EGENS Pregnancy Test Midstream I, EGENS Pregnancy Test Midstream II

K232864 · Nantong Egens Biotechnology Co., Ltd. · LCX · Jan 26, 2024 · Clinical Chemistry

Device Facts

• Record ID: K232864
• Device Name: EGENS Pregnancy Test Midstream I, EGENS Pregnancy Test Midstream II
• Applicant: Nantong Egens Biotechnology Co., Ltd.
• Product Code: LCX · Clinical Chemistry
• Decision Date: Jan 26, 2024
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1155
• Device Class: Class 2

Intended Use

The EGENS Pregnancy Test Midstream I is intended for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period. EGENS Pregnancy Test Midstream II is intended for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period.

Device Story

Lateral flow chromatographic immunoassay for qualitative hCG detection in urine; utilizes mouse anti-beta hCG monoclonal antibody-dye conjugate and goat anti-hCG polyclonal antibody membrane coating. Sample absorbed via tip; capillary action moves sample across membrane; hCG-antibody-dye complex captured at test line (T). Midstream I produces red band for positive; Midstream II produces plus sign (+) for positive. Used at home by lay users; dip or instream sampling. Results interpreted visually by user; aids in early pregnancy confirmation. Benefits include rapid, accessible pregnancy screening.

Clinical Evidence

Bench testing included precision, analytical specificity, interference, hook effect, and detection limit studies. Clinical performance evaluated via method comparison (n=300/306) against predicate, showing 100% concordance. Clinical specificity (n=300) was 100%. Early pregnancy detection study (n=65) tracked hCG detection from 8 days before expected period. Lay user study (n=306) demonstrated 100% agreement with professional results. Lay user spiked sample study confirmed performance at 5-10 mIU/mL concentrations.

Technological Characteristics

Lateral flow immunochromatographic assay; nitrocellulose test strip in plastic housing with absorbent tip. Calibrated against WHO 5th IS (NIBSC 07/364). Cut-off 10 mIU/mL. No electronic components or software.

Indications for Use

Indicated for qualitative detection of hCG in urine to aid in early pregnancy detection. Intended for over-the-counter use by lay persons.

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

• Wondfo One Step HCG Urine Pregnancy Test Strip, Wondfo One Step HCG Urine Pregnancy Test Cassette, Wondfo One Step HCG Urine Pregnancy Test Midstream (K150022)

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

K232864

B Applicant

Nantong Egens Biotechnology Co., Ltd.

C Proprietary and Established Names

EGENS Pregnancy Test Midstream I, EGENS Pregnancy Test Midstream II

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 EGENS Pregnancy Test Midstream I is intended for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period.

EGENS Pregnancy Test Midstream II is intended for the qualitative detection of human chorionic gonadotropin (hCG) in urine, as an aid in early detection of pregnancy, in some cases as early as five (5) days before the expected period, i.e., as early as six (6) days before the day of the missed period.

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

C Special Instrument Requirements:
None

IV Device/System Characteristics:

A Device Description:
EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II are qualitative immunochromatographic assays consisting of a single nitrocellulose test strip assembled in a plastic housing with an absorbent tip. The tests can be used in dip or instream mode.

B Principle of Operation:
EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II are lateral flow chromatographic immunoassays. When the absorbent end is immersed into a sample, the sample is absorbed into the device by capillary action and mixes with the antibody-dye conjugate (mouse anti-beta hCG monoclonal antibody), flowing across the pre-coated (goat anti-hCG polyclonal antibody) membrane. If present in the sample, hCG reacts with the dye conjugate and forms a complex. The complex migrates along the membrane to the hCG antibody line (T) and remains captured in the T line.

In the EGENS Pregnancy Test Midstream I test, a single red colored band develops in the test zone (T line), indicating a positive result. If there is no hCG in the urine, there is no red band in the test zone, indicating a negative result. In the EGENS Pregnancy Test Midstream II test, a plus sign (+) appears at the T line, indicating a positive result. A single vertical line at the T line (|) indicates a negative result. The control line (C line) should develop in the control zone regardless of the test result on both tests. If the control line does not appear (no color appears at the control line after application of the sample), the test is invalid, and the specimen should be retested with a new device.

