This week, 21 Biotechnology stocks are worse, according to the Portfolio Graderdatabase. Each of these rates a “D” (“sell”) or “F” overall (“strong sell”).

This week, Regeneron Pharmaceuticals, Inc. (REGN) drops from a C to a D rating. Regeneron Pharmaceuticals, Inc. researches, develops and commercializes therapeutics to treat human disorders and conditions. The company also gets F’s in earnings revisions and earnings surprise. For more information, get Portfolio Grader’s complete analysis of REGN stock.

Celgene Corporation (CELG) gets weaker ratings this week as last week’s C drops to a D. Celgene Corporation is a global integrated biopharmaceutical company engaged in the discovery, development, and commercialization of therapies designed to treat cancer and immune-inflammatory related diseases. For more information, get Portfolio Grader’s complete analysis of CELG stock.

Kite Pharma, Inc. (KITE) is having a tough week. The company’s rating falls from a C to a D. The company also gets F’s in earnings revisions, earnings momentum, and return on equity. For more information, get Portfolio Grader’s complete analysis of KITE stock.

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

SAGE Therapeutics, Inc. (SAGE) experiences a ratings drop this week, going from last week’s C to a D. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of SAGE stock.

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

Alder Biopharmaceuticals, Inc. (ALDR) earns a D this week, moving down from last week’s grade of C. The company also gets F’s in sales growth, earnings revisions, earnings momentum, and return on equity. For more information, get Portfolio Grader’s complete analysis of ALDR stock.

FibroGen, Inc. (FGEN) slips from a C to a D this week. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of FGEN stock.

This is a rough week for Atara Biotherapeutics Inc (ATRA). The company’s rating falls to D from the previous week’s C. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of ATRA stock.

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

Esperion Therapeutics, Inc.’s (ESPR) rating weakens this week, dropping to a F versus last week’s 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 ESPR stock.

This week, Retrophin, Inc.’s (RTRX) rating worsens to a D from the company’s C rating a week ago. The company also gets F’s in earnings revisions, earnings surprise, and earnings momentum. For more information, get Portfolio Grader’s complete analysis of RTRX stock.

Applied Genetic Technologies Corp. (AGTC) is having a tough week. The company’s rating falls from a C to a D. The company also gets F’s in return on equity. For more information, get Portfolio Grader’s complete analysis of AGTC stock.

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

Ironwood Pharmaceuticals, Inc. Class A (IRWD) gets weaker ratings this week as last week’s D drops to a F. Ironwood Pharmaceuticals, Inc. Class A discovers, develops, manufactures, and commercializes marketed drugs. The company also gets F’s in earnings revisions, earnings surprise, and return on equity. For more information, get Portfolio Grader’s complete analysis of IRWD stock.

Momenta Pharmaceuticals, Inc.’s (MNTA) rating weakens this week, dropping to a F versus last week’s D. Momenta Pharmaceuticals, Inc. is a biotechnology company which specializes in sequencing and engineering of complex sugars for the development of improved versions of existing drugs, the development of novel drugs, and the discovery of new biological processes. The company also gets F’s in earnings revisions and return on equity. For more information, get Portfolio Grader’s complete analysis of MNTA stock.

This week, Bellicum Pharmaceuticals Inc (BLCM) drops from a D to a F rating. 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 BLCM stock.

This is a rough week for Calithera Biosciences, Inc. (CALA). The company’s rating falls to D from the previous week’s C. 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 CALA stock.

Chimerix, Inc. (CMRX) 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 CMRX stock.

Genocea Biosciences, Inc. (GNCA) experiences a ratings drop this week, going from last week’s C to a D. 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 GNCA stock.

Kindred Biosciences, Inc. (KIN) earns a F this week, moving down from last week’s grade of D. 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 KIN 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.