Antioxidants for prevention of methionine oxidation in recombinant monoclonal antibody HER2

Recombinant humanized monoclonal antibody HER2, rhuMAb HER2, in liquid formulations undergoes oxidation when exposed to intense light and elevated temperatures (30 & 40 degrees C). Met-255 in the heavy chain of the Fc region of the antibody is the primary site of oxidation. Met-431 of the Fc fragment can also be oxidized under extreme conditions. The amount of oxidation was determined by cleaving the Fab and Fc fragments by papain digestion, and the oxidized Fc fragment was detected by hydrophobic interaction chromatography. Oxidation of rhuMAb HER2 was also formulation dependent. The presence of NaCl in the rhuMAb HER2 formulation caused an increase in oxidation at higher temperatures after contact with stainless steel containers or stainless steel components in the filling process. The corrosion of stainless steel by chloride ions at the low pH of the formulation buffer generated iron ions that catalyzed methionine oxidation in rhuMAb HER2. Temperature-induced oxidation of rhuMAb HER2 occurred by the formation of free radicals, and light-induced oxidation of rhuMAb HER2 occurred via single oxygen pathway. Antioxidants, such as methionine, sodium thiosulfate, catalase, or platinum, prevented Met oxidation in rhuMAb HER2, presumably as free radicals or oxygen scavengers. The minimum effective levels (molar ratios of protein to antioxidant) required to inhibit temperature-induced oxidation were 1:5 and 1:25 for methionine and thiosulfate, respectively. A thiosulfate adduct of rhuMAb HER2 was observed by cation-exchange chromatography. These studies demonstrate that stoichiometric amounts of methionine and thiosulfate are sufficient to eliminate temperature-induced oxidation of rhuMAb HER2 caused by free radicals that were generated by the presence of metal ion and peroxide impurities in the formulation.     

Cytarabine and cisplatin as salvage therapy in patients with metastatic colorectal cancer who failed 5-fluorouracil + folinic acid regimen. French Northern Oncology Group

The combination of CDDP and ARA-C has shown some clinical efficiency as first-line therapy in advanced colorectal cancer. Our study was aimed to evaluate the therapeutic activity of this combination in advanced colorectal cancer who failed 5-fluorouracil (FU) and folinic acid (LV) regimen. Seventeen patients with measureable metastatic colorectal cancer who failed 5FU-LV therapy as first line (n = 14) or second line treatment (n = 3), entered the study. Three patients who recurred during adjuvant treatment with 5FU and levamisol, were also included. Median age was 59.5 (40-69). Performance status was as follows: 0 (n = 5), 1 (n = 11), 2 (n = 3), 3 (n = 1). Site of metastases included liver (n = 16), lung (n = 7), abdomen (n = 2), pelvic recurrences (n = 2), cutaneous (n = 1). Seven patients had 2 metastatic sites and two 3. The treatment was given as follows: ARA-C 75 mg/m2/day, days 1-3, followed 1 hour later by CDDP 30 mg/m2/day, days 1-3, every 28 days. The median number of cycles was 3 (range: 1-6 cycles). All patients but one were evaluable for both response and toxicity. Of these patients, 50% experienced severe hematologic toxicity and nonhematologic toxicity mainly consisted of fatigue and/or vomiting. No objective response was observed, but there were 3 stabilizations and 16 progressive diseases. Median time to progression was 10 weeks. Thus, the CDDP/ARA-C regimen is not of clinical value as salvage therapy in advanced colorectal cancer because of its toxicity and its lack of efficiency.     

