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Moderator: Kemba Ford

03-31-21/12:15 pm ET

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FDA Virtual Town Hall Series –

Immediately in Effect Guidance on 

Coronavirus (COVID-19) Diagnostic Tests

Moderator: Irene Aihie

March 31, 2021

12:15 pm ET

Coordinator: Welcome and thank you for standing by. At this time all participants are in a 

listen-only mode until the question-and-answer session of today's conference. 

At that time you may press Star 1 on your phone to ask a question. I would 

like to inform all parties that today's conference is being recorded. If you 

have any objections, you may disconnect at this time. I would now like to 

turn the conference over to Kemba Ford. Thank you. You may begin.

Kemba Ford: Thank you, (Courtney). Hello. I’m Kemba Ford of (CDRH)’s Office 

Communication and Education. I would like to welcome you to the FDA's 

49th in a series of virtual town hall meetings designed to help answer 

technical questions about the development and validation of tests for SARSCoV-2 during the public health emergency.

Today, Timothy Stenzel, Director of the Office of In-vitro Diagnostics and 

Radiological Health with the Office of (Products) Evaluation and Quality. 

And Toby Lowe, our Associate Director of the Office of In-vitro Diagnostics 

and Radiological Health from CDRH will provide a brief update. Following 

their opening remarks, we will open the line for your questions related to the 

development and validation of tests for SARS-CoV-2. 
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Please remember that during this town hall, we are not able to answer or 

respond to questions about the specific submissions that might be under 

review. 

I will now turn the call over the Toby.

Toby Lowe: Thank you, Kemba and thanks everyone for joining us again this week. I have 

a couple of updates and I will go through some of the questions that we 

received by email. Then we can get started with live questions.

So first, I wanted to share with everyone that we posted a new webpage 

yesterday with information on the impact of viral mutation on COVID-19 

tests. This is a follow-up to the letter to healthcare providers and clinical 

laboratory staff that we issued in January regarding the potential for falsenegative results due to the impact of viral mutations on molecular SARSCoV-2 tests.

The webpage includes information about viral mutations and the potential 

impact as well as listing specific molecular tests that are impacted or where 

we have seen the potential for impact by viral mutations and specific 

recommendations for those tests. Right now the webpage includes the three 

tests that were included in the January safety alert as well as new information 

on three (seitan) tests based on new information that we have received.

Going forward, we intend to include updates related to viral mutations and the 

potential impact on tests on this webpage and we will announce any updates 

through this venue as well as email blasts out to the email list and inclusion on 

the regular COVID update press releases. So we'll use that as a central 

location for those types of updates rather than individual safety alerts each 

time there are issues that we become aware of.
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So that website, you can find that on our webpage and there's an email that 

went out yesterday as well that I believe most people on this call likely 

received.

Timothy Stenzel: Thanks, Toby. This is an effort to keep everybody updated on the current 

status of mutations and testing. It's there for easy access. So thanks Toby and 

the team for making that happen. As before, currently we do not know of any 

significant impact of mutations on overall test performance. That includes the 

new addition with (seitan) which is a multi-target assay. Only one target was 

affected by two different mutations as updated in the mutation update.

So that test and the others still remain, you know, strong options for fighting 

this pandemic. It's out of an abundance of caution that we make these updates 

and we know that users might spot potential problems ahead of developer

and/or the FDA and we ask your assistance in identifying concerns and 

bringing them to us. Thank you. Back over to you, Toby.

Toby Lowe: Great, thanks, Tim. So we also had a couple of questions last week that we 

wanted to follow up on. One is regarding whether vaccinated people can be 

included or must be excluded from validation studies for molecular diagnostic 

and antigen diagnostic of CoV-2 tests. Generally, we do think that it's okay to 

include vaccinated individuals for validated an (unintelligible) population, but 

those should be analyzed separately from unvaccinated individuals.

Timothy Stenzel: I would add, if I could add something.

