Steven Joffe

Phase 3 Trials of Solanezumab for Mild-to-Moderate Alzheimer's Disease

BACKGROUND Alzheimers disease is characterized by amyloid-beta plaques, neurofibrillary tangles, gliosis, and neuronal loss. Solanezumab, a humanized monoclonal antibody, preferentially binds soluble forms of amyloid and in preclinical studies promoted its clearance from the brain. METHODS In two phase 3, double-blind trials (EXPEDITION 1 and EXPEDITION 2), we randomly assigned 1012 and 1040 patients, respectively, with mild-to-moderate Alzheimers disease to receive placebo or solanezumab (administered intravenously at a dose of 400 mg) every 4 weeks for 18 months. The primary outcomes were the changes from baseline to week 80 in scores on the 11-item cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS-cog11; range, 0 to 70, with higher scores indicating greater cognitive impairment) and the Alzheimers Disease Cooperative Study-Activities of Daily Living scale (ADCS-ADL; range, 0 to 78, with lower scores indicating worse functioning). After analysis of data from EXPEDITION 1, the primary outcome for EXPEDITION 2 was revised to the change in scores on the 14-item cognitive subscale of the Alzheimers Disease Assessment Scale (ADAS-cog14; range, 0 to 90, with higher scores indicating greater impairment), in patients with mild Alzheimers disease. RESULTS Neither study showed significant improvement in the primary outcomes. The modeled difference between groups (solanezumab group minus placebo group) in the change from baseline was -0.8 points for the ADAS-cog11 score (95% confidence interval [CI], -2.1 to 0.5; P=0.24) and -0.4 points for the ADCS-ADL score (95% CI, -2.3 to 1.4; P=0.64) in EXPEDITION 1 and -1.3 points (95% CI, -2.5 to 0.3; P=0.06) and 1.6 points (95% CI, -0.2 to 3.3; P=0.08), respectively, in EXPEDITION 2. Between-group differences in the changes in the ADAS-cog14 score were -1.7 points in patients with mild Alzheimers disease (95% CI, -3.5 to 0.1; P=0.06) and -1.5 in patients with moderate Alzheimers disease (95% CI, -4.1 to 1.1; P=0.26). In the combined safety data set, the incidence of amyloid-related imaging abnormalities with edema or hemorrhage was 0.9% with solanezumab and 0.4% with placebo for edema (P=0.27) and 4.9% and 5.6%, respectively, for hemorrhage (P=0.49). CONCLUSIONS Solanezumab, a humanized monoclonal antibody that binds amyloid, failed to improve cognition or functional ability. (Funded by Eli Lilly; EXPEDITION 1 and 2 ClinicalTrials.gov numbers, NCT00905372 and NCT00904683.).

A Phase 3 Trial of Semagacestat for Treatment of Alzheimer's Disease

BACKGROUND Alzheimers disease is characterized by the presence of cortical amyloid-beta (Aβ) protein plaques, which result from the sequential action of β-secretase and γ-secretase on amyloid precursor protein. Semagacestat is a small-molecule γ-secretase inhibitor that was developed as a potential treatment for Alzheimers disease. METHODS We conducted a double-blind, placebo-controlled trial in which 1537 patients with probable Alzheimers disease underwent randomization to receive 100 mg of semagacestat, 140 mg of semagacestat, or placebo daily. Changes in cognition from baseline to week 76 were assessed with the use of the cognitive subscale of the Alzheimers Disease Assessment Scale for cognition (ADAS-cog), on which scores range from 0 to 70 and higher scores indicate greater cognitive impairment, and changes in functioning were assessed with the Alzheimers Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, on which scores range from 0 to 78 and higher scores indicate better functioning. A mixed-model repeated-measures analysis was used. RESULTS The trial was terminated before completion on the basis of a recommendation by the data and safety monitoring board. At termination, there were 189 patients in the group receiving placebo, 153 patients in the group receiving 100 mg of semagacestat, and 121 patients in the group receiving 140 mg of semagacestat. The ADAS-cog scores worsened in all three groups (mean change, 6.4 points in the placebo group, 7.5 points in the group receiving 100 mg of the study drug, and 7.8 points in the group receiving 140 mg; P=0.15 and P=0.07, respectively, for the comparison with placebo). The ADCS-ADL scores also worsened in all groups (mean change at week 76, -9.0 points in the placebo group, -10.5 points in the 100-mg group, and -12.6 points in the 140-mg group; P=0.14 and P<0.001, respectively, for the comparison with placebo). Patients treated with semagacestat lost more weight and had more skin cancers and infections, treatment discontinuations due to adverse events, and serious adverse events (P<0.001 for all comparisons with placebo). Laboratory abnormalities included reduced levels of lymphocytes, T cells, immunoglobulins, albumin, total protein, and uric acid and elevated levels of eosinophils, monocytes, and cholesterol; the urine pH was also elevated. CONCLUSIONS As compared with placebo, semagacestat did not improve cognitive status, and patients receiving the higher dose had significant worsening of functional ability. Semagacestat was associated with more adverse events, including skin cancers and infections. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT00594568.)

Clinical Trials and Medical Care: Defining the Therapeutic Misconception

A key component of informed consent to participate in medical research includes understanding that research is not the same as treatment.

Cost-effectiveness of respiratory syncytial virus prophylaxis among preterm infants.

Objectives. To evaluate the costs and benefits of two new agents, respiratory syncytial virus immune globulin (RSVIG) and palivizumab, to prevent respiratory syncytial virus (RSV) infection among premature infants discharged from the neonatal intensive care unit (NICU) before the start of the RSV season. Method. Decision analysis was used to compare the projected societal cost-effectiveness of three strategies—RSVIG, palivizumab, and no prophylaxis—among a hypothetical cohort of premature infants. Probabilities and costs of hospitalization were derived from a cohort of 1721 premature infants discharged from six Kaiser Permanente–Northern California NICUs. Efficacies of prophylaxis were based on published trials. Costs of prophylaxis were derived from published sources. Mortality among infants hospitalized for RSV was assumed to be 1.2%. Future benefits were discounted at 3%. Results. Palivizumab was both more effective and less costly than RSVIG. Cost-effectiveness varied widely by subgroup. Palivizumab appeared most cost-effective for infants whose gestational age was ≤32 weeks, who required ≥28 days of oxygen in the NICU, and who were discharged from the NICU from September through November. In this subgroup, palivizumab was predicted to cost

Actionable exomic incidental findings in 6503 participants: challenges of variant classification

12 000 per hospitalization averted (after taking into account savings from prevention of RSV admissions) or

Significant Improvement in Survival After Allogeneic Hematopoietic Cell Transplantation During a Period of Significantly Increased Use, Older Recipient Age, and Use of Unrelated Donors

33 000 per life-year saved, and the number needed to treat to avoid one hospitalization was estimated at 7.4. However, for all other subgroups, ratios ranged from

Ethics and Genomic Incidental Findings

39 000 to

Equipoise and the Dilemma of Randomized Clinical Trials

420 000 per hospitalization averted or

Rehospitalization for respiratory syncytial virus among premature infants

110 000 to

What do patients value in their hospital care? An empirical perspective on autonomy centred bioethics

1 200 000 per life-year saved, and the number needed to treat extended from 15 to 152. The results were sensitive to varying assumptions about the cost and efficacy of prophylaxis, as well as the probability of hospitalization, but were less sensitive to the cost of hospitalization. Conclusion. In our model, the cost of prophylaxis against RSV for most subgroups of preterm infants was high relative to the benefits realized. Lower costs might permit the benefits of prophylaxis to be extended to additional groups of preterm infants.