UBS analysts reiterated a Buy rating on Pfizer Inc. (NYSE:PFE) with a price target of $38 a piece after Novartis AG released successful Phase 3 trial data of rival breast cancer treatment ribociclib. The analysts contend ribociclib does not seem to have any clinical advantage over Pfizer’s Ibrance.
Novarti had already top-lined that the Phase 3 study called Monaleesa-2, which combined its CDK4/6 inhibitor ribociclib with an older cancer drug letrozole, met the primary endpoint of clinically meaningful improvement in progression-free survival (PFS) in 1L HR+/HER2- advanced breast cancer. The study was stopped early in May as a consequence. This weekend, the Swiss drugmaker presented the first raw data release from the trial at a medical meeting.
While the median PFS for patient arm treated with ribociclib + letrozole has not been reached, but the hazard ratio (HR) of 0.556 demonstrated a statistically significant 44% reduction in the risk of disease progression-free death. Pfizer’s rival drug Ibrance, the first CDK4/6 drug to win approval recently, had delivered similar data in a comparable Phase 3 Paloma-2 study. Ibrance, tested in combination with letrozole, showed a statistically significant HR of 0.58. The patient arm treated with letrozole alone in both studies reported comparable mPFS data, suggesting that the patient populations in both arms are likely similar as well.
“The key differences in the overall patient population include the proportion of patients with disease-free interval ≤12 most (22% PALOMA-2 vs. 2% MONALEESA-2) and visceral metastasis (49% PALOMA-2 vs. 59% MONALEESA-2), but these differences don't appear to meaningfully differentiate the results,” UBS report read. The analysts note that safety profiles of Ibrance and Novartis’ ribociclib also look similar, with both drugs even demonstrating Grade 3-4 neutropenia and leukopenia.
Based on these results, UBS analysts continue to believe that Pfizer’s Ibrance could capture/ maintain 70% of the CDK4/6 opportunity in the $8 billion HER2-/HR+ metastatic breast cancer market, given Ibrance’s significant first mover advantage. According to Bloomberg’s compiled estimates, the drug is expected to pull in sales of $2.16 billion this year, while JP Morgan sees a peak sales potential of more than $5 billion from the drug.