Karen Sundell

Phase 3 solanezumab trials: Secondary outcomes in mild Alzheimer's disease patients

EXPEDITION and EXPEDITION2 were identically designed placebo‐controlled phase 3 studies assessing effects of solanezumab, an antiamyloid monoclonal antibody binding soluble amyloid‐β peptide, on cognitive and functional decline over 80 weeks in patients with mild‐to‐moderate Alzheimers disease (AD). Primary findings for both studies have been published.

Modifications in the B10 and B26–30 regions of the B chain of human insulin alter affinity for the human IGF-I receptor more than for the insulin receptor

Summary Inversion of the natural sequence of the B chain of human insulin (HI) from ProB28LysB29 to LysB28ProB29 generates an insulin analogue with reduced tendency to self-associate. Since this substitution increases the homology of insulin to insulin-like growth factor-I (IGF-I), we have examined the affinity of a series of insulin analogues with the general modified structure XaaB28ProB29 HI for binding to both human placental insulin and IGF-I receptors. The XaaB28ProB29 HI series is approximately equipotent to HI in binding to the insulin receptor with the exception of when Xaa = Phe, Trp, Leu, Ile, and Gly (40–60 % relative to HI). Substitution with basic residues in the B28 position increased the relative affinity to the IGF-I receptor approximately 1.5−2-fold (ArgB28ProB29 > OrnB28ProB29 = LysB28ProB29). Substitution with acidic residues reduced relative affinity for the IGF-I receptor approximately 2-fold (CyaB28ProB29 = GluB28ProB29 > AspB28ProB29). Combination of AspB10 substitution in conjunction with a modification in the B28–29 position (e.g. AspB10LysB28ProB29 HI) showed an additional 2-fold selective increase in affinity for the IGF-I receptor, suggesting that these two effects are additive. Addition of Arg residues at B31–32, on the backbone of either HI or AspB10 HI, increased affinity for the IGF-I receptor 10 and 28 fold, respectively, compared to HI, confirming the significance of enhanced positive charge at the C-terminal end of the insulin B-chain in increasing selectivity for the IGF-I receptor. This relative increase in IGF-I receptor affinity correlated largely, but not completely, with enhanced growth promoting activity in human mammary epithelial cells. In the case of LysB28ProB29 HI, growth activity correlated with dissociation kinetics from the insulin receptor which were shown to be identical with those of human insulin. [Diabetologia (1997) 40: S 54–S 61]

Effects of first-trimester fluoxetine exposure on the newborn

Objective To determine whether first-trimester exposure to fluoxetine, a selective serotonin reuptake inhibitor commonly used to treat depression and obsessive-compulsive disorders, is associated with increased frequency of fetal malformations. Methods We evaluated outcomes of all pregnancies identified prospectively with confirmed first-trimester fluoxetine exposure contained in the Eli Lilly and Company worldwide fluoxetine pregnancy registry. These outcomes were compared with historic reports of newborn surveys. Results Outcomes were available for 796 pregnancies, 37 from fluoxetine clinical trials and 759 from spontaneous reports. Spontaneous abortions were reported in 110 of the 796 (13.8%) pregnancies. Of the remaining 686, malformations, deformations, and disruptions, including those identified after the perinatal period, were reported in 34 (5.0%). No consistent or recurring pattern of abnormalities was observed. Conclusion Based on comparison with historic reports of newborn surveys, it is unlikely that maternal fluoxetine use during the first trimester of pregnancy results in increased risk of fetal malformations.

Premenstrual daily fluoxetine for premenstrual dysphoric disorder: a placebo-controlled, clinical trial using computerized diaries.

OBJECTIVE To evaluate premenstrual daily dosing with fluoxetine for treatment of premenstrual dysphoric disorder. METHODS After a two‐cycle screening and one‐cycle single‐blind placebo period, 260 women were randomized to fluoxetine 10 mg, fluoxetine 20 mg, or placebo (dosed daily from 14 days before next expected menses through the first full day of bleeding) for three cycles. Women recorded premenstrual dysphoric disorder symptoms daily using a computerized version of the Daily Record of Severity of Problems. RESULTS Premenstrual daily fluoxetine 20 mg demonstrated significant improvement in mean Daily Record of Severity of Problems luteal scores compared with placebo (P = .005); premenstrual daily fluoxetine 10 mg did not (P = .100). Daily Record of Severity of Problems total scores were statistically significantly improved by the first treatment cycle for both active treatment groups. However, only fluoxetine 20 mg remained statistically significantly superior to placebo throughout the active treatment phase of the trial. Both fluoxetine groups showed significant treatment advantage over placebo for mood‐related symptoms (P < .05). Only premenstrual daily fluoxetine 20 mg showed significant treatment advantage over placebo for physical symptoms of breast tenderness (P < .001), bloating (P = .001), and joint/muscle pain (P = .037). Treatment was well tolerated; discontinuations due to adverse events did not differ among the three groups (P = .316). CONCLUSION Premenstrual daily dosing with fluoxetine effectively treats mood, physical, and social functioning symptoms associated with premenstrual dysphoric disorder. Fluoxetine 20 mg appears to have comparable tolerability with, and better efficacy than, fluoxetine 10 mg.

