This week, the ratings of 10 biotechnology stocks on Portfolio Grader are down. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

CEL-SCI Corporation (CVM) is on the decline this week, earning a D (“sell”) after receiving a C (“hold”) last week. CEL-SCI is developing new immune system based treatments for cancer and infectious diseases. In Portfolio Grader’s specific subcategories of Equity and Cash Flow, CVM also gets F’s. To get an in-depth look at CVM, get Portfolio Grader’s complete analysis of CVM stock.

EPIRUS Biopharmaceuticals, Inc.’s (EPRS) rating weakens this week, dropping to a D versus last week’s C. The stock also gets an F in Earnings Revisions. For more information, get Portfolio Grader’s complete analysis of EPRS stock.

This week, Ohr Pharmaceutical Inc’s (OHRP) rating worsens to a D from the company’s C rating a week ago. Ohr Pharmaceutical develops pharmaceuticals for wound care and to treat cachexia. The stock gets F’s in Earnings Revisions and Equity. To get an in-depth look at OHRP, get Portfolio Grader’s complete analysis of OHRP stock.

This week, Trius Therapeutics, Inc. (TSRX) drops from a C to a D rating. Trius Therapeutics is a biopharmaceutical company. The stock gets F’s in Earnings Growth, Earnings Momentum and Equity. Cash Flow and Sales Growth also get F’s. For more information, get Portfolio Grader’s complete analysis of TSRX stock.

Vical Incorporated (VICL) earns a D this week, moving down from last week’s grade of C. Vical researches and develops biopharmaceutical products based on its patented DNA delivery technologies for the prevention and treatment of serious or life-threatening diseases. The stock gets F’s in Equity and Cash Flow. Shares of the stock have been changing hands at an unusually rapid pace, up 7703.4% from the week prior. To get an in-depth look at VICL, get Portfolio Grader’s complete analysis of VICL stock.

Tenax Therapeutics, Inc.’s (TENX) rating falls this week to an F (“strong sell”), down from last week’s D (“sell”). The stock receives F’s in Earnings Momentum, Earnings Revisions and Equity. Cash Flow and Sales Growth also get F’s. Trade volume fell markedly in the past week, standing at half of the previous rate. For more information, get Portfolio Grader’s complete analysis of TENX stock.

Synergy Pharmaceuticals, Inc. (SGYP) gets weaker ratings this week as last week’s D drops to an F. Synergy Pharmaceuticals is a biopharmaceutical company focused on the development of drugs to treat gastrointestinal disorders and diseases. The stock gets F’s in Equity and Cash Flow. As of June 3, 2015, 18.4% of outstanding Synergy Pharmaceuticals, Inc. shares were held short. To get an in-depth look at SGYP, get Portfolio Grader’s complete analysis of SGYP stock.

Verastem, Inc. (VSTM) is having a tough week. The company’s rating falls from a D to an F. Verastem is a biopharmaceutical company which is focused on discovering and developing novel drugs that selectively target cancer stem cells in breast and other cancers along with proprietary companion diagnostics. The stock gets F’s in Equity and Cash Flow. As of June 3, 2015, 10.8% of outstanding Verastem, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of VSTM stock.

Slipping from a C to a D rating, Celldex Therapeutics, Inc. (CLDX) takes a hit this week. Celldex Therapeutics is engaged in the discovery, development and commercialization of products that harness the human immune system to prevent and treat disease. The stock also rates an F in Equity. As of June 3, 2015, 16.9% of outstanding Celldex Therapeutics, Inc. shares were held short. To get an in-depth look at CLDX, get Portfolio Grader’s complete analysis of CLDX stock.

Trevena, Inc. (TRVN) experiences a ratings drop this week, going from last week’s C to a D. The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of TRVN 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.