(225 days)
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No
The device description and performance studies detail a standard ELISA assay based on chemical reactions and optical density measurements, with no mention of AI or ML algorithms for data analysis or interpretation.
No
The device is an in vitro diagnostic test system used to detect and semi-quantitate human antibodies to mouse IgG1 (HAMA). It helps monitor patients who have received murine monoclonal antibodies for diagnostic and/or therapeutic purposes, but it does not directly treat or diagnose a disease.
Yes
Explanation: The device is an enzyme-linked immunosorbent assay (ELISA) test system for the detection and semi-quantitation of human antibodies to mouse IgG. This information is used to assess significant titers of human anti-mouse antibody (HAMA) which have been associated with patients receiving injections of murine monoclonal antibody for diagnostic and/or therapeutic purposes, thus providing information for a diagnosis.
No
The device is a laboratory test system (ELISA) that involves physical reagents, microwell strips, and requires a microwell strip reader for measurement. It is not solely software.
Based on the provided information, the device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The intended use explicitly states it's for the "detection and semi-quantitation of human antibodies to mouse IgG1" in patient samples. This is a diagnostic purpose performed in vitro (outside the body).
- Device Description: The description details a laboratory test system (ELISA) that analyzes biological samples (diluted test sample) to detect a specific analyte (human antibodies to mouse IgG). This is characteristic of an IVD.
- Clinical Studies: The clinical studies involve testing patient samples to evaluate the performance and clinical utility of the assay in a diagnostic context (e.g., determining HAMA incidence, evaluating in patients receiving treatment).
The information clearly indicates that this device is designed to be used in a laboratory setting to perform tests on biological specimens for diagnostic purposes, which aligns with the definition of an In Vitro Diagnostic device.
N/A
Intended Use / Indications for Use
The ImmuSTRIP® HAMA IgG ELISA Test System is a direct enzyme-linked immunosorbent assay for the detection and semi-quantitation of human antibodies to mouse IgG1. Significant titers of human anti-mouse antibody (HAMA) have been associated with patients receiving injections of murine monoclonal antibody for diagnostic and/or therapeutic purposes2.
Product codes
DAK
Device Description
The ImmuSTRIP" HAMA IgG ELISA Test System is a direct enzyme linked immunosorbent assay for the semi-quantitative detection of human antibodies to mouse IgG (HAMA).
The HAMA assay is a two-stage test carried out in plastic microwell strips which have been coated with mouse IgG, whole molecule.
In the first stage, mouse IgG conjugated to horseradish peroxidase (conjugate) is added to the microwell. Diluted test sample is then added and incubated for a specified length of time. If antibody to the mouse IgG is present in the test sample, bridging will occur with the solid phase mouse IgG, the test sample antibody, and the conjugate. If antibody is not present in the test sample, the unbound conjugate will be removed in the subsequent washing step.
In the second stage, enzyme substrate is added to the microwell. If bound conjugate is present, the substrate will be reduced; the reduced end product of the catalytic reaction oxidizes the colorless chromogen resulting in a colored end product. Acid is added to stop the reaction and fix the color.
The color intensity is proportional to the amount of bound conjugate and, therefore, to the amount of precipitable antibody present in the sample. The color intensity is measured with a microwell strip reader.
The ImmuSTRIP" HAMA ELISA Test System may be performed manually or with existing microtiter equipment. Results, which are determined by optical density at 488-492 nm, are available in less than one hour. The test has been standardized against primate anti-mouse IgG serum and has a sensitivity of approximately 40 ng/ml. Final values are reported as nanograms of precipitable antibody equivalents per ml.
The assay system is a rapid, efficient, and semi-quantitative method. Specific reagent formulation has eliminated the problem of background interference currently existing in this type of assay.
