Report on New Patented Drugs – Gynazole-1

Under its transparency initiative, the PMPRB publishes the results of the reviews of new patented drugs by Board Staff, for purposes of applying the PMPRB's Price Guidelines, for all new active substances introduced after January 1, 2002.

Brand Name: Gynazole-1

Generic Name: butaconazole nitrate

DIN: 02248417 2% vaginal cream

Patentee: Ferring Inc.

Indication - as per product monograph: For the local treatment of vulvovaginal infections caused by Candida albicans

Notice of Compliance: December 23, 2003

Date of First Sale: April 27, 2004

ATC Class: G01AF15
Gynecological Antiinfectives and Antiseptics – Imidazole Derivatives

Application of the Guidelines

Summary:

The introductory price of Gynazole-1 was found to be within the Guidelines because the cost of therapy did not exceed the cost of therapy of existing drugs in the therapeutic class comparison and the price did not exceed the range of prices in other comparator countries where Gynazole-1 is sold.

Scientific Review:

The PMPRB's Human Drug Advisory Panel (HDAP) recommended that Gynazole-1 be reviewed as a category 3 new drug product (provides moderate, little or no therapeutic advantage over comparable medicines).

The Therapeutic Class Comparison (TCC) test of the Guidelines provides that the price of a category 3 new drug product cannot exceed the prices of other drugs that treat the same disease or condition. Comparators are generally selected from among existing drug products in the same 4th level of the Anatomical, Therapeutic, Chemical (ATC) System that are clinically equivalent in addressing the approved indication. The Guidelines provide that it may, however, be appropriate to include products from other ATC classes if they are clinically equivalent to the appropriate indication to the drug product under review. See the PMPRB's Compendium of Guidelines, Policies and Procedures for a more complete description of the Guidelines and the policies on TCCs.

Vulvovaginal candidiasis is one of the most frequently encountered vaginal infections and is estimated to occur in 5 to 8 percent of women during their reproductive years. Treatment management approaches include individual episode or use of prophylactic antimycotic medications.

Gynazole-1 is an imidazole derivative, single dose, antifungal agent with some gram-positive antibacterial activity. Three other similar single day therapy agents from the same 4th level ATC are available on the Canadian market; Canestan 1 cream (clotrimazole), Monistat 1 vaginal ovule and Monistat 1 combination pack (miconazole) and one from another 4th level ATC, Diflucan 150 (fluconazole). All these drugs share the approved indication of Gynazole-1 and were recommended by the HDAP as the most appropriate comparators.

The PMPRB's Guidelines provide that the dosage recommended for comparison purposes will normally not be higher than the maximum of the usual recommended dosage. The recommended comparable dosage regimens for Gynazole-1 and the comparators are based on the respective product monographs and supported by clinical literature.

Price Review:

Under the Guidelines, the introductory price for a new category 3 drug product will be presumed to be excessive if it exceeds the price of all of the comparable drug products in the TCC test, or if it exceeds the prices of the same medicine in the seven countries listed in the Patented Medicines Regulations.

The price of Gynazole-1 was within the Guidelines as the cost of treatment did not exceed the cost of treatment of the comparator medicines.

1 AQPP, October 2004
2 Shopper Drug Mart Retail Price, October 2004
3 ODB, January 2003, as of Update E, November 2004, no price change

In 2004 Gynazole-1 was also sold in the United States. In compliance with the Guidelines, the price in Canada did not exceed the price in that country.

The comparators and dosage regimen referred to in the Summary Report have been selected by Board Staff and the HDAP, for the purpose of carrying out the PMPRB's regulatory mandate which is to review the prices of patented medicines sold in Canada to ensure that such prices are not excessive. This publication is also part of the PMPRB's commitment to make its price review process more transparent.

The information contained in the PMPRB's Summary Report should not be relied upon for any purpose other than its stated purpose and is not to be interpreted as an endorsement, recommendation or approval of any drug nor is it intended to be relied upon as a substitute for seeking appropriate advice from a qualified health care practitioner.

Evidence/References Considered by HDAP

1. Brown D, Zenzl MR, Kaufman RH et al. Butoconazole nitrate 2% for vulvovaginal candidiasis. J Reprod Med 1999;44(11):933-8.

2. Weinstein L, Henzel MR, Tsinia IW. Vaginal retention of 2% butoconazole nitrate cream: comparison of a standard and a sustained-release preparation. Clin Ther 1994;16(6):930-4.

3. Health Canada. Canadian STD Guidelines. 1998 Edition. Available from: www.hc-sc.gc.ca/pphb-dgspsp/publicat/std-mts98/pdf/std98_e.pdf (accessed 11 Aug 2004).

4. Centers for Disease Control and Prevention. Sexually Transmitted Disease Treatment Guidelines 2002. MMWR 2002;51:RR-6. Available from: www.cdc.gov/std/treatment/rr5106.pdf (accessed 2004 Aug 11).

5. Gilbert DN, Moellering RC Jr, Eliopoulos GM, Sande MA, eds. Sanford Guide to Antimicrobial Therapy. 34th ed. Antimicrobial Therapy, Inc. Hyde Park, VT. 2004. P. 17, 77.

6. Health Canada. Drug Product Dictorate. Drug Product Database. Available from: http://www.hc-sc.gc.ca/hpb/drugs-dpd/index.html (Accessed 13 August 2004).

7. Package Insert of Gynazole-1 (butaconazole nitrate) Vaginal Cream, 2%. Ther-Rx Corporation. St. Louis, MO. Available from: http://www.ther-rx.com/products/pdf/64011000108_PIS.pdf (Accessed 13 Aug 2004.)

8. Fan E. New Drug: Gynazole-1 (butoconazole nitrate vaginal cream 2%). Pharm Let/Prescrib Let 2004;20:DN200421.

9. Repchinsky C, ed. Compendium of Pharmaceuticals and Specialties. Canadian Pharmacists Association. Ottawa, ON. 2004.

10. World Health Organization. ATC/DDD Index. Available from: www.whocc.no/atcddd/indexdatabase/index.php?query=G01AF. (accessed 28 July 2004).

11. Nyirjesy P, Sobel JD. Vulvovaginal candidiasis. Obstet Cynecol Clin N Am 3002;20:671-84.

12. Product Monograph of Gynazole-1 vaginal cream (butoconazole nitrate). Ferring Inc. dated December 18, 2003.