Gilead Sciences said Monday morning that Trodelvy is the first TROP-2-targeted ADC to show statistically significant and “clinically meaningful” results in overall survival from a second interim analysis of a Phase 3 trial in patients with HR+/HER2-metastatic breast cancer those prior endocrine therapy, CDK4/6 inhibitors and two to four lines of chemo.
The announcement surprised Wall St analysts after Gilead unveiling less than stellar OS results after the first interim analysis at ASCO in June. But now Gilead said it has filed an sBLA with the FDA for this new breast cancer indication, but it also said it won’t present actual OS data from the second interim analysis until an unidentified upcoming medical conference.
“These survival results from the TROPiCS-02 trial are important to the breast cancer community and we are encouraged by the potential it may have to help patients who otherwise have limited alternatives,” said Merdad Parsey, CMO of Gilead, in a statement. “We look forward to discussing these results with global health authorities, as patients with pre-treated HR+/HER2-metastatic disease currently have limited treatment options and poor quality of life.”
Hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer is the most common form of breast cancer, accounting for approximately 70% of all new cases, or nearly 400,000 diagnoses worldwide each year. But nearly 1 in 3 early-stage breast cancers are metastatic, and in patients with HR+/HER2-metastatic disease, the relative five-year survival rate is 30%, according to Gilead.
SVB Securities analysts added, “We expect the FDA to approve Trodelvy for HR+/HER2-mBC, but we need OS data to assess its competitive profile against AZNs (OP, Berens) Enhertu.”
RBC Capital Markets said in an investor note that most investors had written off results for Trodelvy in this indication after March PFS data was “positive but of uncertain clinical significance,” adding today:
This morning’s announcement that TROPiCS-02 demonstrated statistically significant and reportedly clinically meaningful OS benefits in a second interim analysis GILD took of its investigation of the oncology drug Trodelvy in a key indication for metastatic breast cancer is a surprising victory for the company, as we believe the market had largely written off the drug for this indication.
OS at the first interim analysis was 13.9 months for Trodelvy, compared to 12.3 months for chemo, RBC analysts also noted, adding that the difference was “probably below the bar for clinical significance at the time.”
Trodelvy’s 2021 sales totaled $380 million for Gilead, as the company said it continued approved treatment in the US and Europe for second-line metastatic triple-negative breast cancer, as well as second-line metastatic urothelial cancer in the US.
Since then, sales have jumped into 2022, which is welcome news for the company after Gilead took a $2.7 billion write-off for Trodelvy last quarter after another vague pivotal readout.
The drug company received harsh reviews from analysts in March when it revealed that Trodelvy had met its primary endpoint of progression-free survival in late-line metastatic HR+/HER2 breast cancer, but did not share the hard data.