Pfizer Unveils Oncology Business Unit, Gives Failed Compounds Another Try

CHICAGO - With 22 oncology compounds in clinical studies, firm initiates two Phase III studies since Jan. 1; plans to start another five before year-end.

CHICAGO - With a newly created business unit for oncology, a commitment to "invest to win" and 22 percent of the company's overall R&D budget, Pfizer's oncology business is moving forward swiftly. Some of the progress, however, involves moving a couple of its compounds that have failed Phase III back into Phase II.

During a June 2 analyst briefing at the American Society of Clinical Oncology annual meeting in Chicago, Pfizer confirmed that two of its programs - cytotoxic T-lymphocyte-associated antigen 4 candidate tremelimumab and toll-like receptor 9 compound PF-3,512,676 - are going back to the drawing boards of Phase II to get ready for another go around.

Pfizer discontinued a Phase III trial evaluating the CTLA-4 (cytotoxic T lymphocyte-associated antigen 4) inhibitor as a single agent in patients with advanced melanoma April 1 after an interim review showed it performed no better than standard chemotherapy (¹ (Also see "Weak Result Stops Pfizer’s Tremelimumab Phase III Trial" - Pink Sheet, 2 Apr, 2008.)).

Meanwhile, Bristol-Myers Squibb and partner Medarex gave an ASCO presentation June 1 detailing three trials that showed ipilimumab, their immunotherapy for melanoma, has greater efficacy at higher but also more toxic doses (² (Also see "Bristol/Medarex’s Ipilimumab Toxic, But Could Extend Life" - Pink Sheet, 2 Jun, 2008.)).

Last June, Pfizer halted four mid- to late-stage trials of the TLR9 compound after an interim analysis found no difference in efficacy when testing '676 with chemotherapy against standard chemo (³ (Also see "Pfizer Halts Lung Cancer Trials Of Toll-Like Receptor Agent" - Pink Sheet, 21 Jun, 2007.)).

For tremelimumab, Pfizer is reviewing all available data on the compound - including some from the disappointing Phase III trial that was presented at ASCO. In the second attempt at Phase II, Pfizer's plan is to look for biomarkers and immune response to find the best patient population with which to move forward, Worldwide Development Leader-Oncology Charles Baum said.

Pfizer intends to try the drug in combination with its cancer vaccines, since it should improve immune response. "We have to figure out how," Baum added.

When asked whether the difficulty in Phase III was due to the dose schedule used in that study, Baum noted that Pfizer had the best tolerated dose with a response. The firm's hypothesis is not that the problems were due to dose selection, but were a matter of needing to select a better patient population.

Tremilimumab and the TLR9 agent are both part of Pfizer's immunotherapy platform, which has been augmented significantly by its deals with Coley Pharmaceuticals and Avant Immunotherapeutics. Pfizer's current oncology strategy includes three other platforms: anti-angiogenesis, signal transduction inhibitors, and cytotoxics/potentiators.

All told, the firm has 22 oncology compounds in clinical studies. So far this year, Pfizer has initiated two Phase III studies, and plans to start another five before year-end.

Those trials include Sutent (sunitinib) in first-line hepatocellular cancer and second-line metastatic hormone refractory prostate cancer; axitinib in second-line metastatic renal cell carcinoma and first-line non-small cell lung cancer; and CP-751,871 in NSCLC in combination with gemcitabine and cisplatin.

Pfizer's new oncology business unit began operations in March, although its leader - Senior VP/General Manager Garry Nicholson - was just appointed last week. Reporting to Nicholson are Worldwide Commercial Leader Alison Ayers, WW Development Leader Baum, WW Medical Leader Craig Eagle, and U.S. General Manager Pat Andrews. Pfizer regional commercial operations are under Ayers and regional medical operations fall in Eagle's group.

Ayers explained the philosophy behind the reorganization to the assembled analysts: the goal is an integrated team with the ability to implement plans and manage resources. She assured them that the necessary resources will be there, as Pfizer has designated oncology an "invest to win" therapeutic area.

- Mary Jo Laffler ([email protected])