A. Le Cesne

Phase II Study of ET-743 in Advanced Soft Tissue Sarcomas: A European Organisation for the Research and Treatment of Cancer (EORTC) Soft Tissue and Bone Sarcoma Group Trial

PURPOSE This nonrandomized multicenter phase II study was performed to evaluate the activity and safety of Ecteinascidin (ET-743) administered at a dose of 1.5 mg/m(2) as a 24-hour continuous infusion every 3 weeks in patients with pretreated advanced soft tissue sarcoma. PATIENTS AND METHODS Patients with documented progressive advanced soft tissue sarcoma received ET-743 as second- or third-line chemotherapy. Antitumor activity was evaluated every 6 weeks until progression, excessive toxicity, or patient refusal. RESULTS One hundred four patients from eight European institutions were included in the study (March 1999 to November 2000). A total of 410 cycles were administered in 99 assessable patients. Toxicity mainly involved reversible grade 3 to 4 asymptomatic elevation of transaminases in 40% of patients, and grade 3 to 4 neutropenia was observed in 52% of patients. There were eight partial responses (PR; objective regression rate, 8%), 45 no change (NC; > 6 months in 26% of patients), and 39 progressive disease. A progression arrest rate (PR + NC) of 56% was observed in leiomyosarcoma and 61% in synovialosarcoma. The median duration of the time to progression was 105 days, and the 6-month progression-free survival was 29%. The median duration of survival was 9.2 months. CONCLUSION ET-743 seems to be a promising active agent in advanced soft tissue sarcoma, with no cumulative toxicities. The 6-months progression-free survival observed in advanced soft tissue sarcoma compares favorably with those obtained with other active drugs tested in second-line chemotherapy in previous European Organisation for the Research and Treatment of Cancer trials. The median overall survival was unusually long in these heavily pretreated patients mainly due to the high number of patients who benefit from the drug in terms of tumor control.

Soft tissue and visceral sarcomas: ESMO–EURACAN Clinical Practice Guidelines for diagnosis, treatment and follow-up

Fondazione IRCCS Istituto Nazionale dei Tumori and University of Milan, Milan, Italy; Instituto Portugues de Oncologia de Lisboa Francisco Gentil, EPE, Lisbon, Portugal; University Hospital Essen, Essen, Germany; Department of Oncological Orthopedics, Musculoskeletal Tissue Bank, IFO, Regina Elena National Cancer Institute, Rome, Italy; Klinikum Stuttgart-Olgahospital, Stuttgart, Germany; Institut Curie, Paris, France; NORDIX, Athens, Greece; Department of Pathology, Leiden University Medical Center, Leiden, The Netherlands; Vienna General Hospital (AKH), Medizinische Universität Wien, Vienna, Austria; Hospital Universitario Virgen del Rocio-CIBERONC, Seville, Spain; Centro di Riferimento Oncologico di Aviano, Aviano; Ospedale Regionale di Treviso “S.Maria di Cà Foncello”, Treviso, Italy; Integrated Unit ICO Hospitalet, HUB, Barcelona, Spain; Sarcoma Unit, University College London Hospitals, London, UK; Skane University Hospital-Lund, Lund, Sweden; N. N. Blokhin Russian Cancer Research Center, Moscow, Russian Federation; Institute of Scientific Hospital Care (IRCCS), Regina Elena National Cancer Institute, Rome; Pediatric Oncology Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan; Istituto Ortopedico Rizzoli, Bologna; Azienda Ospedaliera Universitaria Careggi Firenze, Florence, Italy; Department of Medical Oncology, Leiden University Medical Centre, Leiden, The Netherlands; Institut Jules Bordet, Brussels, Belgium; Candiolo Cancer Institute, FPO IRCCS, Candiolo, Italy; Department of Radiotherapy, The Netherlands Cancer Institute, Amsterdam and Department of Radiotherapy, Leiden University Medical Centre, Leiden, The Netherlands; Turku University Hospital (Turun Yliopistollinen Keskussairaala), Turlu, Finland; Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Mannheim University Medical Center, Mannheim; Department of Medicine III, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany; Helsinki University Central Hospital (HUCH), Helsinki, Finland; Royal Marsden Hospital, London; The Institute of Cancer Research, London, UK; University Medical Center Groningen, Groningen; Radboud University Medical Center, Nijmegen, The Netherlands; University Hospital Motol, Prague; Masaryk Memorial Cancer Institute, Brno, Czech Republic; Gustave Roussy Cancer Campus, Villejuif, France; Maria Skłodowska Curie Institute, Oncology Centre, Warsaw, Poland; Tel Aviv Sourasky Medical Center (Ichilov), Tel Aviv, Israel; Medical Oncology, University Hospital of Lausanne, Lausanne, Switzerland; Azienda Ospedaliera, Universitaria, Policlinico S Orsola-Malpighi Università di Bologna, Bologna; Azienda Ospedaliero, Universitaria Cita della Salute e della Scienza di Torino, Turin, Italy; Fundacio de Gestio Sanitaria de L’hospital de la SANTA CREU I Sant Pau, Barcelona, Spain; Helios Klinikum Berlin Buch, Berlin, Germany; YCRC Department of Clinical Oncology, Weston Park Hospital NHS Trust, Sheffield, UK; Aarhus University Hospital, Aarhus, Finland; Leuven Cancer Institute, Leuven, Belgium; Department of Medical Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands; Fondazione Istituto di Ricovero e Cura a Carattere Scientifico, Istituto Nazionale dei Tumori, Milan, Italy; Department of Oncology, Oslo University Hospital, The Norwegian Radium Hospital, Oslo, Norway; Institute of Oncology of Ljubljana, Ljubljana, Slovenia; Netherlands Cancer Institute Antoni van Leeuwenhoek, Amsterdam, The Netherlands; University College Hospital, London, UK; Gerhard-Domagk-Institut für Pathologie, Universitätsklinikum Münster, Münster, Germany; Oslo University Hospital, Norwegian Radium Hospital, Oslo, Norway; Centre Leon Bernard and UCBL1, Lyon, France