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V Substantial Equivalence Information:

A Predicate Device Name(s):
Wondfo One Step HCG Urine Pregnancy Test Strip, Wondfo One Step HCG Urine Pregnancy Test Cassette, Wondfo One Step HCG Urine Pregnancy Test Midstream

B Predicate 510(k) Number(s):
K150022

C Comparison with Predicate(s):

| Device & Predicate Device(s): | K232864 | K150022 |
| --- | --- | --- |
| Device Trade Name | EGENS Pregnancy Test Midstream I, EGENS Pregnancy Test Midstream II | Wondfo One Step HCG Urine Pregnancy Test Strip, Wondfo One Step HCG Urine Pregnancy Test Cassette, Wondfo One Step HCG Urine Pregnancy Test Midstream |
| General Device Characteristic Similarities | | |
| Intended Use/Indications for Use | Qualitative detection of human chorionic gonadotropin (hCG) as an aid in early detection of pregnancy | Same |
| Early Detection Claim | Pregnancy can be detected as early as five (5) days before the expected period (as early as six (6) days before the day of the missed period) | Same |
| Methodology | Chromatographic immunoassay | Same |
| Specimen type | Urine | Same |
| Sensitivity | 10 mIU/mL | Same |
| General Device Characteristic Differences | | |
| Time to results | 3 minutes | 5 minutes |
| Target User | Over-the-counter use | Over-the-counter and Prescription use |

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VI Standards/Guidance Documents Referenced:

None.

VII Performance Characteristics (if/when applicable):

A Analytical Performance:

1. Precision/Reproducibility:

A precision study was performed using negative female urine samples spiked with hCG traceable to the 5th WHO IS to obtain samples with hCG concentrations of 0, 2.5, 5, 6.5, 8, 9, 10, 15, 25 and 50 mIU/mL. Each sample was tested using three lots of EGENS Pregnancy Test Midstream I and three lots of EGENS Pregnancy Test Midstream II. Samples were tested in replicates of 5 per concentration, over 5 consecutive days, by 3 different operators (1 per lot) per device, in both dip and instream sampling methods (150 total results per concentration). The tables below summarize the precision data when both dip and instream sampling methods are combined. The data is representative of each sampling method.

EGENS Pregnancy Test Midstream I (instream and dip sampling methods combined)

| hCG Conc. (mIU/mL) | Lot 1 | | Lot 2 | | Lot 3 | | Total results | | % Negative | % Positive |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | - | + | - | + | - | + | - | + | | |
| 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 2.5 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 5 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 6.5 | 47 | 3 | 46 | 4 | 47 | 3 | 140 | 10 | 93% | 7% |
| 8 | 25 | 25 | 22 | 28 | 27 | 23 | 74 | 76 | 49% | 51% |
| 9 | 7 | 43 | 5 | 45 | 4 | 46 | 16 | 134 | 11% | 89% |
| 10 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 15 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 25 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 50 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |

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EGENS Pregnancy Test Midstream II (instream and dip sampling methods combined)

| hCG Conc. (mIU/mL) | Lot 1 | | Lot 2 | | Lot 3 | | Total results | | % Negative | % Positive |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| | - | + | - | + | - | + | - | + | | |
| 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 2.5 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 5 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0 | 100% | 0% |
| 6.5 | 48 | 2 | 47 | 3 | 46 | 4 | 141 | 9 | 94% | 6% |
| 8 | 27 | 23 | 24 | 26 | 24 | 26 | 75 | 75 | 50% | 50% |
| 9 | 5 | 45 | 3 | 47 | 7 | 43 | 15 | 135 | 10% | 90% |
| 10 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 15 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 25 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |
| 50 | 0 | 50 | 0 | 50 | 0 | 50 | 0 | 150 | 0% | 100% |

The device cutoff is 10 mIU/mL hCG.