Toby Lowe: Yes.
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Timothy Stenzel: I would add that there are now reports of breakthrough infections with some 

of the vaccines and what I've seen is no more that mild symptoms if any. But 

of course, we don’t know if the viral levels in those patients who have been 

vaccinated are going to be any different than unvaccinated individuals who 

are infected for the first time. So that's just something to be aware of. 

Thanks, Toby.

Toby Lowe: Thanks for the addition, Tim. Another question that we had from last week is

regarding the template for at-home testing. There was a question about the 

age inclusion in that template in one place it lists the lower end of the age 

range as 3 and in another place in the template it was 2. That is a typo, 2 is 

the age that should be included in both of those places in that template. We 

do recommend starting at 2 years old for nasal swabs. For saliva, we 

recommend slightly older to include school age, 5 to 6 because we have seen 

some usability issues with younger kids, but we do welcome you to 

demonstrate usability in younger kids with the usability study if you're design 

is conducive to that.

We also have heard from sites that had a difficult time enrolling kids for the 

clinical study and often are not getting any positives in that population. We 

are asking that either the usability study or the clinical study or both if 

possible include children if you're intending to include children in your 

indication.

Moving onto some of the questions that we received by email. We have one 

regarding seeking an EUA for an extended respiratory panel and whether

EUA requests for extended respiratory panels will be prioritized or not 

because there have been some. This question is asking about a particular one 

that was deprioritized.
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So we just want to clarify that there are many factors that go into our 

prioritization decision and some of those factors may not be publicly evident 

regarding the tests that are authorized. 

We have previously stated that we prioritize review of the A requests for tests 

that increase testing accessibility such as point of care, home collection and 

at-home tests. Tests that would significantly increase testing capacity such as 

tests that reduce reliance on test supplies, high throughput, widely distributed 

tests to address the public health needs. We do recommend that if you have 

questions about a decision about your particular test that you reach out to ask 

that specific question.

Timothy Stenzel: I would add that at this time pandemic is very different. Our needs are very 

different as a nation than they were at the beginning of the pandemic and what 

was possible at the beginning of the pandemic. So we seek to focus review 

attention and prioritization. And basically call out to developers what the, to 

give incentive to develop tests that are really needed right now. 

So high volume, accurate results, whether they're in the laboratory or they're 

at home or home collection or in point of care are the priorities right now. I 

just wanted to clarify that. Thanks, Toby.

Toby Lowe: Thanks, Tim. Our next question is about using an EUA comparator method 

for clinical study for a 510K submission and asking. We did talk about this 

last week that even though the biofire assay has been granted in de novo, that 

we still view intense you consider EUA, sorry CoV-2 assays to be an 

appropriate comparator for future 510K submissions.

However, this question is specifically asking about using an EUA assay as a 

comparator for the flu component or flu, RSV, other respiratory 
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(unintelligible) in a multi-analyte respiratory panel. We do want to clarify 

that for evaluating the clinical performance of your multi NIHS, we 

recommend that deduction of the non-SARS-CoV-2 analytes such as flu and 

RSV should be compared to a FI10K cleared molecular test. The EUA 

authorized test may be used as a (unintelligible) for SARS-CoV-2. 

We received another question about at-home COVID tests asking why there 

are not more. We do have four at-home COVID tests that are currently 

authorized. We do continue to encourage the development and submission of 

at-home tests. We previously discussed that we do continue to support 

innovation in testing and providing support and flexibility to test developers 

with the goal of increasing the availability of accurate and reliable tests.

We do need to point out that FDA does not develop tests. We cannot compel 

test developers to develop tests for specific characteristics although we have 

indicated our priorities which do include tests for home use.

We're also not involved in the production or distribution of tests. So we do 

encourage the availability of tests that we have authorized but we are not 

involved in that. Our role is to determine whether the tests submitted by test 

developers for emergency authorization meet the criteria for authorization so 

that we can provide a level of assurance that they produce results that 

American's can trust.

We will continue to work with test developers to support the availability of 

more innovative testing options. 