Clinical evaluation of continuous daily dosing of sunitinib malate in patients with advanced gastrointestinal stromal tumour after imatinib failure

AIMS To assess the antitumour activity, safety, pharmacokinetics and pharmacodynamics of continuous daily sunitinib dosing in patients with imatinib-resistant/intolerant gastrointestinal stromal tumour (GIST) and to assess morning dosing versus evening dosing. PATIENTS AND METHODS In this open-label phase II study, patients were randomised to receive morning or evening dosing of sunitinib 37.5mg/day. The primary end-point was clinical benefit rate (CBR; percent complete responses+partial responses [PRs]+stable disease [SD] 24 weeks). Secondary end-points included progression-free survival (PFS), overall survival (OS), safety, pharmacokinetic parameters and plasma biomarker levels. RESULTS Sixty of 61 planned patients received treatment (30 per dosing group); 26 completed the study. Overall, the CBR was 53% (95% exact CI, 40-66): eight patients (13%) achieved objective PRs; 24 (40%) achieved SD 24 weeks. Median PFS was 34 weeks (95% CI, 24-49); median OS was 107 weeks (95% CI, 72 - not yet calculable). Most adverse events (AEs) were of grade 1 or 2 in severity, and were manageable through dose modification or standard interventions. No new AEs were apparent compared with the approved intermittent dosing schedule. Antitumour activity and safety were generally similar with morning and evening dosing. Continuous daily sunitinib dosing achieved and sustained effective drug concentrations without additional accumulation across cycles. Decreases from baseline in plasma levels of soluble KIT after 20 and 24 weeks of dosing correlated with longer OS. CONCLUSION For patients with imatinib-resistant/intolerant GIST, continuous daily sunitinib dosing appears to be an active alternative dosing strategy with acceptable safety.

Randomised phase II trial of pegylated liposomal doxorubicin (DOXIL®/CAELYX®) versus doxorubicin in the treatment of advanced or metastatic soft tissue sarcoma : a study by the EORTC Soft Tissue and Bone Sarcoma Group

