Celcuity’s gedatolisib doubled progression-free survival versus standard of care in certain patients with advanced breast cancer. Still, the biotech’s stock dropped more than 25% Tuesday.
Celcuity’s breast cancer candidate halved the risk of death or disease progression in a Phase 3 study, setting the drug up to become what analysts called a “practice-changing” treatment in the field.
Despite the positive readout, the Minneapolis biotech slid more than 25% to $91.42 per share at the end of Tuesday’s trading session.
In the Phase 3 VIKTORIA-1 study, Celcuity enrolled more than 700 patients with HR-positive, HER2-negative advanced or metastatic breast cancer with PIK3CA mutations. Results disclosed Tuesday showed that Celcuity’s drug gedatolisib, when used alongside AstraZeneca’s Faslodex and Pfizer’s Ibrance, resulted in a 50% progression-free survival (PFS) benefit as compared with Faslodex plus Novartis’ Piqray, a current standard-of-care (SOC) schedule in the space.
Meanwhile, an investigational doublet consisting of gedatolisib and Faslodex had similar outcomes, cutting the risk of disease progression or death by 49% versus Piqray plus Faslodex.
This degree of PFS improvement “is practice-changing in our view,” Jefferies told investors in a note on Tuesday. “The geda triplet arm doubled PFS” versus Piqray controls, the analysts continued, “a meaningful improvement vs SOC that could drive near-term rapid uptake.”
The firm also addressed the selloff, attributing Celcuity’s stock weakness to “higher Street expectations on absolute PFS numbers.” Celcuity on Tuesday reported median PFS of 11.1 months the triplet group, versus 5.6 months in controls.
Jefferies also noted that another reason for the share slump is that there was “seemingly no PFS benefit” to the gedatolisib triplet over the doublet regimen—the two groups showed very similar PFS outcomes—“making real-world commercial use a little less clear-cut.”
On this point, however, the analysts argued that the three-drug combo elicited a higher objective response rate and earlier separation on overall survival, “which may support triplet use in 2L for fitter pts or more broadly.” Overall survival data were immature by the time of Celcuity’s readout.
Jefferies remains bullish on gedatolisib overall, contending that the drug “can dominate” in breast cancer, with a “major place” in second-line care and even potentially in the frontline setting.
Gedatolisib is already under FDA review for HR-positive, HER2-negative patients with advanced breast cancer who don’t have PIK3CA mutations, with a decision expected on July 17. Celcuity intends to file VIKTORIA-1 data as a supplement to this application, the company said Tuesday, though it didn’t specify a timeline for this submission.
