March 23, 2021
UPS EXPRESS MAIL

Mr. Gene Kakaulin
Chief Executive Officer
Curex, Inc.
95 Fifth Avenue
Floor 4
New York, NY 10003


Dear Mr. Kakaulin:

The Office of Compliance and Biologics Quality in the Center for Biologics Evaluation
and Research of the United States Food and Drug Administration (FDA) has reviewed
your firm’s Internet website www.getcurex.com.

Based on our review, you and your firm market mixtures of allergenic extracts intended
for sublingual immunotherapy (SLIT), which you refer to on your website as “allergy
drops” and “drop compounds”. For example, your website states:

• “Curex treats people who suffer from all types of allergies . . . .”

• “Curex allergy drops (also known as sublingual immunotherapy) is an equally
effective, much less invasive way to treat allergies from home.”

• “We use FDA-approved extracts in a clinically proven practice that, when done
diligently with proper medical care, can significantly reduce your allergy
symptoms.”

• “You take sublingual immunotherapy by putting a daily drop of the compound
under your tongue . . . .”

• “Our doctors will assist you at the different stages of your allergy care journey.
They will help you start drops and will monitor your treatment to see if drop
compounds and/or dosages need to be adjusted.”
U.S. Food & Drug Administration
10903 New Hampshire Avenue Silver
Spring, MD 20993 www.fda.gov
 
Page 2 – Mr. Gene Kakaulin, Curex, Inc.
• “Our doctors formulate a unique treatment for you that may include multiple
allergies, including pets, dust mites, grasses, pollens, molds and fungi, and many
more.”
• “The therapy is a formulation of specific allergens that helps reduce allergy
symptoms and the need for allergy medications (i.e., antihistamines) over time.
Each compound is customized to the individual patient based on their medical
profile, test results, and lifestyle needs.”
The “allergy drops” and “drop compounds” marketed on your website are drugs as
defined under section 201(g) of the Federal Food, Drug, and Cosmetic Act (the FD&C
Act) [21 U.S.C. 321(g)] and biological products as defined in section 351(i) of the Public
Health Service Act (PHS Act) [42 U.S.C. 262(i)].
In order to lawfully market a drug that is also a biological product, a valid biologics
license must be in effect [42 U.S.C. 262(a)]. Such licenses are issued only after a
demonstration that the product is safe, pure, and potent. While in the development
stage, such products may be distributed for clinical use in humans only if the sponsor
has an investigational new drug application (IND) in effect as specified by FDA
regulations [21 U.S.C. 355(i); 42 U.S.C. 262(a)(3); 21 CFR Part 312; 21 CFR Part
601.21].
Licensed biological products may not be combined with other licensed biological
products, either therapeutic, prophylactic, or diagnostic, except as a license is obtained
for the combined product [21 CFR 610.17]. Accordingly, to be lawfully marketed, a
mixture of licensed allergenic extracts must be the subject of an approved biologics
license application (BLA).
Your products are not the subject of an approved BLA nor is there an IND in effect for
any of your products. Therefore, the marketing and distribution of such products
appears to violate the FD&C Act and the PHS Act.
Please be advised that biological products subject to licensure under section 351 of the
PHS Act are not eligible for the exemptions for compounded drugs under sections 503A
and 503B of the FD&C Act. For additional information, we recommend that you review
FDA’s Guidance for Industry, Mixing, Diluting, or Repackaging Biological Products
Outside the Scope of an Approve Biologics License Application (January 2018),
available at https://www.fda.gov/files/drugs/published/Mixing--Diluting--orRepackagingBiological-Products-Outside-the-Scope-of-an-Approved-BiologicsLicenseApplication.pdf.
This letter is not intended to be an all-inclusive review. You and your firm are
responsible for ensuring that all your products fully comply with the FD&C Act, PHS Act,
and all applicable regulations. We request a written response within 30 days of your
receipt of this letter. Your response should be sent to the following address: U.S. Food 
Page 3 – Mr. Gene Kakaulin, Curex, Inc.
and Drug Administration, Center for Biologics Evaluation and Research, 10903 New
Hampshire Avenue, Bldg. 71, Silver Spring, MD 20993. In addition, you may also
submit an electronic copy of your response to
CBERDCMRecommendations@fda.hhs.gov. If you have any questions regarding this
letter, please contact the Division of Case Management, CBER at (240) 402-9155.
Please be advised that only written communications are considered official. 
Sincerely,
Mary A. Malarkey
Director
Office of Compliance and Biologics Quality
Center for Biologics Evaluation and Research