UPDATE 3-Cancer drug Erbitux seen limited threat to Avastin

(Adds ImClone, Genentech, Bristol-Myers shares; more reaction from analysts and doctor)

By Ben Hirschler

LONDON, June 2 (Reuters) - Roche Holding AG (ROG.VX) and Genentech Inc DNA.N shares jumped on Monday as investors decided new clinical data meant rival drug Erbitux posed no immediate threat to their cancer blockbuster Avastin.

The weekend news from the world's top cancer meeting, suggesting earlier fears were overdone, hit the stocks of Erbitux developer ImClone Systems Inc IMCL.O and its partners Merck KGaA (MRCG.DE) and Bristol-Myers Squibb Co (BMY.N).

Although Erbitux showed some encouraging results, presentations at the American Society of Clinical Oncology (ASCO) annual meeting in Chicago did not amount to a knockout blow for the rival treatment, industry analysts said.

Andrew Baum and Steven Harr of Morgan Stanley wrote in a note that Avastin had emerged "a relative winner".

Deutsche Bank said the perception of Avastin's competitive profile had been strengthened by the ASCO updates and the brokerage reiterated its forecast that Avastin sales would reach 10.2 billion Swiss francs ($9.8 billion) by 2012.

Roche participation certificates, its most widely traded form of equity, gained 4.7 percent to 188.10 Swiss francs by 1515 GMT, as Merck slid 3.3 percent to 87.39 euros.

In New York trading, Genentech added 3.2 percent to $73.13, as ImClone fell 5.9 percent to $41 and Bristol-Myers lost 3 percent to $22.11.

New findings that colon cancer patients with a certain genetic mutation were unlikely to benefit from Erbitux added to concerns about its commercial prospects.

Both UBS and Goldman Sachs said Erbitux had not produced clinical data to threaten Avastin's outlook, while JP Morgan -- initiating Roche coverage with an "overweight" rating -- said the risk to Avastin from Erbitux in the key areas of colorectal and lung cancer was limited.

LUNG CANCER

Avastin is approved for treating colorectal, lung and breast cancer, while Erbitux is currently approved for colorectal and head and neck cancer.

Most attention at ASCO was focused on a new study of Erbitux in lung cancer, which found patients taking it with chemotherapy lived about five weeks longer than patients treated with chemotherapy alone [ID:nN31394375].

Credit Suisse described this 1.2-month survival increase as "unremarkable", while analysts at Equinet said they had been hoping for a benefit of more than two months.