REPORTS ON SEMINARS

(1) Seminar on “Current Progress in Radiation Oncology”
November 21-23, 1991
University of Michigan
Ann Arbor, Michigan

This meeting was held under the auspices of the National Cancer Institute of the United States and the Japanese Society for the Promotion of Science. It was attended by 12 representatives from Japanese radiation oncology. Twenty American speakers participated. The number who could attend and speak was augmented by using many outstanding scientists located at the University of Michigan and in Detroit
The meeting concentrated on the following subjects: hyperthermia, brachytherapy, basic biology, precision radiotherapy, modern techniques in treatment planning - parts I, II, and III, clinical trials of combined modality treatment, chemical modifiers of radiotherapy, and molecular biology. It was an extremely interesting meeting and reviewed the status of most of the currently important work in radiation oncology in Japan and the U.S. Attached to this report is a list of the participants and the complete agenda A complete set of the papers presented is available and will be submitted to the NCI upon request. The following will be a brief summary of each session with a review of the presentations.

Session A - HYPERTHERMIA
The hyperthermia session reviewed the current status of hyperthermia in Japan and the United States and then contained specific presentations on radiofrequency and ultrasound systems and specialized systems for esophageal cancer.
Professor Abe reviewed the progress of hyperthermia in cancer therapy in Japan. A large series of patients treated by RP capacitive heating was presented with a smaller group treated by phased array microwaves. The complete response rate was a function of tumor size ranging from 65% for tumors of less than 4 cm to 15% for tumors over 10 cm in diameter. Response improved with increased temperature and was less for deep seated tumors than for superficial tumors. They also found that the appearance of low density areas on CT following radiotherapy correlated with eventual control.
Jae Ho Kim then reviewed the current status of hyperthermia in the United States and indicated that an excellent palliative response occurs in patients with recurrent chest wall lesions, multiple cutaneous malignant melanomas, and in large cervical lymph nodes. In these 3 types of tumors the control rates are increased by a factor of approximately 2-fold with the addition of hyperthermia New directions include improved interstitial techniques and scanned focused ultrasound.
Yasushi Nagata then reviewed the results of multi-modality treatment using hyperthermia for liver tumors. One hundred and thirty-seven patients were treated with radiation plus radiofrequency hyperthermia in Kyoto and in 78 patients the temperature could be evaluated. They found that cholangio-arcinoma and metastatic liver tumors were more susceptible to hyperthermia than hepatocellular carcinoma Tue best response was obtained with combined radiation and heat with lesser responses for heat plus embolization and heat plus chemotherapy.
Charles Cain of the University of Michigan then discussed his bioengineering group’s new approaches to the delivery of ultrasound hyperthermia. They are employing large phased arrays which are conformally fitted and controlled by computer. These have the potential of selectively heating structures at any depth within the body with exquisite focusing and uniform temperatures without the use of mechanical scanning. This approach appears to have a great deal of promise for future application and is being prepared for clinical trials.
Mitsunobu Uda then discussed multi-modality treatment using hyperthermia, radiation, and chemotherapy for esophageal cancer. They employed intraluminal microwave hyperthermia in 17 patients in combination with bleomycin and cisplatinum. Occlusion of the azygos vein increased the temperatures achieved. The total response rate indicated 3 CRs, 11 PRs and 3 patients with no change.
This session indicated that hyperthermia techniques are improving with particular emphasis on interstitial and ultrasound methods. Sufficient data has been collected and presented in Japan to gain approval for hyperthermia as an accepted treatment modality.

Session B - BRACHYTHERAPY
This session reviewed the progress in several areas of interstitial radiation and systemic radiation including a comparison of therapy in cervix cancer, 1251 temporary implants, and the use of systemic 89SR for the treatment of prostate bone metastases.
Toshihiko Inoue and colleagues reported on a comparison of high dose rate afterloaded radiation and conventional low dose rate brachytherapy in cervix cancer. Four hundred thirty patients with stage I, II, and III were evaluated. They found no statistical difference between those treated with conventional or with high dose rate radiation. They indicated that a cooperative study is now underway comparing high dose rate to low dose rate intracavitary radiotherapy for cervix cancer. Ivaro Martinez and his colleagues reported on substitution of high intensity 1251 seeds for indium seeds in temporary interstitial implants. They concluded on the basis of 42 temporary iodine implants that there was no difference in acute toxicity as compared to iridium and there were significant advantages in decreased exposure to personnel as well as decreased exposure to radiosensitive organs. Difficulties were also encountered with seed loading and there is a problem with the expense of this approach.
Professor Arthur Porter then reported on his results with 89SR in the treatment of metastatic prostate cancer. This agent is a pure beta emitter which is taken up in blastic metastatic lesions. It imitates the biodistribution of calcium. The prominent toxicity has been the thrombocytopenia They conclude that although this is an active agent against bone pain the optimal dose has not yet been established and a randomized placebo controlled clinical triai is required to answer the question of its overall efficacy.

