L

DOE GRANT # DE FG03-84ER60233

DOE ANNUAL REPORT

1988-89

DISCLAIMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or use- fulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any spc- cific commercial product, process, or service by trade name, trademark, manufac- turer. or otherwise does not necessarily constitute or imply its endorsement, m m - mendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER

Portions of this document may be illegible electronic image products. Images are produced from the best available original document.

DOE DE-FG(X384ER60ZX3 salv J. Mardo, M.D.

DWELOPMENT OF DOSIMElRIC APPROACHES TO TREATMENT PLANNING FOR RADIOIMMUNOMERAPY

RESEARCH ACCOMPLISHMENTS (PROGRESS)

The objective of quantitative imaging is to provide pharmacokinetic information for patients that is analogous to that provided by biodistribution studies in mice. Radionuclide images depict the distribution of labeled antibodies in-vivo; thus the amount of radionuclide in a specific organ or site can be estimated by relating the counts detected in a defined region of interest to the total radionuclide content. This pharmacokinetic information can be used to obtain definitive and relevant answers to basic questions of importance for optimizing radioimmunoimaging and radioimmunotherapy and, in addition, can provide a data base from which to calculate the distribution of radiation absorbed doses.

The projects supported by this program routinely employ quantitative imaging in evaluating therapies. Quantitative imaging is performed by a certified nuclear medicine technician using the Siemens gamma camera interfaced with the microVAX II. The technician processes the imaging data and obtains pharmacokinetic information from it using programs developed by us and others. During this grant period project staff have acquired and analyzed a large amount of data on the pharmacokinetics, dosimetry and toxicity of radiolabeled monoclonal therapy. Important dosimetry data on the whole body, marrow and tumor doses are available and all studies are archived so that they can be retrospectively analyzed. Although the radiation absorbed doses delivered to tumor sites were modest, significant biological responses were found.

During this grant period substantial improvements were made in the equipment available for this work. An additional camera was purchased to allow for concurrent imaging studies of two patients. A new facility was provided to house this equipment. It is now possible to safely transport the therapeutic or imaging radiopharmaceutical by dumbwaiter directly from the Pharmacy to the Imaging Suite. The storage space on the MicroVAX was increased to 600 mb to accommodate the growing data base of imaging information as well as additional imaging and pharmacokinetics analysis programs.

During the grant period substantial work was done on standardizing procedures used by the technicians. Special studies including repeat readings of results by two technicians were done to evaluate sources of variability in interpretation, and procedures were modified to minimize this variability.

Considerable work has also been done on the computer programs used. A comprehensive software system has been developed to provide pharmacokinetic data and radiation dosimetry for any portion of a patient from sequential planar images of patients who received radiolabeled antibody. This software, in concert with our quantitative imaging methods, provides a major step in our ultimate goal to develop a comprehensive treatment planning approach which allows us to evaluate individual patients relative to the suitability of radioimmunotherapy, and to compare therapeutic efficacy and toxicity with estimated radiation absorbed doses. The program provides calculated radiation absorbed doses for: the whole body, the red marrow and tumorslorgans that demonstrate detectable uptake of a radiolabeled monoclonarantibody (MoAb) in sequential gamma camera images. Various options in this computer program provide organ and tumor volumes from SPECT images, attenuation correction factors for various sites from a whole body

. -

DOE DE-FG(X384ER60233 Salty J. DeNardo. M.D. ~~~

transmission image, and allow the user to visualize and stack images in various time sequences that aid clinical interpretation.

S T A R T

I 1 J 1

Patient Pharmacohinetics D a t a Observation Parameter Estimator Parameter T h e r a p y Planner

Kinettc and c c E s trmates ECT, Gamma Camera, elc Observational Model

Radionuclide Data

Other hledical Data e . g . T C T and E C T mass a n d location est imd t r s Kinetic .Model.

Radiation Ouse Distr ibut ion

I

Patient Treatment O t h e r Wedical D a t a influencing treatment

herapy Pldl -

Figure 1. Treatment planning system using kinetic models. A kinetic model combined with a parameter estmator is applied to patient data to obtain distribution and cumulated activity estimates. These estimates are then. used as inputs to a therapy planner which produces a plan for the patient therapy, The process is iterated, if necessary, to complete the therapy regimen.

