Correlation between in vivo toxicity and preclinical in vitro parameters for the immunotoxin anti-B4-blocked ricin.

Anti-B4-blocked ricin (Anti-B4-bR) is an immunotoxin comprised of the anti-B4 monoclonal antibody and the protein toxin, "blocked ricin." In blocked ricin, the galactose-binding sites of the ricin B-chain which mediate nonspecific binding to cells are blocked by covalently linked affinity ligands prepared from N-linked oligosaccharides of fetuin. Blocked ricin consists of two species, one with two covalently attached ligands and one with three covalently attached ligands. In a Phase I dose escalation clinical trial, Anti-B4-bR was administered to patients with relapsed and refractory B-cell neoplasms by 7-day continuous infusion. Although several different lots of Anti-B4-bR had similar IC37 values as determined by in vitro cytotoxicity testing on cultured human cell lines, these lots differed in their in vivo toxicity when administered to patients. Thus, IC37 values alone were not sufficient to predict in vivo toxicity. We report that the degree of cell kill at concentrations of drug that saturate the B4 antigen and murine 50% lethal dose values provide additional parameters that may be predictive of in vivo cytotoxicity. Furthermore, we performed detailed cytotoxicity studies of the ricin species containing two and three covalently attached ligands, respectively. In vitro cytotoxicity testing using these samples revealed that Anti-B4-bR made with blocked ricin containing two covalently attached ligands is capable of depleting five logs of target cells in an in vitro cytotoxicity assay, while Anti-B4-bR comprised of blocked ricin with three ligands can deplete only one log of cells. Log cell kill at antigen saturating concentration, murine 50% lethal dose and biochemical analysis of the composition of blocked ricin are therefore important considerations for establishing the potential efficacy and safety of Anti-B4-bR.

Monoclonal antibody-based therapies for hematologic malignancies.

PURPOSE: To review recent advances in the development and clinical roles of monoclonal antibody (MoAb)-based therapies in the treatment of hematologic malignancies. DESIGN: A search of MEDLINE and CANCERLIT was conducted to identify relevant publications. The bibliographies of these references also were used to identify articles and abstracts. These references were then reviewed. RESULTS: In the two decades since the first patient was treated with MoAb therapy, there have been significant advances in the biology, pharmacology, and clinical application of MoAb-based therapies. Three distinct fields of research have emerged: unconjugated MoAbs, immunotoxin-conjugated MoAbs (ITs), and radionuclide-conjugated MoAbs (RICs). The unconjugated MoAbs are less toxic but depend on host mechanisms to mediate cytotoxicity. The ITs carry a potent toxin, although at the cost of a narrow therapeutic index that may limit clinical use. The RICs offer significant potency, even in refractory disease, but their complexity may limit their use to large cancer centers. The current challenges in the development of MoAb-based therapies are to identify the proper target antigens, contend with bulk disease in which penetration may be limited, and choose the optimal clinical settings for their use, such as the minimal residual disease state or in combination with conventional chemotherapy. CONCLUSION: Although significant research is still needed, MoAb-based therapies promise to offer new options for the treatment of patients with hematologic malignancies.

Phase II study of rituximab in combination with chop chemotherapy in patients with previously untreated, aggressive non-Hodgkin's lymphoma.

PURPOSE: To determine the safety and efficacy of the combination of the chimeric anti-CD20 antibody Rituxan (rituximab, IDEC-C2B8; Genentech Inc, South San Francisco, CA) and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) chemotherapy in patients with aggressive non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Thirty-three patients with previously untreated advanced aggressive B-cell NHL received six infusions of Rituxan (375 mg/m2 per dose) on day 1 of each cycle in combination with six doses of CHOP chemotherapy given on day 3 of each cycle. RESULTS: The ORR by investigator assessment confirmed by the sponsor was 94% (31 of 33 patients). Twenty patients experienced a complete response (CR) (61%), 11 patients had a partial response (PR) (33%), and two patients were classified as having progressive disease. In the 18 patients with an International Prognostic Index (IPI) score > or = 2, the combination of Rituxan plus CHOP achieved an ORR of 89% and CR of 56%. The median duration of response and time to progression had not been reached after a median observation time of 26 months. Twenty-nine of 31 responding patients remained in remission during this follow-up period, including 15 of 16 patients with an IPI score > or = 2. The most frequent adverse events attributed to Rituxan were fever and chills, primarily during the first infusion. Rituxan did not seem to compromise the ability of patients to tolerate CHOP; all patients completed the entire six courses of the combination. The bcl-2 translocation of blood or bone marrow was positive at baseline in 13 patients; 11 patients had follow-up specimens obtained (eight CR, three PR), and all had a negative bcl-2 status after therapy. Only one patient has reconverted to bcl-2 positivity, and all patients remain in clinical remission. CONCLUSION: This is the first report to demonstrate the safety and efficacy of the Rituxan chimeric anti-CD20 antibody in combination with standard-dose CHOP in the treatment of aggressive B-cell lymphoma. The clinical responses are at least comparable to those achieved with CHOP alone with no significant added toxicity. The presence or absence of the bcl-2 translocation did not affect the ability of patients to achieve a CR with this regimen. The ability to achieve sustained remissions in patients with an IPI score > or = 2 warrants further investigation with a randomized study.