Session C - BASIC BIOLOGY
This session addressed some basic mechanisms controlling tumor response as well as metastatic potential and the molecular mechanisms of normal tissue injury. Norio Suzuki reported on post-irradiation tumor size changes, changes in tissue PO2, blood flow, and NMR spectra as correlated with tumor cell death. He concludes that classic reoxygenation precedes cell inactivation or reproductive cell death. The combination of tumor size regression as well as cell viability, blood flow, and NMR spectra may well give better predictors of the effectiveness of treatment.
Philip Rubin then reported on the use of growth factor measurement in predicting radiation injury to lung. This very exciting work indicates that there are 2 distinctive lethal events when both lungs are irradiated, i.e. acute pneumonitis and subsequent fibrosis. Activated macrophages appear to be the source of growth regulating proteins, thus stimulating the existing fibroblast population and the synthesis of extracellular matrix proteins. His presentation indicated that this was the first demonstration of the release of trophic factors or cytoknes, after in vivo irradiation.
Norio Suzuki then discussed the clonogenic tumor cell release assay and its relationship to metastasis. They concluded that this assay may serve to determine the role of clonogenic tumor cells released during metastasis and to predict metastatic potential.

Session D - PRECISION RADIOTHERAPY
This session concentrated on delivering high• doses to limited volumes with high L.E.T. particles, conformal radiotherapy, fast neutron therapy, charged particle treatment with heavy ions, charged particle therapy with protons, and stereotactic radiosurgery. These methods allow the delivery of either a physically higher dose or a biologically more effective dose, or in the case of heavy ions, the combination.
Hiroshi Tsunemoto spoke on and summalized the experience at the National Institute of Radiologic Sciences with neutron therapy. Nineteen hundred and fifty-one patients were treated between 1975 and 1991. Treatment was with neutrons produced by 30 MeV deuterons with a beryllium target. They found that carcinomas of the salivary gland and prostate; and sarcomas of soft tissue and bone appeared to respond better and be controlled at a higher incidence with neutron therapy.
Theodore Phillips then reported on the experience at Lawrence Berkeley Laboratory with 1367 patients treated with helium ions and/or heavy ions including primarily neon, but also carbon, silicon, and argon. The trial began in 1 976 with the treatment of uveal melanoma with helium and it has extended to the present time. Currently trials are underway in sarcomas of the base of skull, paraspinus tumors, sinus tumors, sarcomas, and carcinoma of the prostate. Neon ion therapy has proven, at least as compared to retrospectlve controls, to be superior in salivary gland, sinus, soft tissue sarcoma, bone sarcoma, advanced prostate cancer, and biliary tumors. New developments in beam scanning and delivery as well as 3-D conformal planning will allow even higher doses and more precise delivery of helium and neon ions.
Hirohiko Tsujii then presented the results of proton therapy in Japan at the Proton Medical Research Center of the University of Tsukuba as well as a lower energy trial, at the National Institute of Radiologic Sciences, for eye tumors. A 250 MeV proton beam has been used at Tsukuba utilizing an unusual fractionation scheme because of limited availability of the accelerator. A total of 147 patients were treated with curative intent to doses between 70 and 90 Gy at fraction sizes of over 3 Gy. Acute toxicities were minimal. Results were particularly encouraging for carcinomas of the lung, esophagus, cervix, and prostate, and for ocular melanomas.
Todd Wasserman reported on the experience with stereotactic external beam radiosurgery in St. Louis. He reviewed the technique and then reported on the relative response of various sites and lesions to linear accelerators compared to gamma knife irradiation. He also discussed the proposed RTOG protocol evaluating the addition of etanidazole to radiosurgery for recurrent gliomas.