CAELYX/DOXIL, pegylated liposomal doxorubicin, has shown antitumour activity and reduced toxicity compared with standard doxorubicin in other tumour types. In this prospective randomised trial, 94 eligible patients with advanced soft-tissue sarcoma (STS) were treated, 50 with CAELYX (50 mg/m(2) by a 1 h intravenous (i.v.) infusion every 4 weeks) and 44 with doxorubicin (75 mg/m(2) by an i.v. bolus every 3 weeks). Histological subtypes were evenly matched, 33% were leiomyosarcoma (CAELYX: 18; doxorubicin: 13). Primary disease sites were well matched. CAELYX was significantly less myelosuppressive, only 3 (6%) patients had grade 3 and 4 neutropenia, versus 33 (77%) on doxorubicin; febrile neutropenia occurred in 7 (16%) patients given doxorubicin, but only 1 (2%) given CAELYX. 37 (86%) patients on doxorubicin had grade 2-3 alopecia, but only 3 (6%) on CAELYX, and the major toxicity with CAELYX was to the skin. Palmar-plantar erythrodysesthesia with CAELYX was grade 1: 4 (8%) patients, grade 2: 11 (22%) patients, grade 3: 9 (18%) patients and grade 4: 1 (2%) patient. Other non-haematological grade 3 and 4 toxicities were rare. Confirmed responses were observed with both agents: CAELYX: complete response (CR) 1 (uterine), partial response (PR) 4 (response rate (RR) 10%); and doxorubicin: CR 1, PR 3 (RR of 9%); with the best response being stable disease (NC) in 16 and 18 patients, respectively. The reason for the low response rate is unknown, but it may be due partly to a high proportion of gastrointestinal stromal tumours. In conclusion, CAELYX has equivalent activity to doxorubicin in STS with an improved toxicity profile and should be considered for further investigation in combination with other agents such as ifosfamide.

Randomized Phase III Study Comparing Conventional-Dose Doxorubicin Plus Ifosfamide Versus High-Dose Doxorubicin Plus Ifosfamide Plus Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor in Advanced Soft Tissue Sarcomas: A Trial of the European Organization for Research and Treatment of Cancer/Soft Tissue and Bone Sarcoma Group

PURPOSE This randomized multicenter study was designed to compare the activity of a high-dose doxorubicin-containing chemotherapy regimen with a conventional standard-dose regimen in adult patients with advanced soft tissue sarcomas (ASTS). PATIENTS AND METHODS Between 1992 and 1995, 314 patients were randomized to receive a standard-dose regimen (arm A), containing doxorubicin (50 mg/m(2) on day 1) and ifosfamide (5 g/m(2) on day 1), or an intensified regimen (arm B), combining doxorubicin (75 mg/m(2) on day 1), the same ifosfamide dose, and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF; sargramostim, 250 microgram/m(2) on days 3 to 16); all courses were repeated every 3 weeks. RESULTS The median age of the 294 eligible patients was 50 years. They received a median of five chemotherapy cycles. The median dose and relative doxorubicin dose-intensity achieved were 245 mg and 97% in arm A and 360 mg and 99% in arm B, respectively. Thirty-eight percent and 23% of patients presented with leiomyosarcomas and liver metastases, respectively. Objective responses were observed in 31 (21%) of 147 assessable patients in arm A and in 31 (23.3%) of 133 in arm B (P =.65). No change was observed in 41.6% and 46.2% of patients in arm A and B, respectively. Progression-free survival (PFS) was significantly longer in the intensive arm (P =.03). The median duration of the time to progression was 19 weeks in the conventional arm and 29 weeks in the intensified arm. There was no difference in overall survival (P =.98) between the two therapeutic arms. Toxicities were manageable in both arms. A grade 3/4 neutropenia and infection occurred in 92% and 4.6% of patients in arm A, respectively, and in 90% and 16.6% in arm B, respectively. Grade 3/4 thrombocytopenia was more frequent in arm B. CONCLUSION The use of rhGM-CSF allowed safe escalation of chemotherapy doses. Despite a 50% increase of the doxorubicin dose-intensity, the high-dose regimen failed to demonstrate any impact on survival in patients with ASTS. The low complete response rate, the high incidence of leiomyosarcomas, and liver metastases may in part explain these results. However, the lengthening of the PFS in the intensive arm, because of the quality of stable disease and inappropriate tumor evaluation policies that potentially lead to an underestimation of antitumor activity, does not definitively refute the use of a high-dose chemotherapy regimen in selected patients with ASTS.

High-dose ifosfamide: circumvention of resistance to standard-dose ifosfamide in advanced soft tissue sarcomas.