Timothy Stenzel: Yes, and unfortunately today with regards to molecular and anagen tests, 

specifically we simply have a positive of fully validated for home use tests 

submitted. So we do encourage test developers to come in with home use 
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tests and we've made it much easier now to get that OTC claim beginning 

without any data on any symptomatic prior to authorization. That pathway 

was outlined last week where if your performance meets a certain level, inhome user studies, for symptomatic patients, then you can simply agree to 

update your label with the serial testing claim and we will update your 

authorization for OTC and look forward to receiving a post market study 

showing adequate performance in the symptomatic population via that serial 

testing program. Thanks, Toby.

Toby Lowe: Yes, that's a good point that new pathway will hopefully speed things up for 

at-home tests. 

Last week we also talked a little bit about the use of thermology tests after 

vaccination and we received a question about which thermology tests would 

show antibodies after you've gotten the vaccination. So we do want to clarify

that the currently authorized SARS-CoV-2 antibodies are not validated or 

authorized to evaluate protective immunity and they're not specifically 

enabled for use after vaccinations.

So clinical significance of a positive or negative SARS-CoV-2 antibody test 

results in individuals that have received a COVID-19 vaccination is currently 

unknown. Not all the testable antibodies are protective and for other illnesses 

and SARS-CoV-2 antibody tests do not directly evaluate other components of 

the adoptive immune response such ad cellular immunity which may 

contribute to protection from infection after vaccination.

Additionally, since vaccines induce antibodies to specific viral protein targets, 

post-vaccination serologic tests results will be negative in persons without 

history of previous natural infection if the test that was used does not detect 

antibodies induced anything the vaccine.
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Timothy Stenzel: Thanks, Toby. I would add all three authorized vaccines in the US have only 

(spiked) protein component in them. So obviously, a serology test that doesn't 

target a spike protein will not be a good measure of whether there is an 

immune response to the vaccine. We have received reports of false negatives 

when clinicians have ordered (unintelligible) protein serology tests following 

vaccination one of the three authorized vaccines. Thanks, Toby.

Toby Lowe: That's for adding that. We received a question about whether there are any 3D 

printed materials used in COVID-19 tests. We do have - we are aware of 

some manufacturers that have produced 3D printed swabs and we have 

additional information about that on our COVID-19 test at the G-page. There 

is a section on 3D printed swabs specifically.

Timothy Stenzel: I would add that the 3D printing can be applied to other components other 

than swabs and there's no prohibition against the use of 3D printing to say 

presets or other components. We would just simply ask to put that 

information into if it's a new test and develop, it's into the pre-EUA to ask any 

questions that might be relevant to that method of manufacturing. Back over 

to you, Toby.

Toby Lowe: That's a great point. The next question that we have is about the restricting of 

the diagnostic EUA webpage. I think we mentioned this last week that we 

broke it out so that there will be separate pages now for molecular antigen and 

serology. This was a function of the page getting too big with so many tests 

having been authorized. So separating them should improve usability and 

functionality of the page.

The question that we received is about why we removed certain information 

specifically to the date that EUAs were first issued. And so I want to clarify 
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that we did not remove that. There was no information that changed with the 

split. It was just split into separate pages, but the information that was on the 

original page is now on the separate pages for molecular antigen and serology.

As it was before I met the individual or a single page, there was - there is a 

column. The first column is the date of the latest update. And the date that 

the EUA was first issued is included in the column with the link to the letter of 

the authorization. So that remains the same as it was.

We have a question about an antigen self-collect over the counter on rapid 

diagnostic tests with a companion app where the companion app supports 

patients in understanding how to properly administer the test and also supports 

public health reporting. And the question is about what to do if the - if an 

over-the-counter customer does not own a compatible device and whether an 

employee mechanism must be provided for public health reporting.

So, if a test may be performed with either a companion app or an alternate 

form of instructions, we would expect to see validation with - validation data 

with both options. We generally recommend that you develop a test 

procedure that is easy to follow in the form of a quick lesson instruction and 

user instruction should be oriented to users that no higher than a seventh grade 

reading level. 

It's highly recommended that you consider adding pictures and diagrams to 

facilitate performance of the test (unintelligible) user and that the instructions 

be limited to one to two pages. We do agree that where the mobile 

application-based material such as videos may be particularly helpful. 

