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Vaccines, Blood & Biologics

Evaluation of Proposed Proprietary Name - Pentacel


Public Health Service
Food and Drug Administration

Center for Biologics Evaluation and Research

Date: April 23, 2008

To: Theresa Finn, PhD., Chairperson, OVRR/DVRPA/BVB, HFM-481
Edward Wolfgang, Regulatory Coordinator, OVRR/DVRPA, HFM-475

Through: Ele Ibarra-Pratt, RN, MPH, Branch Chief, APLB, HFM-602

From: Maryann R. Gallagher, CSO, APLB, HFM-602

Subject: Re-evaluation of Proposed Proprietary Name Pentacel®
BLA # 125145

Recommendation: ACCEPTABLE

Executive Summary:

APLB performed a re-evaluation of the proposed proprietary name Pentacel, to determine if any new products have been approved since our previous review on May 11, 2007. APLB found that no new products have been approved whose names resemble Pentacel, therefore, APLB recommends that the proposed proprietary name, Pentacel, be found acceptable with concerns, as expressed in previous reviews.


On January 3, 2008, OVRR notified the Pentacel review committee that sanofi pastuer submitted a response to the last item of the June 2007 CR letter. The action due date is June 21, 2008. APLB re-reviewed the proprietary name because substantial time has passed since our last review and to ensure that our review was within 90 days of approval. APLB found that no new products have been approved whose names resemble Pentacel, however, there appears to be a minimal risk for medication errors with the proprietary names for other marketed products due to the prefix “Penta” taking into account similarity in spelling, pronunciation, handwriting, and marketing status. However, this risk is minimized due to the differences in dose, dosage form, administration route, indication, pharmacological-categories and storage condition.

Chronological History:

  • May 31, 2002, APLB reviewed the proposed proprietary name PENTACEL that was submitted to the IND and recommended that the proposed name is unacceptable
  • October 1, 2002, Prevnar (vaccine) was approved
  • December 13, 2002, Pediarix (vaccine) was approved
  • February 13, 2003, Aventis Pasteur submitted a request for a reevaluation of their proposed proprietary name, PENTACEL with additional detail to justify the acceptability of the proposed proprietary name.
  • March 31, 2003, APLB re-reviewed the proposal for proprietary name, PENTACEL and recommended that it was acceptable.
  • June 10, 2005, ADACEL (vaccine) was approved on June 10, 2005.
  • July 26, 2005, Aventis Pasteur submitted the BLA for PENTACEL.
  • September 6, 2005, ProQuad (vaccine) was approved.
  • November 22, 2005, Aventis Pasteur, Inc requested review of the PENTACEL trade name.
  • January 3, 2006, APLB requested additional information and requested a complete data report from research conducted for the proposed name.
  • March 31, 2006, teleconference with Dr. Finn and Sanofi Pasteur regarding the potential for confusion due to similarities in the tradenames for PENTACEL and DAPTACEL.
  • April 27, 2006, Sanofi Pastuer submitted complete Medical Error Prevention Analysis (MEPA) report in support of the proposed proprietary name, Pentacel.
  • May 16, 2006, APLB re-reviewed the proposed proprietary name, PENTACEL and recommended that it was acceptable. APLB recommended that the name be revised to use lower case letters to avoid confusion with DAPTACEL.
  • April 4, 2007, OVRR requested another review of the proposed proprietary name Pentacel.
  • April 23, 2007, OVRR issued a CR letter for the Pentacel BLA.
  • May 11, 2007, APLB re-reviewed the proposal for proprietary name, PENTACEL and determined that it was acceptable.


Pentacel may be confused with the proprietary or the established names of other products (listed below) because of similarity in spelling, pronunciation, and handwriting. Since, drug products are prescribed through written, verbal, and /or electronic orders, such forms of communication may lead to medication errors, particularly if proprietary and /or established names sound or look alike. Even when proprietary names are only slightly similar, overlapping product characteristics may create a greater potential for confusion.

APLB also has concerns with similar letters in the first part of a proprietary or established name because the prescriber's handwriting may become less legible at the end of the name making these names indistinguishable from sound-alike, look-alike names for products that already exist in the U.S. marketplace. For example, there are a number of marketed products with the “Pen” prefix included in their proprietary name. Those that are of high/moderate concern include: Pen… (topical), Pentam (inhalation and injection), Pentasa (oral), Penicillin G procaine (injection), Penicillin V Potassium (oral), Penicillin VK (oral), Pentolair (ophthalmic), and Pentoxil (oral).

