The top after-market NASDAQ gainers Thursday were Vertex Pharmaceuticals, Amarin Corporation, AMC Networks Inc, Microsoft Corporation, and Cepheid. The top after-market NASDAQ losers were Air Methods Corp, PRGX Global, Insight Enterprises Inc and Lattice Semiconductor.

Gainers

Vertex Pharmaceuticals Inc. (NASDAQ:VRTX) shares climbed 51.79 percent to $80.25 in post-market trading. The company said on Thursday that data from a mid-stage trial showed significant improvements in recovery from lung function among adults with the most common type of the cystic fibrosis, validating the company's research strategy on the disease.

Amarin Corporation (NASDAQ:CERS) shares climbed 3.16 percent to $6.85 in post-market trading. Amarin announced on Thursday the approval of the Supplemental New Drug Application (sNDA) to the U.S. Food and Drug Administration (FDA), to add Chemport Inc. as an additional Vascepa (icosapent ethyl) active pharmaceutical ingredient (API) supplier.

AMC Networks Inc. (NASDAQ:AMCX) shares surged 3.13 percent to $65.26 in post-market trading after losing more than 2 percent in regular trading on Thursday. The stock has a 52-week low of $34.78, a 52-week high of $66.13 and $4.58 billion in market capitalization.

Microsoft Corporation. (NASDAQ:MSFT) shares gained 2.92 percent to $29.63 in post-market trading. Microsoft Corp.'s third quarter earnings rose 19 percent as its business software and Windows units performed well in the face of weak demand for personal computers, and the company announced that Chief Financial Officer Peter Klein will be leaving this summer. The company reported quarter three EPS of $0.72, $0.04 better than the analysts' estimate of $0.68. Revenues for the quarter came in at $20.49 billion versus the consensus estimate of $20.56 billion.

Cepheid (NASDAQ:CPHD) shares advanced 1.91 percent to $36.80 in post-market trading after losing more than 2.88 percent in regular trading on Thursday. The company said on Thursday that it turned a profit in the first quarter as reagent and disposable product sales grew 22 percent to $75.9 million during the quarter. Cepheid reported earnings of $313,000 and broke even on a per share basis against the analysts’ expectation of a loss of 2 cents per share. A year ago, Cepheid reported a loss of $5.5 million, or 8 cents per share. Total revenues rose 19 percent to $91.9 million from $77.3 million.

Losers

Air Methods Corp. (NASDAQ:AIRM) shares tumbled 18.30 percent to $37.50 in post-market trading after the company said preliminary net revenues per community-based transport for the first quarter 2013 was $9,108, as compared with $10,072 in the prior-year quarter, a 10 percent decrease and the company expects to report a net loss of approximately $0.14 to $0.16 per share for the first quarter of 2013, compared to a net income of $0.32 per share in the prior year quarter.

PRGX Global Inc. (NASDAQ:PRGX) shares slumped 17.98 percent to $5.11 in post-market trading. The company announced that it expects first quarter net loss per share to be in the range of $0.01 to $0.03 and revenues to be 12% to 14% lower than revenues reported in the first quarter of 2012. Analysts' estimate for first quarter indicates $0.03 earnings per share on revenues of $52.91 million.

Insight Enterprises Inc. (NASDAQ:NSIT) shares declined 6.64 percent to $17.30 in post-market trading. The company reported that net sales for the quarter ended March 31, 2013 is expected to be approximately $1.2 billion, representing a decrease of approximately 5 percent from the first quarter of 2012.

Lattice Semiconductor Inc. (NASDAQ:LSCC) shares fell 5.67 percent to $4.99 in post-market trading. The stock gained 9.30 percent in regular trading on Thursday.

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