The top pre-market NASDAQ Stock Market gainers are: Netlist, Optimer Pharmaceuticals, Aeterna Zentaris, Affymax, Star Scientific, Medicines Co., and Canadian Solar. The top pre-market NASDAQ Stock Market losers are: Avago Technologies, RF Micro Devices, Transition Therapeutics, Avanir Pharmaceuticals, and Vodafone Group.

Gainers

Netlist Inc. (NLST) stock grew 6.11 percent to $2.43 in the pre-market trading.

Optimer Pharmaceuticals, Inc. (OPTR) stock grew 5.93 percent to $13.75 in the pre-market trading. The company said the U.S. Food and Drug Administration has approved its antibiotic Dificid or Fidaxomicin for the treatment of Clostridium difficile diarrhea infection in adult patients, making it the first drug to be cleared in nearly thirty years to treat the disease. Clostridium difficile is a gram-positive anaerobic bacterium that can cause diarrhea and lead to colitis, other serious intestinal conditions, and death in severe cases.

The safety and efficacy of Dificid were demonstrated in two trials that included 564 patients with Clostridium difficile-associated diarrhea that compared Dificid with vancomycin, a common antibiotic used to treat Clostridium difficile-associated diarrhea. The clinical response was similar in the Dificid group compared with the vancomycin group in both studies. In the Dificid trials, a greater number of patients treated with Dificid had a sustained cure three weeks after treatment ended versus those patients treated with vancomycin. The most common side effects reported with Dificid included nausea, vomiting, headache, abdominal pain, and diarrhea.

Aeterna Zentaris Inc. (AEZS) stock grew 5.02 percent to $2.49 in the pre-market trading. Needham & Co. initiated coverage of Aeterna Zentaris with a buy rating and a price target of $5.

Affymax, Inc. (AFFY) stock gained 4.89 percent to $7.51 in the pre-market trading. The company said it has submitted a New Drug Application to the U.S. Food and Drug Administration for its investigational erythropoiesis-stimulating agent Peginesatide (formerly known as Hematide) to treat anemia associated with chronic renal failure in adult patients on dialysis. Peginesatide is co-developed by Japan-based Takeda Pharmaceutical Company Ltd. Peginesatide is a synthetic, PEGylated peptidic compound that binds to and activates the erythropoietin receptor and thus acts as an erythropoiesis stimulating agent (ESA).

The NDA includes data from two Phase 3 studies (EMERALD 1 and 2) that evaluated the efficacy and safety of peginesatide, dosed once every four weeks, compared to epoetin alfa or epoetin beta, dosed more frequently (according to the product labels), in maintaining hemoglobin (Hb) levels. In the studies, CRF patients on dialysis who were receiving stable doses of epoetin, were randomized to receive once-monthly peginesatide or continue treatment with epoetin. The EMERALD findings suggested that once-monthly peginesatide was similar to epoetin in maintaining Hb levels in CRF patients on dialysis with anemia on a similar adverse event rate.

Star Scientific, Inc. (CIGX) stock increased 4.84 percent to $5.20 in the pre-market trading.

Medicines Co. (MDCO) stock increased 4.24 percent to $19.16 in the pre-market trading. Standard & Poor's, a subsidiary of The McGraw-Hill Companies Inc. (MHP), announced that Medicines Co. will replace RehabCare Group Inc. (RHB) in the S&P SmallCap 600 index after the close of trading on June 1. RehabCare Group is being acquired by S&P MidCap 400 constituent Kindred Healthcare Inc. (KND) in a deal expected to be completed on or about that date pending final approvals.

Canadian Solar Inc. (CSIQ) stock rose 3.88 percent to $9.64 in the pre-market trading. The company and Suzhou GCL Photovoltaic Technology Co., Ltd., a subsidiary of GCL-Poly Energy Holdings Limited, announced a major solar joint-venture to build a 600 MW capacity wafer plant in Suzhou dedicated to Canadian Solar's requirements. The initial 600 MW can be expanded to 1.2 GW. The total capital expenditure for the first phase of the project is about $77 million, which is expected to be financed 33.3 percent through the registered capital and 66.7 percent through debt. Under the terms of the agreement, GCL-Poly Energy will contribute 90 percent of the registered equity, and Canadian Solar will contribute 10 percent.

Canadian Solar remains on track to expand its annualized capacity for solar cells to around 1.3GW to 1.4GW by mid-2011. In addition, Canadian Solar also plans to announce a joint venture to build a 600MW solar cell facility that will enable it to reach approximately 2GW of internal solar cell capacity during the first quarter of 2012. The Company is also on track to reach 2GW of annualized capacity for module lamination by mid-2011. As a result, the Company is on track to achieve a 2GW 'virtual vertical integration' from wafer to cell and module at the beginning of 2012.

Losers

Avago Technologies Ltd. (AVGO) stock fell 3.17 percent to $33.90 in the pre-market trading. The company announced the sale of 25 million ordinary shares by certain existing shareholders to Deutsche Bank Securities Inc., Barclays Capital Inc. and Citi, as underwriters in the registered public offering of those shares.

Avago said all of the shares are being sold by existing shareholders identified in the prospectus supplement relating to the offering. Besides, the underwriters have a 30-day option to purchase from certain of the shareholders up to an additional 3.75 million ordinary shares to cover over-allotments, if any. The company said it will not receive any proceeds from this offering.

RF Micro Devices Inc. (RFMD) stock declined 1.14 percent to $6.08 in the pre-market trading. The company said it has extended its portfolio of broadband components to include two new low power IQ Modulators featuring integrated fractional-N synthesizers and voltage controlled oscillators (VCO). The RFMD2080 and RFMD2081 are broadband devices capable of generating output frequencies from 45MHz to 2700MHz.

The company said they are suitable for a wide range of applications, including satellite communications, Point-to-Point radio, software defined radio, and other wireless and wireline applications requiring QPSK/QAM modulators. The broadband nature of the components and the integration of the local oscillator offer customers a competitive combination of functionality, versatility, and size. RF Micro Devices will exhibit the above components at the IEEE International Microwave Symposium (IMS) 2011, June 6-8, at the Baltimore Convention Center, in Booth 1402.

Transition Therapeutics Inc. (TTHI) stock decreased 1.07 percent to $3.70 in the pre-market trading.

Avanir Pharmaceuticals (AVNR) stock moved down 0.64 percent to $4.64 in the pre-market trading.

Vodafone Group plc (VOD) stock moved down 0.36 percent to $28 in the pre-market trading.

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