The treatment of human epidermal growth factor receptor 2-negative (HER2-) breast cancer, which encompasses the hormone receptor-positive (HR+) and triple-negative breast cancer (TNBC) subtypes, has evolved rapidly in recent years.

From 2015–2019, the introduction of CDK4/6 inhibitors, PARP inhibitors, a checkpoint inhibitor and a PI3K inhibitor has significantly changed the treatment landscape. This period has ushered in an era of personalised therapy for breast cancer patients, offering rationally designed therapeutic options for specific patient sub-populations based on well-characterised molecular targets.

In 2019, the FDA and the European Medicines Agency (EMA) approved first-in-class Genentech’s Tecentriq (atezolizumab) in combination with Celgene’s Abraxane (nab-paclitaxel) in first-line TNBC. In 2020, this space will likely see greater uptake of Tecentriq as national regulatory agencies make decisions on its launch in individual European countries.

The pivotal Phase III KEYNOTE-355 trial investigating a competitor product, Merck’s Keytruda (pembrolizumab), in combination with chemotherapy of physician’s choice, is expected to lead to an approval in Q1 2020. This trial is seen as the closest parallel to the Impassion130 trial, in terms of its combinatorial regimen and line of therapy, which led to Tecentriq’s approval in March 2019.

Physicians are expecting the KEYNOTE-355 trial to demonstrate a clinically meaningful benefit, leading to the approval of Keytruda and providing competition for Tecentriq in 2020. Further interesting Phase III trial results to watch for in 2020 include those from the Impassion131, which is investigating Tecentriq in combination with generic paclitaxel.

Due to the high price tag associated with the Tecentriq + Abraxane combination, positive data from Impassion 131 could lead to greater market penetration for Tecentriq in cost-conscious European and Asian markets in 2020. Together, the trials will help clarify the role of checkpoint inhibitors in the treatment of breast cancer and the optimal combinatorial regimen, as well as consolidate the use of this class of agents in the first-line TNBC metastatic setting.

Other positive developments in breast cancer include the expected FDA approval of Immunomedics’ sacituzumab govitecan in Q1 2020 for the treatment of metastatic TNBC in later lines of therapy. In January 2019, sacituzumab govitecan was rejected due to issues related to ‘chemistry, manufacturing and control matters’.

In addition, Immunomedics resubmitted a new biologics license agreement, which was accepted by the FDA in December. GlobalData has noted enthusiasm from key opinion leaders concerning the drug that is expected to provide a welcome addition to the increasingly personalised arsenal of targeted therapies to tackle the historically difficult to treat cancer. Together, the changes are expected to lead to a positive year in the development of novel therapies for breast cancer treatment.