Mentions image processing
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Mentions AI, DNN, or ML
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Input Imaging Modality
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Anatomical Site
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Indicated Patient Age Range
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Intended User / Care Setting
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Description of the training set, sample size, data source, and annotation protocol
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Description of the test set, sample size, data source, and annotation protocol
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Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Preclinical laboratory studies were conducted to determine the purity and specificity of the reagents. Immunogen preparation and immunization schedule for baboons to produce baboon anti-mouse antibody for the ImmuSTRIP HAMA IgG Reference Standard are described. The preparation of the ImmuSTRIP HAMA reference standard involved collecting and pooling serum samples from immunized baboons, assaying them by RID until significant levels of anti-mouse antibody were achieved, and preparing a standard dilution of 220 ng of precipitable antibody equivalents/ml.
Performance Characteristics:
- Reproducibility: Within run and between run assay reproducibilities were evaluated using low (50 ng/ml), medium (75 ng/ml), and high (200 ng/ml) control samples. Within run CVs were 74 ng/ml), with no apparent correlation between RF level and interference.
Real-time stability data on 12 lots supported a shelf life of 12 months when stored at 2° to 8°C.
Clinical Studies:
- Distribution of HAMA values in a normal population: 464 healthy individuals (250 males, 214 females, 104 pregnant) were assayed. 98% of males, 100% of non-pregnant females, and 96.1% of pregnant females were negative ( 400 ng/ml).
- Comparison with CEA-Scan (Arcitumomab) study: Of 240 patients monitored, 213 (89%) had negative baseline HAMA-IgG and HAMA Fragment and remained negative. 24 (10%) patients had at least one serum sample positive with ImmuSTRIP HAMA IgG but negative with HAMA Fragment. Only 3 (1.3%) of 240 patients tested positive with the ImmuSTRIP HAMA Fragment Assay. Most patients did not appear to develop HAMA after CEA-Scan administration.
- Comparison with a double-antigen, radiometric assay ("The Reference Method"): 61 samples (19 pre-injection, 42 post-injection) from 28 patients were compared. For pre-injection samples, ImmuSTRIP HAMA IgG yielded 1 positive (5.3%) while the Reference Method yielded 3 positives (15.8%). For post-injection samples, ImmuSTRIP HAMA IgG yielded 30 positives (71.4%) and the Reference Method yielded 27 positives (64.3%).
- Clinical impact of elevated HAMA levels on pharmacokinetics and dosimetry: A study of 57 patients receiving 131I-labeled anti-CEA IgG antibody showed that HAMA titers below 300 ng/ml had no apparent effect on antibody clearance rates, while titers above this threshold led to rapidly increasing plasma and whole-body clearance rates and decreasing red marrow and whole-body doses.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Sensitivity: 37 ng of precipitable antibody equivalents/ml.
For post-injection samples (n=42) compared to a Reference Method (RIA):
Sensitivity = 85.2%
Accuracy = 78.6%
Specificity = 66.7%
Positive Predictive Value (PPV) = 82.1%
Predicate Device(s)
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Reference Device(s)
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Predetermined Change Control Plan (PCCP) - All Relevant Information
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§ 866.5240 Complement components immunological test system.
(a)
Identification. A complement components immunological test system is a device that consists of the reagents used to measure by immunochemical techniques complement components C1q , C1r , C1s , C2 , C3 , C4 , C5 , C6 , C7 , C8 , and C9 , in serum, other body fluids, and tissues. Complement is a group of serum proteins which destroy infectious agents. Measurements of these proteins aids in the diagnosis of immunologic disorders, especially those associated with deficiencies of complement components.(b)
Classification. Class II (performance standards).
0
IV SUMMARY OF SAFETY AND EFFECTIVENESS
General Information
MAR 17 1998
Enzyme Linked Immunosorbent Assay for the Detection and Generic Name: Semi-Quantitation of Human Antibodies to Mouse IgG (HAMA).
ImmuSTRIP HAMA IgG Trade Name:
Applicant's Name and Address:
Immunomedics, Inc. 300 American Road Morris Plains, NJ 07950
ImmuSTRIP" is a registered trademark of Immunomedics, Inc. All references herein to ImmuSTRIP" are to the registered trademark.