Regarding reporting to public health authorities we are, I mentioned on this 

call previously, we are not requiring a reporting mechanism at the time of 
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authorization for at-home tests. But we do encourage all test developers to 

consider and approach to facilitate the reporting of test results to public health 

authorities. Since this is not a requirement at the time of authorization, we can 

discuss further options during the review of an EUA request.

Our next question is regarding the development of rapid tests for antigen and 

antibody. Basically a few questions about at-home serology tests and whether 

there's a template available. We have not yet published a template for athome serology tests and we're not able to speak to when or whether there will 

be one that is published. 

However, we know that some test developers have received some draft 

feedback from the review team and that is a good starting point. If you have 

specific questions about your own validation or study design, you can reach

out through the mailbox or to your review team if you already have one.

There's additionally a question about a test, a serology test that has already 

received an EUA to the point of care and what additional performance data is 

needed. So we would expect to see validation in an at-home setting if you are 

looking to have an at-home claim. 

There are multiple questions about the transition from EUA to 510K and 

regarding study designs. So we do encourage test developers that are 

interested in feedback on studies for a 510K to consider submitting a pre-sub 

so that we can make sure that we're giving complete and appropriate feedback 

for your specific submissions.

Timothy Stenzel: I would include the number of samples of each type that we're recommended 

for validation. Thanks, Toby.
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Toby Lowe: For asymptomatic claims and a point of care antigen test, we've received 

questions about the right proportion of symptomatic verse asymptomatic for 

inclusion in a clinical study. The antigen template for testing developers does 

include a recommendation that performance be confirmed by testing a 

minimum of 30 positive and 30 negative specimens in a randomized blinded 

fashion. 

That if you're seeking authorization for screening individuals without 

symptoms or other reasons with respect to COVID-19 that you include the 

intended population in your clinical study. So in addition to the 30 and 30, we 

would recommend that you enroll at least 20 positive asymptomatic 

individuals. You may also want to consider the approach that we aligned in 

the recent issues supplemental template for serial screening that Tim also 

mentioned a little earlier on this call where you can request a serial screening 

clean based on only symptomatic validation data with a post-authorization 

condition to validate serial screening.

Timothy Stenzel: As you're doing the original pathway of testing asymptomatic patients 

preauthorization we will accept this year as 10 asymptomatic patients in the

application to make a decision with the commitment after post-market 

authorization of completing the 20-hour requirement in the conditions of 

authority of authorization rather. Thanks, Toby.

Toby Lowe: Just to go a little further on the post-market topic, we have had some questions 

about if the clinical study was based on symptomatic subjects can the test 

developer add asymptomatic post-market and how many. And outside that is 

what we were just referring to both for the serial screening clean as well as if 

you have only 10 positive symptomatic, what with would consider 

authorization without that additional asymptomatic data with the postauthorization commitment. We will discuss the post-authorization study 
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during your review. Please submit your proposed post-authorization 

validation study in your supplemental EUA request to extend that indication.

We received a question about serology tests seeing point of care authorization 

and whether we can include - whether a manufacturer could include a subset 

of individuals who have received at least one dose of a COVID vaccine as 

long as they were previously identified as infected and then were subsequently 

vaccinated. 

Generally, we recommend referring to our template for serology tests for 

recommendations for clinical validation and at this time, we don't have any 

recommendations on study designs to support these of serology assays as an 

aid to assessing an immune response of individuals that have previously been 

immunized with the SARS-CoV-2 vaccine.

Our last present question is regarding the manufacturing of a serology test in 

the US versus manufacturing in China. And it is asking for a list of 

government approved components. So we can clarify that we do not have a 

list of government approved components for use in manufacturing. We do 

review EUA request for the final, finished devices. And the EUA applicant 

would be responsible for all data manufacturing and other FDA requirements 

applicable to the finished device including any quality system requirements 

that are not waived per the letter of authorization.

And with that, Tim, if you have any other updates or we can go onto the live 

questions.

