SITC Releases Immunotherapy Clinical Practice Guideline for Breast Cancer

In the wake of immunotherapy combinations becoming available in breast cancer, including triple-negative breast cancer (TNBC), the Society for Immunotherapy of Cancer (SITC) has published clinical practice guidelines for physicians treating in this setting.¹

“Immunotherapy is now offering some patients with breast cancer clinically meaningful benefit in early stage and advanced disease,” Jennifer Litton, MD, chair of the SITC Breast Cancer Immunotherapy Guideline Expert Panel, said in a statement.² “It is important for clinicians and patients to understand that immunotherapy is very different from traditional breast cancer treatments, and this new guideline offers the expert guidance needed to safely consider these treatments.”

Trials investigating the use of immune checkpoint inhibitor (ICI) and chemotherapy combinations in advanced or metastatic TNBC have shown progression-free and overall survival for subsets of patients. Because of this clinical benefit, ICI combined with chemotherapy has been approved by the FDA for use in TNBC. These therapies include atezolizumab (Tecentriq) and pembrolizumab (Keytruda).

However, the optimal strategy for using immunotherapy in patients earlier in their disease, which chemotherapy backbone to use for the combination, appropriate selection of patients through biomarkers, and potential use in histological subtypes other than TNBC are all questions that remain. SITC convened a multidisciplinary panel of experts to guide the oncology community on these questions, among others, using published literature and clinical experience.

The clinical practice guideline contains evidence-based and consensus-based recommendations for healthcare professionals regarding different aspects of treatment with immunotherapy for patients with breast cancer. This includes immune-related adverse events, patients’ quality of life considerations, diagnostic testing, and treatment planning.

“Breast cancer has historically been a disease for which immunotherapy was largely unavailable,” SITC president Patrick Hwu, MD, said in a press release. “The new clinical practice guideline is the first to be published by SITC on breast cancer and is the twelfth manuscript published in SITC’s Cancer Immunotherapy Guidelines series.”

“This guideline serves as vital resource for oncologists managing the various unexpected adverse events that may arise with treatment. This is a pivotal step forward for SITC as the world leader in advancing the science and application of cancer immunotherapy and demonstrates a continued commitment to ensuring that breast cancer patients have the most optimal outcomes while receiving FDA-approved immunotherapies,” Hwu concluded.

The clinical practice guidelines first cover PD-L1 inhibitors in advanced or metastatic breast cancer. They subsequently discuss emerging data in the early-stage or locally advanced setting with PD-L1 inhibitors, diagnostics and biomarkers, evaluation and management of treatment response, toxicity considerations, patient education, and novel combination strategies and future directions, all with panel recommendations at the end of each section.

These new guidelines, published in the Journal for Immunotherapy of Cancer, were modeled after the Institute of Medicine’s (IOM) Standard for Developing Trustworthy Clinical Practice Guidelines. As such, the guidelines were developed by a multidisciplinary expert panel, with funding sources and conflicts of interest readily reported.

“It’s an exciting time for immunotherapy in breast cancer,” Leisha Emens, MD, PhD, chair of the SITC Breast Cancer Immunotherapy Guideline Expert Panel, said in a statement. “This new guideline will help clinicians navigate the nuances of a dynamic and rapidly evolving field to offer their patients the benefits immunotherapy may provide.”

_References:

_{1. Emens LA, Adams S, Cimino-Mathews A, et al. Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of breast cancer. J Immunother Cancer. 2021;9:e002597. doi:10.1136/jitc-2021-002597}

_{2. Society for Immunotherapy of Cancer published clinical practice guideline on immunotherapy for the treatment of breast cancer. New release. The Society for Immunotherapy of Cancer. Published August 18, 2021. Accessed August 23, 2021.https://prn.to/3sDuI4Q}