PURPOSE The study was designed to assess the toxicity and activity of high-dose ifosfamide (HDI) administered by continuous infusion at a dose of 4 g/m2/d over 3 days every 4 weeks in adult patients with advanced soft tissue sarcomas (ASTS) pretreated with doxorubicin and/or a standard-dose ifosfamide (SDI)-containing regimen. PATIENTS AND METHODS Between January 1991 and November 1993, 40 patients with progressive ASTS were entered onto the study. Twenty-eight patients had been pretreated with a multidrug regimen that contained SDI and were classified as follows: SDI-refractory (n = 21), SDI-resistant (n = 2), and indeterminate SDI-sensitive (n = 5). Patients were treated until progression or major toxicity. RESULTS One hundred forty-seven cycles of HDI were administered. Neutropenia was dose-limiting, with 100% of patients experiencing grade 3 to 4 toxicity and 12 admissions for febrile neutropenia (30% of patients). Neurotoxicity (17% of patients) was significantly associated with acute renal failure (n = 4) (P < .001), grade 4 thrombocytopenia (P < .01) and febrile neutropenia (P = .048). Chronic renal toxicity (n = 4) was significantly associated with retroperitoneal masses and/or prior nephrectomy (P = .008). Partial responses (PRs) were observed in 12 of 36 assessable patients (33%) and eight patients (22%) experienced disease stabilization. All but one response occurred in patients pretreated with SDI, with five PRs among SDI-refractory patients. Leiomyosarcomas appear resistant to HDI. The median response duration was 8 months (range, 6 to 13+) and the median overall survival time was 12 months. CONCLUSION The activity of HDI in these pretreated ASTS patients and the apparent circumvention of SDI resistance suggest a real dose-response relationship for ifosfamide and deserve further evaluation. Although toxic, this treatment appears feasible and manageable using routine clinical support. Since prophylaxis of ifosfamide-induced renal damage remains unknown, frequent monitoring of renal and tubular functions during therapy is highly recommended.

Weekly vinorelbine is an effective palliative regimen after failure with anthracyclines and taxanes in metastatic breast carcinoma.

BACKGROUND Currently, there is no gold standard for the treatment of patients with metastatic breast carcinoma who have experienced failure with anthracyclines and taxanes. A biologic rationale suggests that the mechanism of taxane resistance could be because of an excess of depolymerized tubulin that could enhance sensitivity to vinorelbine. The objective of the study was to assess the tolerance and efficiency of weekly vinorelbine in metastatic breast carcinoma after failure with taxanes. METHODS Patients with measurable disease, a World Health Organization performance status of less than 3 and a life expectancy longer than 3 months were eligible. Persistent taxane-induced neuropathy higher than Grade 1 was an exclusion criterion. The initial planned dose was 30 mg/m(2)/week on an outpatient basis without granulocyte colony-stimulating factor (G-CSF). Neutrophil and platelet counts of 1.0 and 80 g/L, respectively, were required before each new injection; otherwise vinorelbine was delayed for 7 days with a dose reduction of 5 mg/m(2) at the second episode. The dose also was reduced if Grade 3 or 4 toxicity occurred. If the adverse event persisted or if the delay exceeded 14 days between 2 injections given at a dose of 20 mg/m(2), vinorelbine was definitively discontinued. RESULTS Between November 1997 and March 1999, 40 patients with a median age of 49 (range, 39-69) were enrolled. All of them had previously received anthracyclines and taxanes. Because of the delays in neutrophil recovery, the median dose intensity did not exceed 22.5 mg/m(2)/week (range, 11.25-30), and the initial planned dose of 30 mg/m(2)/week appeared unfeasible without G-CSF. The starting dose therefore was 25 mg/m(2)/week after the first 6 patients. Neutropenia led to fever in only three patients. Other severe toxicities were Grade 2-3 neuropathy (n = 5), Grade 2-3 ileus (n = 7), Grade 3 anemia (n = 4), and Grade 3 sepsis (n = 1). Objective responses were observed in 10 of 40 patients (25%), 7 of whom had visceral metastases and 4 who were refractory to taxanes (including 2 patients with liver involvement > 50%). The median time to failure was 6 months (range, 4-12) for responding patients. Disease stabilization was achieved in 9 patients (23%) for a median duration of 5 months (range, 4-6). The median survival duration for the whole population was 6 months (range, 2-18+). CONCLUSIONS Weekly vinorelbine is an active salvage therapy for metastatic breast carcinoma after failure with anthracyclines and taxanes, even in patients with taxane-refractory metastatic breast carcinoma. This confirms that vinorelbine and taxanes are not cross-resistant.We would like to dispute some of the statements made in the article by Zelek et al. in Volume 92, Issue 9. The authors state that “currently, there is no gold standard for the treatment of patients with metastatic breast carcinoma who have experienced failure with anthracyclines and taxanes.” They later mention that “among newer drugs, capecitabine appears to be promising with an [objective response] rate of 20% and a favorable tolerance profile.” Capecitabine (Xeloda ; Hoffmann-LaRoche, Nutley, NJ) is the only approved agent for use in this indication and has received regulatory approval in both the United States and Europe. Therefore, from a regulatory standpoint, capecitabine can be considered a reference treatment for patients with anthracyclineand taxanepretreated metastatic breast carcinoma. Capecitabine is a novel oral fluoropyrimidine carbamate with high activity against metastatic breast carcinoma and a favorable safety profile. By exploiting the significantly greater activity of thymidine phosphorylase against tumor tissue compared with healthy tissue, capecitabine delivers 5-fluorouracil preferentially at the tumor site. In 4 multicenter studies, capecitabine (1250 mg/m twice daily for 14 days, followed by a 7-day rest period) demonstrated considerable antitumor activity in patients with anthracyclineand taxanepretreated metastatic breast carcinoma 6 (Table 1). The authors also state that “other agents such as gemcitabine or pemetrexed (MTA, LY231514) are potential candidates, but to our knowledge no specific trial addressing their activity in taxaneresistant patients has been published to date with these drugs.” In a recently published report of a Phase II study investigating gemcitabine in this indication, there were no objective responses to gemcitabine, the median time to disease progression was 1.9 months, and the median overall survival was 7.8 months. The investigators in that study concluded that gemcitabine is ineffective in patients with heavily pretreated metastatic breast carcinoma and should not be used in that setting. Gemcitabine therefore appears not to be a potential candidate for treatment of anthracyclineand taxane-pretreated metastatic breast carcinoma. In the study performed by Zelek et al., vinorelbine yielded an objective response rate similar to the rate observed with capecitabine. However, the median overall survival of patients treated with vinorelbine was a disappointing 6 months. In contrast, over the course of four studies, capecitabine consistently has yielded noteworthy activity and survival results in this difficult-to-treat population (Table 1). 1325

