A regulatory warning led to Big Pharma blues and a bit of red on Tuesday while a settlement and drug approval shifted other biotech names.

GlaxoSmithKline

(GSK) - Get Report

confirmed Tuesday that it received a warning letter from the Food and Drug Administration regarding study data on diabetes drug Avandia that was omitted in Glaxo's submissions to the agency. Shares scaled back 4% to $43.24.

Pozen

(POZN)

, which is partnered with Glaxo for migraine drug Treximet, saw its shares decline as well -- down 95 cents, or 8.2%, to $10.70.

Glaxo was one culprit behind the lagging Amex pharmaceutical index, which trailed in performance to its also-saggy biotech counterparts. Another stock weighing it down,

King Pharmaceuticals

( KG) gave up 3.7% to $9.05 and

AstraZeneca

(AZN) - Get Report

declined $1.40, or 3.4%, to $39.85.

Pharma index peers

Forest Laboratories

(FRX)

,

Schering-Plough

( SGP) and

Pfizer

(PFE) - Get Report

were all down more than 2.2% Tuesday as well.

Meanwhile,

Repligen

(RGEN) - Get Report

said Tuesday that it settled its patent infringement suit -- dating back to January 2006 -- with

Bristol-Myers Squibb

(BMY) - Get Report

regarding rheumatoid arthritis treatment Orencia.

The news gave Repligen's shares a 79-cent, or 14%, bump to $6.23.

Bristol will pay Repligen $5 million initially, and then a 1.8% royalty on the first $500 million of U.S. net sales of Orencia, a 2% royalty for the next $500 million and a 4% royalty on any sales in excess of $1 billion between Jan. 1 of 2008 and the end of 2013. In return, Repligen and the University of Michigan granted Bristol an exclusive worldwide license under certain patent rights.

Bristol's shares edged down 16 cents, or 0.7%, to $21.84.

And elsewhere,

Antigenics

(AGEN) - Get Report

rose 56 cents, or 22.7% to $3.03, after it said Tuesday that its Oncophage, a treatment for kidney cancer patients, won its first approval in Russia in patients with intermediate risk of cancer relapse. The company said it will launch in Russia in the second half of 2008 and will seek conditional approval in Europe later this year.

Oncophage is derived from each individual's tumor, and contains what the company calls the "antigenic fingerprint" of the patient's particular cancer. Thus, it's designed to reprogram the body's immune system to target only cancer cells bearing this fingerprint, according to the company.