A comparative investigation of methods for longitudinal data with limits of detection through a case study.

The statistical analysis of continuous longitudinal data may be complicated since quantitative levels of bioassay cannot always be determined. Values beyond the limits of detection (LOD) in the assays may not be observed and thus censored, rendering complexity to the analysis of such data. This article examines how both left-censoring and right censoring of HIV-1 plasma RNA measurements, collected for the study on AIDS-related Non-Hodgkin's lymphoma (AR-NHL) in East Africa, affects the quantification of viral load and explores the natural history of viral load measurements over time in AR-NHL patients receiving anticancer chemotherapy. Data analyses using Monte Carlo EM algorithm (MCEM) are compared to analyses where the LOD or LOD/2 (left censoring) value is substituted for the censored observations, and also to other methods such as multiple imputation, and maximum likelihood estimation for censored data (generalized Tobit regression). Simulations are used to explore the sensitivity of the results to changes in the model parameters. In conclusion, the antiretroviral treatment was associated with a significant decrease in viral load after controlling the effects of other covariates. A simulation study with finite sample size shows MCEM is the least biased method and the estimates are least sensitive to the censoring mechanism.

Changes in the influence of lymphoma- and HIV-specific factors on outcomes in AIDS-related non-Hodgkin lymphoma.

BACKGROUND: We undertook the present analysis to examine the shifting influence of prognostic factors in HIV-positive patients diagnosed with aggressive non-Hodgkin lymphoma (NHL) over the last two decades. PATIENTS AND METHODS: We carried out a pooled analysis from an existing database of patients with AIDS-related lymphoma. Individual patient data had been obtained prior from prospective phase II or III clinical trials carried out between 1990 until 2010 in North America and Europe that studied chemo(immuno)therapy in HIV-positive patients diagnosed with AIDS-related lymphomas. Studies had been identified by a systematic review. We analyzed patient-level data for 1546 patients with AIDS-related lymphomas using logistic regression and Cox proportional hazard models to identify the association of patient-, lymphoma-, and HIV-specific variables with the outcomes complete response (CR), progression-free survival, and overall survival (OS) in different eras: pre-cART (1989-1995), early cART (1996-2000), recent cART (2001-2004), and contemporary cART era (2005-2010). RESULTS: Outcomes for patients with AIDS-related diffuse large B-cell lymphoma and Burkitt lymphoma improved significantly over time, irrespective of baseline CD4 count or age-adjusted International Prognostic Index (IPI) risk category. Two-year OS was best in the contemporary era: 67% and 75% compared with 24% and 37% in the pre-cART era (P < 0.001). While the age-adjusted IPI was a significant predictor of outcome in all time periods, the influence of other factors waxed and waned. Individual HIV-related factors such as low CD4 counts (<50/mm(3)) and prior history of AIDS were no longer associated with poor outcomes in the contemporary era. CONCLUSIONS: Our results demonstrate a significant improvement of CR rate and survival for all patients with AIDS-related lymphomas. Effective HIV-directed therapies reduce the impact of HIV-related prognostic factors on outcomes and allow curative antilymphoma therapy for the majority of patients with aggressive NHL.

PSP94, an upstream signaling mediator of prostasin found highly elevated in ovarian cancer.

Ovarian cancer is a leading cause of cancer death as diagnosis is frequently delayed to an advanced stage. Effective biomarkers and screening strategies for early detection are urgently needed. In the current study, we identify PSP94 as a key upstream factor in mediating prostasin (a protein previously reported to be overexpressed in ovarian cancer) signaling that regulates prostasin expression and action in ovarian cancer cells. PSP94 is overexpressed in ovarian cancer cell lines and patients, and is significantly correlated with prostasin levels. Signaling pathway analysis demonstrated that both PSP94 and prostasin, as potential upstream regulators of the Lin28b/Let-7 pathway, regulate Lin28b and its downstream partner Let-7 in ovarian cancer cells. Expression of PSP94 and prostasin show a strong correlation with the expression levels of Lin28b/Let-7 in ovarian cancer patients. Thus, PSP94/prostasin axis appears to be linked to the Lin28b/Let-7 loop, a well-known signaling mechanism in oncogenesis in general that is also altered in ovarian cancer. The findings suggest that PSP94 and PSP94/prostasin axis are key factors and potential therapeutic targets or early biomarkers for ovarian cancer.

