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Practical Issues in Combination Products
Primary Mode of Action & Request for Designation
AdvaMed MTL Conference -- May 25, 2006

Practical Issues in Combination Products
Primary Mode of Action & Request for Designation
AdvaMed MTL Conference
May 25, 2006

Suzanne O'Shea

Product Classification Officer

Office of Combination Products

Food and Drug Administration


In the beginning…


Office of Combination Products


OCP's Roles:


OCP Objectives

Ensure that regulation of every combination product is:


In a nutshell

OCP answers four questions products might ask -- if they could talk:

1. What am I?

2. Where do I go?

3. What do I do when I get there?

4. How can I get out of there as quickly as possible?


Where is OCP?

Commissioners Office
Office of Combination Products
Center for Biologic Evaluation and Research
Center for Devices and Radiological Health
Center for Drug Evaluation and Research


I am a combination product

Where do I go?

Drugs - CDER
Devices - CDRH
Biologics - CBER


Primary Mode of Action

Primary mode of action is the statutory criterion FDA must use to determine the agency component with primary jurisdiction for the review and regulation of a combination product.

21 U.S.C. § 503(g)


PMOA continued


Mode of Action


Primary Mode of Action

Primary mode of action is the single mode of action of a combination product that provides the most important therapeutic action of the combination product. The most important therapeutic action is the mode of action expected to make the greatest contribution to the overall intended therapeutic effects of the combination product.

21 CFR 3.2(m)


PMOA algorithm

If unable to determine most important therapeutic action with reasonable certainty, consider:


PMOA
CDER or CDRH?

Drug Eluting Stent
Primary Mode of Action: Stent opens artery
Secondard Action: Drug prevents inflamation and restenosis of artery.
Regulated by CDRH under device provisions.

Drug Eluting Disk
Primary Mode of Action: Cancer chemotherapy of brain tumor
Secondary Actions: Local drug delivery of drug by device.
Regulated by CDER under drug provision.


More PMOA examples

Spinal fusion device coated with therapeutic protein intended to treat degenerative disc disease


Two modes of action:
- mechanically maintain intervertebral spacing;
- encourage formation of bone within fusion cage.

PMOA attributable here to device component's action to mechanically maintain spacing and stabilize spine

- Protein cannot maintain space and stabilize alone

- Spinal fusion can be obtained without protein


More PMOA examples

Contact Lens Combined with Drug to Treat Glaucoma

Two modes of action: to correct vision
to administer glaucoma drug

Not possible to determine which MOA provides greatest contribution to overall therapeutic effect

Assignment Algorithm:

      1. Other combination products presenting similar S & E questions

      2. Agency component with most expertise pertaining to presenting S & E questions

?? What about second contact lens combined with ??
?? glaucoma drug product ??


The last PMOA example

Interferon Ribavirin Combination Therapy
to treat chronic hepatitis C

Interferon: biologic to treat chronic hepatitis C by causing decline in hepatitis C virus RNA titer

Ribavirin: drug improves liver function in hepatitis C patients, but they relapse

Products used together more effective than interferon alone.

Two modes of action: interferon treats disease; ribavirin enhances efficacy of interferon

PMOA: Interferon


Request for Designation (RFD)


Who should file an RFD?

An RFD should be filed when the

is unclear or in dispute.


What happens if
I don't file an RFD?

FDA may stay the review clock while a determination is being made.

21 CFR 3.10


When should I file an RFD?


RFD Content

21 CFR §3.7 (c)

Also, see Guidance Document on How to Write a Request for Designation at


Guidance Document

How to Write a Request for Designation


Guidance Document

How to Write a Request for Designation


RFD Processing


RFD processing

RFD decision letter must issue within

60 days.

Otherwise,

Sponsor's recommendation takes effect.

21 CFR 3.8(b)


What if I disagree with RFD decision?

Request for Reconsideration

21 CFR 3.8(c)


What's the effect of an
RFD letter?

Designated agency component may be changed without the consent of sponsor only to protect the public health or for another compelling reason.

21 CFR § 3.9(b)


RFD Statistics

October 1, 2005 March 31, 2006

Total Decisions Issued: 16

9 combination product

7 non-combination products

Mean Total Review Time: 34 days

Median Total Review Time: 31.5 days

Range of Total Review Time: 16 to 57 days

Requests for Reconsideration: 2

Response to Requests for Reconsideration 15 days

OCP agrees with sponsor's PMOA recommendation

72 per cent of the time.


How to find out…

See our website at:


Intercenter Agreements

ICA's premised on "most important therapeutic action"

For example: assignment to CDRH of "device incorporating a drug component with the combination product having the primary intended purpose of fulfilling a device function."

Underlying assumption: device provides most important therapeutic action.

1991 ICA's continue to provide helpful guidance but do not address many combination products developed since that time.


Intercenter Agreements


Jurisdictional Determinations


Jurisdictional Updates


RFD letters


Examples of Approved
Combination Products


Chemical Action


Perhaps the easiest
way to find out…

CALL US!


Contact Us!

Office of Combination Products

15800 Crabbs Branch Way

Suite 200, HFG-3

Rockville, Maryland 20855


Contact Us!


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