Distinct® Early Detection Pregnancy Test

K193318 · ACON Laboratories, Inc. · LCX · Aug 20, 2020 · Clinical Chemistry

Device Facts

• Record ID: K193318
• Device Name: Distinct® Early Detection Pregnancy Test
• Applicant: ACON Laboratories, Inc.
• Product Code: LCX · Clinical Chemistry
• Decision Date: Aug 20, 2020
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1155
• Device Class: Class 2

Intended Use

The Distinct® Early Detection Pregnancy Test is an aid for the early detection of pregnancy intended for home use. The device is a chromatographic immunoassay that performs qualitative detection of human chorionic gonadotropin (hCG) in urine. This test can help determine pregnancy as early as 6 days before the day of the missed period (5 days before the day of the expected period).

Device Story

The Distinct® Early Detection Pregnancy Test is a lateral flow chromatographic immunoassay for qualitative hCG detection in urine. Designed for home self-testing, the device consists of a test strip and absorbent tip housed in plastic. The user applies urine via midstream or dip method; capillary action draws the specimen across the strip. If hCG is present, it forms a sandwich complex with labeled monoclonal antibodies and pre-coated antibodies, resulting in a blue plus (+) sign in the test window. A procedural control line confirms proper wicking. Results are read visually after 3 minutes. The device aids in early pregnancy detection, allowing users to confirm pregnancy status at home without professional intervention.

Clinical Evidence

Clinical performance evaluated via user study (n=205) and early pregnancy detection study (n=65). User study demonstrated >99% accuracy compared to professional testing. Early detection study showed 100% sensitivity at the expected menstrual period (EMP) and 49.2% sensitivity 6 days before the missed period (EMP-6). Analytical testing confirmed no cross-reactivity with LH, FSH, or TSH, and no interference from common urine substances, pH (4-9), or specific gravity (1.003-1.035). No high-dose hook effect observed up to 1,000,000 mIU/mL.

Technological Characteristics

Lateral flow chromatographic immunoassay. Materials: monoclonal anti-hCG antibodies, goat anti-mouse polyclonal antibodies, plastic housing. Qualitative detection; 10 mIU/mL cutoff. Calibrated to WHO 5th International Standard for hCG. Standalone device; no software or electronics.

Indications for Use

Indicated for home use by individuals seeking early pregnancy detection via qualitative hCG urine testing. Suitable for use as early as 6 days before the missed period.

Regulatory Classification

Identification

A human chorionic gonadotropin (HCG) test system is a device intended for the early detection of pregnancy is intended to measure HCG, a placental hormone, in plasma or urine. A human chorionic goadotropin (HCG) test system is a device intended for any uses other than early detection of pregnancy (such as an aid in the diagnosis, prognosis, and management of treatment of persons with certain tumors or carcinomas) is intended to measure HCG, a placental hormone, in plasma or urine.

Predicate Devices

• First Response Early Result Pregnancy Test (K123436)

Submission Summary (Full Text)

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FDA U.S. FOOD & DRUG ADMINISTRATION

# 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY

ASSAY ONLY

## I Background Information:

A 510(k) Number

K193318

B Applicant

Acon Laboratories Inc.

C Proprietary and Established Names

Distinct® Early Detection Pregnancy Test

D Regulatory Information

| Product Code(s) | Classification | Regulation Section | Panel |
| --- | --- | --- | --- |
| LCX | Class II | 21 CFR 862.1155 - Human Chorionic Gonadotropin (HCG) Test System | CH - Clinical Chemistry |

## II Submission/Device Overview:

A Purpose for Submission:

New Device

B Measurand:

Human chorionic gonadotropin (hCG)

C Type of Test:

Qualitative chromatographic immunoassay

Food and Drug Administration

10903 New Hampshire Avenue

Silver Spring, MD 20993-0002

www.fda.gov

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# III Intended Use/Indications for Use:

## A Intended Use(s):
See Indications for Use below.

## B Indication(s) for Use:
The Distinct® Early Detection Pregnancy Test is an aid for the early detection of pregnancy intended for home use. The device is a chromatographic immunoassay that performs qualitative detection of human chorionic gonadotropin (hCG) in urine. This test can help determine pregnancy as early as 6 days before the day of the missed period (5 days before the day of the expected period)

## C Special Conditions for Use Statement(s):
OTC - Over The Counter

## D Special Instrument Requirements:
Not applicable.

# IV Device/System Characteristics:

## A Device Description:
The Distinct® Early Detection Pregnancy Test is a rapid chromatographic immunoassay for in vitro qualitative detection of human chorionic gonadotropin in urine to aid in the early detection of pregnancy. It is for self-testing. The test strip and absorbent tip are assembled in a plastic housing.

## B Principle of Operation:
The test strip contains monoclonal anti-hCG antibodies and goat anti-mouse polyclonal antibodies. The test result is shown in the result window and read visually after 3 minutes of urine application.