Prostasin may contribute to chemoresistance, repress cancer cells in ovarian cancer, and is involved in the signaling pathways of CASP/PAK2-p34/actin.

Ovarian cancer is the deadliest of gynecologic cancers, largely due to the development of drug resistance in chemotherapy. Prostasin may have an essential role in the oncogenesis. In this study, we show that prostasin is decreased in an ovarian cancer drug-resistant cell line and in ovarian cancer patients with high levels of excision repair cross-complementing 1, a marker for chemoresistance. Our cell cultural model investigation demonstrates prostasin has important roles in the development of drug resistance and cancer cell survival. Forced overexpression of prostasin in ovarian cancer cells greatly induces cell death (resulting in 99% cell death in a drug-resistant cell line and 100% cell death in other tested cell lines). In addition, the surviving cells grow at a much lower rate compared with non-overexpressed cells. In vivo studies indicate that forced overexpression of prostasin in drug-resistant cells greatly inhibits the growth of tumors and may partially reverse drug resistance. Our investigation of the molecular mechanisms suggests that prostasin may repress cancer cells and/or contribute to chemoresistance by modulating the CASP/P21-activated protein kinase (PAK2)-p34 pathway, and thereafter PAK2-p34/JNK/c-jun and PAK2-p34/mlck/actin signaling pathways. Thus, we introduce prostain as a potential target for treating/repressing some ovarian tumors and have begun to identify their relevant molecular targets in specific signaling pathways.

PSP94 contributes to chemoresistance and its peptide derivative PCK3145 represses tumor growth in ovarian cancer.

Tumor drug resistance remains a major challenge in the treatment of cancer. Here, we show that Prostatic secretory protein 94 (PSP94) levels are reduced in ovarian cancer patients with high levels of excision repair cross-complementing 1 (ERCC1), a marker for chemoresistance. We find that PSP94 is decreased in an ovarian cancer drug-resistant cell line, and plays an important role in the development of drug resistance in vitro. Our studies indicate that PSP94 can partially reverse drug resistance in mouse tumor models in vivo and that a PSP94 peptide derivative PCK3145 suppresses chemoresistant cancer cell and tumor growth in vitro and in vivo. Our investigation of the involved molecular mechanisms suggests that PSP94 may confer drug resistance by modulating the Lin28b/Let-7 signaling pathway. We introduce PSP94 and its peptide derivative PCK3145 as potential target to reverse chemoresistance in ovarian cancer and have begun to identify their relevant molecular targets in specific signaling pathways.

Kaposi's sarcoma in patients with and without human immunodeficiency virus infection, in a tertiary referral centre in Kenya.

The clinical features of Kaposi's sarcoma (KS), in patients with and without HIV infection, were investigated in a tertiary referral centre in Kenya between 1997 and 1999. Although 186 cases were identified prospectively, the data analysis was restricted to the 91 (49%) cases who had pathological confirmation of Kaposi's sarcoma and documented HIV serostatus. Among these 91 subjects (58% of whom were male), the age-group holding the largest number of KS cases was that of individuals aged 31-40 years; most of the paediatric cases were aged 6-10 years. The ratio of HIV-seropositives to HIV-seronegatives was 8.5:1 for the adult cases and 0.9:1 for the paediatric. Of the signs and symptoms of Kaposi's sarcoma seen at presentation, only peripheral lympadenopathy was found to be significantly associated with underlying HIV infection (P = 0.05). The median survival was 104 days. It is apparent that, as the HIV epidemic advances in regions of the world with endemic KS, the clinical presentation and natural history of the endemic KS are blending with those of the epidemic or AIDS-associated disease, leading to a reduction in the mean age of the cases and a nearly identical incidence in men and women. In regions of the world where patients have ready access to such chemotherapy, the impact of treatment with highly active antiretroviral drugs on the incidence and natural history of KS has been dramatic. It will be important to monitor the clinico-pathological features of KS in the developing world, as more active antiretroviral regimens become available in clinical practice there.

Clinical characteristics of Burkitt's lymphoma from three regions in Kenya.