Glucose Transporter Levels in Tissues of Spontaneously Diabetic Zucker fa/fa Rat (ZDF/drt) and Viable Yellow Mouse (Avy/a)

We used antibodies to the fat/muscle glucose transporter (GLUT4) and the liver glucose transporter (GLUT2) to measure levels of these proteins in various tissues of two rodent models of non-insulin-dependent (type II) diabetes mellitus: the obese spontaneously diabetic male Zucker fa/fa rat (ZDF/drt) and the male viable yellow Avy/a obese diabetic mouse. The ZDF/drt strain generally develops overt diabetes associated with decreased plasma insulin levels. Depending on the age of the animals, the ZDF/drt rats can be arbitrarily segregated into age-matched obese, mildly diabetic (blood glucose < 11 mM) and obese, and severely diabetic (blood glucose > 20 mM) groups. Avy/a mice are comparably hyperglycemic but unlike the ZDF/drt rats are severely hyperinsulinemic. In both groups of diabetic animals, GLUT4 in adipose tissue, heart, and skeletal muscle was reduced 25–55%, and GLUT2 in liver was increased 30–40%, relative to lean, age-matched controls. However, when the mildly diabetic ZDF/drt rats were compared to the lean controls, the only significant difference was a 25% reduction of GLUT4 in heart. Within all of the ZDF/drt rats (excluding the lean controls), GLUT2 in liver and GLUT4 in adipose tissue, heart, and skeletal muscle correlated significantly with glycemia. These data suggest that, in these two models of type II diabetes, glucose transporter levels in muscle, adipose tissue, and liver are regulated in a tissue-selective manner in response to changes in insulin and glucose. Furthermore, at least in the ZDF/drt rat, alterations in GLUT2 and/or GLUT4 protein levels appear not to be associated with obesity per se but appear to be secondary to the severely diabetic state. In both rodent models, similar alterations in GLUT2 and/or GLUT4 levels were observed under comparable glycemia, but quite distinct insulin levels, consistent with the possibility that glucose itself may be an important contributing regulator of glucose transporter expression.

Protein Kinase C Alpha Expression in Breast and Ovarian Cancer

In recent years research has focused on the development of specific, targeted drugs to treat cancer. One approach has been to block intracellular signaling proteins, such as protein kinase C alpha (PKC-α). To help support the rationale for clinical studies of a PKC-α-targeted therapy in breast and ovarian cancers, we reviewed publications studying PKC-α expression in these tumors. Since these investigations were mostly performed in cell lines, we supplemented this review with some preliminary findings from studies examining PKC-α expression in tumor tissue biopsies obtained from patients with breast and ovarian cancer. Based on the reviewed publications using representative cell lines and our preliminary findings on tumor tissue of patients with breast cancer, we infer that PKC-α levels may especially be increased in breast cancer patients with low or negative estrogen receptor (ER) levels. Thus, clinical studies determining efficacy of selective or specific inhibitors of PKC-α should include determination of ER status in order to help answer whether blocking PKC-α in patients with low or absent ER can result in clinical benefit.