A blue sign of plus (+) at the test window indicates that hCG has been detected (pregnant). Absence of the plus (+) and only a blue line (-) in the Test Window suggests no hCG has been detected. To serve as a procedural control, a blue line will always appear in the Control Window indicating that proper volume of specimen has been added and membrane wicking has occurred.

# V Substantial Equivalence Information:

## A Predicate Device Name(s):
First Response Early Result Pregnancy Test

## B Predicate 510(k) Number(s):
K123436

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C Comparison with Predicate(s):

| Device & Predicate Device(s): | K193318 | K123436 |
| --- | --- | --- |
| Device Trade Name | Distinct® Early Detection Pregnancy Test | First Response Early Result Pregnancy Test |
| General Device Characteristic Similarities | | |
| Intended Use/Indications For Use | Qualitative detection of human chorionic gonadotropin in urine to aid in the early detection of pregnancy | Same |
| Specimen | Urine | Same |
| Indications/Intended Users | Over the Counter (OTC) | Same |
| Test Principle | Lateral Flow Immunoassay | Same |
| Format | Dip and Midstream | Same |
| Detection Time | Early detection of pregnancy; 5 days before the expected period (6 days before the day of the missed period) | Same |
| General Device Characteristic Differences | | |
| Traceability | WHO 5^{th} International Standard for hCG | WHO 4^{th} International Standard for hCG |
| Read Time | 3 to 10 minutes | 3 minutes |

VI Standards/Guidance Documents Referenced:

CLSI EP07 Interference Testing in Clinical Chemistry.

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility:

The sponsor performed a study to evaluate the imprecision of the device with different trained operators using both formats. Thirty negative urine specimens were collected and spiked with WHO 5^th International hCG standard to the following concentrations: 3, 6, 8, 10,

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12, and 15 mIU/mL. Results were read in duplicate by three operators over five days and the results were read at 3 and 10 minutes using three lots of the device. Results are summarized below:

Dip Method:

| hCG levels (mIU/ml) | Result | % Positive |
| --- | --- | --- |
| 0 | Negative 90
Positive 0 | 0% |
| 3 | Negative 90
Positive 0 | 0% |
| 6 | Negative 56
Positive 34 | 37.8% |
| 8 | Negative 28
Positive 62 | 68.9% |
| 10 | Negative 0
Positive 90 | 100% |
| 12 | Negative 0
Positive 90 | 100% |
| 15 | Negative 0
Positive 90 | 100% |

Simulated Urine Stream Method:

| hCG levels (mIU/ml) | Result | % Positive |
| --- | --- | --- |
| 0 | Negative 90
Positive 0 | 0% |
| 3 | Negative 90
Positive 0 | 0% |
| 6 | Negative 61
Positive 29 | 32.2% |
| 8 | Negative 17
Positive 73 | 81.1% |
| 10 | Negative 0
Positive 90 | 100% |
| 12 | Negative 0
Positive 90 | 100% |
| 15 | Negative 0
Positive 90 | 100% |

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The sponsor also performed a study to evaluate the imprecision of the device using both formats when read by laypersons.

Thirty negative urine specimens were collected and spiked with WHO 5th International hCG standard to the following concentrations: 3, 5, 6, 7.5, 8, 8.5, 10, 12, 15 and 25 mIU/ml. The samples were blinded and randomized prior to being read. A total of 300 lay users performed the test using three lots of the devices; however, the total number of readings was not identical for each concentration, as specified below. Results are summarized below:

Dip Method:

| hCG levels (mIU/ml) | Number of results at this concentration | Results | % Positive |
| --- | --- | --- | --- |
| 0 | 84 | Negative 84
Positive 0 | 0 |
| 3 | 81 | Negative 81
Positive 0 | 0 |
| 5 | 81 | Negative 70
Positive 11 | 14 |
| 6 | 81 | Negative 50
Positive 31 | 38 |
| 7.5 | 81 | Negative 38
Positive 43 | 53 |
| 8 | 81 | Negative 25
Positive 56 | 69 |
| 8.5 | 81 | Negative 20
Positive 61 | 75 |
| 10 | 81 | Negative 0
Positive 81 | 100 |
| 12 | 81 | Negative 0
Positive 81 | 100 |
| 15 | 84 | Negative 0
Positive 84 | 100 |
| 25 | 84 | Negative 0
Positive 84 | 100 |

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Simulated Urine Stream Method:

| hCG levels (mIU/ml) | Number of results at this concentration | Result | % Positive |
| --- | --- | --- | --- |
| 0 | 84 | Negative 84
Positive 0 | 0 |
| 3 | 81 | Negative 81
Positive 0 | 0 |
| 5 | 81 | Negative 68
Positive 13 | 16 |
| 6 | 81 | Negative 52
Positive 29 | 36 |
| 7.5 | 81 | Negative 41
Positive 40 | 49 |
| 8 | 81 | Negative 26
Positive 55 | 68 |
| 8.5 | 81 | Negative 22
Positive 59 | 73 |
| 10 | 81 | Negative 0
Positive 81 | 100 |
| 12 | 81 | Negative 0
Positive 81 | 100 |
| 15 | 84 | Negative 0
Positive 84 | 100 |
| 25 | 84 | Negative 0
Positive 84 | 100 |

2. Linearity:

Not Applicable. This is a qualitative test.

