USA- Gilead Sciences has tagged Merck in a study where Trodelvy (sacituzumab govitecan), a Trop-2 targeting antibody-drug conjugate will be paired with Merck’s Keytruda (pembrolizumab) in a new phase 3 trial in previously untreated subjects with locally advanced or metastatic Triple Negative Breast Cancer (TNBC).
According to Gilead, Trodelvy has already established itself as a go-to therapy for TNBC patients whose disease has progressed after prior treatments, whereas Keytruda is approved as a first-line therapy for the cancer in patients with PD-L1 scores of 10 or higher, in combination with chemotherapy.
Gilead Sciences chief medical officer Merdad Parsey said: “Trodelvy has already been established as a preferred treatment option in second-line metastatic TNBC.”
“Looking ahead, we are excited about the opportunity to advance Trodelvy as a potential treatment for first-line metastatic TNBC. This helps further our ambition of displacing chemotherapy with Trodelvy to improve outcomes for people living with cancer.”
Merck is an obvious partner for that ambition, as Keytruda is the dominant checkpoint inhibitor for TNBC, having recently received FDA approval for pre-surgery alongside chemotherapy in the neoadjuvant setting, as well as post-surgery (adjuvant) as a monotherapy, to prevent tumor recurrence.
The combination treatment will be evaluated as first-line therapy for patients with locally advanced or metastatic TNBC.
Competitor drug Tecentriq (atezolizumab) had its accelerated approval in first-line TNBC withdrawn by developer Roche in the US after failing a confirmatory trial, but is currently in late-stage testing as a treatment for early-stage TNBC.
With the lowest survival rate of any type of breast cancer, metastatic TNBC has an urgent need for novel treatments that can improve patient outcomes.
Trodelvy combined with an immune-stimulating drug like Keytruda could offer a new treatment for first-line metastatic TNBC, according to Gilead.
Trodelvy is an antibody-topoisomerase inhibitor conjugate that acts directly on the Trop-2 receptor, whereas Keytruda is an anti-programmed cell death protein 1 (PD1) therapy. Trodelvy is also approved in the United States to treat metastatic urothelial cancer.
Trop-2 is a protein that is overexpressed in a variety of epithelial tumors. Trodelvy acts on Trop-2-expressing cells to facilitate the local delivery of a cytotoxic payload that destroys the targeted cells.
Gilead will fund an international Phase III trial of the combination therapy, according to the agreement. In first-line subjects with locally advanced or metastatic TNBC, Trodelvy plus Keytruda will be compared to the standard of care, which includes Keytruda plus chemotherapy.
Trodelvy is a critical new product for Gilead as it faces pressure on its HIV franchise, which has been hit by lower diagnoses and new therapy starts as a result of the COVID-19 pandemic, with revenue falling 8% to US$4.2 billion.
Trodelvy plus Keytruda is not currently approved by any regulatory authorities in any therapy setting, and the combination’s safety and efficacy are still being studied.