Timothy Stenzel: Let's go into Q&A. Thanks.
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Coordinator: Thank you. We will now begin the question and answer session. If you would 

like to ask a question, please press Star 1. Unmute your phone and record 

your name clearly. Your name is required to introduce your question. If you 

need to withdraw your question, press Star 2. Again, to ask a question, please 

press Star 1. Our first question comes from (Wendy Chow).

(Wendy Chow): Hello.

Timothy Stenzel: Hi, (Wendy).

(Wendy Chow): Thank you. Can you hear me?

Timothy Stenzel: Yes.

(Wendy Chow): Okay, thanks. I have a question on the asymptomatic and symptomatic 

requirement for the study of the either antigen or molecular test. I have this 

question for a while. Because I think at the end it's the sensitivity or OD that 

matters regarding this symptomatic or asymptomatic because we know for 

some asymptomatic people their viral load is super high as well. In, of course, 

more symptomatic people have higher viral load. I think as (unintelligible) 

the study covers the whole spectrum of the viral load, it should be okay, right? 

Not like asymptomatic people have different (unintelligible) or respond 

differently to the testing. So that's a question actually in my mind for a while. 

Why should we activate different shape of two populations? Instead of just 

use the OD or sensitivity or in terms of molecular test, just use the safety 

distribution of the CT. 

And so this is a related question is about LDT. So for LDT we actually put a 

lot of emphasis on the sensitivity on the LOD. We, really analytic part really 

don't care about the people come with symptoms or not. It's nice we have the 
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good sensitivity we can detect anyone. So that's my question here. What's the 

philosophy or what's the point behind (unintelligible) the shape of this 

population?

Timothy Stenzel: Yeah, so you know, asymptomatic carriers of the, you know, the DSL3 virus 

is unusual. And you know, and we're still learning about the biology of the 

disease. The data that we've seen are mixed is whether for a given device and 

a given population, whether viral loads and detection of asymptomatic are 

equivalent to symptomatic. And in other words we have seen differences 

between those populations and when we see differences the viral loads are 

lower for asymptomatic carriers. 

And therefore, when you look at the whole test and how it's performed which 

is more - which is important and not just LOD because LOD assessment can 

vary from developer to developer. There aren't necessarily good ways to 

harmonize and also to translate that into clinical sensitivity. So we have really 

because there are EUA authorizations, we have the authority under the law to 

lower the recommendations for validation and you know instead of a couple 

hundred virus positive patients in a clinical study for full authorization, we 

have required only for symptomatic populations, 30 positive as a minimum.

Then to add an asymptomatic claim premarket again, only 10 positive 

symptomatic patients. So, with as appropriate with an agreement to complete 

more asymptomatic tests studies after authorization.

So the bottom line is that we look at the performance of the whole test not just 

in the laboratory LOD. Because that tells you how the test will perform and 

watch closely in the real world. And we have seen significant differences in 

viral load and detection, actual sensitivity or PPA between symptomatic and 

asymptomatic individuals in the same study.
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(Wendy Chow): Because of yeah, the two population. Great like in the symptomatic there's a 

lot more people with a high viral load and instead of asymptomatic, they're 

much less people with higher viral load as we have more weak ones. I think

that the problem recognize we don’t really have an international standard to 

determine the LOD. The LOD everywhere you really can't rely on that 

number. Once we have an international standard to determine LOD and then 

it becomes to the use of the lab or developer or use as a standard. Then there's 

the common comparison.

Then it will be much important to - right now we just kind of use the live 

samples from people where these populations are population, their viral load

distribution is different. So, of course, the result will be different or 

sometimes the sampling could be different maybe in the symptomatic they 

will have more in some specific anatomic side versus asymptomatic. What 

I'm thinking is that the lack of those international standard may push to go to 

kind of empirically to get all those populations.

So that's what I'm thinking here and I just trying to figure out what is an 

efficient way.