Adjuvant therapy of stage III and IV malignant melanoma using granulocyte-macrophage colony-stimulating factor.

PURPOSE: To evaluate granulocyte-macrophage colony-stimulating factor (GM-CSF) as surgical adjuvant therapy in patients with malignant melanoma who are at high risk of recurrence. PATIENTS AND METHODS: Forty-eight assessable patients with stage III or IV melanoma were treated in a phase II trial with long-term, chronic, intermittent GM-CSF after surgical resection of disease. Patients with stage III disease were required to have more than four positive nodes or a more than 3-cm mass. All patients were rendered clinically disease-free by surgery before enrollment. The GM-CSF was administered subcutaneously in 28-day cycles, such that a dose of 125 microg/m(2) was delivered daily for 14 days followed by 14 days of rest. Treatment cycles continued for 1 year or until disease recurrence. Patients were evaluated for toxicity and disease-free and overall survival. RESULTS: Overall and disease-free survival were significantly prolonged in patients who received GM-CSF compared with matched historical controls. The median survival duration was 37.5 months in the study patients versus 12.2 months in the matched controls (P <.001). GM-CSF was well tolerated; only one subject discontinued drug due to an adverse event (grade 2 injection site reaction). CONCLUSION: GM-CSF may provide an antitumor effect that prolongs survival and disease-free survival in patients with stage III and IV melanoma who are clinically disease-free. These results support institution of a prospective, randomized clinical trial to definitively determine the value of surgical adjuvant therapy with GM-CSF in such patients.

Anti-B4-blocked ricin: a phase I trial of 7-day continuous infusion in patients with B-cell neoplasms.

PURPOSE: This phase I trial was undertaken to determine the maximum-tolerated dose (MTD) and dose-limiting toxicities (DLTs) of the B-cell-restricted immunotoxin anti-B4-blocked ricin (anti-B4-bR) when it is administered by 7-day continuous infusion. PATIENTS AND METHODS: Thirty-four patients with relapsed and refractory B-cell neoplasms (26 non-Hodgkin's lymphoma [NHL], four chronic lymphocytic leukemia [CLL], four acute lymphoblastic leukemia [ALL]) received 7-day continuous infusion anti-B4-bR. Successive cohorts of at least three patients were treated at doses of 10 to 70 micrograms/kg/d for 7 days with the dose increased by 10 micrograms/kg/d for each cohort. The initial three cohorts of patients (10, 20, and 30 micrograms/kg/d x 7 days) also received a bolus infusion of 20 micrograms/kg before beginning the continuous infusion. RESULTS: The MTD was reached at 50 micrograms/kg/d x 7 days. The DLTs were National Cancer Institute Common Toxicity Criteria (NCI CTC) grade IV reversible increases in AST and ALT, and grade IV decreases in platelet counts. Adverse reactions included fevers, nausea, headaches, myalgias, hypoalbuminemia, dyspnea, edema, and capillary leak syndrome. Potentially therapeutic serum levels of anti-B4-bR could be sustained for 4 days in patients treated at the MTD. Two complete responses (CRs), three partial responses (PRs), and 11 transient responses (TRs) were observed. CONCLUSION: Anti-B4-bR can be administered safely by 7-day continuous infusion with tolerable, reversible toxicities to patients with relapsed B-cell neoplasms. Although occasional responses were seen, future trials will use anti-B4-bR in patients with lower tumor burdens to circumvent the obstacle of immunotoxin delivery to bulk disease.

Potential impact on survival of improved tumor downstaging and resection rate by preoperative twice-daily radiation and concurrent chemotherapy in stage IIIA non-small-cell lung cancer.

