Adding carboplatin to doxorubicin and cyclophosphamide, followed by taxane therapy, results in significant improvement in event-free survival (EFS) among patients with early-stage triple-negative breast cancer (TNBC), as shown in the PEARLY trial.
“Unique among phase III platinum trials, PEARLY demonstrates a significant benefit across both the neoadjuvant and adjuvant settings, marking an important advance for the full spectrum of these patients,” the investigators said.
A total of 868 patients with TNBC across 22 institutions in the Republic of Korea were randomized to either the carboplatin group or the control group between January 2016 and June 2020. [Ann Oncol 2026;37:1386-1395]
Over a median follow-up of 57.2 months, carboplatin significantly improved EFS (hazard ratio, 0.67, 95 percent confidence interval, 0.49‒0.92; p=0.012) compared with control. EFS rates improved from 75.1 percent to 82.3 percent at year 5, with an absolute difference of 7.2 percent.
Other endpoints assessed, including overall survival (OS), invasive disease-free survival (IDFS), and distant recurrence-free survival (DRFS), also showed a consistent trend favouring carboplatin, but none were statistically significant.
Grade ≥3 treatment-related adverse events occurred more frequently in the carboplatin group than the control group (74.7 percent vs 56.7 percent), driven mainly by haematologic toxicity.
“Despite a higher incidence of grade ≥3 adverse events in the carboplatin group, no clinically meaningful deterioration in quality of life was observed, supporting a favourable risk–benefit profile for carboplatin incorporation into early TNBC treatment,” the investigators said.
Survival benefits
Two phase III adjuvant trials conducted in China (CITRINE and RJBC 1501) independently showed significant OS and disease-free survival benefits following adjuvant carboplatin therapy in patients who underwent primary surgery. [BMJ 2025;391:e085457; J Clin Oncol 2026;44:143-152]
“The convergence of results across three independent phase III trials—initiated at different time points, conducted in different countries, and employing different carboplatin schedules—argues for a generalizable platinum sensitivity in early TNBC rather than a regimen- or schedule-specific effect,” the investigators said.
“Within this evidence base, PEARLY occupies a unique position as the only phase III trial to evaluate carboplatin independently of immunotherapy across both the neoadjuvant and adjuvant settings within a single randomized design,” they added.
Notably, the KEYNOTE-522 study established neoadjuvant chemoimmunotherapy (carboplatin plus pembrolizumab) as a standard of care for patients with high-risk early TNBC. However, it did not confirm whether carboplatin contributed to independent survival benefit without immunotherapy. [N Engl J Med 2020;382:810-821; N Engl J Med 2022;386:556-567; N Engl J Med 2024;391:1981-1991]
“The significant EFS benefit demonstrated in PEARLY directly addresses this gap, confirming that carboplatin confers meaningful survival benefit independent of pembrolizumab,” the investigators said.
The PEARLY trial enrolled patients with stage II or III TNBC, who received either standard therapy with doxorubicin and cyclophosphamide, followed by a taxane (control group) or carboplatin in addition to a taxane following doxorubicin and cyclophosphamide (carboplatin group).
EFS served as the primary endpoint, while secondary endpoints included OS, IDFS, DRFS, pathologic complete response rate, and safety.
“The PEARLY multicentre, randomized, phase III trial investigated the efficacy and safety of adding carboplatin to standard anthracycline-based and taxane chemotherapy for patients with early-stage TNBC in the neoadjuvant or adjuvant settings,” the investigators said.