These programs represent important contributions to the field. The programs are readily transportable to any site with a Siemens microVAX II computer system running MAXDELTA terminals as workstations. They have been installed by Dr. Mark Groth at RushSt. Luke’s- Presbyterian Medical Center in Chicago and Dr. Macey recently installed them at the M.D.Anderson Cancer Center in Houston when he moved there. There are over 300 microVAX I t computer systems running MAXDELTA software in departments of nuclear medicine in the U.S.A. which can run this treatment planning program.

The initial RIT dosimetry program was designed around the calculation of absorbed doses for two radionuclides: 1-131 and Cu-67. The U.S. Department of Energy MlRD program MIRDOSE 2 has recently been incorporated into the present treatment planning program so that radiation absorbed doses for up to 60 radionuclides can be readily calculated. Also doses to organs, such as the kidney, bladder and stomach, with variable filling and emptying rates can be calculated for the individual patient. Doses to 1 to 25 target organs from 1 source organ or to

DOE DE-FGCEHWER60233 Sally J. Mardo, M.D.

1 target organ from 1 to 25 sources in the body can be provided with this approach for the newborn, infant, ten year old or standard man,

The radiation absorbed dose delivered to the red marrow is of special concern for RIT because it often sets the toxicity limit for therapy. A special purpose program has been developed to estimate the dose contribution to marrow from specific uptake of the radiolabeled MoAb in red marrow. The calculation is based on the uptake in 3 lumbar vertebrae. This approach relies on determining the accumulation of the radiolabeled monoclonal antibody in total red marrow by extrapolation from the uptake measured in 3 lumbar vertebrae. This red marrow dose from specific uptake is added to the estimated dose delivered to marrow from the activity in whole body and activity in whole blood.

During this time studies have also been initiated to identify possible sources of error in dose calculations. The influence of remaining body activity on the calculated radiation absorbed doses delivered to various organs/sites in the body has been investigated for patients receiving diagnostic and therapy doses of 1-131 labeled Lym-1 considering the her as both the target and the source. Good agreement was found using the corrected cumulated activity and the corrected 'S' factor methods. Doses are overestimated by up to 20% for the liver using the straightforward MlRD approach. This correction factor is small for typical tumor sites of less than 100 ml with uptakes of less than 1 % of the administered dose. The magnitude of this correction factor for organs and uptakes sites at various distances from high uptake organs/sites in the body merits further consideration. The remaining body activity correction factor can be elegantly calculated for any site in the body from a whole body image. The validity of the remaining whole body activity approach can be examined and refined for a specific target organ/site in the body.

-

Studies were also done using a phantom io evaluate several methods for quantitating radionuclide and radiation absorbed doses for the liver and spleen using planar imaging. All 3 planar methods were accurate for the liver, but underestimated the spleen if background was subtracted.

Significant errors have been found with 1-131 photopeak count rates as low as 20,000 counts per second due in part to the comparatively large number of scatter events detected outside the photopeak used for imaging. Methods are being explored that can be used to correci all planar gamma camera images for the resolving time errors encountered by the gamma camera over the range of activrty levels administered to patients receiving therapy doses of radiolabeled monoclonal antibodies. Preliminary work has been done to evaluate a method in which a small volume source containing approximately 1 % of the radionuclide dose administered to each patient is imaged in the same field of view of each image acquired. The number of counts from that source are expressed as a ratio of the counts detected from an image of the same source in air alone to determine the dead time error for each frame.

DOlE DE-FGWSQER60233 Salk J. Mardo, M.D.

BIOLOGICAL MOAB DWELOPMENT AND THERAPY FEASIBIW

MAJOR RESEARCH ACCOMPLISHMENTS

Teta Lym-1 : Preliminary Patient Dose Escalation from Imaging Pharmacokinetics to Therapy: Our treatment with '311-Lyrn-1 in B cell lymphoma has led to a response rate greater than 75% in 40 patients. While 1-131 has been effective in this system, it does pose problems relative to radiation safety and 'dehalogenation'. Several metal chelated antibodies have been shown to accumulate in tumors better than the corresponding iodinated antibody, but in studies with DTPA analogues there is evidence that they escape the conjugating chelate and follow other pathways: In the case of some yttrium-90 chelated antibodies, this occurred in therapy trials at two different centers and produced unexpected myelosuppression. 67Cu has a physical half life of 61.5 hours, abundant beta emissions of 577 (20%), 486 (35%), and 395 (45%) keV and moderately abundant gamma emissions of 93 (24%) and 184 (47%) keV. We have pursued chelates for copper that would tightly bind this metal and these efforts resulted in the development of the new macrocycle, 6-p-nitrobenzyl-TETA. The bifunctional chelating agent para- bromoacetamidobenzyl-TETA was conjugated to Lym-1 without significantly altering its immunoreactivity and tumor uptake of 67Cu-Lym-l in mice with RAJl lymphoma implants was comparable to and more prolonged than that of '371-Lym-l. There was no evidence of active uptake by other organs.

