High-priced big-cap biotechs are having a great year this year and you may be wondering whether two biotech leaders, Regeneron (NASDAQ:REGN) and Celgene (NASDAQ:CELG), still have room to run.

Both stocks have outpaced the S&P 500 handily thanks to positive news including expanded labels and positive trial results for high profile drugs in their pipelines. Both have also climbed more than the broader S&P Biotech ETF, too.

But, just because shares in these companies have rallied doesn't mean they'll continue to head higher. It is important to consider their earnings growth and earnings consistency, as well as their valuation, before jumping in and buying.

Debating earnings
Regeneron has increased its research and development spending and underdelivered on analysts' earnings estimates the past two quarters as a result. That's prompting analysts to curb earnings per share forecasts for next year to $5.55 from $5.71 just 90 days ago. On the bright side, the Street did lift those expectations from $5.46 a week ago, and earnings are expected to climb nicely through 2016.

Unlike Regeneron, Celgene has overdelivered on earnings in each of the past four quarters. That encouraged analysts to lift earnings forecasts for next year to $7.23 from $6.96 90 days ago. Their enthusiasm doesn't wane as you looking further out, either. They think Celgene's earnings could top $11 over the next three fiscal years.

REGN EPS Estimates for Current and Next 3 Fiscal Years Chart

REGN EPS Estimates for Current and Next 3 Fiscal Years data by YCharts.

Debating valuation
While both companies are expected to see impressive earnings growth over the coming years, Celgene appears more attractively priced.

Regeneron is trading a seemingly rich 55 times next year's earnings and more than 38 times its expected earnings in 2016. Celgene is trading 25 times next year's forecasts and just 13 times estimates for 2016.

REGN PE Ratio (Forward 1y) Chart

REGN P/E Ratio (Forward 1y) data by YCharts.

Or, looking at it differently, investors are currently paying significantly less for each dollar of Celgene's compared to Regeneron's expected sales next year.

REGN Price to Sales Ratio (Forward 1y) Chart

REGN Price to Sales Ratio (Forward 1y) data by YCharts.

The Foolish Final Take
Both Regeneron and Celgene have blockbuster drugs in Eylea and Revlimid, respectively. And both have rich pipeline opportunities. Regeneron and its partner Sanofi just reported positive results for phase 3 drug alirocumab for lowering bad cholesterol. Celgene's Apremilast and Abraxane have plenty of opportunity for label expansion thanks to a slate of autoimmune and oncology trials. But, investors are currently pricing Regeneron's future opportunity more expensively than Celgene's, suggesting you may want to focus more on Celgene until either Regeneron's price falls or analyst earnings estimates climb.