Merck (MRK - Get Report) shares have risen $1.81% to $65.10 after winning U.S. approval Wednesday to use its immunotherapy Keytruda in combination with chemotherapy to treat patients newly diagnosed with non-small cell lung cancer. The approval marks the first time that an immunotherapy has been combined with another drug to kill cancer cells more effectively. Keytruda is now the only PD-1 or PD-L1 checkpoint inhibitor approved to treat first-line lung cancer either as monotherapy or as part of a combination therapy.

SciClone Pharmaceuticals (SCLN) , a U.S.-based specialty pharma focus on drugs "relevant to the Chinese patient population" was up 2.07% to $9.85 Thursday after reporting an 18% increase in first quarter 2017 revenue. Revenue from its lead drug Zadaxin were $39.5 million in the first quarter of 2017, a $5.9 million or 17% increase, compared to $33.6 million for the same period in 2016. Zadaxin is used for the treatment of hepatitis B and C, certain cancers, and as an immune system enhancer.

Hologic (HOLX - Get Report) shares were falling despite reporting after close of the market Wednesday that its second quarter revenues rose 3 percent, driven in part by solid growth in molecular diagnostics. The shares were down 4.85% to $43.73. Troubling to investors may have been discussion on the company's earnings call with analysts regarding the need to rebuild the salesforce at bodysculpting segment Cynosure, which was acquired in March. Hologic CEO Stephen MacMillan said leaks while Cynosure was being shopped led some of the sales team to leave that company. "We lost some good people in that realm. We're completely rebuilding those."

Teva (TEVA - Get Report) shares, though not among the biggest movers, were down about a percent at the open and trading on heavy volume after Interim Chief Executive Officer Yitzhak Peterburg set a more ambitious target for cost-reductions this year, raising the goal to $1.5 billion. The company also said it would sell assets including its global women's health and European cancer and pain-treatment divisions to help pay down its debt.

Tel Aviv-based Teva said on Thursday it had clocked EPS of $1.06 per share in the first quarter excluding one-time items in the quarter, down from $1.20. Revenue, however, grew 17 percent to $5.6 billion.

Shares of Nasdaq-listed, Canada-based Merus Labs International (MSLI)  were up about 55% midday Thursday to $1.19 apiece, after the specialty drugmaker agreed to be acquired by Dutch pharma company Norgine.

The European drug company will pay $1.65 in cash for Merus stock, which values the target's equity at around $165 million and makes for an enterprise value of $342 million. The offer for the shares represents a 63.4% premium to the May 10 closing price.

Adam Feuerstein contributed to this story.

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