PURPOSE: The main objectives of this study were (a) to ascertain the feasibility and toxicity of preoperative twice-daily radiation therapy and concurrent chemotherapy, surgery, and postoperative therapy in stage IIIA (N2) non-small-cell lung cancer (NSCLC), and (b) to evaluate tumor response, resection rate, pathologic tumor downstaging, and survival. METHODS: Eligibility included biopsy-proven N2 lesion (stage IIIA) by mediastinoscopy, Karnofsky performance score > or = 70, and weight loss less than 5% in the 3 months before diagnosis. The treatment program consisted of two courses of preoperative cisplatin, vinblastine, and fluorouracil (5-FU); 42 Gy concurrent radiation at 1.5 Gy per fraction in two fractions per day; surgery on day 57; and one more course of postoperative chemotherapy and 12 to 18 Gy of concurrent twice-daily radiation. RESULTS: Forty-two patients with stage IIIA (N2) NSCLC (27 men and 15 women, age 38 to 77 years) were enrolled onto this prospective study. Forty of 42 patients tolerated the intended dose (42 Gy) of preoperative radiation and 37 of 39 resected patients received prescribed postoperative radiation. The intended dose of chemotherapy was given in 100%, 70%, and 60% of patients for the first, second, and third courses of chemotherapy. Marked dysphagia that required intravenous hydration was noted in 14% of patients (six of 42). Myelotoxicities included grade > or = 3 granulocytopenia in 23% and thrombocytopenia in 6% of 113 chemotherapy courses. Febrile neutropenia that required hospital admission was noted in 9% of 113 chemotherapy courses. Surgical resection was performed in 93% of patients. Treatment-related mortality was noted in 7% of patients. The overall survival rates by the Kaplan-Meier method were 66%, 37%, and 37% at 2,3, and 5 years, respectively, with a median follow-up time of 48 months. Pathologic examination of the surgical specimen showed a downward shift in tumor extent from stage IIIA (N2) to stage II (N1) in 33%, to stage I (NO) in 24% (10 of 42), and to stage 0 (TONO) in 9.5%, for a total of 67%. The degree of tumor downstaging was also translated into a survival benefit: 5-year survival rates from the time of surgery were 79%, 42%, and 18% for postoperative tumor stages 0 and I, II, and III, respectively (P = .04). CONCLUSION: Concurrent chemoradiotherapy using twice-daily radiation is an effective induction regimen that resulted in 67% tumor downstaging, and an encouraging 37% 5-year survival rate. The degree of tumor downstaging may be a useful intermediate end point for survival benefit in stage IIIA (N2) NSCLC.

Autologous bone marrow transplantation in poor-prognosis intermediate-grade and high-grade B-cell non-Hodgkin's lymphoma in first remission: a pilot study.

PURPOSE: Using high-dose therapy and autologous bone marrow transplantation (ABMT) to overcome cellular resistance and eradicate minimal disease, we initiated a pilot study during first remission in patients with non-Hodgkin's lymphoma (NHL) to examine whether the long-term disease-free survival (DFS) rate can be improved for patients with poor-prognosis intermediate/high-grade NHL. PATIENTS AND METHODS: Twenty-six patients with advanced-stage diffuse intermediate/high-grade B-cell NHL (including 16 patients with diffuse small cleaved-cell [DSC]) were selected at presentation by histologic and clinical characteristics to have less than a 25% probability of long-term DFS with conventional treatment. After induction chemotherapy, 16 patients were in complete remission (CR) and 10 were in a minimal disease state. Patients were then treated with high-dose cyclophosphamide, total-body irradiation (TBI), and anti-B-cell monoclonal antibody-purged ABMT. RESULTS: Following ABMT, no acute in-hospital treatment deaths occurred, and engraftment of granulocytes and platelets was significantly faster than for patients undergoing ABMT who were in second or subsequent remission. Of 26 patients, 21 remain in CR maintained without continued therapy, three relapsed in sites of prior nodal disease (4.8, 5.4, and 28 months post-ABMT), and two died in remission. The DFS rate is estimated to be 85% at 28 months and thereafter. The median follow-up period for the 21 patients who are alive and disease-free is 32 months. CONCLUSION: This pilot study suggests that consolidation of first remission with ABMT may improve the long-term DFS rate for diffuse intermediate/high-grade NHL patients at high risk for relapse.

Long-term update of a phase II study of rituximab in combination with CHOP chemotherapy in patients with previously untreated, aggressive non-Hodgkin's lymphoma.

