UPDATE 4-FDA puts brakes on Roche, ImmunoGen cancer drug

* FDA rejects accelerated approval for T-DM1 application

* Roche says it will broaden late-stage study

* Says will use extended study data to support 2012 filing

* Roche shrs close up 0.5 pct, underperforms sector index

* Co-developer ImmunoGen slides 41 pct to 17-month low (Adds analyst comment on ImmunoGen; updates stock movement)

By Martin de Sa'Pinto and Katie Reid

ZURICH/BANGALORE, Aug 27 (Reuters) - Roche's (ROG.VX) pipeline of cancer drugs faced another setback on Friday after the U.S. Food and Drug Administration rejected the Swiss drugmaker's request to fast-track a licence application for a new treatment.

Roche, once seen as the darling of the pharmaceuticals industry, has seen its crown slip after blows to its development programme this year and investors are now waiting to see whether the FDA will revoke approval for its blockbuster breast cancer drug Avastin. [ID:nLDE66K1H3]

The news also came as a blow to ImmunoGen Inc (IMGN.O), which co-develops the drug with Roche unit Genentech, sending its shares tumbling 41 percent to their lowest since March 2009 and forcing the U.S. biotechnology firm to withdraw its fiscal 2011 outlook. [ID:nWNAB1398]

The drug trastuzumab-DM1 (T-DM1) comprises ImmunoGen's DM1 cancer-cell-killing agent linked to the HER2-targeting antibody trastuzumab, or Herceptin.

The drug's approval may be delayed until the first half of 2013, Oppenheimer & Co analyst Bret Holley said.

"While this delay is a significant setback, we believe that T-DM1's clinical benefit has been well established, and the drug's ultimate potential is unchanged," he said.

The rest of ImmunoGen's pipeline was also under-appreciated, the analyst said.

According to ImmunoGen's website, the company has six other anti-cancer compounds in early to mid-stage development. Friday's delay pertains to the drug's approval as a treatment for third-line metastatic breast cancer.

Roche stock closed up 0.5 percent at 137.80 Swiss francs, trailing a 0.78 percent rise in the European healthcare index .SXDP.

Roche said on Friday the U.S regulator had issued a "Refuse to File" letter for accelerated approval of a Biologics License Application for its trastuzumab-DM1 for people with advanced HER2-positive breast cancer who had previously received other treatments.

Roche submitted the application in July after a mid-stage study showed T-DM1 shrank tumours in one-third of women with advanced breast cancer.

"The impact to (Roche) earnings is marginal," said Vontobel analyst Andrew Weiss. "However, the news is disappointing from a sentiment point of view."

The success of new drugs is key for Roche as competitors work on products to rival some of Roche's best-selling medicines. The group had said the T-DM1 could eventually rake in sales of over 2 billion Swiss francs.

Roche's blockbusters MabThera and Herceptin could become vulnerable to so-called biosimilar drugs as they lose their patent protection in several European countries in 2014 and 2015.

"Roche billed T-DM1's July filing as one of 2010's major milestones, which raises yet more questions on the Roche pipeline," analysts at Collins Stewart said.

"Given T-DM1 is due to replace Herceptin that also adds to the biosimilar risk, as Roche doesn't now expect to file T-DM1 in second line breast cancer until mid-2012, with first line filing not due till 2014," the analysts said, reiterating their "sell" rating on the stock and adding they preferred rival Novartis (NOVN.VX).

Novartis was given a boost on Friday after it got U.S. backing for a new treatment of high blood pressure, broadening the use of Tekturna, the successor to the group's best-selling drug, Diovan. [ID:nLDE67Q05M]

Roche said it would continue with its ongoing late-stage study, and amend it to evaluate overall survival in addition to progression-free survival in patients using the drug.

It said it would use the study data to file a global regulatory submission in mid-2012.

The FDA said the T-DM1 trials had not met the standard for accelerated approval because all available treatments approved for metastatic breast cancer had not been tried in the study population. ($1=1.024 Swiss Franc) (Additional reporting by Esha Dey in Bangalore; Editing by Sharon Lindores, Mark Potter and Vinu Pilakkott)