The U.S. Supreme Court said yesterday that it would hear an appeal by Merck & Co. Inc. seeking to block a shareholders' lawsuit over its withdrawn pain reliever Vioxx.

A federal appeals court ruling in Philadelphia reinstated the class-action securities lawsuit in 2008 after a U.S. district judge in New Jersey dismissed it on grounds that the claims had been filed too late under statutes of limitations.

The Supreme Court agreed to hear arguments during its term that begins in October.

Merck, which employs about 12,000 people in the Philadelphia area, contends that investors waited more than two years to sue after the first warnings that Vioxx might be unsafe.

The investors' suit is unrelated to the $4.85 billion Merck agreed to pay in November 2007 to settle thousands of lawsuits filed by patients and their survivors over Vioxx.

To date, more than 48,000 plaintiffs have filed claims relating to injuries or economic loss under the settlement.

Brian McNamee, who told federal investigators that Clemens used performance-enhancing drugs, contends the pitcher defamed him after McNamee spoke to investigators for former Senate Majority Leader George Mitchell. The summons, filed in Queens Supreme Court last week, preserves McNamee's right to sue, Richard Emery, a lawyer for McNamee, said Tuesday.

Clemens filed his own defamation suit against McNamee in January after the trainer said in the Mitchell Report that he regularly injected Clemens with steroids and human growth hormone. Clemens later told a congressional committee under oath he had never taken steroids.

In the federal case in Texas, McNamee's attorneys say the trainer was forced to talk to investigators under threat of prosecution, rendering him immune from any defamation lawsuit. A federal prosecutor backed McNamee's claim, but a judge has yet to rule on his request to toss the case.

The Justice Department's Civil Division notified Merck in a Sept. 10 letter that the department is investigating whether the drugmakers' promotion of Vytorin resulted in false claims to federal health care programs, Merck noted in a filing to the Securities and Exchange Commission late Monday. If so, federal health programs could seek to recover money they have spent on the drug.

A group of 35 state attorneys general are jointly investigating whether the partners violated state consumer protection laws in their marketing of Vytorin, Merck reported.

And, since January, Merck has been served with or become aware of about 140 civil class-action lawsuits alleging consumer fraud claims in connection with two cholesterol drugs sold and promoted by the partners' joint venture. Some lawsuits allege personal injuries or seek medical monitoring for people who used the drugs, the filing said.

"We take this matter very seriously," Skip Irvine, a spokesman for the joint venture, said Tuesday. "We're cooperating with the request for information that the Justice Department is seeking."

Merck also said in the SEC filing that it is cooperating with the other investigators.

Vytorin and one of its components, Zetia, have been blockbusters in the lucrative cholesterol market, with a combined $5.2 billion in 2007 revenue. But repeated bad news about the drugs this year has cut revenue by about 15 percent since last fall — they brought in only a combined $1.1 billion in the third quarter — contributing to new rounds of layoffs at both Merck and Schering-Plough.

In January, under pressure from congressional investigators, the companies released results of a long-delayed study showing that pricey Vytorin was no better at reducing plaque buildup than its second component, a generic cholesterol drug called Zocor costing about one-third as much.

That led to the investigations by congressional committees as to whether the companies deliberately delayed releasing the study's results to boost sales of Vytorin and Zetia, a charge the companies have denied.

The investigations are being conducted by the Senate Finance Committee and the House Committee on Energy and Commerce's Subcommittee on Oversight and Investigations. They have sought witness interviews, documents and information related to the companies' promotion of Vytorin, the delayed release of results on the patient study, called ENHANCE, and stock sales by officers of the companies.

The Oversight and Investigations subcommittee also made requests on Aug. 21 and Sept. 2 for documents and information related to another patient study, called SEAS, that linked Vytorin to a possible increased risk of various cancers and showed it didn't prevent deterioration, surgery or death in patients with diseased heart valves, as the companies had hoped.

"In a normal environment, this would not be a big deal," analyst Steve Brozak of WBB Securities said of the Justice Department investigation. But pharmaceutical companies are getting lots of scrutiny these days, he said, and all the new litigation could distract the companies from their core business.

"It doesn't mean anything today, but it can have a compounding effect that could mean something tomorrow," he said.

Brozak said all the lawsuits by the class-action attorneys and state attorneys general are "a standard piling-on," but the class-action lawyers are familiar with Merck's successful defense strategy from litigation over its withdrawn painkiller Vioxx and are not likely to "make the same mistakes as they did with Vioxx," he said.

Merck shares closed up almost 4 percent at $31.13, and Schering-Plough shares finished the day up almost 7 percent at $15.50 on a generally positive day on Wall Street.

Six of the court's 11 justices upheld a 2005 law allowing embryonic stem cell research and turned down a petition filed that same year by then-Attorney General Claudio Fontelles, who argued the law was unconstitutional because it violates the right to life.