Many prescriptions or medications are written using the established or generic names. Products that could be confused with Pentacel, that contain “Pen” in their established name. Those that are of high/moderate concern include: Penicillin (many different dose strengths and products in oral and injection), penicillin g benzathine (injection), pentamidine (inhalation and injection), pentobarbital (oral and injection), pentostatin (injection), pentazocine (oral and injection), pentetate calcium (solution, inhalation, and injection), and pentetate zinc (solution, inhalation, and injection), and pentoxifylline (oral). Since the names begin with “Pen,” the same first three letters as Pentacel, there is a significant potential for medication error due to similarity in spelling and pronunciation of these products with Pentacel.

Penicillins are widely dispensed and some commonly used proprietary names for pencillins include: V-cillin K, Wycillin VK, Beepen VK, Ledercillin VK, and Pen V. In addition, written or verbal orders for oral penicillin often utilize the term, Pen VK. The penicillin products are the only marketed products that often use V or VK modifiers with their name and could easily be confused with the sponsors V, VF or F proposed modifiers. Therefore, there appears to be significant potential for medication errors with Penicillins and Pentacel due to similar sounding beginning, frequent use, storage and dosage form.

There are a number of marketed products with the “Pan” prefix included in their proprietary name which could sound similar to “Pen” and lead to confusion due to similarity in pronunciation of the first part of the name. Of moderate/high concerns are: Pandel (topical), Panhematin (injection), Panheparin (injection). Since prescriptions are often written and products stored utilizing established names, confusion could occur with an order for Pentacel. There are a number of marketed products with the “Pan” prefix included in the established name. Those that are of moderate/higher concern include: Pancuronium (injection) and pantoprazole (oral). Because the names begin with “Pan” there is a potential for medication error due to similarity in spelling and pronunciation of these products with Pentacel.

Marketed products whose proprietary name contains the “cel”, have the potential to sound alike or look alike other products with the same suffix if the first part of the name is written illegibly, i.e., Evicel (fibrin sealant), and Carticel (tissue). In addition, products whose proprietary name contains the “sil” suffix, have the potential to sound like or look-like (handwriting) products ending in “cel”, i.e., Gardasil (vaccine) and Lamisil (oral). However, the beginnings of their proprietary names are not similar to Pentacel but they have a similar sounding ending, there is a potential risk for confusion with Pentacel.

There is a potential for confusion with Pentacel and other sanofi pasteur vaccines, that end with the “cel” suffix which could potentially result in a medication error, i.e., Adacel and DAPTACEL. sanofi pasteur agreed to use lower case letter for Adacel and Pentacel to avoid confusion with DATACEL.

Since vaccine products may be stored together, have very similar looking dosage forms (little vials or syringes), doses, and route of administration there is the potential for confusion with Pentacel. Examples of injectable marketed vaccines that begin with the letter “P” in their proprietary name: PedvaxHIB, Pneumovax 23, Pediarix, ProQuad, and Prevnar. These products are approved for different indications and age groups but could be confused because of poor handwriting.


APLB recommends that the proposed proprietary name, Pentacel, be found acceptable with concerns at this time.

If OVRR accepts our recommendation that the proposed proprietary name Pentacel is acceptable, please include the following text in your letter to the manufacturer:

We have re-evaluated your proposed proprietary name Pentacel in consultation with CBER's Advertising and Promotional Labeling Branch (APLB) and conclude that under 21 CFR Part 201 the proposed proprietary name is acceptable at this time.

The following references were used:

  1. 2002 American Drug Index
  2. (2007 Physicians' Desk Reference)
  3. (Electronic Orange Book)
  4. http://www.rxlist.comRxList
  5. (CDER New and Generic Drug Approvals: August 2006 to April 2008)
  6. (CBER approvals from August 2006 to March, 2008)
  7. (American Medical Association Website-Newly Approved USAN stems through January 25, 2008)
  8. (Drug Facts and Comparisons)
  9. http://cdspoca.cder.fda.poca/home.aspx (Phonetic and Orthographic Computer Analysis)

If you have any questions with regards to this review, please contact Maryann Gallagher at 301-827-3028

Contact FDA

(800) 835-4709
(240) 402-8010
Consumer Affairs Branch (CBER)

Division of Communication and Consumer Affairs

Office of Communication, Outreach and Development

Food and Drug Administration

10903 New Hampshire Avenue

Building 71 Room 3103

Silver Spring, MD 20993-0002

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