FIGURE 1

DOE DEiG(XE84ER60233 Sally J. Mardo, M.D. ~~ ~~ ~ ~~ ~~~ ~

Eight patients with lymphoma have been given 0.6 - 10 mCi of 67Cu-TFTA-Lym-l (1 0-35 mg Lym- 1) after a preload of 20 mg of unconjugated Lym-I. Immunoreactivity was essentially that of unconjugated Lym-I. Blood clearance of 67Cu Lym-1 was comparable to that of 7311-Lym-l for 48h hrs (Figure 2), but 67Cu Lym-1 had a longer clearance from tumor and from the body and diminished urinary excretion when compared to 1-131 Lym-1 (Figure 3). Trace amounts of 67Cu was excreted in the stool (1.0 +/- 0.5% ID total excretion in stool over 5 days),

FIGURE 2

3 :< r f : I 1 5

TIME j i l a u r s i

FlGlJRE 3

W v) 0 0 C u t

F- z w 0 U w n

I-IJi Lym-i Firs: Dodo Foibwng Cu-57 Lym-i Rx

I S 5

‘ I 7 : I 4

TIME [HourY)

Cu-67 Lyrn-1 RECPRCCXL OF URINE CLEARANCE

- .-

lo -* 0 2 4 4 8 7 2 9 6 1 2 0 1 4 4 1 6 8 1 9 2

TIME (Hours)

DOE DEFG0384ER60233 Sally J. DeNardo, M.D.

Figure 4 Anterior pelvic image 24 hours after the injection of 4 4mCi Cu67 Lym 1 Tumor uptake is demonstrated in abdominal, pelvic and inguinal lymphomatous nodes

While these studies were pharmacologic in nature, the patient that received 4.4 mCi of 67Cu Lym-1 had relief of bone pain and more than a 70% reduction in the size of a nodal mass. Two of the three patients receiving 10 mCi doses had 30-60% decrease in measurable tumor volumes. In patients without marrow lymphoma, no marrow uptake was observed. Marrow dosimetry is included in the C d 7 dosimetry /mCi calculated using our treatment planning dosimetry software developed under this DOE grant (Table 2). These results provide suppori for our continued enthusiasm relative to the potential of 67Cu labeled antibodies

DOE Cited Publications

1988

1988

1988

1988

1988

1988

1988

1988

1988

1988

Meares, C.F., M.J. McCall, S.V. Deshpande, S.J. DeNardo, D.A. Goodwin. Chelate radiochemistry: Cleavable linkers lead t o altered levels of radioactivity in the liver. International Journal of Cancer, Supplement 2:99-102.

Moi, M.K., C.F. Meares, S.J. DeNardo. The Petide Way to macrocyclic bifunctional chelating agents: Synthesis of 2-p-Nitrobenzyl- 1,4,7,10- tetraazacyclododecane-N,N'N'',N'"-tetraacetic acid, and study of i ts yttrium (111) complex. Journal of the American Chemical Society 1 10:6266-6267.

Macey, D.J., G.L. DeNardo, S.J. DeNardo. Comparison of three boundary detection methods for SPECT using compton scattered photons. Journal of Nuclear Medicine 29:203-207.

Deshpande, S.V., S.J. DeNardo, C.F. Meares, M.J. McCall, G.P. Adams, M.K. Moi, G.L. DeNardo. Copper-67 labeled monoclonal antibody Lym-1 , a potential radiopharmaceutical for cancer therapy: Labeling and biodistribution in RAJl tumored mice. Journal of Nuclear Medicine, 29:217-225.

DeNardo, S.J., G.L. DeNardo, L.F. O'Grady, N.B. Levy, S.L. Mills, D.J. Macey, J.P. McGahan, C.H. Miller, A.L. Epstein. Pilot studies of radioimmunotherapy of B-Cell Lymphoma and Leukemia using 1-1 31 Lym-1 monoclonal antibody. Antibody, Immunoconjugates, and Radiopharmaceuticals 1 : 1 7-33.

