Determination of Regulatory Review Period for Purposes of Patent Extension; IMMITICIDERegister

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Food and Drug Administration

[Docket No. 95E-0364]

Determination of Regulatory Review Period for Purposes of Patent

Extension; IMMITICIDE

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 IMMITICIDE 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 animal 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 animal drug products, the

testing phase begins on the earlier date when either a major

environmental effects test was initiated for the drug or when an

exemption under section 512(j) of the Federal Food, Drug, and Cosmetic

Act (21 U.S.C. 360b(j)) became effective and runs until the approval

phase begins. The approval phase starts with the initial submission of

an application to market the animal 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 an animal

drug product will include all of the testing phase and approval phase

as specified in 35 U.S.C. 156(g)(4)(B).

FDA recently approved for marketing the animal drug product

IMMITICIDE (melarsomine dihydrochloride).

IMMITICIDE is indicated for the treatment of stabilized Class

1, 2, and 3 heartworm disease caused by immature (4-month old, stage

L5) to mature adult infections of Dirofilaria immitis in dogs.

Subsequent to this approval, the Patent and Trademark Office received a

patent term restoration application for IMMITICIDE (U.S.

Patent No. 4,514,390) from Rockefeller University and the Patent and

Trademark Office requested FDA's assistance in determining the patent's

eligibility for patent term restoration. In a letter dated November 24,

1995, FDA advised the Patent and Trademark Office that this animal drug

product had undergone a regulatory review period and that the approval

of IMMITICIDE represented the first commercial marketing 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

IMMITICIDE is 2,650 days. Of this time, 2,037 days occurred

during the testing phase of the regulatory review period, while 613

days occurred during the approval phase. These periods of

[[Page 11055]]

time were derived from the following dates:

1. The date an exemption under section 512(j) of the Federal Food,

Drug, and Cosmetic Act became effective: April 20, 1988. FDA has

verified the applicant's claim that the date the investigational new

drug application became effective was April 20, 1988.

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

the animal drug product under section 512(b) of the Federal Food, Drug,

and Cosmetic Act: November 16, 1993. The applicant claims November 5,

1993, as the date the new animal drug application (NADA) for

IMMITICIDE (NADA 141-042) was initially submitted. However, a

review of FDA records reveals that the date of FDA's official

acknowledgment letter assigning a number to the NADA was November 16,

1993, which is considered to be the initially submitted date for the

NADA.

3. The date the animal drug was approved: July 21, 1995. FDA has

verified the applicant's claim that NADA 141-042 was approved on July

21, 1995.

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 1,095 days of

patent term extension. -

Anyone with knowledge that any of the dates as published is

incorrect may, on or before April 17, 1996, 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 September 16, 1996, for a determination regarding whether

the applicant for extension acted with due diligence during the

regulatory review 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: March 8, 1996.

Stuart L. Nightingale,

Associate Commissioner for Health Affairs.

[FR Doc. 96-6454 Filed 3-15-96; 8:45 am]

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