INDICATIONS FOR USE A.
The ImmuSTRIP HAMA IgG ELISA Test System is a direct enzymelinked immunosorbent assay for the detection and semi-quantitation of human antibodies to mouse IgG1. Significant titers of human anti-mouse antibody (HAMA) have been associated with patients receiving injections of murine monoclonal antibody for diagnostic and/or therapeutic purposes2 .
Background
The expanding use of murine-derived monoclonal antibodies for in-vivo diagnostic and therapeutic procedures has resulted in an increased incidence of HAMA titers in patients receiving such antibodies. Circulating levels of HAMA may bind with the injected antibody, forming complexes that may adversely affect the biodistribution and pharmacokinetics of the injected antibody 1. In order to avoid injecting murine monoclonal antibodies into such patients who would receive no benefit, there is a need for an assay to predict potential complexations 10. Additionally, HAMA has been shown to significantly interfere with many commercial assays utilizing murinederived monoclonal antibodies, resulting in both false-positive and falsenegative results 11-18.
1
B. DEVICE DESCRIPTION
The ImmuSTRIP" HAMA IgG ELISA Test System is a direct enzyme linked immunosorbent assay for the semi-quantitative detection of human antibodies to mouse IgG (HAMA).
The HAMA assay is a two-stage test carried out in plastic microwell strips which have been coated with mouse IgG, whole molecule.
In the first stage, mouse IgG conjugated to horseradish peroxidase (conjugate) is added to the microwell. Diluted test sample is then added and incubated for a specified length of time. If antibody to the mouse IgG is present in the test sample, bridging will occur with the solid phase mouse IgG, the test sample antibody, and the conjugate. If antibody is not present in the test sample, the unbound conjugate will be removed in the subsequent washing step.
In the second stage, enzyme substrate is added to the microwell. If bound conjugate is present, the substrate will be reduced; the reduced end product of the catalytic reaction oxidizes the colorless chromogen resulting in a colored end product. Acid is added to stop the reaction and fix the color.
The color intensity is proportional to the amount of bound conjugate and, therefore, to the amount of precipitable antibody present in the sample. The color intensity is measured with a microwell strip reader.
The ImmuSTRIP" HAMA ELISA Test System may be performed manually or with existing microtiter equipment. Results, which are determined by optical density at 488-492 nm, are available in less than one hour. The test has been standardized against primate anti-mouse IgG serum and has a sensitivity of approximately 40 ng/ml. Final values are reported as nanograms of precipitable antibody equivalents per ml.
The assay system is a rapid, efficient, and semi-quantitative method. Specific reagent formulation has eliminated the problem of background interference currently existing in this type of assay.
2
C.
ALTERNATIVE PRACTICES AND PROCEDURES
Current Methods to Measure HAMA
Currently, the research methods that are available to measure HAMA are (1) Radioimmunoassay (RIA), (2) radial immunodiffusion (RID), (3) Ouchterlony, (4) rocket electrophoresis, (5) precipitation analysis and (6) passive hemagglutination. The aforementioned methodologies are currently being performed on samples from patients who have been injected with murine monoclonal antibodies 17.3. These methods may be insensitive, labor intensive, and/or require as many as 2-3 days for the results to be available.
D. MARKETING HISTORY
From 1988 to 1994. Immunomedics, Inc. has manufactured the ImmuSTRIP" HAMA IgG ELISA Test System and it has been available for research use only. Since 1994 Scimedx Corp., 400 Ford Road, Denville, New Jersey 07839, has manufactured the ImmuSTRIP" HAMA IgG ELISA for Immunomedics, Inc.
POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH E.
When this device is used according to the instructions provided, accurate assay results should be obtained. An error in the assay, however, which would produce a falsely low result could adversely affect the biodistribution and pharmacokinetics of the subsequent antibody injection. In this case, the quality of the imaging or therapy intended could be adversely affected. A falsely elevated result could lead to a medical decision resulting in the delay of a diagnostic or therapeutic procedure utilizing a murine-based monoclonal antibody.