Session E, F. and G - TREATMENT PLANNING
This session begins an in-depth discussion of what was one of the main foci of the meeting, 3-dimensional conformal treatment planning. The use of CT and MRI scans to provide 3-dimensional anatomic data has revolutionized the delivery of external beam radiotherapy. A number of speakers addressed various aspects of this new development in the following sessions. Sessions E, F, and G will be discussed together since they all cover aspects of this modem development in computer treatment planning.
The session began with a presentation by Yasushi Nagata on the clinical application of a CT simulator. A number of institutions in Japan have collaborated on the development of a CT simulator which replaces the standard simulator and computerized planning. A laser beam projector is then used to draw the field outlines on the patient after the plan is developed. They have found that the laser beam projector is extremely useful in accurate set-ups and have developed a new 3-dimensional dose calculation algorithm. Over 600 patients have been planned using the system. Dose volume histograms, beams eye views, and reconstructed simulation images are employed. They conclude that this is an extremely valuable device. They feel that it needs direct linkage to the treatment delivery system and that improved methods of verification are required.
Allen Lichter of the University of Michigan then reported on 3-dimensional treatment planning for brain tumors. He particularly emphasized the comparison if CT and MR with the finding that both studies yielded valuable information and that the composite volume would be larger than a volume determined by either study and gives the optimum target for 3-dimensional treatment planning.
Teruki Teshima then reported on the impact of treatment planning on glottic cancer employing an individualized wedge filter technique using a shell, immobilization, and a smaller field size. They concluded that using the more precise methods a smaller treatment volume could be used with less side effects and equal control.
Howard Sandler of the University of Michigan then presented a report on their dose escalation trial in prostate cancer using 3-dimensional planning. Local control is a major problem with conventional radiotherapy in prostate cancer and higher doses are clearly required. The use of standard techniques above 70 Gy gives unacceptable morbidity but by using conformal therapy with either 6 coplanar fields or 4 non-coplanar fields, doses may be escalated to as high as 80 Gy. Current status in 29 patients shows only 2 deaths and no grade for rectal toxicities.
Sei-ichi Nakagawa then discussed his experience with treatment verification using megavoltage computed tomography. This system includes a megavoltage CT scanner, a fully computerized treatment unit, and a high speed treatment planning computer. They conclude that a CT detector mounted on the treatment delivery unit allows better detection of positioning errors and better quantitation. They conclude that simulation on the megavoltage device may be more accurate than simulation on another unit with transfer of the patient.
Larry Antonuk of the University of Michigan then reported on a solid state real time imager for radiotherapy. He is in the process of developing a solid state detector with immediate image presentation after either one monitor unit or as much as a complete treatment. The goal is 25 X 25 to a 50 X 50 cm imaging surface with spatial resolution of at least one pixel per millimeter and a thin profile with clinical practicality. Several real time imaging systems exist but are generally bulky in the case of fiber optic camera and mirror systems or slow as in the case of linear scanners and ion chambers. The area detector is an ideal imager and employs multi-element amorphous silicon detector arrays. The research is involved in developing methods to produce a large array suitable for imaging the entire radiotherapy portal. Excellent progress is being made although the group has not yet achieved the ultimate goal of the large sized array.
Kozo Morita then discussed quality assurance for a computer controlled conformal radiotherapy system. He concluded that improvement in the accuracy of conformal radiotherapy requires improved decision as to the target region, optimal computer calculation of the dose distribution and optimization of set-up and limitation of movement of the patient on the treatment couch. The addition of an x-ray stimulator in the treatment rooms was found to improve set-up accuracy. New algorithms and dose calculations also developed improve the treatment delivery.
Benedick Fraass of the University of Michigan then•discussed computer controlled conformal therapy with a race track microtron and a Varian clinac with multi-leaf collimators. The ultimate dynamic conformal therapy will involve constant motion of the collimator, the machine, the table, and the multiple leaves of a multi-leaf collimator. This is, of course extremely complex. The systems employ a combination of external computer, main control computer, and separate controls for the multi-leaf collimators and scanning systems. The goals of the project are the routine implementation of computer controlled conformal therapy with high degrees of safety and quality assurance.
Steven Leibel then discussed the biologic basis of conformal radiation therapy. In studies of both carcinoma of the prostate and head and neck cancer, he showed that improved local control which could be achieved with conformal therapy using higher doses could lead to higher survival through the reduction of failure due to distant metastases. It is postulated that failure to control locally leads to the development in the recurrence interval of distant metastases which can be prevented by high initial local control rates.
Marc Kessler of the University of Michigan discussed semi-automated object definition for radiotherapy treatment planning. The state-of-the-art in artificial intelligence is not yet sufficient to completely include clinical experience and intuition into algorithms thus interaction between an oncologist or physicist and the computer is necessary. On the other hand, contouring of organs and tumors can be markedly speeded up by the use of common, typical shapes of these organs and then optimization of the fitting through human interaction.
Atsuo Akanuma then reported on the experience of his group with conformal arc therapy using multi-leaf collimators. Four hundred ninety patients have been treated with a multi-leaf collimator mounted to a linear accelerator since 1983. This system at the University of Tokyo is mounted on a 20 MeV linear accelerator. They have reviewed their results with initial experience in glioblastoma multiforme and showed some improvement with an increased dosage from 55-70 Gy.
Daniel McShan from the University of Michigan then discussed interactive design methodologies in conformal radiation therapy. The goals of the system are to conform the coverage to the target, minimize dose in normal anatomy, and yet still have a clinically viable plan. Tools include the placement of beams on arbitrary cross sections, beams eye view, and dose volume histograms. Volumetric analysis is essential and future goals include improvement in the ease of 3-D planning reduction of the parameter space for optimization and volumetric analysis and automated assessment of possible a roach an les for initial plan optimization.

