Abstract 1901
Background
AEs resulting from placebo administration have not been well studied in oncology. The aim of this study was to describe the incidence of AEs in the placebo arms of target and immunotherapy cancer drugs in all treatment settings, and to analyze their relation with AEs reported in the active arms of included trials.
Methods
Based on PRISMA guidelines, a systematic literature search was performed including phase 3, randomized, double-blind, placebo-controlled trials from 1/1/2000 to 1/5/19. Adjuvant and advanced-stage studies using targeted and immunotherapy were included. Trials involving active anticancer treatment in addition to placebo in the control group were excluded. Random-effects meta-analysis was performed to estimate the incidence of grade 3-4 placebo AEs.
Results
Of 4396 studies screened, 40 trials were eligible (adjuvant n = 14; advanced n = 26) including 10 cancer types and 28,520. Median incidence of any-grade placebo AEs was 90% (IQR 89-91%) in the adjuvant and 89.5% (IQR 72-96%) in the advanced trials. Grade 5 drug-related AEs were reported in 19 pts receiving placebo. 4 trials reported a higher frequency of grade 3-4 AEs in the placebo arm than in the active treatment arm. The overall, random-effects pooled incidence of grade 3-4 placebo AEs was 22% (95% CI, 17-27%; [I2= 95%]) for the adjuvant and 27% (95% CI, 20-35%; [I2= 97%]) for the advanced trials. No statistical differences were observed comparing both settings (Wilcoxon rank-sum test, P = 0.2). Frequency of grade 3-4 placebo AEs was found to be correlated between the treatment and placebo arms in both adjuvant (ρ = 0.5; P = .042) and advanced studies (ρ = 0.6; P = .003).
Conclusions
Placebo administration was associated with a substantial incidence of grade 3-4 placebo AEs in adjuvant and advanced settings. An association between the active treatment and placebo arms was observed in both scenarios. These findings should be taken into consideration by the medical community in the toxicity evaluation criteria of a placebo-controlled clinical trial.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
2023 - Patients with brain metastases treated with afatinib in clinical practice – results from the prospective non-interventional study GIDEON
Presenter: Eckart Laack
Session: Poster Display session 1
Resources:
Abstract
1613 - Lerociclib (G1T38), an oral CDK4/6 inhibitor, dosed continuously in combination with osimertinib for EGFRmut non-small cell lung cancer: initial Phase 1b results
Presenter: David Berz
Session: Poster Display session 1
Resources:
Abstract
2853 - Real-world implementation of sequential targeted therapies for EGFR-mutated NSCLC
Presenter: Petros Christopoulos
Session: Poster Display session 1
Resources:
Abstract
1974 - A Phase II Open-Label, Multicentre Study to Assess the Anti-tumour Activity of Afatinib in Patients with Activating Epidermal Growth Factor Receptor mutation (EGFRm) from Circulating Tumor DNA (CtDNA)
Presenter: Young-Chul Kim
Session: Poster Display session 1
Resources:
Abstract
3370 - Influence of cow’s milk on the absorption and exposure of erlotinib in NSCLC patients
Presenter: Geerten Veerman
Session: Poster Display session 1
Resources:
Abstract
5900 - PTEN loss as Predictor of Tumor Heterogeneity (TH) and Poor Prognosis in EGFR-mutant Advanced Non-Small Cell Lung Cancer (ANSCLC) Patients (pts) Receiving Tyrosine-Kinase Inhibitors (TKIs).
Presenter: Miriam Ferrara
Session: Poster Display session 1
Resources:
Abstract
1302 - Safety of lorlatinib in subgroups of patients from a phase 1/2 trial
Presenter: Enriqueta Felip
Session: Poster Display session 1
Resources:
Abstract
1497 - Brigatinib (BRG) in Asian vs non-Asian patients (pts) with crizotinib (CRZ)-refractory ALK+ NSCLC in the phase 2 ALTA trial
Presenter: Dae Ho Lee
Session: Poster Display session 1
Resources:
Abstract
2349 - The safety assessment of crizotinib and alectinib from real world data of 840 ALK-inhibitor naïve patients with NSCLC harboring ALK-rearrangement (WJOG9516L).
Presenter: Kei Kunimasa
Session: Poster Display session 1
Resources:
Abstract
1120 - Brigatinib in ALK TKI-pretreated ALK+ metastatic non-small cell lung cancer (mNSCLC): the Use Via Expanded Access to Brigatinib (UVEA-Brig) study
Presenter: Silvia Novello
Session: Poster Display session 1
Resources:
Abstract