3
SUMMARY OF STUDIES F.
1. Pertinent Publications
- Detection of Human Anti-Murine Kaladas PM, et al. a. Antibody (HAMA) Following Infusion of OncoScint" CR103. Comparison of ImmuSTRIP" ELISA with a Double Antigen Radiometric Assay. Antib Immunoconj Radiopharm 1993; 4:309-317.
- Massuger L. et al. Specific and Nonspecific Immunoassays b. to Detect HAMA After Administration of Indium-111-Labeled OV-TL 3 F(ab'), Monoclonal Antibody to Patients with Ovarian Cancer. J Nucl Med 1992; 33:1958-1963.
- Seybold K, Trinkler M, Frey L, et al. Antigenicity of C. Different Antigranulocytes Antibodies Assessed by HAMA Follow-up in Patients Undergoing Immunoscintigraphic Detection of Infections. Presented at the German Nuclear Medicine Congress, Cologne, Germany, April 15-17, 1993.
- Behr TM, et al. Phase I/II Clinical Radioimmunotherapy ત . with an Iodine-131-Labeled Anti-Carcinoembryonic Antigen Murine Monoclonal Antibody IgG. J Nucl Med 1997; 38: 858-870.
4
-
Summary of non-clinical studies 2.
Preclinical laboratory studies were conducted to determine the purity and specificity of the reagents. -
Production of the baboon anti-mouse antibody for the a. ImmuSTRIP" HAMA IgG Reference Standard.
Immunogen Preparation
Description of Antibody
The Immunomedics anti-CEA monoclonal antibody used as the immunogen was NP-4, later referred to as IMMU-4. IMMU-4 is a Class-III anti-CEA antibody of the immunoglobulin IgG, subclass. It is specific for CEA, not reacting with antigens that share CEA-related epitopes, such as meconium antigen and normal cross-reactive antigens. To prepare the IgG, ascites was produced in viral antibodyfree mice with the IMMU-4 hybridoma cell line. The ascites was aseptically removed, centrifuged to remove cells, and the supernatant solution was frozen and stored at -80° C. After thawing, the ascites was further clarified by passing through an ion-exchange column, using pH and ionic conditions that prevented binding of the IMMU-4 to the ion-exchange matrix. IgG was isolated from the clarified supernatant solution by Protein A affinity chromatography, and further purified by ion-exchange chromatography. Purity and identity of the purified IMMU-4 IgG were proven by immunoelectrophoresis and SDS gel electrophoresis. (Refer to Section VI, Volume III).
Lampire Biologicals, located at 217 Farmschool Road, Ottsville, PA was contracted by Immunomedics to perform the immunization of the baboons, and to maintain the animals.
5
Immunization Schedule
Immunogen: 0.5 ml immunogen (IMMU-4 IgG, 1 mg/ml) was emulsified in 0.5 incomplete Freund's adjuvant and divided into aliquots for four subcutaneous injection sites per animal.
| Schedule | Boost | Bleed |
|---|---|---|
| Week of | ||
| 10/30/86 | 1.0 ml | 50 ml |
| 11/06/86 | 1.0 ml | 0 ml |
| 11/13/86 | 1.0 ml | 0 ml |
| 11/20/86 | 1.0 ml | 0 ml |
| 11/27/86 | 1.0 ml | 50 ml |
| 12/25/86 | 1.0 ml | 50 ml |
| 12/11/86 | 1.0 ml | 50 ml |
| 01/08/87 | 1.0 ml | 50 ml |
| 01/22/87 | 1.0 ml | 50 ml |
| 02/05/87 | 1.0 ml | 50 ml |
| 11/09/87 | 1.0 ml | 20 ml |
| 11/28/87 | 1.0 ml | 100 ml |
| 12/07/87 | 1.0 ml | 100 ml |
| 12/21/87 | 1.0 ml | 100 ml |
Preparation of the ImmuSTRIP* HAMA reference standard b.
