The grades of 7 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.

Enanta Pharmaceuticals, Inc. (ENTA) earns a B this week, jumping up from last week’s grade of C. The company also gets A’s in return on equity and free cash flow. For more information, get Portfolio Grader’s complete analysis of ENTA stock.

This week, Grifols, S.A. Sponsored ADR Class B’s (GRFS) ratings are up from a C last week to a B. Grifols, S.A. Sponsored ADR Class B develops, manufactures, and markets plasma derivatives, IV Therapy, Enteral nutrition, diagnostic systems, and medical materials. The company also gets A’s in sales growth, earnings revisions, and return on equity. For more information, get Portfolio Grader’s complete analysis of GRFS stock.

MiMedx Group, Inc. (MDXG) shows solid improvement this week. The company’s rating rises from a C to a B. MiMedx Group, Inc. operates as a medical device company. The company also gets A’s in sales growth, operating margin growth, earnings growth, earnings surprise, and return on equity. For more information, get Portfolio Grader’s complete analysis of MDXG stock.

ZIOPHARM Oncology, Inc. (ZIOP) improves from a C to a B rating this week. ZIOPHARM Oncology, Inc. is a biopharmaceutical company that engages in the development and commercialization of small molecule and synthetic biology approaches to cancer therapies in the United States. The company also gets A’s in sales growth and earnings revisions. For more information, get Portfolio Grader’s complete analysis of ZIOP stock.

This week, Stellar Biotechnologies, Inc. (SBOT) pushes up from a C to a B rating. The company also gets A’s in sales growth. For more information, get Portfolio Grader’s complete analysis of SBOT stock.

The rating of MediciNova, Inc. (MNOV) moves up this week, rising from a B to a A. MediciNova, Inc. acquires, develops, and commercializes small molecule therapeutics. The company also gets A’s in earnings momentum. For more information, get Portfolio Grader’s complete analysis of MNOV stock.

This is a strong week for NanoViricides, Inc. (NNVC). The company’s rating climbs to B from the previous week’s C. For more information, get Portfolio Grader’s complete analysis of NNVC 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.