This week, the overall grades of 5 Biotechnology stocks are lower, according to the Portfolio Grader database. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This is a rough week for Clovis Oncology, Inc. (CLVS). The company’s rating falls to F from the previous week’s D. Clovis Oncology, Inc. is a biopharmaceutical company which focuses on acquiring, developing and commercializing innovative anti-cancer agents in the U.S., Europe and additional international markets. The company also gets F’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of CLVS stock.

Concert Pharmaceuticals, Inc. (CNCE) declines this week from a D to a F. The company also gets F’s in sales growth, earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of CNCE stock.

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

Synergy Pharmaceuticals, Inc. (SGYP) earns a F this week, moving down from last week’s grade of D. Synergy Pharmaceuticals, Inc. is a biopharmaceutical company focused on the development of drugs to treat gastrointestinal disorders and diseases. The company also gets F’s in earnings surprise and free cash flow. For more information, get Portfolio Grader’s complete analysis of SGYP stock.

This week, Onconova Therapeutics Inc. (ONTX) drops from a D to a F rating. 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 ONTX 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.