Serum samples from the immunized baboons were collected during the immunization procedure. These samples were tested by RID until significant levels of anti-mouse antibody were achieved. Large bleeds of the animals were then performed and serum samples were pooled and frozen at -80°C. Aliquots of the pooled sera were assayed by RID and the HAMA activity was determined. A dilution of the pooled sera, to a concentration of 220 ng of precipitable antibody equivalents/ml, was prepared in phosphate buffered saline, sterile filtered and maintained as a reference standard.
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- Performance Characteristics c.
Reproducibility 1 .
Within run and between run assay reproducibilities were evaluated by performing the ImmuSTRIP® HAMA IgG assay utilizing low, medium and high control samples. The control samples were prepared by enriching normal human serum with purified The assigned control values were as HAMA. follows:
low control = 50 ng/ml medium control = 75 ng/ml high control = 200 ng/ml
Within run coefficients of variations (percent CVs) were calculated for replicates of three.
Between run CVs were calculated for replicates of three, from assays performed on different days. The CVs for within run values were ≤10%, and between run CVs were 74 ng/ml). There was no apparent correlation between the level of RF in the sample and the severity of interference with the ImmuSTRIP" HAMA IgG assay.
12
Real time stability data were determined on 12 lots of ImmuSTRIP® HAMA IgG kits stored at 2° to 8°C. These data are reported as valid or invalid based on the criteria for a valid assay." These stability data support a shelf life of 12 months.
| ImmuSTRIP®
| HAMA IgG Lot # | Day 0 | 3 Months | 6 Months | 9 Months | 12 Months |
|---|---|---|---|---|---|
| 1604 | Valid | Valid | Valid | Valid | Valid |
| 1606 | Valid | Valid | Valid | Valid | Valid |
| 1607 | Valid | Valid | Valid | Valid | Valid |
| 1608 | Valid | Valid | Valid | Valid | Valid |
| 1611 | Valid | Valid | ND | Valid | Valid |
| 1613 | Valid | Valid | Valid | Invalid | Valid |
| 1620 | Valid | Valid | ND | ND | Valid |
| 1623 | Valid | Valid | Valid | Valid | Valid |
| 1631 | Valid | Valid | Valid | Valid | ND |
| 1633 | Valid | Valid | Valid | Valid | Valid |
| 1634 | Valid | Valid | Valid | Valid | Valid |
| 1636 | Valid | Valid | Valid | TBD | TBD |
| NOTE: The studies are on-going for lot 1636. | |||
|---|---|---|---|
| ---------------------------------------------- | -- | -- | -- |
ND = Not Done TBD = To be determined
*Criteria for a Valid Assay: Correlation coefficient (R2): ≥ 0.950 Slope: 0.005 to 0.015 Y-intercept: ≤ 0.200
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3. Clinical Studies
Clinical studies were conducted at two medical institutions and at one reference laboratory. The investigators and their institutions were: Robert M. Sharkey, Ph.D., Center for Molecular Medicine and Immunology (CMMI), H. Abdel-Nabi, M.D., State University of New York at Buffalo, Dept. of Nuclear Medicine, and Dianon Systems, Inc., Stratford, CT (a commercial reference laboratory).
The objectives of the clinical studies were to:
- retrospectively determine the incidence of HAMA in serum samples a. from a normal, apparently healthy population.
- retrospectively evaluate the ImmuSTRIP® HAMA IgG assay to b. detect and quantitate HAMA in patients receiving murine-derived monoclonal antibodies for diagnostic and/or therapeutic purposes.
- prospectively evaluate the ImmuSTRIP" HAMA IgG assay to detect C. and quantitate HAMA in patients receiving a murine-derived monoclonal antibody fragment for imaging colorectal cancer, (CEA-Scan", Arcitumomab).
- compare the ImmuSTRIP" HAMA IgG assay values to those d. obtained with a reference method.
- determine the clinical impact of elevated HAMA levels on e. pharmacokinetics and dosimetry in patients receiving 13'1-labeled murine anti-carcinoembryonic antigen (CEA) monoclonal antibody.
