Amgen disappointed investors, sending shares down 4.7 percent on Thursday, by failing to reveal detailed clinical data related to its colon cancer drug panitumumab as it reported its fourth-quarter earnings that fell just shy of expectations.

disappointed investors, sending shares down 4.7 percent on Thursday, by failing to reveal detailed clinical data related to its colon cancer drug panitumumab as it reported its fourth-quarter earnings that fell just shy of expectations.

“The only thing surprising about this is that the company ever promised investors it would do so,” wrote SG Cowen analyst Eric Schmidt. “We believe Amgen will benefit commercially by not tipping its hand to the competition and keeping the PACCE data under wraps until just prior to panitumumab’s launch.”

Panitumumab is the first of a class of drugs called monoclonal antibodies that is aimed at a receptor in the body called epidermal growth factor receptor. The drug is thought a likely competitor to ImClone’s drug Erbitux, which treats colon cancer by interfering with the same receptor (see Street Unsure of ImClone Sale and Amgen: $1B to Expand Capacity).

Amgen: $1B to Expand Capacity

Amgen also released its fourth-quarter earnings, narrowly missing analysts’ expectations.

Excluding special items largely related to its Immunex acquisition, fourth-quarter profits rose 24 percent to $928 million, or $0.75 per share, from $749 million, or $0.58 per share in the year-ago quarter. The results fell a penny short of the consensus expectation of $0.76 per share, according to Thomson Financial’s survey of 37 analysts.

Immunex

Revenue rose 12 percent to $3.27 billion from $2.91 billion.

Shares closed down $3.57 at $71.90.

CEO Kevin Sharer noted the company cleared four major regulatory milestones during 2005 and added six new molecules to Amgen’s pipeline of new products.

‘Positive’ Results

“During the fourth quarter, we received positive data from a pivotal trial with panitumumab, which could potentially advance the treatment of colorectal cancer,” added Mr. Sharer, repeating an earlier claim. “This contributed to our strategic decision to acquire Abgenix.” (See Amgen Buys Abgenix for $2.2B).

Amgen Buys Abgenix for $2.2B

The company also said that it expects to increase its research and development spending by 30 to 40 percent during 2006 because of a significant increase in the number of late-stage clinical trials.

Currently Amgen has late stage trials of denosumab in osteoporosis and metastatic bone disease; aranesp in patients with chronic kidney disease and heart failure; as well as cancer trials of panitumumab.