Resistance of HER2/neu-overexpressing tumor targets to lymphokine-activated-killer-cell-mediated lysis: evidence for deficiency of binding and post-binding events

HER2/neu-overexpressing tumor cell lines are relatively resistant to lymphokine-activated killer (LAK) cell cytotoxicity when compared to HER2/neu-nonexpressing lines. HER2/neu+ targets were also resistant to binding by LAK large granular lymphocytes (LGL) as shown by visualization at the single-cell level, a target monolayer binding assay and in "cold" target inhibition experiments. HER2/neu+ LAK-resistant ovarian cell lines demonstrated an absence of ICAM-1 expression while expression of LFA-3, N-CAM, laminin and beta 1 integrins was comparable to that of HER2/neu- targets. In contrast, the HER2/neu+ breast cell line, SKBR-3, which was also resistant to lysis and binding by LAK LGL, demonstrated normal expression of ICAM-1. Anti-ICAM-1 antibodies blocked binding and lysis of HER2/neu- carcinoma targets by LAK cells, further supporting the notion that lack of ICAM-1 expression on HER2/neu+ cells contributes to their resistance. The modest binding and lysis of HER2/neu+ targets by LAK cells was significantly inhibited by anti-LFA-1 antibodies, suggesting the existence of another counter-receptor for LFA-1 on HER2/neu+ targets. The following also supported deficiencies in post-binding events when HER2/neu+ cells resisted the lytic activity of LAK cells: (a) when the relative resistance to effector cell binding was overcome by exogenous lectin. HER2/neu+ cell lines were still resistant to LAK cytolysis, and (b) HER2/neu+ targets were resistant to perforin-containing granule extracts obtained from the CTLL-R8 cytotoxic lymphocyte cell line. These results indicate that deficiency in effector binding as well as post-binding events contributes to the resistance of HER2/neu-overexpressing tumor targets to LAK-cell-mediated lysis.     

Results of combination therapy of UFT-E with low-dose CDDP for patients with advanced recurrent breast cancer]

CDDP, as a modulator for 5-FU, has already been described as a very effective treatment for gastrointestinal tract cancer. We administered a dose of 400 mg of UFT-E orally every day, and 10 mg of CDDP by drip infusion twice weekly, for more than 10 weeks to 12 outpatients with metastatic local, pulmonary, hepatic, osteal or multiple-organ cancer which showed a poor response to the pretreatment, and assessed its efficacy and drug toxicity. In terms of the clinical efficacy of this therapy, CR was noted in one patient and PR in 2 patients with a response rate of 25%. The incidence of drug toxicity was low. Complications included temporal transient nausea and anorexia in two patients and leukopenia grade 2 as bone marrow suppression in 3 patients. From the standpoint of QOL, as well as in terms of both antitumor effect and drug toxicity, the therapy mentioned above was believed to be effective for outpatients with advanced recurrent breast cancer.     

Effect of CDDP/5'-DFUR combination chemotherapy for advanced or recurrent gastric cancer

CDDP/5'-DFUR combination chemotherapy was performed on 17 patients with non-resected and recurrent gastric cancer (clinical stage were IVb in all patients). They were treated with 1,400 mg/m2 of 5'-DFUR on days 1-4 orally following by withdrawal 10 days, every 2 weeks repeatedly and 80 mg/m2 of CDDP (c. i. v., on day 5, every 4 weeks). This chemotherapy was performed for at least 2 courses on all patients. Eight of 17 patients achieved a partial response and the overall response rate was 47.1% (differentiated type 57.1%, undifferentiated type 45.5%). Response rates of each lesion were as follows: primary foci 42.9%, abdominal lymph nodes 57.1%, hepatic metastasis 60.0% and ascites 33.3%, respectively. Improvement of performance status was seen in 12 of 17 patients (70.6%). The overall median survival time was 227 days. The median outpatient period was 113 days. There was no high-grade toxicity over grade 2. Therapeutic toxicity of grade 2 was manifested as renal dysfunction (23.5%), nausea/vomiting (17.6%), leukopenia (5.9%) and anemia (5.9%). We evaluated the therapeutic effect by visual examination after completion of the second course. However, poor effect and high incidence of renal dysfunction were found in patients treated with this therapy over four times. Therefore, the maximum effect seemed to be revealed after completion of the fourth course. From the present study, CDDP/5'-DFUR combination chemotherapy seems to be effective for patients with high-grade advanced gastric cancer and improved their quality of life.     