The results of each of the above studies are summarized on the following pages.
14
Summary of Clinical Studies:
Distribution of HAMA values in a normal population a.
Blood samples obtained from 464 healthy individuals (250 males and 214 females, 104 of which were pregnant) were assayed with ImmuSTRIP HAMA IgG by Dianon Systems, Inc., Stratford, CT.
Results were obtained following the manufacturer's directions for use; all samples were assayed in duplicate and final values are expressed as the mean of the duplicate results.
The following table summarizes the distribution of HAMA values in an apparently healthy population.
| Healthy Subjects | 74 ng/ml) at least once during the post-injection test interval(s).
Of the 51 patients provided by Dr. Hani Abdel-Nabi of the VA Medical Center, Buffalo, NY, 21 patients (41.2%) were positive for HAMA post-injection with murine-derived antibodies. Dr. Nabi's laboratory prepared a 1:10 dilution of patient sample with specimen diluent prior to assay with ImmuSTRIP* HAMA IgG. Immunomedics, Inc. initially recommended a 1:10 dilution, but subsequently changed the recommended sample dilution to 1:2. Specimen dilution studies resulted in acceptable expected vs. actual values and percent CV's, therefore no difference was expected in 1:2 vs. 1:10 sample dilution HAMA values. The ImmuSTRIP" HAMA IgG assay was positive (> 400 ng/ml: sensitivity 40 ng/ml X 10 [dilution factor]), at least once during the post-injection test interval(s).
c. ImmuSTRIP® HAMA and ImmuSTRIP HAMA Fragment assay results for patients receiving CEA-Scan", (Arcitumomab).
Two HAMA enzyme immunoassays, ImmuSTRIP" HAMA IgG and ImmuSTRIP HAMA Fragment, were used to quantify HAMA in patient sera obtained in the CEA-Scan Phase III study. CEA-Scan is an FDA-approved (BLA #1205) imaging agent for colorectal cancer. (Please note that the ImmuSTRIP" HAMA Fragment ELISA assay kit is the subject of a separate 510(k) submission, therefore, clinical results are provided here for informational purposes only.) Sera subsets were also assayed for drug-reactive HAMA with an HPLC assay that is used, and has been validated, to determine purity immunoreactivity, and stability of CEA-Scan". HAMA determined by this assay will be referred to as "drug-reactive HAMA." To perform the drug-reactive HAMA assay, a vial of CEA-Scan" is labeled with 990"Tc-pertechnetate according to the package insert. Twenty ng of the labeled drug contained in one ul of saline-HSA (1% human serum albumin in saline) is added to 100 ul of patient serum. The specimen is incubated for one hour at 37°C, and then analyzed for drug-reactive HAMA by application of 50 ul of the serum onto a HPLC size exclusion column, and continuously monitoring the radioactivity eluting from the column. If drug-reactive HAMA is not present in the serum, the primary peak of radioactivity elutes at a time consistent with its molecular weight of
18
50,000 daltons. If drug-reactive HAMA is present in the sera, the radiolabeled drug is bound by the antibody, and the resultant complex that has a molecular weight of 200,000 daltons or greater, elutes from the column prior to the elution of the 50,000 Dalton Fab'-SH. To determine if drug-reactive HAMA is directed against the constant region of the Fab', or the variable region of the Fab', 10 ug of an irrelevant murine Mab is added to the 100 ul of serum prior to addition of the labeled drug, and the assay repeated. Thus, HAMA reactive with the constant region of Fab' is neutralized and an antibody-drug complex is not formed. HAMA reactive with the variable region is not neutralized and the elution time of the radioactivity is not changed by addition of the irrelevant MAb.
Results:
Of 382 patients entered into the Phase III trials, 240 of the patients had a baseline determination and at least one follow-up measurement with ImmuSTRIP" HAMA-IgG and ImmuSTRIP" HAMA Fragment Assays (data on file at Immunomedics).
