SDS-PAGE. Our findings demonstrate that N-linked glycosylation and phosphorylation, but not palmitoylation or O-linked glycosylation, contribute to the structural heterogeneity of the alpha(1B)-AR as it is observed in SDS-PAGE. The modifications found are similar in the different mammalian expression systems explored. Our findings indicate that the Semliki Forest virus system can provide large amounts of functional and fully glycosylated alpha(1B)-AR protein suitable for biochemical and structural studies. The results of this study contribute to elucidate the basic steps involved in the processing of G protein-coupled receptors as well as to optimize strategies for their overexpression.