Timothy Stenzel: Yes, we're going to move onto the next caller. There are - there is an 

international standard available for molecular tests. And so that can be used at 

least for a truly quantitative test which most molecular tests aren't truly 

quantitative. They haven't been developed for that purpose. They haven't

been calibrated for that purpose. Then, of course, we'll all want to see data, 

you know, when you have an international standard related quantitative 

molecular tests and look at CTs and look at things like impactivity. 
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However, to gather that data what's truly a level of infectivity even if you 

could harmonize the way samples are collected, because there is variable and 

there are many variables in determining the viral level with the respiratory 

with respiratory samples and it's not as easy as a HIV quant is and 

straightforward because that sample type is whole blood or a venous puncture 

and sample.

And it is more challenging with respiratory sample and very clearly APHL 

and CAP and the CDC has said that correlating CTs with infectivity or 

determining a level of below or above which you can make clinical decisions 

is very challenging. So we're going to move onto the next caller. Thank you.

Coordinator: Our next question comes from (Susan Sheldon).

(Susan Sheldon): Hi, Tim and Tony, thank you so very much for all your efforts in these town 

hall meetings. I appreciate them and learn a lot. I have two quick questions. 

One, if we have two sample types, can we include them in the same 

emergency authorization if we provide the data in one? Or do we have to 

have separate one for each sample, the in-home testing?

Timothy Stenzel: No, for in-home use, different sample types we would want to see 

performance and usability and user comprehension for both types of sampling.

(Susan Sheldon): I understand, but do you need them in two separate emergency authorization 

requests or can I put them in the same, in one?

Timothy Stenzel: They can go into the same solution.

(Susan Sheldon): Okay, the next question is that if we instruct the patient to cough and spit in a 

cup, would you be calling that specimen saliva splash sputum? What would 
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be the appropriate name regulatory-wise? That's the instruction to the patient. 

What would we call the sample?

Timothy Stenzel: Yeah, so that's a bit of an unusual sample collection method and I would 

invite you to reach to a pre-EUA to develop or to review staff to address that 

specific question since that's not going to be a hugely common sample type.

(Susan Sheldon): How would I do that?

Timothy Stenzel: You take the template for whatever test you're developing and you only have 

to ask the questions that you want in there and you would be asking how to, 

you know, whatever your question you have about that particular sample type, 

you can put into the EUA template and send it in. Since you're not submitting 

an EUA, you're not submitting data, you're asking questions. You classify

that as a pre-EUA submission and you send it to the template's email address 

and they will log it in as a pre-EUA so we can track it and get responses back 

to you.

Coordinator: As a reminder, if you have a question, please press Star 1. If you can please 

only ask one question so we can get to everyone today. Thank you. Our next 

question comes from (Marcella Vasgrove).

(Marcella Vasgrove): Hello. Hi, I'm with (unintelligible) human factor specialist representing 

user-wide consulting. We have a client in South Korea who would like to 

conduct clinical testing for a COVID-19 antigen test kit in the Philippines. 

Are they required to seek IRB oversight and (unintelligible) for the study if 

they wish to submit this data for a EUA? Also theoretically if an international 

antigen test kid manufacturer desired to conduct a clinical study in a country 

with no IRB requirements, would they be able to submit this data to the US 

FDA after having no IRB oversight or no? 
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Timothy Stenzel: So, you know, we encourage developers to follow local, state and federal rules 

where the studies are done. It is not something that we're asking or reviewing 

for EUAs at this time. Is this a point of care or home use study?

(Marcella Vasgrove): COVID antigen test kit.

Timothy Stenzel: Yeah, so we're encouraging a point of care and home use antigen and other 

rep in molecular rapid tests, that the studies be performed in the US if 

possible. So that we are simulating and mimicking how the test are going to 

be used in the US. We've seen challenges with international studies for home 

and/or point of care where the sites, for example, really aren't point of care. 

And so this since the US market is very large, for these type of devices, we 

want to know how it's going to perform.

These are recommendations. If somebody wants to do this a different way, 

then we would encourage them to first check with the FDA on the study 

design to make sure that it would be acceptable for review and authorization if 

the data looked good.

(Marcella Vasgrove): So the (unintelligible) client would be required for IRBS oversight?