The present study aimed to determine the long-term safety and efficacy of chimeric anti-CD 20 antibody rituxan (rituximab, Biogen IDEC, San Diego, CA, USA; Genentech, South San Francisco, CA, USA) in combination with cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) chemotherapy in previously untreated patients with aggressive non-Hodgkin's lymphoma (NHL). Thirty-three patients with previously untreated aggressive B-cell NHL received six infusions of rituximab (375 mg/m(2) per dose) on day 1 of each cycle of CHOP chemotherapy, given on day 3 of each cycle of therapy. Currently, the patients now have a median follow-up of 63 months (range 34 - 82 months). The overall response (OR) rate was 94% and the complete response (CR) rate was 61% at the end of therapy. Of the 33 patients, 2 patients experienced disease progression and subsequently died of their disease, 2 patients experienced disease progression but were alive at last follow-up following additional therapy, and 2 patients died without experiencing disease progression: one due to a cerebral vascular accident at 9 months after therapy and a second patient due to small cell lung carcinoma at 55 months. The 5-year survival rate was 88% (95% confidence interval (CI) 72 - 97) and the 5-year progression-free survival was 82% (95% CI 64 - 93). There were no long-term adverse events noted directly related to the rituximab. The long-term follow-up of patients in this phase II trial of rituximab with CHOP chemotherapy for previously untreated aggressive NHL demonstrates a high response rate, which remains very durable with high 5-year overall and progression-free survivals.

Phase II clinical trial of bolus infusion anti-B4 blocked ricin immunoconjugate in patients with relapsed B-cell non-Hodgkin's lymphoma.

Immunotoxins, composed of a monoclonal antibody conjugated to a protein toxin, mediate cell death through novel cytotoxic mechanisms. Anti-B4-blocked ricin (anti-B4-bR) recognizes CD19-positive cells, which includes most B-cell non-Hodgkin's lymphomas (NHLs). Previous Phase I clinical studies of anti-B4-bR, using both bolus and continuous dosing regimens, demonstrated no safety or efficacy advantage to the continuous infusion regimen. This Phase II trial in 16 patients with relapsed CD19-positive NHL was conducted to evaluate the efficacy of anti-B4-bR when administered at the previously established maximum tolerated dose using a daily bolus for a 5 consecutive days schedule. Serum pharmacokinetics were measured in selected patients. Tissue samples of involved lymph nodes and bone marrow were also obtained from a portion of patients for determination of anti-B4-bR penetration into tissues. Toxicity was similar to what has been described previously for anti-B4-bR and consisted mainly of reversible elevations of hepatic transaminases and mild to moderate thrombocytopenia. No sustained clinical responses were documented. Pharmacokinetic measurements demonstrated that serum levels compatible with 3 logs of cell kill in vitro could be sustained for several hours in most patients. Immunohistochemical analysis of tissue samples provided some insight into the low efficacy. The immunotoxin could be detected in three of the four bone marrow aspirate samples but in only two of the seven lymph node specimens. Thus, anti-B4-bR, using a single daily bolus for a 5 consecutive day schedule, is not an active agent in relapsed NHL. Poor penetration into certain sites of disease may be one explanation for its lack of efficacy.

A Phase II study of adjuvant therapy with anti-B4-blocked ricin after autologous bone marrow transplantation for patients with relapsed B-cell non-Hodgkin's lymphoma.

This Phase II trial was undertaken to determine the safety, toxicity, and potential efficacy of the B-cell restricted immunotoxin anti-B4-blocked ricin (Anti-B4-bR) when administered as adjuvant therapy to patients in complete remission (CR) after autologous bone marrow transplantation (ABMT) for B-cell non-Hodgkin's lymphoma (NHL). Forty-nine patients with B-cell NHL in CR 46-202 days (median, 112 days) post-ABMT received Anti-B4-bR at a dose of 30 microg/kg lean body weight/day for 7 days by continuous i.v. infusion. Patients were eligible for up to two additional courses of therapy at 14-day intervals. A total of 83 courses of Anti-B4-bR were administered, with 31 patients receiving two or more courses of therapy. The mean serum level on day 7 of the first course was 0.77+/-0.41 nM. Reversible toxicities included hepatic transaminase elevations, thrombocytopenia, myalgias, fatigue, nausea, hypoalbuminemia, and dyspnea. Human antimouse antibody (HAMA) and/or human antiricin antibody (HARA) responses occurred in 23 patients at a median of 22 days from the initiation of Anti-B4-bR therapy (range, 11-100 days). The 4-year disease-free survival and overall survival are estimated at 56 and 72%, respectively. Twenty-six patients remain in CR after a median follow-up of 54.5 months. This study demonstrates that Anti-B4-bR can be administered safely to patients as adjuvant therapy early after ABMT for B-cell NHL. The toxicities are tolerable and reversible. Although the early estimate of disease-free survival was very encouraging in this single-armed trial, the 4-year follow-up data demonstrate continued relapse.