3. Analytical Specificity/Interference:

Cross-Reactivity

The sponsor performed a study to evaluate potential cross-reactivity from LH, FSH and TSH with the candidate device by measuring hCG in samples with various concentrations of hCG, LH, FSH and TSH as specified in the table below.

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| Solution | Concentrations |
| --- | --- |
| 1 | 0 mIU/mL and 1000 mIU/mL FSH |
| 2 | 0 mIU/mL and 1000 mIU/mL LH |
| 3 | 0 mIU/mL and 1000 μIU/mL TSH |
| 4 | 3 mIU/mL hCG and 1000 mIU/mL FSH |
| 5 | 3 mIU/mL hCG and 1000 mIU/mL LH |
| 6 | 3 mIU/mL hCG and 1000 μIU/mL TSH |
| 7 | 10 mIU/mL hCG and 1000 mIU/mL FSH |
| 8 | 10 mIU/mL hCG and 1000 mIU/mL LH |
| 9 | 10 mIU/mL hCG and 1000 μIU/mL TSH |

The prepared samples were tested with the candidate device in triplicate using three lots and the results were read at 3 and 10 minutes. All results at 0 and 3 mIU/mL were negative and all results at 10 mIU/mL were positive.

## Interfering Substances

The sponsor performed a study to evaluate potential interference from common exogenous and endogenous compounds. Negative urine was spiked with potentially interfering substances and hCG standard solution to the concentrations listed in the table below.

Spiked samples were tested in triplicate using one lot of the candidate device. There were no deviations from the expected positive or negative results. Results are summarized below.

## Endogenous Substances

| Analyte | Concentration Tested | Results at 0 mIU/mL hCG | Results at 3 mIU/mL hCG | Results at 10 mIU/mL hCG |
| --- | --- | --- | --- | --- |
| Bilirubin | 50 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Hemoglobin | 1000 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Albumin | 2000 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Glucose | 2000 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Urea | 2000 mg/ dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Uric acid | 150 mg/ dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Oxalic acid | 50 mg/ dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Creatinine | 250 mg/ dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Sodium nitrite | 10 mg/ dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |

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Exogenous Substances

| Analyte | Concentration Tested | Results at 0 mIU/mL hCG | Results at 3 mIU/mL hCG | Results at 10 mIU/mL hCG |
| --- | --- | --- | --- | --- |
| Acetaminophen | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Ascorbic Acid | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Caffeine | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Gentisic Acid | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Salicylic Acid | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Acetylsalicylic | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Ethanol | 1.0 % | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Tetracycline | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Theophylline | 20 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| Ibuprofen | 50 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |
| EDTA | 80 mg/dL | 3 neg / 0 pos | 3 neg / 0 pos | 0 neg / 3 pos |

## Effects of Urine pH

The sponsor performed a study to evaluate the effect of urine pH on the results. A negative urine pool was split and separately adjusted in pH increments of 1.0 from pH 4.0 to 9.0. Aliquots of each pH adjusted urine sample were then spiked with hCG to concentrations of 3 and 10 mIU/mL and read at 3 and 10 minutes. There were no deviations from the expected positive or negative results.

## Specific Gravity

The sponsor performed a study to evaluate the effect of urine specific gravity on the results. A negative urine pool was split and adjusted with sodium chloride or purified water to produce samples with a specific gravity ranging from 1.003 – 1.035. Aliquots of each specific gravity adjusted urine sample were then spiked with hCG to concentrations of 3 and 10 mIU/mL and read at 3 and 10 minutes. There were no deviations from the expected positive or negative results.

## High Dose Hook Effect Study

The sponsor performed a study to evaluate whether very high concentrations of hCG could produce a hook effect with the candidate device. Samples were prepared by spiking a negative urine pool with hCG to concentrations of 500, 1,000, 10,000, 100,000, 500,000 and 1,000,000 mIU/mL. Sample were tested in triplicate using three lots of the device. All concentrations of hCG with all three lots produced the expected positive results and no hook effect was observed.

## 4. Assay Reportable Range:

Not applicable. This is a qualitative test.

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5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods):

Traceability:

The test is calibrated against the WHO 5th International Standard (IS) for Chorionic Gonadotrophin (hCG).