OBJECTIVES: To describe the clinical characteristics of Burkitt's lymphoma (BL) from three regions in Kenya at different altitudes with a view towards understanding the contribution of local environmental factors. DESIGN: Prospective cross-sectional study. SETTING: Kenyatta National Hospital and seven provincial hospitals in Kenya. METHOD: Histologically proven cases of Burkitt's lymphoma in patients less than 16 years of age were clinically examined and investigated. MAIN OUTCOME MEASURES: For every case the following parameters were documented: chief complaint(s); physical examination, specifically pallor, jaundice, oedema, lymphadenopathy, presence of masses, splenomegaly and hepatomegaly. Reports of evaluation of chest radiograph, abdominal ultrasound/scan, bone marrow aspiration, cerebral spinal fluid cytology, liver and kidney function tests, urinalysis, stool occult blood and full blood count results. Stage of disease was assigned A, B, C or D. Cases of BL from three provinces of Kenya with diverse geographical features were analysed: Central, Coast, and Western. RESULTS: This study documented 471 BL cases distributed as follows: Central 61 (males 39 and 22 females), M:F ratio 1.8:1; Coast 169 (111 males and 58 females), M:F ratio 1.9:1; and Western 241 (140 males and 101 females), M:F ratio 1.4:1. The major presenting complaints were: abdominal swelling--Central 36%, Coast 4% and Western 26%; swelling on the face--Central 31%, Coast 81% and Western 64%; and proptosis--Central 3%, Coast 1% and Western 9%. The mean duration of these complaints in weeks were Central 6.9, Coast 6.08, and Western 5.05. The initial physical finding was a tumour mass in 39%, 72% and 54% of cases for Central, Coast and Western respectively. Tumour stage at diagnosis was: stage A--Central 21%, Coast 43% and Western 34%; stage B--Central 10%, Coast 5% and Western 10%; stage C--Central 41%, Coast 34% and Western 30%; and stage D--Central 28%, Coast 17% and Western 26%. For the age and sex matched cases the results show that commonly involved sites were: abdomen--Central 35%, Coast 9% and Western 14%; jaw (mandible)--Central 24%, Coast 22% and Western 31%; maxilla--Central 6%, Coast 24% and Western 11%; and lymph nodes--Central 10%, Coast 4% and Western 8%. The disease stage was A--Central 33%, Coast 44% and Western 36%; stage B--Central 11%, Coast 10% and Western 27%; stage C--Central 39%, Coast 34% and Western 27%; and stage D--Central 21%, Coast 13% and Western 37%. CONCLUSION: This study shows that clinical features of childhood BL vary with geographical region. The variations are documented in proportion of jaw, maxilla, abdominal and lymph nodal sites involvement. The differences observed are potentially due to the local environmental factors within these provinces. BL cases from Western province had features, intermediate between endemic and sporadic. Coastal province BL cases were similar to endemic BL, while BL cases from Central province resembled more or less sporadic BL subtypes. Strategies to explain and investigate the local environmental factors associated with the observed differences may certainly contribute towards improved understanding and clinical management of BL.

Oral combination chemotherapy in the treatment of AIDS-associated Hodgkin's disease.

OBJECTIVES: To determine the effectiveness of an oral combination chemotherapy regimen administered to patients with AIDS-associated Hodgkin's disease. DESIGN: Prospective, pilot phase II clinical trial. SETTING: Consecutive patient recruitment occurred at two medical centers in the United States: Albany Medical Center, Albany, New York, where patients were recruited prior to December 31, 1996 (pre-HAART era); and University Hospitals of Cleveland, Cleveland, Ohio, where patients were recruited after January 1, 1997 (HAART era). INTERVENTION: Oral chemotherapy consisted of lomustine (100 mg/m2 day I for cycle one and odd cycles thereafter); etoposide (200 mg/m2 days 1 through 3); and cyclophosphamide and procarbazine (each 100 mg/m2 days 22 through 31). Cycles were repeated every six weeks. Colony-stimulating factor support (G-CSF in all instances) was allowed. MAIN OUTCOME MEASURES: Clinical demographic variables, peripheral blood counts, serum chemistries, CD4 lymphocyte count, histopathological subtype of Hodgkin's disease were identified for all patients, who were staged according to Ann Arbor criteria. DATA ANALYSIS: Common Toxicity Criteria were utilized to assess safety; response was assessed using ECOG criteria; and survival was analyzed by Kaplan-Meier methods and difference of survival between pre-HAART and HARART era was compared using log-rank test. RESULTS: Eleven patients (six in pre-HAART era), all but one male, with a median age of 36 years, excellent performance status and advanced International Prognostic Score were treated. Myelosuppression was the major side effect and there were minimal other grade 3 or greater toxicity all of which were promptly reversible. An overall objective response rate of 82% (with 18% complete responses) and median survival duration of 24 months (range 2.5 +/- 68) were observed. Survival was markedly improved in patients treated in the HAART era (median not reached versus 7.25 months, p = 0.034). CONCLUSIONS: This feasibility study demonstrates acceptable tolerance and excellent clinical activity of oral combination chemotherapy in patients with AIDS-associated Hodgkin's disease. Improved survival is observed in combination with HAART therapy. Dose-modification of this regimen would be suitable to evaluate in the resource constrained setting and larger confirmatory studies are encouraged.