Advanced soft-tissue sarcoma: a disease that is potentially curable for a subset of patients treated with chemotherapy.

Adult patients with metastatic or locally advanced irresectable soft-tissue sarcoma (ASTS) are generally considered as incurable. Whether some of these patients achieve long-term survival after first-line treatment with chemotherapy is not known. Patients with ASTS still alive 5 years after initial treatment with a doxorubicin-containing regimen, i.e. long-term survivors, were analysed among the 2187 patients included in first-line chemotherapy protocols between 1976 and 1990 in seven trials of the European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group (EORTC STBSG) group. 1888 patients were followed for at least 5 years. The initial clinical characteristics and the outcome of the long-term survivors were investigated. 66 of the 1888 patients were alive at 5 years and the projected 5-year survival was 8% in this series. Age or histological subtypes were similar in the long-term survivors compared with the other patients. The percentages of females (69%), of grade 1 tumours (35%), of patients with an initial performance status (PS) of 0 (63%) were significantly higher in the long-term survivors while liver metastasis (6% versus 21%) were significantly less frequent. Long-term survivors were observed in all subgroups of patients. 31, 31, 31 and 6% of the long-term survivors were in complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD), respectively, after the first-line regimen. A CR to a doxorubicin-containing regimen was the major parameter correlated to 5-year survival. In multivariate analysis using a logistic model, independent parameters correlated to 5-year survival were PS, female gender, grade I tumours, and the achievement of a CR after first-line treatment, which was retained as the most powerful predictor for 5-year survival. 10 of the 66 patients died after 5 years in this series, including 8 patients in PD or SD after first-line treatment versus 2 patients in PR or CR (P=0.01). 8% of patients with ASTS are alive 5 years after first-line chemotherapy with a doxorubicin-containing regimen. Long-term survivors are observed in all prognostic subgroups of patients, in particular those achieving a CR to first-line chemotherapy.

Early lymphopenia after cytotoxic chemotherapy as a risk factor for febrile neutropenia.

