It's been a bad month for Pfizer's

research labs but its head of R&D says the world's biggest drugmaker is on track to hit earlier targets for new drug filings despite the setbacks.

We have had some disappointments, there is no getting away from it, Martin Mackay told Reuters during a visit to Britain.

Dimebon's lack of efficacy in Alzheimer's disease was extremely disappointing, although Mackay said it was a wee bit early to say the drug, which Pfizer has developed with Medivation , was now dead.

Pfizer has also seen failures this month with Sutent in breast cancer and figitumumab in lung cancer.

Some analysts have worried that these problems mean the company will no longer meet its goal of filing 15 to 20 new drugs or new indications for regulatory approval between 2010 and 2012 -- a target that was set in March 2008.

Mackay denied this was the case.

When we had the three failures I went straight to the data and looked at it again to make sure that we could still be on target. And clearly the 15 to 20 was already attrition-adjusted, so we are still within that range, he said.

While the goal was set before Pfizer bought Wyeth last year, Mackay stressed it still referred only to legacy Pfizer products and any filing contributions from Wyeth would be in addition to this total.

$9 BILLION R&D BUDGET

Like many major drugmakers, Pfizer has struggled in recent years to get a decent return out of its vast R&D machine, which currently spends more than $9 billion a year in the hunt for new medicines.

Yet, despite disappointing productivity, Mackay said the science had never been better and he remains confident that Pfizer will have plenty more big drugs coming down the pipeline, even though cutbacks in the research budget are planned in the wake of the Wyeth merger.

It (R&D spending) will drop somewhat over the next two years in line with the commitments we've made to savings, he said. But if we can't come up with great medicines with a budget of $8 billion or $9 billion, shame on us.

Pain drug tanezumab, heart medicine apixaban -- which Pfizer is developing with Bristol-Myers Squibb -- and a JAK3 inhibitor for arthritis all have potential to be significant blockbusters, he added.

In-house research at facilities around the world, including one at Sandwich in the south of England, will remain core to Pfizer's search for new medicines but Mackay said the group would also explore more alliances with rivals.

For sure, you'll see us doing in-licensing, you'll see us doing more academic collaborations and biotech collaborations -- and I think you'll also see more of us working with folks like Glaxo and Bristol-Myers around more creative partnerships, he said.

GlaxoSmithKline and Pfizer struck an unusual alliance last year to create a joint venture in HIV medicine, called ViiV.

(Additional reporting by Kate Kelland; Editing by David Cowell)

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