233P - Incorporation of correlative studies in ovarian cancers in the era of precision medicine: Assessment of accountability and utility

Background

Correlative science is an integral aspect to modern oncology clinical trial design. To adopt a personalized approach to oncology, correlative research is important at all stages of drug development. This study investigated the integration of correlative studies in ovarian cancer (OC).

Methods

A systematic review of phase I, II and III clinical trials in OC published from 2013-2017 was performed. Objectives were to assess type of test; safety and success with obtaining tissue; and reporting of correlative results. Correlative studies were defined as additional tests beyond standard of care, for example biopsies, circulating tumour DNA and immune studies. Changes with time and phase of trial were assessed.

Results

From 1073 abstracts, 175 trials with 30,674 patients were identified. 116 of these were early phase trials (I/II; 66%). Overall, 80 trials included at least one correlative study (46%), 35 included a biopsy (20%) and 28 archival tissue (16%). Other correlative studies were done in 45 studies (26%) with blood-based investigations being the most common (21%). In this review, 73 trials (42%) reported results of the correlative studies within the article. Only 19% published the results of the biopsy tissue analysis. One in ten (10.5%) patients enrolled had a biopsy. Only 3 (9%) trials required two or more biopsies. Biopsies were optional in 6 (3%) trials and mandatory in 29 (17%). 71% of the patient cohort underwent a biopsy in trials where the biopsy was mandatory compared to 55% when optional (p < 0.0001). Biopsies were more likely to be included in phase I/II trials compared to phase III (23 vs 14%; p = 0.16). Safety of biopsies was reported in one of the published trials (0.5%).

Conclusions

Based on this systematic review, less than 50% of the trials published had correlative studies, with only 1 in 5 including biopsies. Results of the studies were published in only 42% of the trials. Mandatory biopsies have higher sampling rates and may be needed to ensure adequate power to address the scientific hypothesis. Adequate sample size and timeliness of results of correlative studies are critical to ensure accountability to patient investment.

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.