Dose-dense therapy with weekly 1-hour paclitaxel infusions in the treatment of metastatic breast cancer

PURPOSE: To evaluate the efficacy and toxicity of paclitaxel administered as a 1-hour infusion on weekly basis, without interruption, to patients with metastatic breast cancer who had received prior therapy. PATIENTS AND METHODS: Thirty patients with metastatic breast cancer received sustained weekly paclitaxel therapy at an initial dose of 100 mg/m2 until disease progression. Prior therapy included adjuvant only (n=17), metastatic only (n=7), or both (n=6). Eighteen patients had received prior anthracycline therapy, 12 of whom had demonstrated progression of disease within 12 months of it. All patients were assessable for efficacy; 29 patients were assessable for toxicity. Pharmacokinetic studies of paclitaxel were also performed. RESULTS: A total of 469 weekly paclitaxel infusions were administered to 30 patients (median, 14 infusions/patient). The median delivered dose-intensity was 91 mg/m2/wk (range, 80 to 108). The overall response rate was 53% (95% confidence interval [CI], 34% to 72%), with 10% complete responses (CRs) and 43% partial responses (PRs). Median response duration was 7.5 months (range, 2 to 11+). Responses were observed in nine of 18 (50%) patients with prior anthracycline therapy, including six of 12 (50%) with disease progression on anthracycline within 1 year (three of four within 6 months). Therapy was well tolerated and remarkable for a lack of overall and cumulative myelosuppression. Grade 3/4 neutropenia occurred in four patients; febrile neutropenia was not observed. Peripheral neuropathy prohibited dose escalation above 100 mg/m2, and grade 3 neuropathy was observed in two of 21 patients at < or = 100 mg/m2. CONCLUSION: Weekly paclitaxel therapy is active and well tolerated in patients with metastatic breast cancer. Weekly therapy should be considered as a current clinical option for these patients and should be incorporated into future comparative clinical trials.     

Paclitaxel with mitoxantrone, fluorouracil, and high-dose leucovorin in the treatment of metastatic breast cancer: a phase II trial

PURPOSE: Paclitaxel is a highly active single agent in the treatment of breast cancer. However, its optimal incorporation into combination regimens awaits definition. In this phase II study, we added paclitaxel, administered by 1-hour infusion, to a previously described combination regimen that included mitoxantrone, fluorouracil (5-FU), and high-dose leucovorin (NFL). PATIENTS AND METHODS: Forty-six patients with metastatic breast cancer received the following regimen as first- or second-line treatment: paclitaxel 135 mg/m2 by 1-hour intravenous (i.v.) infusion on day 1, mitoxantrone 10 mg/m2 by i.v. bolus on day 1, 5-FU 350 mg2/m by i.v. bolus on days 1, 2, and 3, and leucovorin 300 mg i.v. over 30 to 60 minutes immediately preceding 5-FU on days 1, 2, and 3. Courses were administered at 3-week intervals for a total of eight courses in responding patients. RESULTS: Twenty-three of 45 assessable patients (51%) had major responses. Previous chemotherapy, and in particular previous treatment with doxorubicin, did not affect response rate. The median response duration was 7.5 months. Myelosuppression was moderately severe, with 76% of courses resulting in grade 3 or 4 leukopenia. Hospitalization for treatment of fever during neutropenia was required in 13% of courses, and two patients died as a result of sepsis. Two patients developed severe congestive heart failure after a large cumulative anthracycline dose. CONCLUSION: This combination regimen was active as first- or second-line therapy for metastatic breast cancer, although its activity compared with other combination regimens or with paclitaxel alone is unclear. Myelosuppression was more severe than anticipated based on previous results with the NFL regimen or with paclitaxel administered at this dose and schedule as a single agent. The infrequent development of cardiotoxicity in these patients suggests that the paclitaxel/mitoxantrone combination may not share the problems previously reported with the paclitaxel/doxorubicin combination.     