Of the 240 patients, 213 (89%) had negative baseline HAMA-IgG and HAMA Fragment test result, and remained negative after infusion of CEA-Scan ; these patients are listed in Table VII. Sera of 24 of these patients were assayed for drug-reactive HAMA (Vol. 2, Section VI, pages 140-143, Table VII, underlined patient numbers) 2-3 months post-infusion, and all of the sera were negative in this assay. Seventeen of these 213 patients received a second infusion of CEA-Scan and all of these patients remained negative with the HAMA-IgG and HAMA Fragment Assays (Vol. 2, Section VI, Table VIII, pages 144-145). Twenty sera from 12 of these patients that received a second infusion of CEA-Scan" were assayed for drug-reactive HAMA after the second administration of the drug, and all remained negative for drug-reactive HAMA (Vol.2, Section VI, Table VIII, pages 144-145).
Of the 240 patients, 24 (10%) patients had at least one serum sample that tested positive with the ImmuSTRIP" HAMA IgG Assay and negative with the ImmuSTRIP" HAMA Fragment Assay (Vol. 2, Section VI, Table IX. page 146). Twenty-one sera from ten of these patients were tested for drug-reactive HAMA. With the exception of patient 040950, all tested negative. The baseline serum and the two post-infusion sera of patient 040950 bound approximately 50% of the labeled drug, and this HAMA was neutralized by irrelevant IgG. Therefore, this preexistent drug-reactive HAMA is directed against the constant region of the Fab'. Administration of CEA-Scan" did not significantly boost the HAMA titer in this patient. One of the ImmuSTRIP" HAMA IgG positive, ImmuSTRIP" HAMA Fragment negative patients (181801) received a second injection of CEA-Scan
19
(Vol. 2. Section VI, Table VIII, page 145). The baseline HAMA-IgG was 209 ng/mL the day the second dose of CEA-Scan" was given, and the HAMA-IgG in the two post-infusion sera were essentially unchanged (183 ng/mL and 170 ng/mL). Both of these post-infusion sera were negative with the drug-reactive HAMA method.
Only three (1.3%) of the 240 patients tested positive with the ImmuSTRIP" HAMA Fragment Assay at any time (patients 040405, 050602, and 051803); one other patient tested positive for HAMA-Fragment (050991), but was determined to have been injected with OncoScint CR 103 shortly before being given CEA-Scan" (Vol 2, Section VI, Table X, page 147). OncoScint CR 103 contains an intact IgG-MAb, and has been established to induce HAMA-IgG levels of >400 ng/mL in over 30% of patients after a single drug-infusion PM. et al., Antibody Immunoconjugates (Kaladas and Radiopharmaceuticals 4:309-317:1991).
One of the three Phase III patients (051803) that was positive with both the ImmuSTRIP* HAMA IgG and the ImmuSTRIP* HAMA Fragment also received a second injection of CEA-Scan", a year after the first administration (Vol. 2, Section VI, Table X, page 147). The baseline sera at the time of the second injection was negative for both HAMA-IgG and HAMA-Fragment. Both post-infusion sera remained negative for HAMA-Fragment, and only the one-month post-infusion sera demonstrated a low amount of HAMA-IgG (91.7 ng/mL). However, both post-infusion sera were strongly positive with the drug-reactive HAMA test method, and HAMA in neither of the sera was neutralized with irrelevant MAb-IgG, putative evidence that this HAMA is directed against the variable region of the Fab'.
In summary, with the exception of the patient that had received OncoScint CR 103, none of the 240 patients that were monitored in this study for induction of HAMA appear to have developed HAMA.
All clinical samples were run in duplicate, the mean of the duplicate values was reported.
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- d. Comparison of the ImmuSTRIP" HAMA IgG ELISA test system values with values obtained with a double-antigen, radiometric assay method referred to as "The Reference Method."7
Samples, provided by Dr. Robert Sharkey of CMMI, Newark, NJ, from the 28 patients evaluated in the pre- and post- injection HAMA study were assayed by Dr. M. Khazaeli, of HAMA-KINE, Inc, 1075 Thirteenth Street South, Birmingham, Alabama. There were a total of 61 samples (19 pre-injection samples and 42 post-injection samples) from the CMMI study with sufficient quantity to perform comparative testing with the Reference Method.
