The ratings of nine biotechnology stocks are down this week, according to the Portfolio Grader database. 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. For more information, get Portfolio Grader’s complete analysis of CVM stock.

EPIRUS Biopharmaceuticals, Inc. (EPRS) experiences a ratings drop this week, going from last week’s 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.

Slipping from a C to a D rating, Ohr Pharmaceutical Inc (OHRP) takes a hit this week. 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) gets weaker ratings this week as last week’s C drops 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.

Synergy Pharmaceuticals, Inc. (SGYP) ratings are on the decline this week as the company earns an F (“strong sell”). Last week, it received a D (“sell”). 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 Sept. 4, 2015, 20.6% of outstanding Synergy Pharmaceuticals, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of SGYP stock.

This week, Verastem, Inc. (VSTM) drops from a D to an F rating. 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 Sept. 4, 2015, 11.2% 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) earns a D this week, moving down from last week’s grade of C. 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 Sept. 4, 2015, 16.9% of outstanding Celldex Therapeutics, Inc. shares were held short. For more information, get Portfolio Grader’s complete analysis of CLDX stock.

The rating of Trevena, Inc. (TRVN) declines this week from a C to a D. The stock gets F’s in Equity and Cash Flow. Trade volume is up 2339.4% from the previous week. To get an in-depth look at TRVN, get Portfolio Grader’s complete analysis of TRVN stock.

Avalanche Biotechnologies Inc (AAVL) is having a tough week. The company’s rating falls from a C to a D. The stock gets F’s in Equity and Cash Flow. For more information, get Portfolio Grader’s complete analysis of AAVL 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.