Shares of CytomX Therapeutics (CTMX - Get Report) were up 34.4% to $20.40 in premarket trading Monday after the South San Francisco, Calif.-based company and New York-based Bristol-Myers Squibb (BMY - Get Report) on Monday announced they are expanding their collaboration to discover novel therapies that will include up to eight additional targets using CytomX's proprietary Probody platform. The original collaboration was signed in May 2014.

Aevi Genomic Medicine (GNMX) shares were down 59.6% to $2.20. The Philadelphia-based company announced top-line results from the SAGA trial of AEVI-001. The company said that although AEVI-001 did not meet the primary endpoint, "there was an encouraging improvement observed on the inattention subscale."

Shares of Esperion Therapeutics (ESPR) jumped 32.2% to $31.30 after the Ann Arbor, Mich.-based lipid management company said the U.S. Food and Drug Administration "recently confirmed that Esperion's LDL-C lowering program is adequate to support approval of an LDL-C lowering indication for bempedoic acid."

Esperion said it intends to submit a new drug application by the first half of 2019 for an LDL-C lowering indication based on the successful completion of the phase three clinical development program.

Meanwhile, shares of Nektar Therapeutics (NKTR - Get Report) were up nearly 22% to $18.90 after the San Francisco company on Monday unveiled results from the first late-stage clinical trial showing its experimental, addiction-resistant opioid NKTR-181 reduces pain significantly more than a placebo in patients with chronic back problems.

Shares of Array BioPharma (ARRY) were down 10.9% to $9.41. The Boulder, Colo.-based company said Sunday it has withdrawn its new drug application from the FDA for binimetinib monotherapy for the treatment of NRAS-mutant melanoma.

"Based on feedback from the agency, Array concluded that the clinical benefit demonstrated in the Phase 3 NEMO clinical trial would not be found sufficient to support approval of the NRAS-mutant melanoma NDA," Array said.

The company said ongoing clinical trials for binimetinib will continue. The action announced on Sunday will not  affect the planned phase three COLUMBUS trial NDA of binimetinib, in tandem with encorafenib, for the treatment of BRAF-mutant melanoma, Array said.

Adam Feuerstein and Alicia McElhaney contributed to this article