A phase II study of weekly paclitaxel in elderly patients with advanced non-small cell lung cancer.

PURPOSE: Our aim was to evaluate the efficacy, toxicity, and pharmacokinetic behavior of single-agent paclitaxel given weekly to elderly patients with lung cancer. EXPERIMENTAL DESIGN: Previously untreated patients with stage IIIB/IV non-small cell lung cancer were eligible for the study if they were at least 70 years of age and had preserved organ function. Paclitaxel was administered over 1 h at a dose of 90 mg/m(2) for 6 consecutive weeks on an 8-week cycle. The pharmacokinetics of paclitaxel were assessed during the first and sixth week of therapy in a subgroup of eight patients. RESULTS: A total of 35 patients (median age, 76 years; range, 70-85) were enrolled. The overall response rate was 23%. Median time to failure was 5.2 months, whereas the median survival time was 10.3 months. Survival rates after 1 and 2 years were 45 and 22%, respectively. Grade 3/4 toxicities included neutropenia (5.8%), hyperglycemia (17.6%), neuropathy (5.8%), and infection (8.8%). Two patients died from treatment-related toxicity. There was no significant difference (P = 0.18) between the total body clearance of paclitaxel on the first (17.4 +/- 2.9 liters/h/m(2), mean +/- SD) and sixth (15.8 +/- 4.1 liters/h/m(2)) week of therapy. CONCLUSION: Paclitaxel administered as a weekly 1-h infusion at a dose of 90 mg/m(2) is a safe and effective therapy for elderly patients with advanced non-small cell lung cancer. Its pharmacokinetics in elderly patients do not appear to differ from historical data for younger patients, and there was no suggestion of a change in drug clearance after repeated weekly dosing.

Treatment of plasma cell dyscrasias by antibody-mediated immunotherapy.

The use of serotherapy to treat patients with plasma cell dyscrasias (PCDs) has been sought by us and others. Candidate antigens that have been targeted or proposed for targeting in PCDs include the immunoglobulin idiotype, CD19, CD38, CD54, CD126, HM1.24, and Muc-1 core protein. Unfortunately, many of these antigens are not ideal for use in serotherapy since they are not selectively expressed, are either shed or secreted, or have not been fully characterized. Serotherapy with an anti-CD19 monoclonal antibody (B4) conjugated to a blocked ricin toxin had no significant activity in patients with multiple myeloma (MM). Circulating CD20+ clonotypic B cells have been detected in the circulation of most MM and Waldenstrom's macroglobulinemia (WM) patients. Plasma cells from most WM patients express CD20, but most MM patient plasma cells either lack CD20 or express it weakly. In view of recent successes with anti-CD20-directed serotherapy in other B-cell malignancies, we initiated a phase II trial to study the anti-CD20 monoclonal antibody rituximab (Rituxan; IDEC Pharmaceuticals, San Diego, CA, and Genentech, Inc, San Francisco, CA) in patients with MM. We describe two PCD patients (one with WM and one with MM) who responded to therapy. By flow cytometric analysis, CD20+ plasma cells and B cells present in the bone marrow and peripheral blood of a patient with MM disappeared with response to rituximab therapy. However, residual CD20- tumor cells remained in the bone marrow following rituximab therapy, and after 6 months this patient progressed with CD20- myeloma cells. As a potential strategy to overcome this limitation, we demonstrated that interferon-gamma at pharmacologically achievable levels induced CD20 expression on these CD20- plasma cells, consistent with our recent findings that interferon-gamma is a potent inducer of CD20 expression on MM patient plasma cells and B cells. We also characterize a response to rituximab with a decrease in paraprotein and resolution of anemia in a patient with WM whose response to rituximab is ongoing after 19+ months. This preliminary experience supports the potential use of serotherapy targeting CD20 in PCDs. Our studies further suggest that interferon-gamma may enhance CD20 expression on MM plasma cells, thereby increasing their susceptibility to anti-CD20 monoclonal antibody therapies.

A phase I study of ifosfamide/carboplatin/etoposide/paclitaxel in advanced lung cancer.