A two-part phase I trial of high-dose interleukin 2 in combination with soluble (Chinese hamster ovary) interleukin 1 receptor

Our purpose was to determine the maximum tolerated dose and toxicity associated with soluble Chinese hamster ovary [s(CHO)] recombinant human interleukin (IL) 1 receptor (IL-1R; Immunex, Seattle, WA) administration in humans and to determine the effective biological dose and/or maximum tolerated dose of the s(CHO) IL-1R in combination with high-dose IL-2 as determined by reduction in IL-2 toxicity and modulation of its biological effects. Twenty-seven patients with metastatic cancer were treated with escalating doses of s(CHO) IL-1R at 1, 1, 5, 10, 20, 40, and 55 mg/m2 i.v. on days -6 (except cohort 2), 1, and 15 and IL-2 at doses of 300,000 IU/kg (cohort 1) and 600,000 IU/kg (cohorts 2-7) i.v. every 8 h on days 1-5 and 15-19. No toxicity directly attributable to s(CHO) IL-1R was observed. The median number of IL-2 doses was 23. Hypotension and neurotoxicity were the major dose-limiting toxicities for the IL-2/s(CHO) IL-1R combination. Of the 24 patients treated with full-dose IL-2, there were six responses, three complete and three partial (response rate, 25%). Three patients developed thyroid dysfunction, and all 3 responding melanoma patients exhibited vitiligo. The t1/2 of s(CHO) IL-1R alone was 24-30 h and was not significantly altered by coadministration with IL-2. Whole-blood functional assays indicated that sufficient s(CHO) IL-1R was present in the circulation at top dose levels to inhibit the in vitro effects of IL-1beta on IL-8 induction; however, no effect on IL-2-induced IL-8 induction, or on the IL-1beta- or IL-2-induced tumor necrosis factor production, was observed. Suppression of IL-2-mediated tumor necrosis factor alpha and IL-6 induction in vivo during the first 24 h after IL-2 administration was observed, and the neutrophil chemotactic defect normally seen with IL-2 was not observed. IL-1R antagonist induction far exceeded that seen previously with IL-2 alone. No inhibition of either serum C-reactive protein induction or enhanced urinary nitrate excretion and no consistent effect on IL-2-related changes in peripheral blood mononuclear cell phenotype or endothelial adhesion molecule expression were seen. The coadministration of s(CHO) IL-1R produced no apparent reduction in IL-2 clinical toxicity manifested by either the ability to administer more IL-2 than anticipated or a reduction in the toxicity associated with a given amount of IL-2. Therefore, no effective biological dose could be identified for the s(CHO) IL-1R.     

High-dose busulfan, melphalan, thiotepa and peripheral blood stem cell infusion for the treatment of metastatic breast cancer

The purpose of this study was to determine the outcome of patients with metastatic breast cancer treated with high-dose busulfan (Bu), melphalan (Mel) and thiotepa (TT) followed by peripheral blood stem cell (PBSC) infusion. Fifty-one patients with chemotherapy refractory (n = 32) or responsive (n = 19) metastatic breast cancer received Bu (12 mg/kg), Mel (100 mg/m2) and TT (500 mg/m2) followed by PBSC collected after chemotherapy and growth factor (n = 43) or growth factor alone (n = 8). The 100 day treatment-related mortality was 8% including one death from cytomegalovirus pneumonia, one from aspiration pneumonia and two from regimen-related toxicity (RRT). Seven of 28 refractory (25%) and 5/7 (71%) responsive patients with evaluable disease achieved a complete response of all measurable disease or all soft tissue disease with at least improvement in bone lesions (PR*). Fifteen of 51 patients (29%) are alive and progression-free a median of 423 days (range 353-934) after treatment, 5/32 (16%) with refractory disease and 10/19 (53%) with responsive disease. The probabilities of progression-free survival (PFS) at 1.5 years for the patients with refractory (n = 32) and responsive (n = 19) disease were 0.24 and 0.53, respectively. These preliminary data suggest that high-dose Bu/Mel/TT has significant activity in patients with advanced breast cancer and may be superior to some previously published regimens.     

