Two years after going down in flames in a Phase III study for CD22-positive non-Hodgkin's lymphoma, Pfizer ($PFE) has helped resurrect hopes for top drug prospect inotuzumab ozogamicin, saying the drug hit its first primary endpoint for spurring hematologic remission in patients with CD22-positive acute lymphoblastic leukemia.
Investigators in the study are sticking with top-line data only, but Pfizer notes that it compared its armed antibody against standard of care and will now wait and see if overall survival rates hit the second primary endpoint in the pivotal study.
If it does, Pfizer can once again raise hopes that its oncology group can come through with another major drug after winning an early approval for Ibrance (palbociclib). CEO Ian Read once tapped inotuzumab as a top prospect at the pharma giant. Even after the first Phase III failure some analysts continued to rank it high among the list of armed antibodies in the clinic.
The drug has been part of a new wave of antibody-drug conjugates that's following a trail blazed by pioneers like Kadcyla (T-DM1), Roche/Genentech's armed antibody directed against breast cancer. In inotuzumab's case, the antibody is built to target the antigen CD22, which is found on the surface of 90% of all B-cell malignancies. Once it docks on the cancerous cells, it bombs the cancer with the highly toxic calicheamicin.
The drug was initially developed by the U.K.'s Celltech, which was acquired by UCB last year for $2.25 billion.
|Pfizer oncology CMO Mace Rothenberg|
A success here would mark a victory for the company, which has struggled to impress Wall Street with its pipeline. After failing at a much maligned megamerger with AstraZeneca ($AZN), Pfizer has taken out its legendary checkbook to execute a series of licensing and M&A deals. Several months ago it agreed to pay Merck KGaA $850 million up front with $2 billion in milestones to partner on its clinical-stage program for an anti-PD-L1 program, marking the biggest upfront in industry history. The deal also underscored Pfizer's commitment to oncology R&D.
"We are excited about the results of the INO-VATE ALL study especially since relapsed and refractory acute lymphoblastic leukemia is a particularly difficult disease to treat in adults. The top-line results show that inotuzumab ozogamicin has the potential to be an important new treatment option for patients with relapsed or refractory disease," said Dr. Mace Rothenberg, senior vice president of Clinical Development and Medical Affairs and chief medical officer for Pfizer Oncology. "We look forward to discussing these data with the FDA and other regulatory authorities."
- here's the release