A phase I study was conducted to define the maximally tolerated dose and toxicity profile of the ifosfamide/carboplatin/etoposide/paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) (ICE-T) regimen in advanced lung cancer. This chemotherapy program uses paclitaxel given as a 24-hour continuous infusion in conjunction with full-dose ICE chemotherapy with growth factor support. The dosage of paclitaxel was escalated from 75 to 225 mg/m2. Thirty-four patients have been accrued to date onto this study. Because hematologic dose-limiting toxicity was defined in terms of neutropenia and/or thrombocytopenia exceeding 7 days' duration, no patient demonstrated what was defined by the protocol as dose-limiting toxicity. Nonetheless, substantial hematologic toxicity was observed. Overall, 26% had fever and neutropenia, 56% had grade 4 neutropenia, and 26% had grade 4 thrombocytopenia. In all cases, hematologic toxicity was short term and reversible. While grade 3 and 4 myelosuppression was frequently observed, it was not dose related (in terms of paclitaxel dosage). Nonhematologic toxicity also was not dose related and, with only a few exceptions, was not clinically significant. Among 27 patients evaluable for response, 41% achieved an objective response, including 15% with a complete response. All of five patients with small cell lung cancer responded (including two with a complete response). Among 22 patients with non-small cell lung cancer, 27% achieved an objective response (also including two with a complete response). The results of this study suggest that with growth factor support, it is possible to safely administer full-dose, single-agent paclitaxel in conjunction with full-dose ICE chemotherapy. We will soon be initiating a phase II study of the ICE-T regimen using paclitaxel at 225 mg/m2 as a 24-hour continuous infusion in advanced lung cancer. We will also conduct a phase I study of ICE-T, with paclitaxel administered as a 3-hour continuous infusion.

Ifosfamide/carboplatin/etoposide/paclitaxel in advanced lung cancer: update and preliminary survival analysis.

The primary objective of this study was to define the maximum tolerated dose and toxicity profile of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), given as a 24-hour infusion, in conjunction with ifosfamide/carboplatin/etoposide (ICE) chemotherapy in patients with advanced lung cancer. Paclitaxel was escalated from 75 to 225 mg/m2 in 25-mg/m2 increments. All patients received granulocyte colony-stimulating factor 5 microg/kg/d from day 4 until the neutrophil count was > or = 10,000/microL. The study population consisted of 41 patients with a median age of 60 years and a median follow-up of 20.7 months. Stage distribution included 5% stage IIIA, 46% stage IIIB, and 49% stage IV. Histology consisted of 61% adenocarcinoma, 12% squamous cell carcinoma, 10% large cell carcinoma, 15% small cell carcinoma, and 2% mixed. The predominant toxicity was hematologic; 63% of patients experienced grade 4 neutropenia and 49% developed grade 4 thrombocytopenia. Fever and neutropenia occurred in 34% of patients. Hematologic toxicity was, in all cases, short-term and reversible and was not dose related. With few exceptions, nonhematologic toxicity was not clinically important. Among 39 patients evaluable for response, 36% achieved a remission (8% complete, 28% partial, 41% had stable disease, and 23% experienced disease progression). Among 33 patients with non-small cell lung cancer, the response rate was 27% (one complete response, eight partial responses, 15 had stable disease, and nine had progressive disease). Among six patients with small cell carcinoma, the response rate was 83% (two complete responses, three partial responses, and one had stable disease). The median survival of all 41 patients was 13.6 months. Survival was almost identical between stage IIIA and stage IV subsets. We conclude that it is possible to safely administer full-dose single-agent paclitaxel with granulocyte colony-stimulating factor support in conjunction with full-dose ifosfamide/carboplatin/etoposide chemotherapy. While response rates observed were not particularly notable, median survival is considerably longer than that usually achieved with combination chemotherapy in advanced lung cancer.

Stage III thymoma: pattern of failure after surgery and postoperative radiotherapy and its implication for future study.