PURPOSE Febrile grade four (ie, < or = 500/microL) neutropenia (FN) is a frequent life-threatening complication of cancer chemotherapy. Although its incidence correlates to the dose of chemotherapy, FN may occur after almost any cytotoxic regimen. At present, there is no predictive method to identify patients who will experience FN. PATIENTS AND METHODS Univariate and multivariate analyses of risk factors for FN were performed on a retrospective cohort of 112 consecutive patients treated with various chemotherapy regimens. Two independent risk factors were identified by the logistic regression and used to create a risk model for FN. The validity of the model was tested in three distinct groups of patients: two prospective groups of patients treated in two institutions (Centre Léon Berard [CLB] and Institut G. Roussy [IGR]) and the group of patients with intermediate- or high-grade non-Hodgkins lymphoma (NHL) treated with the doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone (ACVBP) regimen between 1988 and 1992 at CLB. RESULTS Within the retrospective group, 23 of 47 (49%) patients with lymphocyte counts < or = 700/microL at day 5 after chemotherapy experienced FN compared with seven of 65 (11%) of other patients (P = .00002). The type of chemotherapy (high dose v others) was also significantly correlated to FN (48% v 11%, P = .0003). Age, performance status, the number of previous chemotherapy cycles, or polymorphonuclear leukocyte (PMN) counts, were not significantly correlated to the incidence of FN in univariate analyses. Two independent risk factors were identified in the logistic regression: day 5 lymphocyte counts (beta = 1.97 +/- 0.53) and the type of chemotherapy regimen (beta = 1.91 +/- 0.53). The calculated probability to experience FN in patients with none, one, and both of these risk factors was 4.3%, 24.0%, and 68.8%, respectively. The validity of this model was tested in the three groups of patients used as validation samples. The observed incidences of FN in the above defined risk subgroups were 3%, 19%, and 67%, respectively, within the CLB prospective series and 6%, 19%, and 75% within the IGR prospective series. In the ACVBP group, the incidence of FN was 33% and 72%, respectively, in patients from the intermediate- and high-risk groups. In the two prospective groups and in the ACVBP series, the observed numbers of FN in the different risk groups did not differ significantly from those calculated by the model (P = .89, P = .86, and P = .72 for these three groups, respectively). CONCLUSION Day 5 lymphocyte counts < or = 700/microL and the type of chemotherapy regimen enable oncologists to define subgroups of patients treated with chemotherapy as those with a high intermediate, and low risk of FN. These criteria could be used to select subjects in whom prophylactic measures for FN, in particular hematopoietic growth factors, should be proposed.

Phase I trial of recombinant adenovirus gene transfer in lung cancer. Longitudinal study of the immune responses to transgene and viral products.

Animal studies indicate that the use of replication-deficient adenovirus for human gene therapy is limited by host antivector immune responses that result in transient recombinant protein expression and blocking of gene transfer when rechallenged. Therefore, we have examined immune responses to an adenoviral vector and to the beta-galactosidase protein in four patients with lung cancer given a single intratumor injection of 10(9) plaque-forming units of recombinant adenovirus. The beta-galactosidase protein was expressed in day-8 tumor biopsies from all patients at variable levels. Recombinant virus DNA was detected by PCR in day-30 and day-60 tumor biopsies from all patients except patient 1. A high level of neutralizing antiadenovirus antibodies was detected in patient 1 before Ad-beta-gal injection whereas it was low (patient 3) or undetectable in the other two patients. All patients developed potent CD4 type 1 helper T cell (Th1) responses to adenoviral particles which increased gradually over time after injection. Antiadenovirus cytotoxic T lymphocyte responses were consistently boosted in the two patients examined (patients 3 and 4). Sustained production of anti-beta-galactosidase IgG was observed in all patients except patient 1. Consistent with anti-beta-gal antibody production, all patients except patient 1 developed intense, dose-dependent Th1 responses to soluble beta-galactosidase which increased over time. Strong beta-galactosidase-specific cytotoxic T lymphocyte responses were detected in patients 2, 3, and 4. Our results clearly show that despite the intensity of antiadenovirus responses, transgene protein expression was sufficient to induce strong and prolonged immunity in three patients. Recombinant adenovirus injected directly into the tumor is a highly efficient vector for immunizing patients against the transgene protein.