Trial of Solanezumab for Mild Dementia Due to Alzheimer’s Disease

BACKGROUND Alzheimers disease is characterized by amyloid‐beta (Aβ) plaques and neurofibrillary tangles. The humanized monoclonal antibody solanezumab was designed to increase the clearance from the brain of soluble Aβ, peptides that may lead to toxic effects in the synapses and precede the deposition of fibrillary amyloid. METHODS We conducted a double‐blind, placebo‐controlled, phase 3 trial involving patients with mild dementia due to Alzheimers disease, defined as a Mini–Mental State Examination (MMSE) score of 20 to 26 (on a scale from 0 to 30, with higher scores indicating better cognition) and with amyloid deposition shown by means of florbetapir positron‐emission tomography or Aβ1‐42 measurements in cerebrospinal fluid. Patients were randomly assigned to receive solanezumab at a dose of 400 mg or placebo intravenously every 4 weeks for 76 weeks. The primary outcome was the change from baseline to week 80 in the score on the 14‐item cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS‐cog14; scores range from 0 to 90, with higher scores indicating greater cognitive impairment). RESULTS A total of 2129 patients were enrolled, of whom 1057 were assigned to receive solanezumab and 1072 to receive placebo. The mean change from baseline in the ADAS‐cog14 score was 6.65 in the solanezumab group and 7.44 in the placebo group, with no significant between‐group difference at week 80 (difference, ‐0.80; 95% confidence interval, ‐1.73 to 0.14; P=0.10). As a result of the failure to reach significance with regard to the primary outcome in the prespecified hierarchical analysis, the secondary outcomes were considered to be descriptive and are reported without significance testing. The change from baseline in the MMSE score was ‐3.17 in the solanezumab group and ‐3.66 in the placebo group. Adverse cerebral edema or effusion lesions that were observed on magnetic resonance imaging after randomization occurred in 1 patient in the solanezumab group and in 2 in the placebo group. CONCLUSIONS Solanezumab at a dose of 400 mg administered every 4 weeks in patients with mild Alzheimers disease did not significantly affect cognitive decline. (Funded by Eli Lilly; EXPEDITION3 ClinicalTrials.gov number, NCT01900665.)

The role of protein kinase C-alpha (PKC-alpha) in melanoma.

In the 1980s, protein kinase C (PKC) was identified as a contributing factor in skin tumorigenesis. As drugs targeting specifically PKC have become available, the intent of this review was to assess the role of PKC, in particular of PKC-alpha in melanoma or other skin cancers. We reviewed and summarized published studies examining the role of PKC-alpha in the development of melanoma or other skin cancers. Most studies to date have been cell-culture based. In models of melanoma, PKC-alpha activation is typically associated with increased tumour cell proliferation, invasiveness and decreased differentiation, suggesting that PKC-alpha inhibitors, such as aprinocarsen, an antisense oligonucleotide directed against PKC-alpha, may be appropriate in the treatment of skin malignancies. Because of the recent developments on selective or specific PKC-alpha inhibitors, including aprinocarsen, there is a growing need to conduct further translational research, especially in melanoma patients, to identify the patient population that might benefit most from PKC-alpha targeted therapy.

The Role of Protein Kinase C-alpha (PKC-α) in Cancer and its Modulation by the Novel PKC-α-Specific Inhibitor Aprinocarsen

As our understanding of tumorigenesis increases, interference with the various signaling pathways of tumor cells has become an attractive approach to arresting tumor cell growth and overcoming chemoresistance. Among many intracellular signaling proteins, protein kinase C (PKC) isoenzymes have been identified as possible targets to render tumor cells more susceptible to apoptosis and growth arrest. We review the known biology of the α-isoenzyme of PKC in different cancers to provide a rational approach for developing targeted therapies using PKC modulators, including aprinocarsen, an antisense oligonucleotide (ASO) against PKC-α.

Safety profile of semagacestat, a gamma-secretase inhibitor: IDENTITY trial findings.

Abstract Objective: Semagacestat, a γ-secretase inhibitor, demonstrated an unfavorable risk–benefit profile in a Phase 3 study of patients with Alzheimer’s disease (IDENTITY trials), and clinical development was halted. To assist in future development of γ-secretase inhibitors, we report detailed safety findings from the IDENTITY study, with emphasis on those that might be mechanistically linked to γ-secretase inhibition. Research design and methods: The IDENTITY trial was a double-blind, placebo-controlled trial of semagacestat (100 mg and 140 mg), in which 1537 patients age 55 years and older with probable Alzheimer’s disease were randomized. Treatment-emergent adverse events (TEAEs) are reported by body system along with pertinent laboratory, vital sign, and ECG findings. Results: Semagacestat treatment was associated with increased reporting of suspected Notch-related adverse events (gastrointestinal, infection, and skin cancer related). Other relevant safety findings associated with semagacestat treatment included cognitive and functional worsening, skin-related TEAEs, renal and hepatic changes, increased QT interval, and weight loss. With few exceptions, differences between semagacestat and placebo treatment groups were no longer significant after cessation of treatment with active drug. Conclusions: Many of these safety findings can be attributed to γ-secretase inhibition, and may be valuable to researchers developing γ-secretase inhibitors.