JNCI: Comparison of three PD-L1 immunohistochemical analysis methods and their correlation with the prognosis of triple-negative breast cancer patients

In the phase 3 IMpassion130 study, atezolizumab combined with nab-paclitaxel (A+nP) was positive for PD-L1 (tumor infiltrating immune cells [IC] ≥ 1%; SP142 immunohistochemistry [IHC]) late/metastatic Clinical benefits have been demonstrated in patients with triple negative breast cancer (TNBC)
.

This study aims to evaluate whether the other two PD-L1 detection methods are consistent with SP142 and the clinical prognosis of patients
.

IHC was used to detect the PD-L1 status (VENTANA SP142, SP263, Dako 22C3) of IC in samples of 614 patients (68.
1% of the patients were the intent-to-treat population) or as a combined positive score (CPS; 22C3)
.

The positive rate of the three detection methods

Using SP142, SP263 and 22C3 experiments, the probability of PD-L1 IC≥1% is 46.
4% (95% CI 42.
5-50.
4%), 74.
9% (71.
5-78.
3%) and 73.
1% (69/6-76.
6%), respectively ; 80.
9% of the samples 22C3 experiment CPS≥1
.

PFS and OS in SP142+ and 22C3+ patients treated with A+nP vs P+nP

PFS and OS in SP142+ and SP263+ patients treated with A+nP vs P+nP

In SP263+ and 22C3+ patients, the clinical activity of A+nP vs.
placebo+nP (PFS hazard ratio [HR] 0.
64-0.
68; overall survival rate [OS]HR: 0.
75-0.
79) was determined by double positive (PFS HR 0.
60–0.
61) ; OS HR = 0.
71-0.
75) rather than a single positive (PFS HR = 0.
68-0.
81; OS HR = 0.
87-0.
95) is driven
.

In conclusion, 22C3 and SP263 tests can identify more PD-L1 positive (IC≥1%) patients than SP142
.

Original source:

Rugo Hope S,Loi Sherene,Adams Sylvia et al.