Abstract 3612
Background
Combination of ICIs and chemotherapy (ICI-C) has become a more favourable design in recent trials. We have previously reported 6-month PFS rate (PFS6) is a good surrogate for 12-month overall survival rate (OS12) within treatment (ICI) arms, but had limited data to examine surrogate endpoints for treatment comparisons. We extend our work to validate prior findings by updating with data from more recent randomized controlled trials (RCTs), especially studies testing combination ICI-C.
Methods
We performed a literature search to identify eligible Phase (Ph) 2 and 3 RCTs of ICI. We excluded studies with sample size of < 100 or control arms without active treatment. Efficacy data including objective response rate (ORR), PFS, OS, PFS6 and OS12 were extracted. We examined the associations of relative treatment comparisons between ORR risk ratio (RR) with hazard ratios (HRs) for PFS and OS. We also studied the correlations between ORR, PFS6 and OS12 within ICI arm. A correlation coefficient (r) of 0 indicates lack of association whereas 1 implies perfect surrogacy.
Results
Forty-six RCTs (5 Ph2; 41 Ph3) with 51 treatment comparisons were identified. Associations between ORR RR with PFS HR, ORR RR with OS HR, and PFS HR with OS HR were r = 0.67, r = 0.42 and r = 0.52 respectively. For the 16 RCTs of ICI-C, these associations were r = 0.79, r = 0.58 and r = 0.64 respectively. For the 35 RCTs of ICI monotherapy, these associations were r = 0.71, r = 0.40 and r = 0.54. Within the ICI arms, associations between ORR and PFS6, ORR and OS12, and PFS6 and OS12 were r = 0.67, r = 0.54 and r = 0.79. Within ICI-C trials, these associations were r = 0.60, r = 0.56 and r = 0.60 respectively. Within ICI monotherapy trials, these associations were r = 0.51, r = 0.46 and r = 0.80 respectively.
Conclusions
In treatment comparison, the correlation between PFS and OS was modest, but stronger in ICI-C trials. Within ICI arms, PFS6 had stronger correlation with OS12 than ORR. PFS is recommended as a surrogate endpoint for ICI trials over ORR.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
M. Friedlander: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution), Lecturer fees: AstraZeneca; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self), Advisory / Consultancy: Takeda. All other authors have declared no conflicts of interest.
Resources from the same session
4021 - Prospective pathological experience with research biopsies in the context of clinical trials at Vall d’Hebron Institute of Oncology
Presenter: Paolo Nuciforo
Session: Poster Display session 3
Resources:
Abstract
5603 - Development of a comprehensive next-generation targeted sequencing assay for detection of gene-fusions in solid tumors
Presenter: Vinay Mittal
Session: Poster Display session 3
Resources:
Abstract
4952 - Next-generation sequencing for better treatment strategy of cancer of unknown primary (CUP)
Presenter: Kang Kook Lee
Session: Poster Display session 3
Resources:
Abstract
4590 - Circulating-free DNA analysis from long-term surviving metastatic colorectal cancer patients undergoing surgery for resectable disease.
Presenter: Michele Ghidini
Session: Poster Display session 3
Resources:
Abstract
3696 - Ultra-sensitive detection of circulating tumor DNA identifies patients in high risk of recurrence in early stages melanoma
Presenter: Filip Janku
Session: Poster Display session 3
Resources:
Abstract
4295 - Identification of the founder BRCA1 mutation c.4117G>T (p.Glu1373*) recurring in Abruzzo and Lazio regions of Central Italy and predisposing to breast/ovarian and BRCA1-related cancers
Presenter: Daniela Di Giacomo
Session: Poster Display session 3
Resources:
Abstract
2214 - Enzalutamide (ENZA) and Apalutamide (APA) In vitro chemical reactivity studies and Activity in a Mouse Drug Allergy Model (MDAM)
Presenter: Mausumee Guha
Session: Poster Display session 3
Resources:
Abstract
5044 - Influence of genetic variation in COMT on cisplatin-induced nephrotoxicity in cancer patients.
Presenter: Bram Agema
Session: Poster Display session 3
Resources:
Abstract
3293 - Cardioprotective and anti-inflammatory effects of Empagliflozin during treatment with Doxorubicin: a cellular and preclinical study
Presenter: Vincenzo Quagliariello
Session: Poster Display session 3
Resources:
Abstract
3324 - Breast Cancer Organoids Model Treatment Response of HER2 Targeted Therapy in HER2-mutant Breast Cancer
Presenter: Xuelu Li
Session: Poster Display session 3
Resources:
Abstract