Immunomedics spells out PFS benefit of Trodelvy in mTNBC, hunting a full OK just weeks after accelerated approval
By the time the FDA finally granted an accelerated OK for Immunomedics’ Trodelvy, we already got a very strong hint that their confirmatory Phase III study in metastatic triple-negative breast cancer was a success.
That’s because the independent data safety monitoring committee recommended that the trial be stopped early. But just what pointed them to the conclusion was still unclear.
“We do not know the totality of their decision other than it’s pretty evident that the primary endpoint was met; otherwise they could not request to halt the study,” Behzad Aghazadeh, the executive chairman, told Endpoints News at the time.
Three months later, Immunomedics has detailed the results from ASCENT, including progression-free survival and overall survival data that the principal investigator said “set a new benchmark” in mTNBC.
PFS was the primary endpoint, and Trodelvy — an antibody-drug conjugate known as sacituzumab govitecan — kept the cancer at bay (and patients from dying) for a median of 5.6 months, compared to 1.7 months on chemotherapy (p<0.0001). The hazard ratio registered at 0.41.
Shares $IMMU rose 6.67% to $40.04.
Immunomedics stopped short of spelling out the OS win, but noted that and other key secondary endpoints such as objective response rate were met.
“Importantly, the ASCENT topline data also validate the manageable safety profile of sacituzumab govitecan, rendering it a good partner candidate for combination with other therapies, including immunotherapy,” Aditya Bardia, the principal investigator and director of precision medicine at Mass General’s Center for Breast Cancer, said.
Trodelvy was approved, with a black box warning for severe neutropenia and severe diarrhea, as a third-line treatment for mTNBC, a tough-to-treat cancer associated with poor prognosis. The new data are expected to support a full OK.
“It is gratifying to see the final confirmatory results of Trodelvy in a randomized study supporting the previously reported Phase 2 data that formed the basis of the accelerated approval of Trodelvy,” Aghazadeh, who has been running the show since Michael Pehl left the helm early 2019 in the wake of an FDA rejection, said in a statement.
Novartis Oncology vet and Ipsen alum Harout Semerjian came on board briefly as CEO in April, only to depart less than two months later as the pandemic created insurmountable challenges for moving his family from London.
The hiccup hasn’t dented Cowen analyst Phil Nadeau’s high expectations of the therapy, which his consultants said will be rapidly adopted as the standard in relapsed or refractory mTNBC, bringing in $1 billion in worldwide revenue by 2025 (Everest Medicines is handling the development and commercialization in China). According to Nadeau, the numbers hit the “upper end of expectations.”
“Investors anticipated that Trodelvy would produce a median PFS of 5-5.5 months consistent with its Ph. I/II, but our sense is that most anticipated a median PFS for chemotherapy of 2.5-3 months,” he wrote.
And that’s not taking into account its potential in ER+/HER2- metastatic breast cancer or urothelial carcinoma, which now seems even more likely given the positive ASCENT data.
“Investors underestimate the sales potential of Trodelvy,” he wrote in a recent note. “Trodelvy’s data suggest it is a similar improvement over the standard of care in r/r ER+/HER2- mBC as it is in mTNBC, and there are approx. 3-4x as many women with r/r ER+/HER2- mBC. This market is a $3-4B opportunity for Trodelvy, not yet fully reflected in estimates or in IMMU’s valuation, despite potentially pivotal data anticipated around YE.”