TOPLINE:
particularly among single-center studies which are more likely to go unreported, and many phase 2 studies failing to translate into successful phase 3 trials.
METHODOLOGY:
- Few immunotherapy agents — only pembrolizumab in the United States, as of December 2023, and atezolizumab in Europe — have received approvals for use in patients with breast cancer, indicating low returns on the large number of breast cancer immunotherapy trials launched in the early 2010s.
- In this cross-sectional study, researchers evaluated 331 immunotherapy trials, initiated between January 2004 and April 2023, that enrolled 48,844 patients with breast cancer.
- Of these, 47 were phase 1 trials, 242 were phase 2 trials, and 42 were phase 3 trials.
- A trial was considered reported if the results were posted on ClinicalTrial.gov or reported as an abstract or a manuscript.
- Overall, 120 trials met their completion date up to November 2022; of these, 30 (25%) failed to report outcomes, which included two phase 3 trials.
TAKEAWAY:
- Phase 1 trials had the highest rate of nonreporting (31.8%), followed by phase 2 (23.6%) and phase 3 (22.2%) trials.
- Single-center studies were more likely to be unreported than multicenter studies (35.2% vs 15.0%; P = .02).
- Of 90 reported trials, 47 (52.2%) met their primary endpoints and 43 (47.8%) did not.
- The majority, 17 out of 19 (89.5%), of the reported randomized trials had negative results.
IN PRACTICE:
“The findings of this study suggest that the large number of immunotherapy trials being run have yielded modest clinical impact,” the authors wrote. “More selective initiation of phase 2 trials, grounded in preclinical and biomarker observations and with optimal statistical designs for early efficacy assessment, is needed to increase trial efficiency.”
SOURCE:
The study, led by Marco Mariani, MD, Università Vita-Salute San Raffaele, Milan, Italy, was published online in JAMA Network Open.
LIMITATIONS:
The study’s reliance on ClinicalTrials.gov as the primary source of trial data might have resulted in some trials being overlooked. In addition, manual data extraction could cause inaccuracies and potentially introduced biases in the interpretation of trial results. Primary study completion date cutoff of December 2022 could have excluded significant data from more recent trials.
DISCLOSURES:
This study received support via Susan Komen Leadership Grant and the Fondazione AIRC per la Ricerca sul Cancro. Several authors reported receiving grants and personal fees and having other ties with various sources.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.