Timothy Stenzel: Again, we would, you know, encourage all developers to follow wherever the 

studies are done local, state and federal requirements for those localities. We 

are not regulating IRB documents for UA reviews. You know, if these studies 

are done in the US, typically there's IRB and/or consent that the local, state 

and federal rules would be required. 

Okay, we're going to have to move onto the next caller.
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Coordinator: Our next question comes from (Deb Payne).

(Deb Payne): Hi, can you hear me?

Timothy Stenzel: Yes.

(Deb Payne): Okay, hi Tim. Thank you for all the work that you're doing here. We're a lab 

where we want to have a prescription home-based collection that where the 

sample is collected and sent back to us. And we had tried to reach out to 

various manufacturers or groups the have previously gotten their collection 

device through right to reference them, but none of those suppliers are really 

too keen in providing us their particular collection device. 

And there is one collection device where it was stated on the, I think, it's a 

foam collection that was stated on the templates that the right to reference was 

granted. Do we need to specifically, I think, it's, I can't remember the 

particular group, do we need to reach out and get a right to reference from that 

group that is stated in the templates already?

Timothy Stenzel: It depends. So there are some. We've now authorized over 50 at-home 

collection submissions. And there are a growing number of manufacturers 

who, you know, are providing opportunities for developers such as yourself to 

participate. Offline it would be great to hear from you. You can send it to the 

template's email address about just what the feedback you're getting from 

some of those are because we would like to understand the challenges faced 

by developers such as yourself in that and getting access to these previously 

authorized home collection kits.

There is one situation where there that I know of and Toby may know of 

others where there's a global auto reference and the individual developers 
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don’t have to go and get that. That's based on, and I'm forgetting both 

partners here, but it was a Gate-sponsored study where they did home 

collection using a nasal swab in a particular media. I'm not sure if it's both 

VTM and saline. The details escape me.

But if you were to mimic exactly what they did in their study which is totally 

acceptable, you know, that works and makes it easy for developers like you to 

them get that right to reference because you don't have to go to Gates to get it. 

It's just global.

So the best way to find out about all that is really to send a specific question 

into the template's email address asking about global right to reference for any 

home collection devices. And Toby you may know if those are also offered 

for other than this nasal swab opportunity. I'll pause for Toby to add 

anything.

Toby Lowe: Yes, I think what you may be referring to, (Deb) is in our FAQs where we do 

refenced this quantigen Gates data and the broad right of reference. That is to 

specific data studies that were done. It's not for a specific home collection kit. 

So as Tim was getting at, if you were to develop your own home collection 

kit, that use the same procedures as what they validated, then you would be 

able to leverage the data that they've already collected and have offered the 

broad right of reference to.

Timothy Stenzel: And you don’t need to go to them to get that permission. That's - they've 

always - they've already granted that globally. We have that documented. So 

you know, to get the particulars then, you know, of this then and about how 

you'd go about using that right to reference and what we would expect in a 

submission. You can come in with a pre-EUA.
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And these home collection kits are a priority for our office.

(Marcella Vasgrove): And this would be prescription-based and I didn't know whether the bar 

would be lower for prescription-based.

Timothy Stenzel: So for prescription-based I believe the Gates quantigen study was on 

symptomatic individuals. And for prescription-based you don't need 

asymptomatic individuals. However, if the performance is good enough you 

can use the serial pathway when talking about for OTC is possible. But for 

prescription, the recommendations are less because we know that a prescriber 

is involved and is taking some responsibility for ensuring oversight as the 

testing and that allows us to be more focused in our review.

(Marcell Vasgrove): Okay, thank you so much.

Timothy Stenzel: You're welcome.

Coordinator: Our next question comes from (Ella Kiocore).

(Ella Kiocore): Thank you for taking my call. I appreciate your efforts in answering our 

questions. My question pertains to use of genetic algorithms and interpretation 

of the raw data to extract the result. How can one gain accessibility of that 

kind of approach? And if that is something that is a matter of the future, then 

my second question would be about using the same group of users for 

validating a test for individual use at the point of contact and by pooling. So 

these are my questions. Thank you.

