Determination of Regulatory Review Period for Purposes of Patent Extension; ZYFLOSUPTM/SUP

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

[Docket No. 97E-0067]

Determination of Regulatory Review Period for Purposes of Patent

Extension; ZYFLOTM

AGENCY: Food and Drug Administration, HHS.

ACTION: Notice.

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SUMMARY: The Food and Drug Administration (FDA) has determined the

regulatory review period for ZYFLOTM and is publishing this

notice of that determination as required by law. FDA has made the

determination because of the submission of an application to the

Commissioner of Patents and Trademarks, Department of Commerce, for the

extension of a patent which claims that human drug product.

ADDRESSES: Written comments and petitions should be directed to the

Dockets Management Branch (HFA-305), Food and Drug Administration,

12420 Parklawn Dr., rm. 1-23, Rockville, MD 20857.

FOR FURTHER INFORMATION CONTACT: Brian J. Malkin, Office of Health

Affairs (HFY-20), Food and Drug Administration, 5600 Fishers Lane,

Rockville, MD 20857, 301-443-1382.

SUPPLEMENTARY INFORMATION: The Drug Price Competition and Patent Term

Restoration Act of 1984 (Pub. L. 98-417) and the Generic Animal Drug

and Patent Term Restoration Act (Pub. L. 100-670) generally provide

that a patent may be extended for a period of up to 5 years so long as

the patented item (human drug product, animal drug product, medical

device, food additive, or color additive) was subject to regulatory

review by FDA before the item was marketed. Under these acts, a

product's regulatory review period forms the basis for determining the

amount of extension an applicant may receive.

A regulatory review period consists of two periods of time: A

testing phase and an approval phase. For human drug products, the

testing phase begins when the exemption to permit the clinical

investigations of the drug becomes effective and runs until the

approval phase begins. The approval phase starts with the initial

submission of an application to market the human drug product and

continues until FDA grants permission to market the drug product.

Although only a portion of a regulatory review period may count toward

the actual amount of extension that the Commissioner of Patents and

Trademarks may award (for example, half the testing phase must be

subtracted as well as any time that may have occurred before the patent

was issued), FDA's determination of the length of a regulatory review

period for a human drug product will include all of the testing phase

and approval phase as specified in 35 U.S.C. 156(g)(1)(B).

FDA recently approved for marketing the human drug product

ZYFLOTM (zileuton). ZYFLOTM is indicated for the

prophylaxis and chronic treatment of asthma in adults and children 12

years of age and older. Subsequent to this approval, the Patent and

Trademark Office received a patent term restoration application for

ZYFLOTM (U.S. Patent No. 4,873,259) from Abbott

Laboratories, and the Patent and Trademark Office requested FDA's

assistance in determining this patent's eligibility for patent term

restoration. In a letter dated March 12, 1997, FDA advised the Patent

and Trademark Office that this human drug product had undergone a

regulatory review period and that the approval of ZYFLOTM

represented the first permitted commercial marketing or use of the

product. Shortly thereafter, the Patent and Trademark Office requested

that FDA determine the product's regulatory review period.

FDA has determined that the applicable regulatory review period for

ZYFLOTM is 3,329 days. Of this time, 2,454 days occurred

during the testing phase of the regulatory review period, while 875

days occurred during the approval phase. These periods of time were

derived from the following dates:

1. The date an exemption under section 505(i) of the Federal Food,

Drug, and Cosmetic Act (21 U.S.C. 355(i)) became effective: October 31,

1987. The applicant claims October 30, 1987, as the date the

investigational new drug application (IND) became effective. However,

FDA records indicate that the IND effective date was October 31, 1987,

which was 30 days after FDA receipt of the IND.

2. The date the application was initially submitted with respect to

the human drug product under section 505(b) of the Federal Food, Drug,

and Cosmetic Act: July 19, 1994. The applicant claims July 18, 1994, as

the date the new drug application (NDA) for ZYFLOTM (NDA 20-

471) was initially submitted. However, FDA records indicate that NDA

20-471 was submitted on July 19, 1994.

3. The date the application was approved: December 9, 1996. FDA has

verified the applicant's claim that NDA 20-471 was approved on December

9, 1996.

This determination of the regulatory review period establishes the

maximum potential length of a patent extension. However, the U.S.

Patent and Trademark Office applies several statutory limitations in

its calculations of the actual period for patent extension. In its

application for patent extension, this applicant seeks 1,398 days of

patent term extension.

Anyone with knowledge that any of the dates as published is

incorrect may, on or before September 16, 1997 submit to the Dockets

Management Branch (address above) written comments and ask for a

redetermination. Furthermore, any interested person may petition FDA,

on or before January 14, 1998 for a determination regarding whether the

applicant for extension acted with due diligence during the regulatory

review

[[Page 38563]]

period. To meet its burden, the petition must contain sufficient facts

to merit an FDA investigation. (See H. Rept. 857, part 1, 98th Cong.,

2d sess., pp. 41-42, 1984.) Petitions should be in the format specified

in 21 CFR 10.30.

Comments and petitions should be submitted to the Dockets

Management Branch (address above) in three copies (except that

individuals may submit single copies) and identified with the docket

number found in brackets in the heading of this document. Comments and

petitions may be seen in the Dockets Management Branch between 9 a.m.

and 4 p.m., Monday through Friday.

Dated: July 8, 1997.

Allen B. Duncan,

Acting Associate Commissioner for Health Affairs.

[FR Doc. 97-18910 Filed 7-17-97; 8:45 am]

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