Session H - CLINICAL TRIALS/COMBINED MODALITIES
This session discussed the use of hyperfractionated irradiation in lung cancer and the evaluation of pulmonary function changes as well as fibrosis after radiotherapy for lung cancer.
Andrew Turrisi first discussed the use of chemoradiotherapy options in small cell lung cancer and in particular, the use of simultaneous chemotherapy with cisplatinum and etoposide with twice daily radiotherapy. High local failure rates and distant metastasis rates with either modality alone suggests that simultaneous integration may be optimal It currently remains to be defined whether initial or neo-adjuvant chemotherapy or simultaneous radiation and chemotherapy are optimal. Combined modalities are obviously the way to go with lung cancer and further improvements may be achieved with conformal radiotherapy in this context.
Atsuo Akanuma then presented data on pulmonary function changes and x-ray findings They conclude that good correlations exist between dose and changes in respiratory function. They feel that improvement in the current scoring systems is needed with prospective evaluations of a new system.

Session I - CHEMICAL MODIFIERS
This session presented a review of the RTOG studies and chemical and biologic modifiers of radiation, a discussion of photodynamic therapy, a new fluorine modified metronidazole, and clinical trials with halogenated pyrimidines.
Todd Wasserman reviewed the large number of RTOG studies which have been carried out using chemical modifiers with increasingly effective compounds. A very large head and neck trial employing etanidazole has recently been completed and is under analysis with over 500 patients entered. This study will be perhaps definitive in evaluation the usefulness of this compound.
Eli Glatstein then discussed the potential for photodynamic therapy using laser light and hematoporphyrin derivative. Their group has concentrated on the treatment of malignant ascites and peritoneal seeding with photodynamic therapy with interesting initial results The conclude that photodynamic therapy represents another useful modality for the treatment of human malignancy. Newer porphyrin compounds may improve the efficacy of photodynamic therapy as well.
Sei-ichi Nishimoto then presented a discussion of a new fluorine modified 2-nitroimidazole, KU-2285. This compound appears to reach higher concentration in tumors then etanidazole. Extensive clinical trials will be required to compare these 2 agents.
Theodore Lawrence reported on the use of halogenated pyrinridines in several clinical trials including that of the Northern California Oncology Group and those of the NCI and University of Michigan. Results are encouraging.

Session J - MOLECULAR BIOLOGY
This session included a review of the melanoma tumor suppresser gene, a review of the molecular cytogenetics of cancer, x-ray induced proteins and genes, and the repair of radiation damage in endothelial cells through growth factors.
Jeffrey Trent presented information on the biological significance of chromosomal abnormalities in human malignant melanoma They have found a recurrent pattern of chromosomal abnormalities on chromosomes 1, 3, 6, 7, 9, and 11. Over 60% of cases have shown abnormalities in chromosome 6 involving the long arm (6q). Studies are underway to determine the genes on chromosome 6 responsible for modulating the suppression of tumorogenicity.
Joe Gray then discussed exciting new methods of staining chromosomes and specific genes which allow the measurement of genetic changes in tumor development genetic injury after radiotherapy, and prediction of radiation sensitivity. These new methods appear to hold great promise for not only early detection of genetic abnormalities and prediction of tumorogenesis, but in prediction of response of both tumors and normal tissues to radiation and other cytotoxic therapies.
David Boothman discussed the immediate induction of changes in the cell following irradiation. DNA damage inducible processes include the induction of DNA repair enzymes as well as other new proteins. They found that in melanoma cells several x-ray induced proteins were identifiable including 8 major polypeptides. One of these proteins, Xn) 269, is postulated as a key regulatory protein required for repair after radiation injury. It may be involved in maintaining an arrested condition allowing repair.
Zvi Fuks presented a paper on the induction of growth factors in endothelial cells after radiation and presented data indicating that these growth factors can be very important in the development of and repair of radiation injury to the vasculature.