PURPOSE: With the conventional approach of surgery and postoperative radiotherapy for patients with Masaoka Stage III thymoma, progress has been slow for an improvement in the long-term survival rate over the past 20 years. The objective of this study was to evaluate the pattern of failure and survival after surgery and postoperative radiotherapy in Stage III thymoma and search for a new direction for better therapy outcome. METHODS AND MATERIALS: Between 1975 and 1993, 111 patients with thymoma were treated at Massachusetts General Hospital. Of these, 32 patients were determined to have Masaoka Stage III thymoma. The initial treatment included surgery for clinically resectable disease in 25 patients and preoperative therapy for unresectable disease in 7 patients. Surgical procedure consisted of thymectomy plus resection of involved tissues. For postoperative radiotherapy (n = 23), radiation dose consisted of 45-50 Gy for close resection margins, 54 Gy for microscopically positive resection margins, and 60 Gy for grossly positive margins administered in 1.8 to 2.0 Gy of daily dose fractions, 5 fractions a week, over a period of 5 to 6.6 weeks. In preoperative radiotherapy, a dose of 40 Gy was administered in 2.0 Gy of daily dose fractions, 5 days a week. For patients with large tumor requiring more than 30% of total lung volume included in the target volume (n = 3), a preoperative radiation dose of 30 Gy was administered and an additional dose of 24-30 Gy was given to the tumor bed region after surgery for positive resection margins. RESULTS: Patients with Stage III thymoma accounted for 29% (32/111 patients) of all patients. The median age was 57 years with a range from 27 to 81 years; gender ratio was 10:22 for male to female. The median follow-up time was 6 years. Histologic subtypes included well-differentiated thymic carcinoma in 19 (59%), high-grade carcinoma in 6 (19%), organoid thymoma in 4 (13%), and cortical thymoma in 3 (9%) according to the Marino and Müller-Hermelink classification. The overall survival rates were 71% and 54% at 5 and 10 years, respectively. Ten of the 25 patients who were subjected to surgery as initial treatment were found to have incomplete resection by histopathologic evaluation. The 5- and 10-year survival rates were 86% and 69% for patients (n = 15) with clear resection margins as compared with 28% and 14% for those (n = 10) with incomplete resection margins even after postoperative therapy, p = 0.002. Survival rates at 5 and 10 years were 100% and 67% for those with unresectable disease treated with preoperative radiation (n = 6) and subsequent surgery (n = 3). Recurrence was noted in 12 of 32 patients and 11 of these died of recurrent thymoma. Recurrences at pleura and tumor bed accounted for 77% of all relapses, and all pleural recurrences were observed among the patients who were treated with surgery initially. CONCLUSION: Incomplete resection leads to poor results even with postoperative radiotherapy or chemoradiotherapy in Stage III thymoma. Pleural recurrence is also observed more often among patients treated with surgery first. These findings suggest that preoperative radiotherapy or chemoradiotherapy may result in an increase in survival by improving the rate of complete resection and reducing local and pleural recurrences.

Intraoperative radiation therapy for locally advanced recurrent rectal or rectosigmoid cancer.

BACKGROUND AND PURPOSE: To update and summarize the experience at the Massachusetts General Hospital of a treatment program of high-dose preoperative irradiation, surgical re-resection, and intraoperative radiation therapy (IORT) as a salvage treatment for patients with recurrent rectal or rectosigmoid carcinoma. PATIENTS AND METHODS: From June 1978 to February 1997, the records of 69 patients with locally recurrent rectal carcinomas or rectosigmoid carcinomas without metastases referred for consideration of IORT were reviewed. Forty-nine patients received IORT and local control and disease-free survival curves were calculated using the actuarial method of Kaplan-Meier. RESULTS: The 5-year overall survival, local control and disease-free survival rates of 49 patients receiving IORT were 27, 35, and 20%, respectively. Thirty-four patients who underwent a macroscopic complete resection had a significantly better 5-year overall survival than the remaining 15 patients with gross residual disease (33 vs. 13%, P=0.05, log rank). For those patients, local control and disease-free survival rates were 46 and 27%, respectively. Patients with a microscopic complete resection had a superior 5-year overall survival than partially resected patients (40 vs. 14%, P=0.0001, log rank). Chemotherapy had no significant influence on overall or disease-free survival. CONCLUSION: The current analysis shows the importance of a microscopic complete resection in a multi-modality approach with IORT for survival and local control. Salvage is rare for patients undergoing subtotal resection.

Assessment of preoperative accelerated radiotherapy and chemotherapy in stage IIIA (N2) non-small-cell lung cancer.

