This week, the ratings of 11 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. Shares of the stock have been trading at an exceptionally rapid pace, up twofold from the week prior. For more information, get Portfolio Grader’s complete analysis of CVM stock.

The rating of EPIRUS Biopharmaceuticals, Inc. (EPRS) slips from a C to a D. The stock also gets an F in Earnings Revisions. To get an in-depth look at EPRS, get Portfolio Grader’s complete analysis of EPRS stock.

Ohr Pharmaceutical Inc (OHRP) gets weaker ratings this week as last week’s C drops to a D. Ohr Pharmaceutical develops pharmaceuticals for wound care and to treat cachexia. The stock gets F’s in Earnings Revisions and Equity. For more information, get Portfolio Grader’s complete analysis of OHRP stock.

Trius Therapeutics, Inc. (TSRX) experiences a ratings drop this week, going from last week’s C to a D. 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. To get an in-depth look at TSRX, get Portfolio Grader’s complete analysis of TSRX stock.

This is a rough week for Vical Incorporated (VICL). The company’s rating falls to D from the previous week’s 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. For more information, get Portfolio Grader’s complete analysis of VICL stock.

Tenax Therapeutics, Inc. (TENX) earns an F (“strong sell”) this week, moving down from last week’s grade of D (“sell”). The stock receives F’s in Earnings Momentum, Earnings Revisions and Equity. Cash Flow and Sales Growth also get F’s. To get an in-depth look at TENX, get Portfolio Grader’s complete analysis of TENX stock.

This week, Synergy Pharmaceuticals, Inc.’s (SGYP) rating worsens to an F from the company’s D rating a week ago. 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 July 1, 2015, 21.5% of outstanding Synergy Pharmaceuticals, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of SGYP stock.

The rating of Verastem, Inc. (VSTM) declines this week 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 July 1, 2015, 11.4% of outstanding Verastem, Inc. shares were held short. To get an in-depth look at VSTM, get Portfolio Grader’s complete analysis of VSTM stock.

Celldex Therapeutics, Inc. (CLDX) is having a tough week. The company’s rating falls from a C to a D. 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 gets an F in Equity. As of July 1, 2015, 16.5% of outstanding Celldex Therapeutics, Inc. shares were held short. Shares of the stock have been exchanging at an usually rapid pace, twice the rate of the week prior. For more information, 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. Shares of the stock are changing hands at twice the rate they were a week ago. To get an in-depth look at TRVN, get Portfolio Grader’s complete analysis of TRVN stock.

Ocata Therapeutics, Inc. (OCAT) earns a D this week, falling from last week’s grade of C. The stock gets F’s in Earnings Surprise and Cash Flow. For more information, get Portfolio Grader’s complete analysis of OCAT 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.