Pfizer Beams As Cancer Drug Efficacy Stops Trial Early and Analysts Predict Game Changer

Published: Apr 17, 2015

Pfizer Beams As Cancer Drug Efficacy Stops Trial Early and Analysts Predict Game Changer
April 15, 2015
By Riley McDermid, BioSpace.com Breaking News Sr. Editor

Pfizer Inc. is enjoying a nice boost Wednesday after announcing that it has stopped its Phase III PALOMA-3 trial for breast cancer drug Ibrance (palbociclib) because it was so overwhelmingly effective. Shares of Pfizer were up slightly on the news to $35.34 in mid-morning trading Wednesday.

Pfizer said it made the decision after assessing data that showed significant efficacy based on an assessment by an independent Data Monitoring Committee (DMC).

“The results of this trial are especially important because they help us understand the potential of Ibrance to improve outcomes in patients with this difficult to treat cancer,” said Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs and chief medical officer for Pfizer Oncology. “We’re gratified to be able to stop the trial early and are engaging in discussions with health authorities regarding a regulatory path forward.”

Palbociclib has already been given the brand name Ibrance and has been warmly received by analysts who follow biotech. Annual sales of the drug have been forecast at $3 billion but some analysts have estimated it could bring in as much as $5 billion annually. It is part of a class of drugs called CDK4/6 inhibitors, which block two enzymes, CDK4 and 6, which typically make cancer cells divide and reproduce rapidly.

Wall Street analysts greeted the news warmly Wednesday, saying the announcement held few surprises for close watchers of the drug, with competitors even more anxious now.

“Recall, Ibrance received accelerated approval in early February for first line therapy in combination with Novartis AG ' Femara in a similar patient population based on a meaningful (~10 months) PFS improvement versus Femara alone in the open label Phase II PALOMA-1 trial,” wrote Mark Schoenebaum, a biotech analyst at ISI Evercore, in a not to investors.

“Therefore, we don't expect the results of PALOMA-3 to add a lot to Ibrance peak sales by itself --we believe most patients will elect to instead take Ibrance first line rather than second line--but this trial should in the short term only add to what already appears a strong early launch by adding second line patients (and facilitating payers' reimbursement of second line patients).”

Schoenebaum added that ISI Evercore believes this trial only adds to the probability of success for the Phase III PALOMA-2 trial confirming the benefit of Ibrance plus Femara in first line patients and “supporting full approval (primary endpoint of trial is PFS and we understand OS benefit not required for full approval).”

The news came as a stamp of validation to analysts that had predicted in January that Ibrance would likely see early approval. Pfizer Inc (PFE) said Jan. 9 that Ibrance had begun its label review by the U.S. Food and Drug Administration (FDA), a sign Wall Street took to mean that the drug will soon be approved for consumers.

Indeed, the FDA talks have appeared to leapfrog the standard advisory committee meeting typically held in this portion of a drug’s regulatory approval process.

In its most recent trial prior to today’s, the drug almost doubled the time it took for breast cancer to progress or get worse, though Pfizer has not yet produced data to show its effects on rates of survival. Dubbed PALOMA 1, the mid-stage study enrolled 165 women who received Ibrance either alone or with a supplementary drug, letrozole. The cancer for the women taking Ibrance did not worsen for 20.2 months on average, which is twice as long as for women only receiving letrozole.

“The statement from Pfizer this morning that there is no FDA Adcom (advisory committee) planned for palbo reaffirms our high confidence for a first pass approval in April," wrote Jeffrey Holford, an analyst for boutique bank Jefferies, in a note to investors.

The drug has long been considered one of the Pfizer’s most promising experimental therapies, with the value it could add to the company’s cancer drug pipeline a considerable factor when analysts have calculated future earnings for the drugmaking giant.

"We think consensus continues to underestimate this opportunity," said Holford. In a note to investors late Thursday, Credit Suisse analyst Vamil Divan said he’s "somewhat surprised" by the news but not surprised that the agency is working hard to make the drug available.

"We have consistently believed this is a product that the FDA sees value in and is committed to getting to the market as quickly as possible," said Divan.



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