Stability:

The shelf life of the Distinct® Early Detection Pregnancy Test were verified by accelerated, open pouch and on-going real-time stability studies. From the results of the study, it was concluded that Distinct® Early Detection Pregnancy Test is stable at 55°C for 10 weeks and 45°C for 22 weeks which support the shelf life up to 24 months at 2 – 30°C (36 – 86°F).

6. Detection Limit:

See section VII.A.1 above.

7. Assay Cut-Off:

The claimed cutoff of the assay is 10 mIU/mL. See section VII.A.1 above for performance around the cutoff.

B Comparison Studies:

1. Method Comparison with Predicate Device:

The sponsor performed a combined lay user and method comparison study to evaluate the accuracy of the candidate device. A total of 205 volunteer participants (lay users) were recruited at three clinical sites with 68 or 69 participants at each clinical site. Laypersons tested their own urine samples using the Distinct® Early Pregnancy Test followed the directions in the package insert. Approximately half of the subjects used the dip method and half used the midstream method. Trained laboratory professionals then tested the same urine samples using the candidate device and the predicate device. The samples were blind labeled before being given to the laboratory professionals for testing. Three lots of the candidate device were used in the study and the results are summarized below:

Candidate device (layperson) vs. predicate device (professional)

| Urine stream Method | Predicate (Professional) | | | |
| --- | --- | --- | --- | --- |
| | | Pos | Neg | Total |
| Candidate (Layperson) | Pos | 51 | 0 | 51 |
| | Neg | 0 | 51 | 51 |
| | Total | 51 | 51 | 102 |

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| Urine Dipping Method | Predicate (Professional) | | | |
| --- | --- | --- | --- | --- |
| | | Pos | Neg | Total |
| Candidate (Layperson) | Pos | 52 | 0 | 52 |
| | Neg | 0 | 51 | 51 |
| | Total | 52 | 51 | 103 |

Candidate device (professional) vs. predicate device (professional)

| Urine stream Method | Predicate (Professional) | | | |
| --- | --- | --- | --- | --- |
| | | Pos | Neg | Total |
| Candidate (Professional) | Pos | 51 | 0 | 51 |
| | Neg | 0 | 51 | 51 |
| | Total | 51 | 51 | 102 |
| Urine Dipping Method | Predicate (Professional) | | | |
| --- | --- | --- | --- | --- |
| | | Pos | Neg | Total |
| Candidate (Professional) | Pos | 52 | 0 | 52 |
| | Neg | 0 | 51 | 51 |
| | Total | 52 | 51 | 103 |

After testing, subjects were asked to complete a questionnaire to collect feedback on the test including ease of use, clarity and readability of the package insert. All of the participants reported that the test instructions were easy to follow and that it was easy to read the test results.

2. Matrix Comparison:

Not applicable. The device is intended for use with urine samples only.

C Clinical Studies:

1. Clinical Sensitivity:

Not Applicable.

2. Clinical Specificity:

Specificity Study to Determine False-Positive Results Rate

A study was performed to determine the incidence of positive test results using the candidate device among non-pregnant women in three age groups: 18-40, 41-45, and 55 and older. A

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total of 300 subjects provided samples with 100 for each age group. Three lots of the candidate device were used for this study. No positive results were observed for any of the age groups.

3. Other Clinical Supportive Data (When 1. and 2. Are Not Applicable):

## Detection of hCG in Early Pregnancy Clinical Samples

Urine from 65 non-pregnant women expecting to become pregnant were collected daily starting 8 days prior to their expected period through the date of their expected menstrual period (EMP), as well as the 6th or 7th day after their EMP. Each patient collected her own urine and sent the sample to a clinical site where they were tested by a laboratory professional. Three lots of the candidate device were used and the pregnancy status was confirmed by ultrasound or a quantitative blood hCG result.

| Time Point | Number of Positive | Number of Negative | % Positive |
| --- | --- | --- | --- |
| EMP +6 or 7 days | 65 | 0 | 100.0% |
| EMP | 65 | 0 | 100.0% |
| EMP-1 day | 65 | 0 | 100.0% |
| EMP-2 days | 65 | 0 | 100.0% |
| EMP-3 days | 63 | 2 | 96.9% |
| EMP-4 days | 61 | 4 | 93.8% |
| EMP-5 days | 49 | 16 | 75.4% |
| EMP-6 days | 32 | 33 | 49.2% |
| EMP-7 days | 13 | 51 | 20.3% |
| EMP-8 days | 6 | 54 | 10.0% |

## D Clinical Cut-Off:

Not applicable.

## E Expected Values/Reference Range:

Not applicable.

## VIII Proposed Labeling:

The labeling supports the finding of substantial equivalence for this device.

## IX Conclusion:

The submitted information in this premarket notification is complete and supports a substantial equivalence decision.

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