Timothy Stenzel: So hang on, to clarify. Are you also developing a detection method for 

SARS-CoV-2 virus? 
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(Ella Kiocore): Correct, it's a molecular detection method, genetic molecular detection 

method with the original method of generating signals different from RTCPR 

that's related, simpler, cleaner, one-step direct and results in 20 minutes. So 

have submitted a pre-request for information and that in the belief that we 

need to refrain from using the IT and machine learning from generating the 

results. I want to verify that this is a correct approach for our future

generations.

Timothy Stenzel: I'm not sure that I understand. You're adding on software. You have a 

detection method that can determine presence or absence of the SARS-CoV-2 

virus in a sample. And you're adding an AI or machine learning software on 

top of it?

(Ella Kiocore): (Unintelligible), that would be something hidden from the user entirely. It 

would be the internal portion of the black box essentially.

Timothy Stenzel: Yes, so that's a very specific question about your device and why artificial 

intelligence or machine learning would be helpful and needed for your test. 

But and developers can choose to do what they want. And we would certainly 

accept it and review it, but there would be additional review questions around 

the use of such software. And that's where a pre-EUA with the specifics of 

what you're development program looks like and the specific questions you 

have around the use of AI or ML in your submission.

(Ella Kiocore): I see.

Timothy Stenzel: There's a software, I think most of the templates have a software section now. 

So this would be covered under the software and you know we have a white 

paper out on artificial intelligence from the CDRH center that gives some high 

level guidance about our current thinking. There are different kinds of uses 
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and ML. That is important for us to consider such as are you going to have a 

learning system? Are you going to use ML to establish your cutoff and then 

you're going to lock it down?

So there's a whole, it's a large area and we just need specifics so we can 

answer your questions that are important for you and your development 

process that are relevant only to your test. Okay, all right let's move onto they 

the next caller, please.

Coordinator: Our next question comes from (Tiawa Wella).

Timothy Stenzel: Hello. Can't hear you.

(Tiawa Wella): Hello.

Timothy Stenzel: Hello, can hear you now. Hello?

(Tiawa Wella): Yes, hello. Yes, I have a question on submission of a pre-EUA file. We're 

developing a (unintelligible) test a level kind of antigen test and we could 

submit our features and explanation of our topics and the elements into. Or 

we could wait a little bit and have more experimental data, limit of detection 

and the first usability study for (unintelligible) evaluation. What would the 

VA prefer to have that you will submit already or we wait a bit to have more 

valuable data to support that project or position?

Timothy Stenzel: Yes, well we're interested in getting a full EUA submission especially for 

home antigen in-home molecular tests as soon as you can get it to us for 

review. We have at-home template that's online that hopefully provides all 

they information you would require to or need to know how to - what our 

recommendations are for validation. 
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If you have any questions that aren't clear from the template, that's the reason 

to submit a pre-EUA. Otherwise if the template is very clear to you on what 

to do, then you know, I would encourage you to work on the studies to go 

ahead and demonstrate the performance of your test and submit that to us as 

soon as possible and as I said, you know, home molecular antigen tests that 

can be produced in high volumes and made available to the US consumers at 

home is one of the highest priorities right now for us.

Coordinator: That concludes our question and answer session. I would now like to turn the 

call back over it Kemba Ford.

Kemba Ford: Thank you. This is Kemba Ford again. We appreciate your participation and 

thoughtful questions during today's town hall. Today's presentation and 

transcript will be available on CDRH Learn webpage at 

www.fda.gov/training/ccrhlearn by Friday, April 9. If you have additional 

questions about today's presentation, please email CDRH-EUATemplate@fda.hhs.gov. 

As we continue to hold these virtual town halls, we would appreciate your 

feedback. Following the conclusion of the virtual town hall today, please 

complete a short 13-question survey about your FDA CDRH virtual townhall 

experience. The survey is live and can be found on 

www.FDA.gov/CDRHwebinar.

Again, thank you for participating. This concludes today's town hall. We 

hope you'll join us again next week.

Coordinator: That concludes today's conference. Thank you for participating. You may 

disconnect at this time.
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END