Chiron Corp. v. SourceCF Inc.

431 F. Supp. 2d 1019, 2006 U.S. Dist. LEXIS 33046, 2006 WL 1329762
CourtDistrict Court, N.D. California
DecidedMay 16, 2006
DocketC 05-01938 WHA
StatusPublished
Cited by1 cases

This text of 431 F. Supp. 2d 1019 (Chiron Corp. v. SourceCF Inc.) is published on Counsel Stack Legal Research, covering District Court, N.D. California primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Chiron Corp. v. SourceCF Inc., 431 F. Supp. 2d 1019, 2006 U.S. Dist. LEXIS 33046, 2006 WL 1329762 (N.D. Cal. 2006).

Opinion

FINDINGS OF FACT AND CONCLUSIONS OF LAW AFTER BENCH TRIAL

ALSUP, District Judge.

INTRODUCTION

The issue presented is the extent to which cystic fibrosis victims, their parents and their doctors are barred by a medical-method patent asserted by Chiron Corporation from using inhaled tobramycin to treat lung infections. Cystic fibrosis victims, their parents and their physicians have long used inhaled antibiotics to treat lung infections. Tobramycin and nebulizers were known well before the invention in question. Neither was invented by Chiron. A drug-device combination using tobramycin with a particular nebulizer came on the market in 1997. Chiron later acquired it and has successfully marketed the combination as TOBI. It is prior art for purposes of Chiron’s later patent asserted herein.

More efficient and more portable nebulizers have been invented by others. Being more efficient, the new nebulizers can cut the treatment duration at least in half. The shorter treatment duration encourages children to comply with their treatment regimens. The new nebulizers are also small and portable, unlike the heavy TOBI machine. It seems undisputed between the parties that the new generation of nebulizers represents an improvement.

Despite this development, Chiron has not come out with a new drug-device combination using a new nebulizer. Instead, it has continued to promote TOBI, which still enjoys a dominant market position. Chiron has, however, successfully sought and obtained a recent medical-method patent *1021 to prevent CF victims, their parents and their physicians from using the new generation of nebulizers with tobramycin, or at least from using those treatment methods within the limits of the claims.

Chiron does not claim to have invented tobramycin or a nebulizer of any type. Rather, Chiron claims to have discovered safe and efficacious concentrations of tobramycin for use in the new nebulizers. Chiron based its patent application on three clinical studies. The clinical studies vetted reduced volumes of Chiron’s standard TOBI solution with more efficient nebulizers. These studies were eventually published as the disclosure in the patent in suit. Significantly, all of the studies involved tobramycin concentrations of 60 mg/ml or 120 mg/ml. All of the claims called out concentrations of “about 60 mg/ ml” or higher. No study in the patent vetted weaker concentrations. No claim called out weaker concentrations.

Through the patent in suit, Chiron asserts that CF victims, their parents and their physicians are barred from using any treatment method administering tobramycin via the new and efficient nebulizers when the total dose to be nebulized is four milliliters or less and the concentration of tobramycin to solution is within the range of “about 60 mg/ml to about 200 mg/ml.” The accused methods of treatment at issue herein, however, all involve concentrations below 60 mg/ml. In one, CF victims, their parents and doctors use a concentration of 50 mg/ml. In the other, the concentration is 40 mg/ml. The issue for decision is whether Chiron’s patent covers and therefore bars use of these methods involving weaker concentrations.

The issue is important to Chiron because its sole entry in the relevant market is TOBI. Although, as stated, Chiron does not sell products for use with the patented method, the emergence of the new class of better nebulizers poses a threat to TOBI’s dominant market share.

After a bench trial, this order holds that Chiron’s patent does not cover the weaker concentrations at issue in this suit. It is true that the lower concentrations seem safe and efficacious. But the patent is limited by the concentrations actually claimed. The patent does not go so far as to claim all safe and effective doses regardless of concentration. The injunction sought by Chiron must be denied.

FINDINGS OF FACT AND PROCEDURAL HISTORY 1

The patent in suit is United States Patent No. 6,890,907 (“the '907 patent”), owned by Chiron Corporation. The '907 patent purportedly discloses a method of treating lung infections, namely using certain concentrations of liquid tobramycin with high-efficiency nebulizers, for patients suffering from cystic fibrosis.

Cystic fibrosis strikes children. The symptoms manifest in early childhood. The average life expectancy of CF patients is thirty-five years. Approximately 30,000 children and adults in the United States currently suffer from CF.

*1022 CF causes mucus in the airways to become thick, dry, and sticky. The mucus builds up rather than continually refreshing itself as would be normal. The buildup is unhealthy, especially in the lungs. The lungs become breeding grounds for harmful bacteria. The most significant of these pathogens is Pseudomonas aeruginosa.

Well before the alleged invention, physicians administered and pharmacists dispensed antibiotics to CF patients to treat pulmonary infections including Pseudomonas aeruginosa. The most successful of such antibiotics was (and remains) tobramcyin. Tobramycin, however, is poorly absorbed across mucosal surfaces.

In the early 1990’s, therefore, physicians began administering tobramycin to CF patients via inhalation therapy. The total doses of tobramycin used at that time ranged from 80 mg to 400 mg. The tobramycin was dissolved in a solution. The doctor would prescribe a concentration, for example, “100 mg/ml” or state “200 mg in 2 ml of saline solution” (which would translate to a concentration of 100 mg/ml). Pharmacists would dispense concentrations pursuant to physicians’ orders. A brand-name version of tobramcyin for inhalation in the early 1990’s was NEBCIN, which came in either a 40 mg/ml concentration in 2 ml volume or in a powder form to allow pharmacists to dispense the medication pursuant to a physician’s specifications. NEBCIN was part of the prior art. It was not Chiron’s product.

The primary inhalation device available for tobramycin in the early 1990’s was the jet nebulizer. A nebulizer is an apparatus that converts a liquid (such as a medication) into aerosol droplets. A jet nebulizer uses gas flow through an aperture to pick up and atomize a solution. Pari Respirator Equipment, Inc. manufactured one such jet nebulizer known as the Pari LC Plus.

Prior to any application for the '907 patent, an earlier patent issued on April 16, 1996, relating to an antibiotic solution for aerosolization for CF patients. This was United States Patent No. 5,508,269 (“the '269 patent”). That patent was obtained by PathoGenesis, later acquired by plaintiff Chiron. The '269 is prior art for our purposes. The '269 described an antibiotic solution for inhalation, limited by amount of antibiotic, total volume, nebulization method and particle size.

On December 22, 1997, the Food and Drug Administration approved TOBI as a drug-device combination. TOBI was essentially the drug-device combination described in the '269 patent. TOBI is a particular concentration of tobramcyin solution for inhalation in the Pari LC Plus. The marketed version of TOBI contained 300 mg/ml of tobramcyin in 5 ml of quarter saline solution, i.e., a concentration of 60 mg/ml.

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431 F. Supp. 2d 1019, 2006 U.S. Dist. LEXIS 33046, 2006 WL 1329762, Counsel Stack Legal Research, https://law.counselstack.com/opinion/chiron-corp-v-sourcecf-inc-cand-2006.