Strategies to overcome myelotoxic therapy for the treatment of Burkitt's and AIDS-related non-Hodgkin's lymphoma.

BACKGROUND: Strategies to circumvent or lessen the myelotoxicity associated with combination chemotherapy may improve the overall outcome of the management of patients particularly in resource poor settings. OBJECTIVES: To develop effective non-myelotoxic therapies for Burkitt's Lymphoma (BL) and AIDS-related non-Hodgkin's lymphoma. DATA SOURCES: Publications, original and review articles, conference abstracts searched mainly on Pubmed indexed for medline. DATA EXTRACTION: A systematic review of the clinical problem of combination chemotherapy. Identification of clinical strategies that circumvent or lessen the myelotoxicity of combination cytotoxic chemotherapy. Length of survival, lack of clinically significant (> grade 3) myelosuppression and weight loss were used as markers of myelotoxicity. DATA SYNTHESIS: Review of published experience with some of these strategies including dose-modification of multi-agent chemotherapy; rationale for targeted therapies, and the preclinical development of a mouse model exploring the role of metronomic scheduling substantiate pragmatism and feasibility of these approaches. CONCLUSION: Myelotoxic death rates using multi-agent induction chemotherapy approach 25% for endemic Burkitt's lymphoma and range between 20% to 60% for AIDS-related malignancy. This is mostly explained by the paucity of supportive care compounded by wasting and inanition attributable to advanced cancer and HIV infection making patients more susceptible to myelosuppressive side effects of cytotoxic chemotherapy. Investigations and alternative approaches that lessen or circumvent myelotoxicity of traditional cytotoxic chemotherapy for the management of Burkitt's lymphoma and AIDS-related non-Hodgkin's lymphoma in the resource-constrained setting are warranted. Pertinent pre-clinical and clinical data are emerging to support the need for abrograting the myelosuppressive effects of traditional cytotoxic chemotherapy. This can be achieved by developing targeted anti-viral and other strategies, such as the use of bryostatin 1 and vincristine, and by developing a preclinical mouse model to frame the clinical rationale for a pilot trial of metronomic therapy for the treatment of Burkitt's and AIDS-related lymphoma. Implementation of these investigational approaches must be encouraged as viable anti-cancer therapeutic strategies particularly in the resource-constrained settings.

Sequential tumor biopsies in early phase clinical trials of anticancer agents for pharmacodynamic evaluation.

PURPOSE: In the setting of target-based anticancer drug development, it is critical to establish that the observed preclinical activity can be attributed to modulation of the intended target in early phase trials in human subjects. This paradigm of target modulation allows us to determine a Phase II or III dose (optimal biochemical/biological modulatory dose) that may not necessarily be the maximum tolerated dose. A major obstacle to target-based (often cytostatic) drug development has been obtaining relevant tumor tissue during clinical trials of these novel agents for laboratory analysis of the putative marker of drug effect. EXPERIMENTAL DESIGN: From 1989 to present, we have completed seven clinical trials in which the end point was a biochemical or biological modulatory dose in human tumor tissues (not surrogate tissue). Eligibility enrollment required that patients have a biopsiable lesion either with computerized tomography (CT) guidance or direct visualization and consent to sequential (pre and posttreatment) biopsies. RESULTS: A total of 192 biopsies were performed in 107 patients. All but 8 patients had sequential pre and posttreatment biopsies. Seventy-eight (73%) of the 107 patients had liver lesion biopsies. In eight patients, either one or both biopsies contained insufficient viable tumor tissue or no tumor tissue at all for analysis. Of a total of 99 patients in whom we attempted to obtain paired biopsies, a total of 87 (88%) were successful. Reasons for failure included patient refusal for a second biopsy (n = 2), vasovagal reaction with first biopsy precluding a second biopsy (n = 1), subcapsular hepatic bleeding (n = 1), and most commonly obtaining necrotic tumor, fibrous, or normal tissue in one of the two sequential biopsies (n = 8). CONCLUSIONS: This is the first and largest reported series demonstrating that with adequate precautions and experience, sequential tumor biopsies are feasible and safe during early phase clinical trials.