2. Linearity:

Linearity is not applicable since this is a qualitative test.

3. Analytical Specificity

Interference from exogenous and endogenous substances:

To evaluate potential interference from certain exogenous and endogenous substances, negative urine samples from normal healthy females containing were spiked to contain 0, 5 and 10 mIU/mL hCG and then spiked with potentially interfering substances at the concentrations listed in the table below. Samples were tested by 3 operators, in triplicate, using 3 lots of the test. No interference was observed at the concentrations shown in the table below:

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| Substance | Concentration |
| --- | --- |
| Acetaminophen | 20 mg/dL |
| Acetylsalicylic | 20 mg/dL |
| Ascorbic acid | 20 mg/dL |
| Atropine | 20 mg/dL |
| Caffeine | 20 mg/dL |
| Gentisic acid | 20 mg/dL |
| Glucose | 2 g/dL |
| Hemoglobin | 20 mg/dL |
| Tetracycline | 20 mg/dL |
| Ampicillin | 20 mg/dL |
| Albumin | 20 mg/dL |
| β-hydroxybutyrate | 2000 mg/dL |
| Ephedrine | 20 mg/dL |
| Phenylpropanolamine | 20 mg/dL |
| Phenothiazine | 20 mg/dL |
| EDTA | 80 mg/dL |
| Salicyclic Acid | 20 mg/dL |
| Benzoylecgonine | 10 mg/dL |
| Cannabinol | 10 mg/dL |
| Codeine | 6ug/dL |
| Ethanol | 1.0% |
| Bilirubin | 2mg/dL |
| Pregnanediol | 1500μg/dL |
| Thiophene | 20 mg/dL |
| Ketone | 20 mg/dL |

**Cross-reactivity of similar compounds:**

To evaluate cross-reactivity, urine pools from healthy, non-pregnant females were spiked to contain 0, 5 and 10 mIU/mL hCG and then spiked with potential cross reactants. Samples were spiked with 500 mIU/mL luteinizing hormone (LH), 1000 mIU/mL follicle-stimulating hormone (FSH), and 1 mIU/mL thyroid-stimulating hormone (TSH). The samples were tested in triplicate using 3 lots of the test by three different operators. No cross-reactivity was observed at tested concentrations.

**Effects of urine pH**

To evaluate the effect of urine pH on test results, urine samples containing 0, 5 and 10 mIU/mL hCG were tested at pH values of 4, 5, 6, 7, 8 and 9. The samples were tested in triplicate using three lots of the test device by 3 operators. The results demonstrated that urine pH ranges between 4 and 9 do not affect test performance.

**Effects of urine specific gravity**

To evaluate the effect of urine specific gravity on test results, urine samples containing 0, 5 and 10 mIU/mL hCG were tested at specific gravities of 1.000, 1.005, 1.010, 1.015, 1.020,

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1.025, 1.030 and 1.035. The results demonstrated that urine with a specific gravity ranging from 1.000 to 1.035 does not affect test performance.

## Hook Effect

Negative urine samples were spiked with varying hCG concentrations up to 500,000 mIU/mL. The samples were tested in five replicates, using three lots, by three operators. All tested concentrations gave a positive result. The results demonstrated that no hook effect was observed at hCG concentration up to 500,000 mIU/mL.

## Effects of hCG β-core fragment

Urine samples (0, 5, 10, and 20,000 mIU/mL hCG) were spiked with hCG β-core fragment (hCGβcf) at concentrations of 50,000 pmol/L, 125,000 pmol/L, 250,000pmol/L and 500,000pmol/L. Test performance is not affected by hCG β-core fragment concentrations up to 500,000 pmol/L.

4. Assay Reportable Range:

Not applicable

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

EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II are calibrated against reference material traceable to WHO International Standard (IS) 5th edition (NIBSC code 07/364).

