Pfizer halts patient enrollments in a lung-cancer drug trial
Independent safety monitors overseeing the study recommended that Pfizer suspend enrollments after finding more serious adverse events, "including fatalities, in patients who were randomized to receive figitumumab," than with patients not receiving the drug. Pfizer says 681 patients were enrolled in trial (of the 820 it planned) as of of Sept. 30, and those patients may continue their treatment in consultation with their physicians.
As in many cancer studies, researchers tried to combine drugs, looking for an improvement in their effect. The study, known as Advigo 1016, compares patients with non-small cell lung cancer who take figitumumab along with two older drugs, paclitaxel and carboplatin, against patients who take only the older drugs. The goal is to assess the safety and efficacy of figitumumab as a potential initial treatment (for more on how drug trials work and the issues involved in volunteering to participate in one, see the accompanying story).
Figitumumab (CP-751,871) is a class known as an IGF-1R inhibitor, which is intended to block a hormone called insulin-like growth factor (which contributes to the making of insulin and also promotes cell growth) following research suggesting that insulin-like growth factor can stimulate cancer cells (which could potentially affect insulin makers). But just as giving insulin to diabetics can help control blood sugar, blocking the effects of insulin and insulin-like substances could lead to excess blood sugar, although it's not clear if this was the cause of the problems.
Pfizer said it notified the Advigo 1016 clinical trial investigators and regulatory agencies, and will work closely with the safety-monitoring committee on analyzing the data before issuing further guidance.
Another Phase III lung-cancer study evaluating figitumumab in combination with Roche's (RHHBY) and OSI Pharmaceuticals' (OSIP) Tarceva is continuing to enroll new patients, Pfizer said.
Earlier this year, Pfizer, which also makes blockbuster cholesterol drug Lipitor and erectile-dysfunction drug Viagra, seemed very upbeat abut figitumumab when it presented the earlier data. It counted on the experimental drug, which analysts estimated could reach $400 million to $1.2 billion in sales by 2015, to replace some of the lost revenue of its top sellers that face patent expirations.
Not only that, Pfizer said earlier it set a goal to boost its global cancer drug sales 10-fold by 2018. Of the 100 medicines Pfizer is testing in human trials, about a quarter are for cancer. Pfizer is also in the process of acquiring Wyeth (WYE) to beef up its research pipeline. But figitumumab isn't the only setback Pfizer has suffered this year. Other Phase III clinical trials that were discontinued included those for testing Sutent against colorectal cancer and breast cancer, for testing axitinib against advanced pancreatic cancer, despite promising Phase II results. It turned out none of these trials reached their efficacy goals.
All these setbacks could make Pfizer's target for cancer-drug sales a long shot.