Ethyol Case Between MedImmune and Sun Pharma Heats Up
by Aaron F. Barkoff
MedImmune Oncology v. Sun Pharm. Indus., No. 04-2612 (D. Md. 2007)
MedImmune (MEDI) earns about $100 million annually from sales of Ethyol (amifostine), an injectable drug approved for the relief of certain side effects of chemotherapy and radiation therapy. Sun Pharmaceutical Industries filed an ANDA to market a generic version of Ethyol. In what appears to have become the standard strategy to protect sales of a brand name drug against generic competition, MedImmune responded by filing both a patent infringement lawsuit in court and a citizen petition with the FDA.
Last week in its patent infringement suit, MedImmune lost one battle and won another. Judge Marvin J. Garbis of the U.S. District Court for the District of Maryland granted Sun's motion for summary judgment of noninfringement as to MedImmune's U.S. Patent No. 5,424,471 and denied Sun's motion for summary judgment of nonfringement as to the other patent in suit, U.S. Patent No. 5,591,731. Click here for the memorandum opinion and order.
MedImmune asserted the product-by-process claims of the '471 patent, arguing on the basis of the Federal Circuit's decision in Scripps v. Genentech, 927 F.2d 1565 (Fed. Cir. 1991), that the claimed product is not limited by the process steps. The court, however, thought the better rule was set forth in Atlantic Thermoplastics v. Faytex, 970 F.2d 834 (Fed. Cir. 1991), which held that process steps of product-by-process claims do impart limitations. Because MedImmune and Sun did not dispute the fact that Sun makes its amifostine without using the process steps recited in the '471 patent, the court granted Sun's motion for summary judgment of noninfringement. (Interestingly, other district courts have opted to follow the Scripps rule.)
The asserted claims of the '731 patent are product claims, directed to "thermally-stable, sterile, crystalline amifostine trihydrate." However, the parties disputed whether the claimed crystalline amifostine must be "vacuum dried." Because the court found that both sides presented reasonable arguments as to the putative inclusion of a "vacuum dried" limitation, the court denied Sun's motion for summary judgment of noninfringment of the '731 patent. The court has scheduled a Markman hearing for June 6, 2007, to make a final determination on claim construction.
MedImmune filed its citizen petition relating to Ethyol on October 10, 2006, asking the FDA "to refuse to approve any ANDA for an amifostine product with labeling that omits dosage, administration, and other information related to the consequences of using the drug to reduce the incidence of xerostomia ["dry mouth"] in head and neck cancer patients being treated with radiotherapy." MedImmune's petition was clearly meant to block approval of Sun's ANDA.
Ethyol is approved for two indications: (1) the reduction of cumulative renal toxicity associated with the repeated administration of cisplatin in patients with advanced ovarian cancer; and (2) the reduction of moderate to severe xerostomia, or dry mouth, in patients undergoing post-operative radiation treatment for head and neck cancer. According to MedImmune's citizen petition, Sun Pharma "carved out" the second indication from the proposed labeling in its ANDA (presumably because MedImmune has method of treatment patents covering that use) and seeks approval for only the first indication. MedImmune asserts in its citizen petition that only 2% of patients taking Ethyol take it for the first indication, which requires a dose three times as high as that for the second indication. MedImmune claims "it would be unsafe to approve a generic version of Ethyol, yet allow the product to contain instructions on a dose that is simply incorrect for most patients for whom the drug is indicated."
MedImmune filed the patent infringement suit in August, 2004, and therefore the 30-month stay on approval is set to expire next month. It will be interesting to see whether the FDA decides MedImmune's citizen petition before then.
(This article was published by BioHealth Investor with permission of Aasron F. Barkoff, author of OrangeBookBlog.com)
RELATED READING:
- Jan. 10 MedImmune press release
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MedImmune Oncology v. Sun Pharm. Indus., No. 04-2612 (D. Md. 2007)
MedImmune (MEDI) earns about $100 million annually from sales of Ethyol (amifostine), an injectable drug approved for the relief of certain side effects of chemotherapy and radiation therapy. Sun Pharmaceutical Industries filed an ANDA to market a generic version of Ethyol. In what appears to have become the standard strategy to protect sales of a brand name drug against generic competition, MedImmune responded by filing both a patent infringement lawsuit in court and a citizen petition with the FDA.
Last week in its patent infringement suit, MedImmune lost one battle and won another. Judge Marvin J. Garbis of the U.S. District Court for the District of Maryland granted Sun's motion for summary judgment of noninfringement as to MedImmune's U.S. Patent No. 5,424,471 and denied Sun's motion for summary judgment of nonfringement as to the other patent in suit, U.S. Patent No. 5,591,731. Click here for the memorandum opinion and order.
MedImmune asserted the product-by-process claims of the '471 patent, arguing on the basis of the Federal Circuit's decision in Scripps v. Genentech, 927 F.2d 1565 (Fed. Cir. 1991), that the claimed product is not limited by the process steps. The court, however, thought the better rule was set forth in Atlantic Thermoplastics v. Faytex, 970 F.2d 834 (Fed. Cir. 1991), which held that process steps of product-by-process claims do impart limitations. Because MedImmune and Sun did not dispute the fact that Sun makes its amifostine without using the process steps recited in the '471 patent, the court granted Sun's motion for summary judgment of noninfringement. (Interestingly, other district courts have opted to follow the Scripps rule.)
The asserted claims of the '731 patent are product claims, directed to "thermally-stable, sterile, crystalline amifostine trihydrate." However, the parties disputed whether the claimed crystalline amifostine must be "vacuum dried." Because the court found that both sides presented reasonable arguments as to the putative inclusion of a "vacuum dried" limitation, the court denied Sun's motion for summary judgment of noninfringment of the '731 patent. The court has scheduled a Markman hearing for June 6, 2007, to make a final determination on claim construction.
MedImmune filed its citizen petition relating to Ethyol on October 10, 2006, asking the FDA "to refuse to approve any ANDA for an amifostine product with labeling that omits dosage, administration, and other information related to the consequences of using the drug to reduce the incidence of xerostomia ["dry mouth"] in head and neck cancer patients being treated with radiotherapy." MedImmune's petition was clearly meant to block approval of Sun's ANDA.
Ethyol is approved for two indications: (1) the reduction of cumulative renal toxicity associated with the repeated administration of cisplatin in patients with advanced ovarian cancer; and (2) the reduction of moderate to severe xerostomia, or dry mouth, in patients undergoing post-operative radiation treatment for head and neck cancer. According to MedImmune's citizen petition, Sun Pharma "carved out" the second indication from the proposed labeling in its ANDA (presumably because MedImmune has method of treatment patents covering that use) and seeks approval for only the first indication. MedImmune asserts in its citizen petition that only 2% of patients taking Ethyol take it for the first indication, which requires a dose three times as high as that for the second indication. MedImmune claims "it would be unsafe to approve a generic version of Ethyol, yet allow the product to contain instructions on a dose that is simply incorrect for most patients for whom the drug is indicated."
MedImmune filed the patent infringement suit in August, 2004, and therefore the 30-month stay on approval is set to expire next month. It will be interesting to see whether the FDA decides MedImmune's citizen petition before then.
(This article was published by BioHealth Investor with permission of Aasron F. Barkoff, author of OrangeBookBlog.com)
RELATED READING:
- Jan. 10 MedImmune press release
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