Randomized comparison of tamoxifen and two separate doses of toremifene in postmenopausal patients with metastatic breast cancer

PURPOSE: To perform a randomized three-arm comparison of tamoxifen (TAM; 20 mg/d) and two separate doses of toremifene (TOR; 60 mg/d [TOR60] and 200 mg/d [TOR200]) in postmenopausal patients with hormone receptor-positive or -unknown metastatic breast cancer. MATERIALS AND METHODS: Six hundred forty-eight patients with hormone receptor-positive or -unknown metastatic breast cancer were randomly assigned to receive TAM (n = 215), TOR60 (n = 221), or TOR200 (n = 212). RESULTS: The combined response rates (by intent to treat) were as follows;: TAM, 44%; TOR60, 50%; and TOR200, 48%. Complete and partial response rates were as follows: TAM, 19%; TOR60, 21%, and TOR200, 23% (not statistically different). Median times to progression and overall survival were not significantly different. Adverse events (lethal, serious but nonlethal, and important but non-life-threatening) were similar in all three arms, except that patients in the TOR200 arm had a statistically significantly increased rate of nausea (37% v 26% and 26% for TOR200, TAM, and TOR60, respectively; P = .027). Quality-of-life assessments were not different among the three arms. CONCLUSION: The activity, toxicity, and side effects of TOR in postmenopausal women with hormone receptor-positive or -unknown metastatic breast cancer are similar if not equivalent to those of TAM. We detected no clear evidence of a dose-response effect for TOR. TOR60 is an effective and safe agent for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer and can be considered an alternative to TAM as first-line treatment for such patients.     

Etoposide, epirubicin and cisplatin (EEP) combination in metastatic cancers of the cardia and the stomach. Groupe de recherche en cancérologie du Nord (GRECNO)

This study was aimed to confirm the therapeutic activity of the combination of etoposide, doxorubicin and cisplatin which has shown some clinical efficiency as first line therapy in advanced gastric cancer. Seventeen patients with metastatic gastric cancer were treated with etoposide (120 mg/m2, i.v., on day 5, 6 and 7), epirubicin (20 mg/m2, i.v., on day 1 and 7) and cisplatin (40 mg/m2, i.v., on day 2 and 8), q 4 weeks. In 16 patients evaluable for response, three (19%) obtained a partial response lasting from 93 to 360 days. Fifteen patients were evaluable for toxicity. Main toxicities > grade 2 included anemia (2/15), neutropenia (5/15), alopecia (8/15), fatigue (3/15), diarrhea (2/15), vomiting (2/15). Twenty nine per cent of severe toxic events were documented all along 52 cycles. Therefore we failed to confirm that this regimen could be of clinical efficiency in advanced gastric cancer as regards the benefits/toxicity ratio.     

Combination chemotherapy of continuous infusion 5-fluorouracil and daily low-dose cisplatin in advanced gastrointestinal and lung adenocarcinoma

Continuous intravenous infusion (c.v.i.) of 5-fluorouracil (5-FU) plus daily low-dose cisplatin (CDDP) was evaluated in 45 patients with advanced and recurrent unresected colorectal, lung, gastric and pancreatic adenocarcinoma. 5-FU was given at a dose of 320 mg/m2/day, c.v.i. for 4 weeks, and CDDP between 3.5 to 7 mg/m2/day, infused for one hour five times a week for 4 weeks. Patients received 1 to 3 cycles of treatment (average 1.5 cycle). Pancreatic cancer cases needed longer treatment periods (2.25 cycles). The response rate of colorectal cancer cases was 57.7% (15/26), pancreas cancer 40%, gastric cancer 62.5%, and lung cancer 66.7%. The overall response rate was 57.8%. No severe side effects occurred in any of these cases. These data indicate that this combination 5-FU + daily low-dose CDDP chemotherapy is effective in the treatment of advanced gastrointestinal and lung adenocarcinoma.     

