* Vertex soars on massive volume after clinical trial
* Micron rises after results, revenue outlook
* Consumer confidence at highest since Jan 2008
* Indexes up: Dow, S&P 500 0.1 pct, Nasdaq 0.5 pct (Updates to open, adds data)
By Ryan Vlastelica
NEW YORK, June 24 (Reuters) - U.S. stocks were little changed on Tuesday as some strong data wasn't enough to solidly lift indexes in the wake of a recent rally, though the Nasdaq index was boosted by gains in technology and biotech shares.
In the latest signs of improving economic conditions, consumer confidence surged more than expected in June, while May new home sales also rose more than had been anticipated. The housing data built on Monday's similarly bullish read on existing home sales, though a report on home prices was below forecasts.
The benchmark index was essentially flat on the day, but the S&P 500 managed to eke out another intraday record and was on track for its seventh advance over the past eight sessions.
"We remain bullish and are advising our clients to remain overweight on equities, but the levels of valuations and investor sentiment are starting to give us pause in the short term," said Bill Greiner, chief investment officer of Mariner Wealth Advisors in Leawood, Kansas. "We're not in nosebleed territory, but we are a bit stretched."
Consumer confidence hit its highest level since January 2008 in June, while new home sales jumped 18.6 percent to a six-year high in May. The PHLX Housing index rose 0.8 percent.
Despite those rosy reports, gains were limited by the S&P/Case-Shiller composite index, which showed single-family home prices rose less than expected in April.
The Dow Jones industrial average rose 8.68 points, or 0.05 percent, to 16,945.94, the S&P 500 gained 1.61 points, or 0.08 percent, to 1,964.22 and the Nasdaq Composite added 19.48 points, or 0.45 percent, to 4,388.15.
The Nasdaq enjoyed stronger gains, thanks to Vertex Pharmaceuticals Inc, the S&P 500's biggest gainer by far, which soared 40 percent to $93.22 in heavy volume to lift the Nasdaq Biotech index 2.3 percent.
That climb came after Vertex said a combination of drugs designed to treat cystic fibrosis succeeded in improving lung function in a pair of closely watched late-stage clinical trials.
Micron Technology Inc also supported the Nasdaq, rising 4.3 percent to $32.58 a day after giving a revenue outlook that exceeded analysts' expectations.
On the downside, Walgreen Co fell 2.3 percent to $72 after reporting its third-quarter results.
Investors continued to eye geopolitical tensions in Iraq and Ukraine. German business sentiment weakened more than expected in June as concern grew among companies in Europe's largest economy that tensions in the regions would hurt their business. (Editing by Bernadette Baum and Nick Zieminski)