While tech trends fluctuate wildly, one survey notes life science VCs have quietly racked up impressive returns.

Biopharmaceutical company Tesaro Inc. has closed a whopping $101 million Series B round led by Kleiner Perkins Caufield & Byers. Existing shareholder New Enterprise Associates also participated, as did new investors InterWest Partners, T. Rowe Price, Pappas Ventures, Oracle Partners, Deerfield Management and Leerink Swann. Tesaro is focused on oncology-related products, including a drug to prevent chemotherapy-induced nausea. The company sealed a $20 million Series A round in 2010.

One-year-old start-up Ultragenyx Pharmaceutical Inc. has closed on a whopping $45 million Series A round co-led by TPG Biotech and Fidelity Biosciences. Other investors include HealthCap and Pappas Ventures. The money will help Novato, Calif.-based Ultragenyx continue development of its rare disease therapeutics. As a result of the round, Eran Nadav of TPG Biotech; Ben Auspitz of Fidelity Biosciences; and Mårten Steen of HealthCap will join the company’s board.

Milestone Pharmaceuticals Inc., a Montreal-based cardiovascular drug development company, has raised $13 million in fresh capital. Pappas Ventures, the Business Development Bank of Canada and GO Capital co-led the round. Fonds de solidarité FTQ, iNovia Healthcare Ventures and Fonds Bio-Innovation also participated. The money will be used for continued development. As a result of the round, Eric Linsley, managing partner of Pappas Ventures; Scott Weiner, senior principal at Pappas Ventures; and Dominic Jaikaran, principal at BDC Health Venture Fund, will join Milestone’s board.

Syndax Pharmaceuticals, the Massachusetts-based oncology company, took on Arlene Morris to its board of directors. Morris was most recently the CEO and board member of Affymax Inc., the biopharma company spun from GlaxoSmithKline. Among Syndax’s backers are Domain Associates, MPM Capital, Avalon, Pappas and Forward Ventures.

CardioDx, a company developing cardiovascular genomic diagnostics, has raised $60 million in new equity funding. New investors Longitude Capital, J.P. Morgan, Acadia Woods Partners, Artiman Ventures, and Bright Capital, the venture arm of RU-COM, participated in the round, which also included the company’s previous investors. The company has raised money previously from Kleiner, Perkins, Caufield & Byers, Mohr Davidow Ventures, TPG Biotech, Intel Capital, Pappas Ventures, DAG Ventures, Asset Management Group and GE Capital. Funding will be used to expand reimbursement coverage in the United States for the company’s blood-based gene expression test for obstructive coronary artery disease, as well as to continue development of future products. The company, based in Palo Alto, Calif., closed a $45 million round in May 2010.

Daiichi Sankyo has agreed to buy Plexxikon for $805 million, providing an exit for venture investors including Belgian firm GIMV. Future milestone payments could total an additional $130 million, the company said. Plexxikon develops novel small molecule pharmaceuticals to treat human disease. Gimv first invested in Plexxikon during a series B financing in 2002. The company is also backed by Alta Partners, ATV, Walden International, Pappas Ventures and CW Ventures.

New Jersey-based medical device company TYRX has raised $20 million in a round led by new investor HLM Venture Partners. The company’s previous investors Clarus Ventures and North Carolina-based Pappas Ventures also contributed to the round. The financing also included $4 million in debt financing from Comerica Bank. HLM Venture Partners’ Edward Cahill joins the TYRX board as a result of the financing. Clarus Ventures has offices in Cambridge, Mass., and in San Francisco. HLM Venture Partners is based in Boston and San Francisco.

Michael Grey has been named a venture partners with Pappas Ventures. Grey has served as a member of the firm’s scientific advisory board for the past six years, and has served as CEO of Auspex Pharmaceuticals, SGX Pharmaceuticals (acquired by Eli Lilly) and Trega Biosciences (acquired by Lion Bioscience).

Pappas Ventures has promoted Sean McCarthy from principal to transactional partner, and Scott Weiner from senior associate to senior principal.