SUMMARY
This two and a half day meeting was extremely valuable to the participants. It allowed leading radiation oncologists from Japan and the U.S. to exchange ideas in important developing areas. The most exciting presentations involved the use of 3-dimensional treatment planning and conformal automated treatment delivery and new developments in the applications of molecular biology to the evaluation of tumor induction and tumor response to treatment. It would appear that in the next several years the development of improving methods for delivering higher doses to more precise volumes and the study of molecular mechanisms in radiation repair will be very important The group would like to hold its next meeting in Chiba immediately following the International Congress of Radiation Oncology in Chiba The meeting would be held at the new heavy ion therapy center in Chiba at the National Institute of Radiologic Sciences and would concentrate on particle therapy, conformal dynamic precision radiotherapy, and the molecular biology of radiotherapy.

(2) Seminar on “New Agents and Differentiating Agents”
Hawaii, February 15 and 16, 1992

Dr. Saito described the differentiating properties of the ganglioside GM3 on AML cells in culture. This sugar molecule inhibits cell growth in a dose dependent manner. This maturational effect is lost with many modifications of the molecule (sugars added for example). Treatment with GM3 yields monocyte differentiation (with HL 60). Mechanistically, some of these molecules can inhibit the TK activity of the beta subunit of the insulin receptor. Interesting data were also presented on combinations of cytotoxic and differentiating drugs -- such as Ara-C + D3 in AML cells. Possible candidates include TGFB, Herbimycin, Erbstatin for potent differentiation.
Dr. Friedman presented data on the NCI’s program for All-Trans Retinoic Acid (ATRA) in a variety of diseases. The data are promising for APL and several epithelial neoplasms.
Dr. Ohno discussed the use of ATRA in APL patients. Twenty-six patients received ATRA 45 mg/m²/day and then chemotherapy. Overall 18/22 had CR. Patients with low peripheral blast counts had 17/17 CR. Four patients had rapid increase in WBC (necessitating early CT). A second study of Ara-C + DRN followed by ATRA was used in 35 patients. Overall 29/33 (85%) had CR. In both series only about 80% of patients had documented t (17;15) translocation. In t (15;17), with RAR alpha rearrangement 82% had CR, in t (15;17) only 86% had CR while only 1/3 with neither had a CR. A study in newly diagnosed APL patients is initiated (JALSG-AML 92) -- for WBC 3000/ mm³ begin ATRA, for WBC 3000/ mm³ will get ATRA + DRN + Ara-C.
Dr. Krakoff then described his experience with 13-Cis RA (CRA)+ IFN Alpha. In patients with SCC of the skin, CRA 1 mg/kg/d + IFN alpha 3 million/unit/d were employed. A total of 28 patients advanced disease and 19/28 had an objective response, always within 3 months (MDR = 3+ months). A second study of women with 1B or greater SCC of the cervix were studied with 1 mg/kg/d CRA and 6 million units/d IFN alpha. Only 1 patient had sufficient toxicity to discontinue therapy (fatigue). These patients had extensive disease and overall 16/32 had objective responses (4/32 CR).
Dr. Tsuruo then discussed PGP mechanisms of drug resistance. He described mechanisms of purifying PGP and studying it in liposome systems. There is also data that PGP is crucial to the Blood Brain Barrier (BBB). The geography of PGP is quite specific (as in kidney, biliary, canniliculi, etc.) He discussed mechanisms for circumventing MDR -- new agents (like MX-2), specific inhibitors (like ATP-ase or C-Kinase), chemicals reactive to PGP. Drugs like cyclosporine and FK506 appear to reverse PGP, as well as the MRK-16 antibody.
Dr. Ozols described studies of methods to circumvent alkylating agents resistance. Thiols detoxify drugs and assist in DNA repair. By direct conjugation or by enzymatic activity (GST-Transferase) alkylator/CDDP efficacy can be affected. A Phase I clinical trial of BSO --- L-PAM has been conducted. Up to 20 patients have been evaluated.
BSO by itself has little toxicity (even at a dose of 10,000 mg/m²) and some increased myelotoxicity with L-PAM (10-15 mg/m²). At 4500 mg/m² of BSO there was a decrease of GSH in peripheral lympocytes to 13% of baseline. In tumor cells, GSH is really only seen in cycling cells (not dormant cells). A major effort will be ongoing to examine GSH, CST, Metalothionein, ERCCI, and 2, and Her 2 neu, in order to make laboratory correlations.
Dr. Takaku discussed the role of CSF’s in cancer therapy in Japan (especially GCSF). One study of patients with extensive SCLC was carried out by Fukuoka