Forty patients with N2 non-small-cell lung cancer (stage IIIA), as determined by mediastinoscopy, were entered into a preoperative neoadjuvant study of chemotherapy (platinum, 5-fluorouracil, vinblastine) and accelerated radiotherapy (150 cGy twice per day for 7 days) for two cycles. Surgical resection was then performed and followed up with an additional cycle of chemotherapy and radiotherapy. All patients completed preoperative therapy. A major clinical response was seen in 87% of patients. Thirty-five patients underwent resection (one preoperative death, one refused operation, one had deterioration of pulmonary function, and two had pleural metastases). Operative mortality rate was 5.7% (2/35). Sixty percent of patients had no complications. Major complications included pulmonary emboli (three), pneumonia (two), and myocardial infarction (one). Down-staging was seen in 46% of patients, with two patients (5.7%) having no evidence of tumor in the specimen, five patients having sterilization of all lymph nodes, and nine patients having sterilization of mediastinal nodes but positive N1 nodes. Median survival of 40 patients was 28 months, with a projected 5-year survival of 43%. Patients with downstaged disease had statistically significant improved survival compared with patients whose disease was not downstaged.

Induction therapy for esophageal cancer with paclitaxel and hyperfractionated radiotherapy: a phase I and II study.

OBJECTIVE: Induction chemoradiotherapy followed by surgery may improve survival rates among patients with esophageal carcinoma. We designed a novel intense induction regimen with paclitaxel and high-dose hyperfractionated radiotherapy to maximize complete response rates. METHODS: Forty patients with esophageal cancer were treated in a phase I and II trial of induction chemotherapy (cisplatin, 5-fluorouracil, and paclitaxel) at three dosage levels (75, 125, and 100 mg/m2) and concurrent hyperfractionated radiotherapy (45 Gy to the mediastinum, 58.5 Gy to the tumor). The mean age was 62 years, and 32 patients (80%) had adenocarcinoma. Twenty-eight of 40 (70%) patients had locally advanced tumors (T3, or stage IIB or greater). RESULTS: The average hospitalization for induction treatment was 17 days. Toxicity was substantial, with esophagitis necessitating nutritional support the most common complication. The maximum tolerated dose of paclitaxel was 100 mg/m2. Two patients died during induction treatment. Thirty-six patients (90%) underwent resection. The median length of stay was 10 days, and two patients died after the operation. Fourteen of 36 patients (39%) had a pathologic complete response. Patients who received all prescribed chemotherapy had a higher pathologic complete response rate (50%) than did patients who required dose reduction (17%; p = 0.076). The 2-year survival rate was 61% (95% CI 35% to 86%) with a median follow-up of 11.9 months. CONCLUSIONS: Paclitaxel at a dose of 100 mg/m2 appears to have acceptable toxicity. The high pathologic complete response rate in this regimen is encouraging, but it is associated with substantial toxicity. The toxicity of this regimen is not acceptable and will require substantial reduction in the radiation component. Survival data are too short-term to confirm enhanced survival.

Paclitaxel/ifosfamide or navelbine/ifosfamide chemotherapy for advanced non-small cell lung cancer: CALGB 9532.

In order to explore non-cisplatin containing regimens for advanced non-small cell lung cancer, Cancer and Leukemia Group B conducted a randomized Phase-II study of two novel combinations, paclitaxel/ifosfamide and vinorelbine/ifosfamide. Both regimens were active with a 38% response rate (95% CI: 24%, 53%) and 31% (95% CI: 18%, 47%), respectively. Median survivals were 8.5 and 7.4 months. Toxicity, mostly neutropenia, was acceptable. These two combinations establish a 'proof of principle' that non-cisplatin containing regimens also have activity in this setting.

Trials of 9-amino-20(S)-camptothecin in Boston.

9-Amino-20(S)-camptothecin (9-AC) is an analog of camptothecin with limited water solubility which has shown significant preclinical activity in a variety of human solid tumor xenografts. A Phase I trial using a soluble formulation of 9-AC, given as a 72-hour continuous infusion, has been completed. Thirty-one patients with resistant cancers received 5-60 micrograms/M2/h at three week intervals. The Maximum Tolerated Dose (MTD) was 45 micrograms/M2/hour. Neutropenia was the dose limiting toxicity, with few significant non-myelosuppressive toxicities. Minor responses were seen in 3/31 patients. Pharmacokinetic studies of 9-AC lactone (closed ring) showed substantial interpatient variability with a predicted half-life of 36 hours. A phase I/II trial of the same formulation of 9-AC is ongoing in refractory leukemia. Stomatitis and diarrhea are the non-myelosuppressive dose limiting toxicities. Evidence of antineoplastic activity has been seen in 3/15 patients. A Phase II trial in previously untreated metastatic breast cancer is also underway. A Phase I trial of a colloidal dispersion formulation, not yet completed, is better tolerated with a MTD > 45 micrograms/M2/h as a 72-hour continuous infusion. Evidence of antineoplastic activity has also been demonstrated.