Randomized trial comparing two different modalities of administration of the same cytotoxic drugs in metastatic breast cancer

This protocol compare the efficacy of continuous infusion fluorouracil (5-FU) with weekly doxorubicin (DOX) and cyclophosphamide (CPM) to a "classical" monthly regimen of the same drugs, as a first line of treatment in metastatic breast carcinoma. The first arm of this protocol consisted of FAC: 5-FU 600 mg/m2 i.v. over 1 hour, day(d) 1, 2, 3, DOX 50 mg/m2 i.v. bolus, d1, and CPM, 400 mg/m2 i.v. bolus, d 1, 2, 3. The second arm consisted of FULON: 5-FU 250 mg/m2 per day continuously infused from d1 to d22, CPM 300 mg/m2 i.v. bolus, d1, 8, 15, 22, and DOX 15 mg/m2 i.v. bolus, day 1, 8, 15, 22. Between January 1990 and June 1993, 258 women with proven metastatic breast carcinoma were randomly assigned either to receive FAC or FULON chemotherapy regimen. Chemotherapy courses were administrated every 4 weeks for FAC regimen and every 6 weeks for FULON. Response rate (54 versus 53%), response duration (14 versus 12 months) and overall survival duration (23 versus 21 months) were not significantly different in the two regimens (FAC versus FULON). Preorative prognostic value of liver metastasis or high LDH level was slightly attenuated in patients treated by FULON. Efficacy of infusional 5-FU in metastatic breast cancer could have been lowered by weekly infusion of doxorubicin in the FULON regimen compared to monthly infusion. According to the modalities of delivery of the drugs, the two regimens seem equally effective.     

Phase II trial of paclitaxel and topotecan with granulocyte colony-stimulating factor support in stage IV breast cancer

PURPOSE: This multicenter phase II trial investigated the efficacy and safety of a combination of paclitaxel and topotecan in patients with pretreated metastatic breast cancer. Plasma levels of paclitaxel and topotecan were obtained during cycle 1 to correlate pharmacokinetic parameters with toxicity. PATIENTS AND METHODS: Paclitaxel was administered intravenously (i.v.) at 230 mg/m2 over 3 hours on day 1 followed by topotecan 1.0 mg/m2 i.v. over 30 minutes on days 1 to 5. Patients received an abbreviated premedication regimen that consisted of ranitidine 50 mg, diphenhydramine 50 mg, and a single 20-mg dose of dexamethasone, all administered i.v. 30 minutes before paclitaxel. Granulocyte colony-stimulating factor (GCSF) was administered at 5 micrograms/kg/d subcutaneously starting on day 6 and continuing until the absolute granulocyte count (AGC) was greater than 10,000/microL. Plasma paclitaxel and topotecan concentrations were assessed during the first cycle using limited-sampling strategies. RESULTS: Seventeen patients were treated. The majority had visceral metastases. Four patients experienced neutropenic fever and one had mild bronchospasm. Only one partial response (PR) was observed. Nadir AGC correlated strongly with both duration of paclitaxel levels greater than 0.05 mumol/L and maximum concentration (Cmax) of paclitaxel. CONCLUSION: This regimen does not produce a response rate superior to that expected with single-agent paclitaxel at doses that do not require growth factor support.     

Drug resistance patterns among tuberculosis patients in Rome, 1990-1992

PURPOSE: A Phase II study to evaluate the effect of a five-drug regimen, VP-16, ifosfamide, cisplatin, vinblastine, and bleomycin (VIP/VB) on complete response rate, continuous disease-free survival, and toxicity in patients with advanced germ-cell tumor. PATIENTS AND METHODS: Twenty male patients with a histologic diagnosis of advanced-stage germ-cell cancer, previously untreated with chemotherapy, received the following: etoposide 75 mg/m2 i.v. days 1-5; ifosfamide (with mesna uroprotection) 1.2 g/m2 i.v. days 1-5; cisplatin 20 mg/m2 i.v. days 1-5; vinblastine 0.18 mg/kg i.v. day 1; bleomycin 30 units i.v. day 1; filgrastim 5 micrograms/kg days 7-16. Chemotherapy was given every 3 weeks (bleomycin weekly x 12) for four courses. RESULTS: All patients entered were evaluable for toxicity, response, and survival. Eleven of 20 (55%) achieved complete remissions with chemotherapy alone and an additional 5 (25%) were rendered disease-free with surgical resection of teratoma (3) or viable cancer (2). Two patients relapsed at 4 and 5 months from complete remission (CR). There was one treatment-related death, from bleomycin lung toxicity after thoracotomy. Thirteen patients (65%) are alive and continuously free of disease, with a median follow-up of 20 months and a minimal follow-up of 12 months. Hematologic toxicity was most common, with 16 patients (80%) having grade 3 or 4 leukopenia. CONCLUSIONS: VIP/VB appears to be a very active regimen in advanced disseminated germ-cell cancer. Hematological toxicity was severe but manageable.     