Ryan, K.P., R.O. Dillman, S.J. DeNardo, G.L. DeNardo, J. Beauregard, P. Hagen, K. Burnett, C. Rulot, R.E. Sobol, R.K. Bartholomew, J.H. Frincke, C. Birdwell, D.J. Carlo, L.F. O'Grady, S.E. Halpern. Breast cancer imaging with In-1 1 1 human IgM monoclonal antibodies: Preliminary Studies. Radiology 167:71-75.

DeNardo, S.J., G. L. DeNardo, L. F. O'Grady, E. Hu, V.M. Sytsma, S.L. Mills, N. B. Levy, D. J. Macey, C. H. Miller, A. L. Epstein. Treatment of B cell malignancies wi th 1-1 31 Lym-1 monoclonal antibodies. International Journal of Cancer 3:96-101.

DeNardo, G.L., DeNardo, S.J., Macey, D.J, Mills, S.L.: Quantitative pharmacokinetics of radiolabeled monoclonal antibodies for imaging and therapy in patients. S. Srivastava (Ed), Radiolabeled Monoclonal Antibodies for lmaaina and Theram, Plenum Publishing, New York.

DeNardo, G.L., S.J. DeNardo, N.P. Miyao, S.L. Mills, J-S Peng, L.F. O'Grady, A.L. Epstein,W.c. Young. Non-dehalogenation mechanisms for excretion of radioiodine after administration of labeled antibodies. International Journal of Biological Markers 3: 1-9.

Macey, D.J., S.J. DeNardo, G.L. DeNardo, J.K. Goodnight, M.W. Unger. Uptake of Indium-1 1 1 -labeled monoclonal antibody ZME-018 as a function of tumor size in a patient with Melanoma. American Journal of Physiologic Imaging 3: 1-6.

1988 DeNardo, S.J., G.L. DeNardo, S.V. Deshpande, G.P. Adams, D. J. Macey, S.L. Mills, A.L. Epstein, C.F. Meares. The design of a radiolabeled monoclonal antibody for radioimmunodiagnosis and radioimrnunotherapy, p. 1 1 1-1 22. In S. Srivastava (Ed.) Radiolabeled Monoclonal Antibodies for Imaaina and TheraDy, Plenum Publishing, N.Y.

1989 DeNardo, S.J., G.L. DeNardo, J-S Peng. Pharmaceutical quality control for radiolabeled monoclonal antibodies and their fragments. American Journal of Physiologic Imaging 4:39-44.

1989 Adams, G.P. S.J. DeNardo, S.V. Deshpande, G.L. DeNardo, C.F. Meares, M.J. McCall, and A.L. Epstein. Effect of mass of In-1 11 Benzyl-EDTA monoclonal antibody on hepatic uptake and processing in mice. Cancer Research 49: 1707- 171 1.

1989 DeNardo, G.L., D.J. Macey, S.J. DeNardo, C.G. Zhang, T.R. Custer. Quantitative SPECT of uptake of monoclonal antibodies. Seminars in Nuclear Medicine 19:22-32.

1989 Mills, S.L., S.J. DeNardo, G.L. DeNardo, S.V. Deshpande, M.J. McCall, C.F. Meares, A.L. Epstein. Radiopharmaceutical preparation of a monoclonal antibody, Lym-1, and i ts F(ab’)2 fragment for imaging lymphoma with In-1 1 1. Journal of Labelled Compounds and Radiopharmaceuticals 27:377-386.

1989 Macey, D.J., G.L. DeNardo, S.J. DeNardo. Dosimetric implications of heterogeneity, p. 223-242. In G.L. DeNardo (Ed.), Bioloav of Radionuclide Theraw. American College of Nuclear Physicians, Washington, D.C.

1989 G.L. DeNardo, J.P. Lewis, A. Raventos, D.J. Macey, S.J. DeNardo, p.1-22. Renaissance of radionuclide therapy. In G.L. DeNardo (Ed.), Bioloav of Radionuclide Theram. American College of Nuclear Physicians, Washington, D.C.

1989 DeNardo, S.J., D.J. Macey, G.L. DeNardo. A direct approach for determining marrow radiation from MoAb therapy, p. 1 10-1 24. G.L. DeNardo (Ed.), Bioloav of Radionuclide Theraw. American College of Nuclear Physicians, Washington, D.C.

1989 Deshpande, S.V., S.J. DeNardo, C.F. Meares, M.J. McCall, G.P. Adams, G.L. DeNardo. Effect of different linkages between chelates and monoclonal antibodies on levels of radioactivity in the liver. Nuclear Medicine Biology. 16~587-597.