Trodelvy notches a win in most common form of breast cancer
Following a promise last year to go “big and fast in breast cancer,” Gilead has secured a win for Trodelvy in the most common form.
The drug was approved to treat HR-positive, HER2-negative breast cancer patients who’ve already received endocrine-based therapy and at least two other systemic therapies for metastatic cancer, Gilead announced on Friday.
Trodelvy won its first indication in metastatic triple-negative breast cancer back in 2020, and has since added urothelial cancer to the list. HR-positive HER2-negative breast cancer accounts for roughly 70% of new breast cancer cases worldwide per year, according to senior VP of oncology clinical development Bill Grossman, and many patients develop resistance to endocrine-based therapies or worsen on chemotherapy.
“As patients progress on endocrine therapies and they get into other combinations like CDK4/6, [they are] really left only with chemotherapy at this stage,” Grossman said. “For the patients from TROPiCS-02, median survival is only approximately one year.”
Gilead touted a better-than-expected readout from the TROPiCS-02 study at last year’s ESMO conference, in which patients with HR+/HER2- metastatic breast cancer who received Trodelvy after prior endocrine therapy, CDK4/6 inhibitors and two to four lines of chemotherapy survived a median of 14.4 months, compared to just 11.2 months for those who received chemo. Trodelvy also posted a 34% reduction in the risk of disease progression or death (p=0.0003), Gilead said Friday.
Trodelvy sales were up 79% last year, totaling $680 million and “reflecting continued adoption in metastatic TNBC in the United States and Europe,” Gilead announced yesterday in its Q4 earnings report. On the Q3 call, execs said they had already begun preparing for a potential launch in HR-positive HER2-negative breast cancer. The drug earned just $380 million in 2021.
While Trodelvy was slapped with a boxed warning back in 2020 for severe neutropenia and severe diarrhea, Grossman said last week that “those are side effects that I think most physicians are very, very accustomed to.” Neutropenia occurs when patients have too few of a type of white blood cell called neutrophils.
“Physicians are pretty well-versed in trying to recognize those side effects early and quick interventions,” he said.
Last year, AstraZeneca and Daiichi Sankyo’s ADC therapy Enhertu became the first therapy approved for a newly defined subset of breast cancer patients called HER2-low. About 60% of HER2-negative patients fall into the HER2-low bucket, meaning they have some HER2 proteins, but not enough to be classified as HER2-positive.
Gilead also posted HER2-low and IHC0 data from the TROPiCS-02 trial at ESMO, with progression-free survival coming in at 6.4 months in the treatment arm for HER2-low patients, and five months for IHC0 patients, the company announced at the time.
“In a post-hoc analysis, data demonstrated Trodelvy’s efficacy across HER2-low and IHC0 status in pre-treated metastatic breast cancer patients in the TROPiCS-02 trial,” Gilead said in a news release on Friday.
Grossman called the drug a “cornerstone, bedrock to our pipeline” at ESMO, while promising to move into earlier lines of therapy and across “a wide number of different tumor types.” He reiterated those plans in an interview ahead of the recent decision.
“We’re going fast and furious” in adding new products to the portfolio, he said. “And Trodelvy is one of those.”