The grades of five Biotechnology stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

Array BioPharma (NASDAQ:ARRY) is progressing from last week’s rating of B (“buy”) as the company improves to an A (“strong buy”) this week. Array BioPharma is a biopharmaceutical company focused on the discovery, development and commercialization of targeted small molecule drugs to treat patients afflicted with cancer, inflammatory and metabolic diseases. In Portfolio Grader’s specific subcategory of Earnings Revisions, ARRY also gets an A. The stock price has risen 42.6% over the past month, better than the 2% increase the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of ARRY stock.

Alnylam Pharmaceuticals (NASDAQ:ALNY) is seeing ratings go up from a B last week to an A this week. Alnylam Pharmaceuticals engages in discovering, developing, and commercializing novel therapeutics based on RNA interference (RNAi). Wall Street has pushed the stock higher by 75.8% over the past month. For more information, get Portfolio Grader’s complete analysis of ALNY stock.

This week, DUSA Pharmaceuticals (NASDAQ:DUSA) is showing significant improvement as the company’s rating hops from a C (“hold”) to a B (“buy”). DUSA Pharmaceuticals is a vertically integrated dermatology company that is developing and marketing pharmaceuticals for the treatment of skin conditions such as actinic keratoses and acne. Wall Street seems to agree with the upgrade and has propelled the stock up 13.4% over the past month. For more information, get Portfolio Grader’s complete analysis of DUSA stock.

This is a strong week for Gentium (NASDAQ:GENT). The company’s rating climbs to B from the previous week’s C. Gentium is a biopharmaceutical company focused on the discovery, research, development, and manufacture of drugs for the treatment and prevention of a variety of vascular diseases and conditions related to cancer and cancer treatments. Investors seem to agree with the upgraded status of the stock, and have pushed the stock up 5.7% over the past month. For more information, get Portfolio Grader’s complete analysis of GENT stock.

This week, Discovery Laboratories‘s (NASDAQ:DSCO) ratings are up from a C last week to a B. Discovery Laboratories is a biotechnology company focused on developing products for the treatment of respiratory disease. Wall Street seems to agree with the upgrade and has propelled the stock up 20.8% over the past month. For more information, get Portfolio Grader’s complete analysis of DSCO 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.