GCSF provided a superior chance of survival. Data was also presented on MCSF (which produces monocytes in bone marrow and increases monocyte function). MCSF also increases antibody dependent and independent cyiotoxicity. Elegant experiments with L 1210 indicate that the sequence MCSF followed by cytoxan or Adriamycin can be curative.
Dr. Umezawa discussed studies of Erbstatin. Protoncogenes can be activated by mutation, amplication or translocation. Sis is similar to PDGP through a TK mechanism; EGF receptor is related to Erb B as is FMS (as well as SRC, ABL, etc.). Several TK inhibitors are being studied including erbstatin, genistein, landuvemycin. Erbstatin inhibits only selected TK activity -- it demonstrates increased fibronectin and actin stress fibres. TK inhibitors suppress Erb B2 as well.
Dr. Ota described new platinum analogs in Japan. Studies have been carried out with 254-S which revealed bone marrow toxicity (DLT) at doses of 100 mg/m² q 4 weeks. Activity was demonstrated in H&N cancer (40%), esophagus (50%), bladder (38%), testis (80%), ovary (38%), and cervix (46%). In a comparison between 254S and CDDP (both with VDS) in NSCLC there was no difference at all.
Dr. Egorin discussed PK (what the body does to drug) and PD (what drug does to body) for platinum compounds. CBDCA is an attractive agent for adoptive dosing methods (based on some pretreatment patient characteristic) that correlates with drug disposition or response). There is a linear relationship between Cr Cl, and CBDCA clearance. A large study of 1028 ovarian cancer patients treated with CBDCA was performed. There were 578 pretreated and 450 previously untreated patients, the majority receiving 400 mg/m². Dr. Egorin demonstrated elegant families of curves for predicting response and toxicity.
Dr. Ogawa discussed CPT- 11 which is a water-soluble Topoisomemse I inhibitor. It has dose limiting leukopenia, as well as alopecia, nausea, vomiting, and diarrhea. The common dosage is 100 mg/m²/week or 200 mg/m² q 4 week. In NSCL there were 24/67 PR noted (no prior CT) and 3/24 PR in prior CT. The MDR was 2 months. In both ovarian and cervix cancer a 25% PR rate was observed. There was no evident cross resistance with platinum. There were 12/43 colorectal PR, 5/29 gastric, and 1/16 pancreatic cancer responses.
Dr. Friedman presented data on several new agents to be introduced in the U.S. in 1992. These included CAI, Rhizoxin, QAC, and Fostericin.
Dr. Donehower discussed Taxol which is an extremely active and interesting drug. Active in ovary and breast cancer. He also presented data on Topotecan which is now entering Phase II trials.
Overall, this meeting provided an outstanding opportunity to exchange information about new agents. The participants were engaged in a most productive exchange.

(3) Seminar on “High Dose Chemotherapy and Hematopoietic Growth Factors”
Tokyo, Japan, March 13-14, 1992

This seminar was held to discuss topics associated with High Dose Chemotherapy and Hematopoietic Growth Factors. It was held in Tokyo on March 13-14, 1992.
Dr. Suda initiated the discussion with a presentation on hematopoietic stem cell enrichment. Only 1 per 10⁴ or 10⁵ cells is stem cell. Cells stained with C-Kit Ab (TK receptor for stem cells) are only about 2.5% of bone marrow cells. Lin -, C-Kit +, Scot1 + cells are capable of reconstituting irradiated mice. More primitive cells respond to many CSF’s but respond best to SCF + IL-3 + IL-6. Human CD34 + cells are progenitor cells (cell surface glycoprotein) without Tyrosine kinase domain. CD34+ are about 1 % Of marrow and 0.01% of peripheral blood. Cross reactivity is seen with CALA (B), CD 13,33 (myeloid) and CD43. Other important fractions include:

It may be possible to utilize anticarbohydrate MoAb to purge leukemic cells from marrow. Although we understand C-Kit, we do not yet understand SCA-1 (Ly 6) or CD34 functions.
Dr. Nakahata discussed the use of combinations of CSF’s for expansion of stem cells. There are at least 16 cytokines able to enhance bone marrow growth. These include IL l,2,3,4,5,6,7,9, G-GM CSF’s, C-Kit etc. His data indicate IL-6 alone is much less effective than IL-3 + IL-6 in stimulating bone marrow cells (multilineage). Hence, he concludes that IL-6 stimulates megakaryopoiesis and the emergence of 5-FU repopulating cells (when synergized with IL-3). In humans the combination of IL-3 + IL-6 demonstrated inconsistent results. The combinations of IL-3 + SCF or IL-6 + SCF or IL- 11 + SCF were most effective* in vitro studies (murine). Models of Ogawa suggests that both promotion and competence factor may be needed. Another model suggests that the more primitive cells require CSF + IL- 3 or 6 or 11 and subsequent cells require IL-3 (or IL-6 --- IL-3).
Dr. Vadhan-Raj next dealt with several topics associated with combination cytokine trials in humans. Her studies began with GM-CSF + Adriamycin in sarcoma patients. Patients receiving CYADIC + various doses of GM-CSF were studied with either Adriamycin or GM-CSF being escalated. It was possible to decrease amount and duration of neutropenia with GM-CSF, but there was no impact on thrombocytopenia Interestingly, not only were episodes of febrile neutropenia reduced, but mucositis was also decreased with GM given immediately after chemotherapy. The number of cycling progenitor cells decreased rapidly, only I day after discontinuing GM-CSF. Studies of IL- I (4 days CI) focused on ovarian cancer patients receiving CBDCA (400 mg/m²), with a 1 day spacing interval. There was some evidence of dose-response for IL-1 Alpha for platelet effect. There was considerable IL- 1 toxicity (for 4 days) including fever, chills, headaches, nausea, etc. Patients require IV fluids and tylenol, at least. No increase in TNF is noted but endogenous IL-1 Alpha and IL-1 Beta is increased.
Clinical trials of PIXY-321 (GM-CSF + IL-3) have also been initiated. This hybrid molecule tries to capitalize on the benefits of both effects. A clinical trial of PIXY-321 in sarcoma patients (CYADIC) is ongoing. PIXY-321 has a short T 1/2, and is started immediately. So far the side effects of PIXY-321 are modest (less fever).
Dr. Takaue described an experience with 41 pediatric patients receiving PBSC therapy. The more PBSC received, the more rapid the recovery for both WBC and platelets. Patients who receive PBSC have elevated GCSF (endogenous) but no change in IL-6. There is also an impact an immune competence (possibly related to CD 4/8 ratio). Patients with ALL, NHL, or AML first receive induction therapy to produce a remission; then phersis occurs. In general (median Day 18). The younger children produce more progenitors. G-SF provides expansion of PBSC pool, permitting better harvest. Toxicity includes hemoglioma, etc. and depends on graft volume. This approach looks quite promising.
Dr. Elias then discussed the PBSC therapy experience at the Dana Farber Cancer Center. In order to lessen the cost and time of therapy (compared to ABMT), to give multiple courses, to decrease days of cytopenia and to study cytokine PBSC interactions studies were performed. Patients with breast cancer received 4 courses of AFM (2 PBSC stimulated by GM-CSF and 1 PBSC alone), CTCbdca was then employed. Most patients had good engraftment but (3/15 had poor platelet recovery requiring back-up ABMT). However the platelet recovery is of concern. Overall, about 20% of all patients experience have CR lasting for 2-4 years. Combinations of cytokines (IL-3 + GM-CSF) will be tested in new treatment programs.
Dr. Harada described the experience with PBSC of Kyushu University. He has performed a number of experiments on the optimal means of cryopreserving PBSC and ABMT cells. Clinical trials with VP16 + Ara-C or Mitoxantrone + Ara-C were employed. There was a generally positive correlation between number of monocytes infused and serum IL-6 levels. These monocytes infused as part of PBSC many speed hematopoietic recovery.
Dr. T. Shea offered remarks on high perspective on the use of PBSC for high dose therapy. He utilized GM-CSF stimulated PBSC harvesting in combination with high dose CBDCA infusion (repeated every 2 weeks as tolerated). In an initial group of patients a number of useful responses were noted and toxicity was real but acceptable. He is also studying ex vivo expansion of PBSC via cytokines. In these studies IL-3 seemed to be more effective than IL-6 or IL-3 + IL-6 (and the increase was about 2 fold). A new study of ICR + PBSC is ongoing, attempting to escalate the dose of VP-16. Responses so far are 2 CR + 1 PR/6 breast cancer patients. This approach appears to be promising.
Dr. Mukaiyama presented data on studies of combination ABMT and PBSC. He has treated 68 patients (38 breast, 15 NHL) with 5 different regimens. Studies of ThioTEPA + Epirubicin were performed (with mucositis being the DLT).
A new protocol for combination dose intensity and high dose therapy has been initiated. For breast cancer patients, induction with CAF + G-CSF followed by ThioTEPA + cytoxan + Epirubicin is being studied. For lymphoma, VP-16 is substituted. A total of 66% of breast and lymphoma patients experience CR. Various hematologic toxicities were diminished by giving PBSC + ABMT.
Dr. Tajima described his studies of ABMT in breast cancer patients. His studies began in 1980 and initially evaluated many tumor types. However, breast cancer demonstrated best responses (17%, 8 year survival for Stage IV disease). Studies of adjuvant (high risk) patients included 51 patients with median age of 46 and follow up of 29 months. Overall 5 year survival was 69% with 34% disease-free survival. All these results appear to be better than historical controls, but no randomized data exist so no definitive conclusions can be reached. He has also treated some patients who have had metastases resected and are left with no apparent residual disease. The doses of chemotherapy are quite modest -- cytoxan 1 gm/m² x 3-5 plus epiAdria 140 mg/m² followed by ThioTEPA + Cytoxan (6 gm/m²).
Dr. Friedman outlined the strategic NCI plan for clinical trials of gene therapy. A new $5 million initiative will support approximately 10 investigators. Four distinct kinds of strategies were outlined -- including immunostimulation, vaccine-type trials, modulation of bone marrow, and reconstitution of defective suppressor or inactivation of oncogenes. Currently there are no studies of gene therapy in patients in Japan.
Dr. Taini presented his preclinical studies of genetic therapy. He has introduced the pyruvate kinase gene into murine bone marrow. These studies could be relevant for those patients with PK deficiency (resulting in anemia). He has also studied fibroblast transfected cells capable of producing G-CSF or INF-alpha These cells function relatively effectively. The exchange of information was exceptionally worthwhile at this meeting. New unpublished data