The HER2/neu-derived peptide p654-662 is a tumor-associated antigen in human pancreatic cancer recognized by cytotoxic T lymphocytes

The protooncogene HER2/neu encodes a 185-kDa transmembrane protein with extensive homology to the epidermal growth factor receptor. It is overexpressed in several human cancers of epithelial origin, such as pancreatic cancer. Previously, we demonstrated that cytotoxic T lymphocytes (CTL) derived from breast, ovarian, and non-small cell lung cancer recognized a peptide derived from HER2/neu. To evaluate whether this HLA-A2-binding peptide is a tumor-associated antigen (TAA) in pancreatic cancer, the ability of HER2/neu-reactive CTL to lyse human pancreatic carcinoma cells was tested. CTL were generated from tumor-associated T lymphocytes from HLA-A2+ HER2/neu+ breast and ovarian cancer patients. All CTL recognized autologous and allogeneic HER2/ neu+ tumor cells in an HLA-A2-restricted fashion. Furthermore, all CTL recognized p654-662 (GP2) derived from HER2/neu. These CTL also recognized HER2/neu+ pancreatic cancer cells in an HLA-A2-restricted fashion. HER2/neu+ HLA-A2- pancreatic cancer were not or only poorly lysed. Repeated stimulation of HLA-A2+ PBL from pancreatic cancer patients using the HER2/neu-derived peptide resulted in specific recognition of this peptide and, more importantly, HER2/neu+ pancreatic tumors in an HLA-A2-restricted fashion. Autologous HLA-A2+ fibroblasts or HLA-A2+ malignant melanoma cells were not recognized. HLA-A2- peptide-stimulated T lymphocytes showed no significant cytotoxicity. These results demonstrate that this HER2/neu-derived peptide is a shared TAA among several adenocarcinomas including pancreatic carcinoma, suggesting a common mechanism of recognition of these human tumors by T lymphocytes. The identification of the HER2/neu-derived peptide GP2 as a TAA in pancreatic cancer provides an opportunity for the design of novel immunotherapy and vaccine strategies.     

Phase II trial of paclitaxel and cisplatin in women with advanced breast cancer: an active regimen with limiting neurotoxicity

PURPOSE: A phase II study of paclitaxel and cisplatin in patients with advanced breast cancer was performed to determine the objective response rate and make further observations about the toxicity of this regimen. PATIENTS AND METHODS: Patients were required to have histologically proven adenocarcinoma of the breast with no more than one chemotherapeutic treatment for advanced disease. Treatment consisted of paclitaxel 200 mg/m2 administered as a 24-hour intravenous (i.v.) infusion followed by cisplatin 75 mg/m2 i.v. Patients received granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg subcutaneously on day 3 until WBC recovery. Cycles were repeated every 21 days. Patients continued to receive therapy until disease progression or unacceptable toxicity. RESULTS: Forty-four patients entered the trial. Forty-two patients were assessable for response. Nineteen patients (43%) had no prior chemotherapy and 41 had no chemotherapy for metastatic disease. The median number of cycles administered per patient was five (range, one to seven). There were five complete responses (CRs) (11.9%) and 17 partial responses (PRs) (40.5%), with an overall response rate of 52.4% (95% confidence interval [CI], 36.4% to 68.0%). Nine patients had stage III disease. The response rate for this group was 66.7% (95% CI, 33.0% to 92.5%), with three CRs and three PRs. Among 35 patients with stage IV disease, there were two CRs and 14 PRs, with an overall response rate of 48.5% (95% CI, 30.8% to 66.5%). Overall, the median response duration was 10.6 months. Thirty patients (68%) developed transient grade 4 neutropenia. Cumulative neuropathy was the major dose-limiting toxicity. After five cycles of chemotherapy, 96% of patients had at least grade 1 neurotoxicity and 52% had at least grade 2 neurotoxicity. One patient had a toxic death after cycle 1 of therapy. CONCLUSION: The combination of paclitaxel and cisplatin as first-line chemotherapy for women with advanced breast cancer is an active regimen. However, the cumulative neurotoxicity was significant and dose-limiting in the majority of patients.     

