The ratings of 18 Biotechnology stocks are down this week, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

TESARO, Inc. (TSRO) experiences a ratings drop this week, going from last week’s C to a D. TESARO, Inc. develops and commercializes cancer therapeutics and supportive care products. The company also gets F’s in earnings surprise, earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of TSRO stock.

This week, SAGE Therapeutics, Inc.’s (SAGE) rating worsens to a F from the company’s D rating a week ago. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of SAGE stock.

Eiger BioPharmaceuticals, Inc.’s (EIGR) rating weakens this week, dropping to a D versus last week’s C. The company also gets F’s in earnings surprise. For more information, get Portfolio Grader’s complete analysis of EIGR stock.

Mirati Therapeutics Inc. (MRTX) slips from a C to a D this week. Mirati Therapeutics Inc. engages in the development of therapeutics for the treatment of cancer. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of MRTX stock.

uniQure N.V. (QURE) gets weaker ratings this week as last week’s D drops to a F. The company also gets F’s in earnings revisions, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of QURE stock.

Proteon Therapeutics, Inc. (PRTO) is having a tough week. The company’s rating falls from a D to a F. The company also gets F’s in earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of PRTO stock.

Pfenex, Inc. (PFNX) declines this week from a D to a F. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of PFNX stock.

Slipping from a C to a D rating, TRACON Pharmaceuticals, Inc. (TCON) takes a hit this week. The company also gets F’s in earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of TCON stock.

Keryx Biopharmaceuticals, Inc. (KERX) earns a D this week, moving down from last week’s grade of C. Keryx Biopharmaceuticals, Inc. focuses on developing and commercializing pharmaceuticals for the treatment of cancer and renal disease. The company also gets F’s in earnings revisions, earnings surprise, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of KERX stock.

This week, VistaGen Therapeutics, Inc. (VTGN) drops from a C to a D rating. The company also gets F’s in free cash flow. For more information, get Portfolio Grader’s complete analysis of VTGN stock.

This is a rough week for Prana Biotechnology Ltd Sponsored ADR (PRAN). The company’s rating falls to F from the previous week’s D. Prana Biotechnology Ltd Sponsored ADR is an Australian biotechnology company which researches and develops therapeutic drugs used for treatment of Alzheimer’s Disease and other age-related degenerative disorders such as Parkinson’s Disease and cataracts. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of PRAN stock.

Vascular Biogenics Ltd. (VBLT) gets weaker ratings this week as last week’s C drops to a D. The company also gets F’s in earnings surprise, earnings momentum, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of VBLT stock.

Affimed N.V. (AFMD) experiences a ratings drop this week, going from last week’s D to a F. The company also gets F’s in sales growth, earnings revisions, earnings surprise, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of AFMD stock.

This week, Tonix Pharmaceuticals Holding Corp.’s (TNXP) rating worsens to a F from the company’s D rating a week ago. The company also gets F’s in earnings surprise, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of TNXP stock.

Fibrocell Science, Inc. (FCSC) slips from a C to a D this week. The company also gets F’s in sales growth, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of FCSC stock.

Actinium Pharmaceuticals, Inc. (ATNM) declines this week from a C to a D. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of ATNM stock.

This week, Idera Pharmaceuticals, Inc. (IDRA) drops from a D to a F rating. Idera Pharmaceuticals, Inc. is engaged in the discovery and development of DNA- and RNA-based drug candidates targeted to Toll-Like Receptors (TLRs) to treat infectious diseases, autoimmune and inflammatory diseases, cancer, asthma and allergies, and for use as vaccine adjuvants. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of IDRA stock.

This is a rough week for Oncothyreon Inc. (ONTY). The company’s rating falls to F from the previous week’s D. Oncothyreon Inc. is a biotechnology company that develops therapeutic approaches to cancer management. The company also gets F’s in earnings revisions, earnings surprise, return on equity, and free cash flow. For more information, get Portfolio Grader’s complete analysis of ONTY stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.