The remaining five judges argued that while the 2005 law is constitutional, research should only be carried out "with restrictions" such as not allowing the embryo to be destroyed and submitting each case for the approval of an ethics commission.

The ruling drew immediate fire from church officials in the world's largest Roman Catholic country.

The National Conference of Brazilian Bishops issued a statement saying it "regretted" the ruling, comparing it to a death sentence. The bishops' conference said its position "is not a matter of religion, but of the defense of human life, beginning with conception."

The law opens the way for research with embryos resulting from in-vitro fertilization that have been frozen for at least three years.

Advocates have said that a favorable Supreme Court ruling could make Brazil Latin America's leader in stem cell research.

They praise Brazilian scientists for their work with adult stem cells for the treatment of cardiovascular diseases and Type 1 diabetes, and have said that similar breakthroughs could be achieved with embryonic stem cells.

A federal advisory panel, in response to mounting safety concerns, called on Thursday for additional restrictions on the use of anemia drugs by cancer patients.

The recommendation by a committee that advises the Food and Drug Administration could lead to an additional decline in sales for the drugs: Aranesp, made by Amgen, and Procrit by Johnson & Johnson.

But the two companies avoided the outcome they most feared: a recommendation that the drugs not be used by any cancer patients. That probably would have meant the loss of at least $1 billion in sales for each company.

“They dodged the really big bullet, but they still took some damage,” said Geoffrey C. Porges, a biotechnology analyst at Sanford C. Bernstein & Company.

Yaron Werber, an analyst with Citigroup, estimated that Amgen would lose about $125 million in Aranesp sales if the recommendations were enacted. That would be about 25 percent of Mr. Werber’s already reduced projections for 2008 sales to cancer patients in the United States. The meeting was held because eight clinical trials suggested that the drugs might make cancer worse for some patients or even shorten their lives. Cancer patients take Aranesp or Procrit to counter the anemia caused by chemotherapy.

The difficulty for the committee was that those eight studies involved high doses of the drugs. There was very little solid information on whether the drugs were dangerous at doses typically used by cancer doctors.

Faced with that information, the panel voted 13 to 1 in favor of recommending that the drugs remain available for use by many cancer patients.

But the committee then voted 9 to 5 in favor of recommending that the drugs not be used by patients with either breast cancer or head and neck cancer because the evidence of a risk was strongest for those types of tumors.

The committee also voted 11 to 2, with 1 abstention, to recommend that the drug not be used by patients being treated with the intent of curing their cancers. The definition of that category is vague, but it generally refers to patients with early-stage cancer who are undergoing chemotherapy after surgical removal of a tumor, in which the doctors hope the cancer has been eliminated. F.D.A. officials said after the meeting that most use of the anemia drugs was for patients with more advanced cancers.

The panel members also recommended that patients be made to sign consents in order to obtain the drugs. But the panel voted against carefully controlling distribution of the drugs.

The court had been scheduled to rule on a 2005 petition by then-Attorney General Claudio Fontelles, who argued that a law passed that same year allowing embryonic stem cell research was unconstitutional because it violates the right to life.

The law opened the way for research with embryos resulting from in-vitro fertilization that have been frozen for at least three years.

The session was suspended, almost five hours after it began, when Justice Carlos Alberto Menezes Direito formally requested more time to consider the issue. He has 10 to 30 days to present his opinion during another session, according to the court's press office.

Before the adjournment, current Attorney General Antonio Fernando Souza and a lawyer for Brazil's Roman Catholic Church argued that embryonic stem cell research should be banned because the process involves destroying embryos, which they said ends human life.

Other attorneys representing the government and Congress defended the 2005 law, saying research with embryonic stem cells could lead to cures of diseases such as Parkinson's, multiple sclerosis and diabetes.

While embryonic stem cell research is currently legal, scientists have put most projects on the back burner pending the Supreme Court's ruling.

As federal health officials offer more evidence that the mercury-containing vaccine preservative thimerosal is safe, many vaccine experts say in retrospect that the U.S. Food and Drug Administration's decision to remove it from childhood vaccines may have done more harm than good by raising public fears.

And still others argue that research and funds still being spent on exploring the risks of thimerosal could be directed to more productive enterprises.

A new study published in the New England Journal of Medicine concludes that early exposure to thimerosal does not cause any neurological problems. Thimerosal, used in vaccines since the 1930s, has been a topic of controversy since the FDA banned it in 1999.

Some claim that the additive causes autism and other brain development disorders in children. But the latest study joins a growing body of literature that shows thimerosal is safe and causes no long-term negative effects on children's health.

Although no concrete evidence at the time showed that thimerosal was harmful, the Centers for Disease Control and Prevention and the American Academy of Pediatrics pushed for its elimination to quell the fears of parents who might otherwise not get their children vaccinated.