Publications.
Ogawa, M.: New antitumor drug and differentiation.
US-Japan Cooperative Cancer Research Program.
Japanese J. Cancer Chemotherapy, 19 (6):927-929,1992
Ogawa, M.: High dose chemotherapy with autogous stemm cell transplantation.
US-Japan Cooperative Cancer Research Program Seminar
Japanese J. Cancer Chemotherapy 19 (7):1105-1108, 1992

Dr. Allen S. Lichter
same as Dr. Antonuk

Dr. Andrew T. Turrisi
same as Dr. Antonnk

Dr. Daniel L. McShan
Radiation Physics
Department of Radiation Oncology
University of Michigan Medical School
1500 E. Medical Center Drive
Ann Arbor. Michigan 48109-0010

Dr. Arthur Porter
Radiation Oncology Department
4201 St. Antoine
Detroic, Michigan 48201

Dr. Alvaro A. Martinez
Chairman, Department of Radiation Oncology
William Beaumont Hospital
3601 West 13 Mile Road
Royal Oak. Michigan 48072

Dr. Joe Ho Kim
Chairman, Department of Radiation Oncology
Henry Ford Hospital
2799 W. Grand Boulevard
Detroit, Michigan 48202

JAPAN

Dr. Mitsuyuki Abe
Chairman, Department of Radiology
Kyoto University
Faculty of Medicine
606 Kyoto

Dr Hiroshi Tsunemoto
Director, Radiotherapy
National Institute of Radiological Sciences
Chiba 260

Dr. Mitsunobu Uda
Radiotherapy
Kansai Medical College
Moriguchi
Osaka 570

Dr. Atsuo Akanuma
Chief, Radiotherapy
National Institute of Radiological Sciences
4-9-1 Angawa
Chiba 260

Dr. Keiichi Nakagawa
Radiotherapy
Shakaio-Hoken Hospital
Tokyo 113

Dr. Yukumasa Aoki
Radiotherapy
Tokyo University
Tokyo 113

Dr. Seiichi Mishimoto
Hydrocarbon Chemistry
Kyoto University
Faculty of Engineering
Kyoto 606

Dr. Toshihiko Inoue
Radiotherapy
Biomedical Research Center
Osaka University
Osaka 553

Dr. Norio Suzuki
Radiobiology
Tokyo University
Tokyo 113

Dr. Kozo Morita
Chief, Radiotherapy
Aichi Cancer Center
Kanokoden
Toshiro-cho Chikusa-ku
Nagoya 464

Dr. Teruki Teshima
Radiotherapy
Osaka University
Osaka 533

Dr. Yasushi Nagata
Radiotherapy
Kyoto University
Kyoto 606

Dr. Hirohiko Tsujii
Radiotherapy
Tsukuba University
Institute of Clinical Medicine
Ibaraki 305



(2) NEW AGENTS AND DIFFERENTIATING AGENTS
February 15-16, 1992 - Kauai, Hawaii

AGENDA