The results of the ImmuSTRIP" HAMA IgG ELISA and Reference Method comparative study are summarized as follows:
21
Of the 19 pre-injection of murine-derived antibody samples, one sample was positive (> 74 ng/ml) with the ImmuSTRIP* HAMA IgG ELISA assay and three were positive (> 10 ng/ml) with the Reference Method. Each test gave a positive result on sample #36; the Reference Method resulted in two additional positive results, samples #42 and #47.
In the post-injection of murine-derived antibody samples (n=42), there were 30 positive (> 74 ng/ml) results (71.4%) with the ImmuSTRIP* HAMA IgG assay method and 27 positive (> 10 ng/ml) results (64.3%) with the Reference Method.
- Comparison of ImmuSTRIP* HAMA IgG (ELISA) assay Table 1. results vs. double-antigen, Radiometric, (RIA) assay results in pre- and post-injection samples.
Pre-iniection (n=19)
| ళ్ళార | Positive |
|---|
|
1
| ****
BIRDINGS
8
1
|
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------|
| Administration
-
| -------
**** |
"ELISA positive > 74 ng/ml, RIA positive > 10 ng/ml.
Post-injection (n=42)
| % Positive* | |
|---|---|
| ELISA | 71.4 (30/42) |
| RIA | 64.3 (27/42) |
"ELISA positive > 74 ng/ml, RIA positive > 10 ng/ml.
22
Summary of and post- injection with murine-derived antibody (n=42)
Direction of the more of the block to the redicametric organ (D) - Summary of and post "injection will merican" and metric assay (RIA)
ELISA
| NEGATIVE | POSITIVE | |
|---|---|---|
| NEGATIVE | 23.8% | |
| (10/42) | 11.9% | |
| (5/42) | ||
| POSITIVE | 9.5% | |
| (4/42) | 54.8% | |
| (23/42) |
| True Positive (TP) | = 23 |
|---|---|
| False Positive (FP) | = 5 |
| True Negative (TN) | = 10 |
| False Negative (FN) | = 4 |
| Sensitivity | = | $\frac{TP}{TP + FN}$ | = | 85.2% |
|---|---|---|---|---|
| Accuracy | = | $\frac{TP + TN}{TP+TN+FP+FN}$ | = | 78.6% |
| Specificity | = | $\frac{TN}{TN + FP}$ | = | 66.7% |
| Positive Predictive Value | ||||
| (PPV) | = | $\frac{TP}{TP + FP}$ | = | 82.1% |
RIA
:共
23
- e. Clinical impact of elevated HAMA levels on pharmacokinetics and dosimetry in patients receiving 131I-Jabeled murine anticarcinoembryonic antigen (CEA) monoclonal antibody.
A total of 57 patients with CEA-expressing tumors received therapeutic doses (4-23 mg of protein and 44-268 mCi of 1311) of anti-CEA (NP-4) IgG antibody. HAMA levels were determined preinjection and post-injection on a weekly basis until 6 weeks posttherapy and then monthly thereafter. The ImmuSTRIP" HAMA IgG assay was used to determine the HAMA values.
The above study was published in The Journal of Nuclear Medicine, June 1997. The publication is provided in this Section for the convenience of the reviewer (page 27). The impact of elevated HAMA levels on pharmacokinetics and dosimetry is discussed in detail under the section "Pharmacokinetics." The study demonstrated that at HAMA titers below 300 ng/ml, no effect on the clearance rates of the (injected) antibody from the blood and whole-body was apparent, whereas with titers above this threshold a rapidly increasing plasma and whole-body clearance rate was observed. which was reflected by decreasing red marrow and whole-body doses (r = - 0.6; significantly different from zero at p