6. Detection Limit:

A detection limit study was performed using negative urine samples spiked with 0, 5, 6.5, 8, 9, 10, 15, and 25mIU/mL hCG (hCG traceable to the 5th WHO IS). The samples were tested using both devices (EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II) using both instream and dip testing sampling methods in replicates of 20 for each of three lots of devices by 24 different operators (2 operators per lot per format and per testing method). The device cut-off is 10 mIU/mL hCG.

7. Assay Cut-Off:

The device cut-off is 10 mIU/mL. See Detection Limit (Section VII.A.6) and Precision/Reproducibility (Section VII.A.1) sections above.

## B Comparison Studies:

1. Method Comparison with Predicate Device:

Urine samples from women aged 21 to 48 years who were suspected of being pregnant were collected. Approximately half of the women were suspected to be pregnant in the early stage of less than 5 weeks. These samples were masked and randomized prior to testing by professionals using the EGENS Pregnancy Test Midstream I, and EGENS Pregnancy Test Midstream II, and the predicate device, in dip and simulated instream sampling methods).

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A total of 300 samples were tested using the EGENS Pregnancy Test Midstream I, 151 in dip sampling mode and 149 in instream sampling mode. Results are summarized below:

Summary of EGENS Pregnancy Test Midstream I (instream)

| Midstream I (Instream) | Predicate device | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| Candidate device | Positive | 77 | 0 | 77 |
| | Negative | 0 | 74 | 74 |
| | Total | 77 | 74 | 151 |

Summary of EGENS Pregnancy Test Midstream I (dip)

| Midstream I (Dip) | Predicate device | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| Candidate device | Positive | 74 | 0 | 74 |
| | Negative | 0 | 75 | 75 |
| | Total | 74 | 75 | 149 |

A total of 306 samples were tested using the EGENS Pregnancy Test Midstream II, 153 in dip sampling mode and 153 in instream sampling mode. Results are summarized below:

Summary of EGENS Pregnancy Test Midstream II (instream)

| Midstream II (Instream) | Predicate device | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| Candidate device | Positive | 76 | 0 | 76 |
| | Negative | 0 | 77 | 77 |
| | Total | 76 | 77 | 153 |

Summary of EGENS Pregnancy Test Midstream II (Dip)

| Midstream II (Dip) | Predicate device | | | |
| --- | --- | --- | --- | --- |
| | | Positive | Negative | Total |
| Candidate device | Positive | 78 | 0 | 78 |
| | Negative | 0 | 75 | 75 |
| | Total | 78 | 75 | 153 |

The test performance of the EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II is 100% concordant when compared to the predicate.

2. Matrix Comparison:

Not Applicable. The device is intended for urine samples only.

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# C Clinical Studies:

1. Clinical Sensitivity: Not applicable.
2. Clinical Specificity:

Specificity study to determine the false-positive result rate

The clinical specificity of the EGENS Pregnancy Test Midstream I and EGENS Pregnancy Test Midstream II was evaluated to determine the incidence of false positive tests results from the candidate device. Urine samples from 100 healthy, non-pregnant female from each of three cohorts: pre-menopausal (ages 18-40 years old), peri-menopausal (41-55 years old) and post-menopausal (>55 years old) women (300 subjects total) were tested. The clinical specificity was calculated as 300/300, or 100%. There was no difference between the two sampling methods (dip and instream). The results are summarized in the tables below:

EGENS Pregnancy Test Midstream I

| Group | Test result | |
| --- | --- | --- |
| | Dip method | Instream method |
| Pre-menopausal (18-40 yrs) | 0+/50- | 0+/50- |
| Peri-menopausal (41-55 yrs) | 0+/50- | 0+/50- |
| Post-menopausal (>55 yrs) | 0+/50- | 0+/50- |