Amonafide: An active agent in the treatment of previously untreated advanced breast cancer--a cancer and leukemia group B study (CALGB 8642)

Amonafide is a new imide derivative of naphthalic acid. The drug had demonstrated significant activity in preclinical studies and some activity in Phase I trials. The drug is extensively metabolized and detected in plasma and urine. Its toxicity has previously been correlated to the formation of an active metabolite, N-acetyl-amonafide. Amonafide was chosen for inclusion in the Cancer and Leukemia Group B (CALGB) master metastatic breast cancer protocol. CALGB 8642 randomizes previously untreated metastatic breast cancer patients either to one of several Phase II agents given for up to four cycles and then followed by standard cyclophosphamide-doxorubicin-5-fluorouracil, or to immediate treatment with standard cyclophosphamide-doxorubicin-5-fluorouracil. The end point of CALGB 8642 is to assess the difference in survival, toxicity, and overall response when limited exposure to Phase II agents precedes standard chemotherapy. This report deals only with amonafide as a Phase II agent. Comparisons with the cyclophosphamide-doxorubicin-5-fluorouracil arm will not be addressed. Patients had to have histologically documented measurable breast cancer and a performance status of 0-1. Patients could not have had prior chemotherapy for metastatic disease. Prior adjuvant chemotherapy was permitted. Patients could not have visceral crisis. Amonafide was given at 300 mg/m2/day i.v. for 5 days, and repeated at 21-day intervals for a maximum of four cycles. Escalation and reduction in dose was mandated dependent on hematotoxicity or lack thereof. Toxicity was primarily hematological and bimodal: 32% had grade 3 or 4 leukopenia and 24% had grade 3 or 4 thrombocytopenia; 22% had no leukopenia and 44% had no thrombocytopenia. The response rate was 18%, including one complete response. When response was analyzed by hematological toxicity, there was a 35.7% response if patients had leukopenia grade 3/4 (versus 8.3%, P = 0.08). There was a 50% response if patients had thrombocytopenia grade 3/4 (versus 7.1%, P = <0.01). We conclude that amonafide is somewhat active in previously untreated breast cancer patients. There may be a steep dose-response curve, based on the significant correlation between myelosuppression and response. Rates of responses in patients adequately dosed (i.e., with significant hematotoxicity) with amonafide ranged from 35 to 50%. Further studies will incorporate individualized dosing based on pretreatment acetylator phenotyping.     

Overexpression of HER2 modulates bcl-2, bcl-XL, and tamoxifen-induced apoptosis in human MCF-7 breast cancer cells

Overexpression of HER2 in estrogen receptor (ER)-positive human breast tumors has been associated with resistance to endocrine therapy. Here we investigated the effects of HER2 on expression of apoptotic pathways and modulation of tamoxifen-induced apoptosis in ER-positive MCF-7 breast cancer cells. We report that HER2 overexpression in MCF-7 cells is accompanied by up-regulation of antiapoptotic Bcl-2 and Bcl-XL proteins and suppression of tamoxifen-induced apoptosis. In addition, human tumor cell lines that are both ER positive and overexpress HER2 also express enhanced levels of Bcl-2 compared to cells that are either ER positive or overexpress HER2 alone. Our findings suggest that possible deregulation of antiapoptotic Bcl-2 and Bcl-XL may be associated with the enhanced survival of HER2-overexpressing and ER-positive breast cancer cells treated with antiestrogens.