The Degree of Programmed Death-Ligand 1 (PD-L1) Positivity as a Determinant of Outcomes in Metastatic Triple-Negative Breast Cancer Treated With First-Line Immune Checkpoint Inhibitors

Lorenzo Di Spazio; Melania Rivano; Luca Cancanelli; Marco Chiumente; Daniele Mengato; Andrea Messori

doi:10.7759/cureus.21065

The Degree of Programmed Death-Ligand 1 (PD-L1) Positivity as a Determinant of Outcomes in Metastatic Triple-Negative Breast Cancer Treated With First-Line Immune Checkpoint Inhibitors

Cureus. 2022 Jan 9;14(1):e21065. doi: 10.7759/cureus.21065. eCollection 2022 Jan.

Authors

Lorenzo Di Spazio¹, Melania Rivano², Luca Cancanelli³, Marco Chiumente⁴, Daniele Mengato⁵, Andrea Messori⁶

Affiliations

¹ Hospital Pharmacy, S.Chiara Hospital, Trento, ITA.
² Clinical Oncology Pharmacy, A. Businco Hospital, Cagliari, ITA.
³ Hospital Pharmacy, Azienda Ulss 2 Marca Trevigiana, Treviso, ITA.
⁴ Scientific Direction, Italian Society for Clinical Pharmacy and Therapeutics, Milano, ITA.
⁵ Hospital Pharmacy, Azienda Ospedale Università di Padova, Padova, ITA.
⁶ Health Technology Assessment (HTA) Unit, Regione Toscana, Firenze, ITA.

Abstract

In metastatic triple-negative breast cancer (TNBC), the efficacy of immune checkpoint inhibitors (ICIs) in combination with chemotherapy has been demonstrated in randomized clinical trials (RCTs). Despite this, an indirect comparison is not yet available. Reconstruction of individual patient data from Kaplan-Meier curves allows the indirect comparison of different treatments. We analyzed six overall survival (OS) curves from three RCTs. In patients with ≥1% positivity, atezolizumab was found to determine a significantly better OS than pembrolizumab. As regards pembrolizumab, adopting a threshold of PD-L1 positivity ≥10% (as opposed to ≥1%) improved median survival to a remarkable extent (23.0 vs 15.5 months).

Keywords: metastatic triple-negative breast cancer; overall survival; pd-1 inhibitors; pd-l1 inhibitors; restricted mean survival time.

Publication types

Review