EGENS Pregnancy Test Midstream II

| Group | Test result | |
| --- | --- | --- |
| | Dip method | Instream method |
| Pre-menopausal (18-40 yrs) | 0+/50- | 0+/50- |
| Peri-menopausal (41-55 yrs) | 0+/50- | 0+/50- |
| Post-menopausal (>55 yrs) | 0+/50- | 0+/50- |

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

Detection of hCG in Early Pregnancy Clinical Samples

A total of 585 urine samples were collected from 65 pregnant women confirmed to be pregnant by ultrasound. The women ranged from 21 to 40 years old and testing was conducted starting from 8 days before the expected menstrual period to the day of the expected menstrual period. Each sample was tested using both formats of the device. The same results were observed for both devices and both sampling methods. The following is a summary for the result for all conditions tested.

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| Days before your expected period | Percentage of pregnancy |
| --- | --- |
| 0 | 100% |
| 1 | 100% |
| 2 | 98% |
| 3 | 97% |
| 4 | 91% |
| 5 | 69% |
| 6 | 38% |
| 7 | 14% |
| 8 | 5% |

## Lay User Study

Three hundred and six (306) women with varying educational and occupational backgrounds with an age range of 21 to 50 years old tested their own urine specimen. Two hundred (200) lay users tested with the EGENS Pregnancy Test Midstream I devices and 106 lay users tested with EGENS Pregnancy Test midstream II devices. Each subject also provided a sample for professional testing. The data demonstrated 100% agreement between lay user results and professional results.

### EGENS Pregnancy Test Midstream I

| EGENS Midstream I
(instream and dip method) | Professional Result | | Total | |
| --- | --- | --- | --- | --- |
| | | Positive | | Negative |
| Lay user Result | Positive | 101 | 0 | 101 |
| | Negative | 0 | 99 | 99 |
| Total | | 101 | 99 | 200 |

### EGENS Pregnancy Test Midstream II

| EGENS Midstream II
(instream and dip method) | Professional Result | | Total | |
| --- | --- | --- | --- | --- |
| | | Positive | | Negative |
| Lay user Result | Positive | 54 | 0 | 54 |
| | Negative | 0 | 52 | 52 |
| Total | | 54 | 52 | 106 |

## Lay user spiked sample study

Urine samples were prepared at 5mIU/mL, 6.5mIU/mL, 8.0mIU/mL and 10mIU/mL hCG concentrations by spiking hCG into negative pooled urine specimens. Each sample was aliquoted into individual containers and blind-labeled. These samples were tested by 200 lay persons of varying educational and occupational backgrounds aged 21 to 50 years old using either the EGENS Pregnancy Test Midstream I or the EGENS Pregnancy Test Midstream II devices in both dip and instream sampling methods. The testing was performed at 3 sites. The results are summarized in the tables below (both dip and instream data combined). The data is representative of each sampling method:

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# EGENS Pregnancy Test Midstream I

| Number of samples | hCG concentration (mIU/mL) | Lay user Result | | Professional Result | | Percent Agreement |
| --- | --- | --- | --- | --- | --- | --- |
| | | Number of positive | Number of negative | Number of positive | Number of negative | |
| 100 | 5 | 0 | 100 | 0 | 100 | 100% |
| 100 | 6.5 | 5 | 95 | 7 | 93 | 98% |
| 100 | 8 | 49 | 51 | 51 | 49 | 98% |
| 100 | 10 | 100 | 0 | 100 | 0 | 100% |

# EGENS Pregnancy Test Midstream II

| Number of samples | hCG concentration (mIU/mL) | Lay user Result | | Professional Result | | Percent Agreement |
| --- | --- | --- | --- | --- | --- | --- |
| | | Number of positive | Number of negative | Number of positive | Number of negative | |
| 100 | 5 | 0 | 100 | 0 | 100 | 100% |
| 100 | 6.5 | 6 | 94 | 7 | 93 | 99% |
| 100 | 8 | 50 | 50 | 52 | 48 | 98% |
| 100 | 10 | 100 | 0 | 100 | 0 | 100% |

## 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.