The clonality of tumor-infiltrating lymphocytes in African Kaposi's sarcoma.

BACKGROUND: African Kaposi's sarcoma (KS) lesions contain human herpesvirus-8 (HHV-8) and Epstein-Barr virus (EBV), both of which are associated with various types of non-Hodgkin's lymphomas and are known to produce several factors suspected of lymphomagenic potential. The aim of this study was to evaluate tumor-infiltrating lymphocytes for the evidence of clonal expansion in African KS. METHODS: We used polymerase chain reaction (PCR)-based assays to determine the clonality of tumor-infiltrating lymphocytes in African KS lesions and compared the results to similar studies of patient-matched uninvolved skin and peripheral blood. RESULTS: T cells were polyclonal in all samples tested. Peripheral blood B cells were also polyclonal; however, a minority of lesional and uninvolved skin samples exhibited evidence of restricted B-cell clonality. Correlation with immunohistological analysis revealed that this clonal B-cell restriction was secondary to the sparse nature of lesional B cells rather than their clonal overgrowth. CONCLUSIONS: We conclude that, despite the putative lymphomagenic potential of HHV-8 and EBV and their co-existence in African KS lesions, tumor-infiltrating lymphocytes in these cases do not show evidence of clonal expansion that might be an early manifestation of lymphoma. Nevertheless, these studies are a case in point that sparse lymphoid subpopulations in lesional and uninvolved extranodal tissues can give rise to restricted clonal patterns that must be interpreted carefully to avoid the misdiagnosis of occult lymphoma.

Adult Burkitt's lymphoma in patients with and without human immunodeficiency virus infection in Kenya.

Prior to the acquired immunodeficiency syndrome (AIDS) epidemic, one or two cases of adult Burkitt's lymphoma (BL) were seen annually at the Kenyatta National Hospital, the national referral medical center in Nairobi, Kenya. To investigate the influence of human immunodeficiency virus (HIV) infection in adult BL in Kenya, we conducted a national prevalence survey of all patients 16 years of age and older with BL. A systematic review of medical records of all patients diagnosed with BL between 1992 and 1996 was performed. The diagnosis of BL was based and confirmed on review of pathological material from time of original diagnosis. HIV serology was confirmed by enzyme-linked immunosorbent assay (ELISA). Twenty-nine adult patients with BL were identified during the 5-year study period. Of these patients, 17 (59%) were males, 12 (41%) were females, and the median age was 26 years. Nineteen patients (66%) with BL were HIV-seropositive. The proportion of men was similar in HIV-seropositive and -seronegative patients (58% vs 60%). HIV-seropositive BL patients were significantly older than seronegatives (median 35 vs 19.5 years, p < 0.001). HIV-seropositive patients uniformly presented with constitutional or B symptoms and advanced BL accompanied by diffuse lymph node involvement, whereas the clinical presentation of HIV-seronegative patients during this time period was reminiscent of the "typical" endemic pattern of disease with complete sparing of peripheral lymph nodes. The overall survival of HIV-seropositive cases was significantly worse than that of the HIV-seronegative cases; median survival in the HIV-seropositive patients was 15 weeks. There is an approximate 3-fold increase in the incidence of adult BL during the time period of this study, which is attributable to the AIDS epidemic. In this setting, patients often present with disseminated disease, diffuse peripheral lymphadenopathy and fever, the latter two of which heretofore have been commonly associated with non-lymphoproliferative disorders such as Mycobacterium tuberculosis and sexually transmitted diseases in Kenya. These observations warrant inclusion of AIDS-related BL in the differential diagnosis of the adult patient with unexplained fever and lymphadenopathy in Kenya. The corollary is that HIV infection is virtually excluded in an adult patient without peripheral lymphadenopathy and biopsy-proven BL.

Paclitaxel added to the cisplatin/etoposide regimen in extensive-stage small cell lung cancer -- the use of complete response rate as the primary endpoint in phase II trials.

Obtaining a complete response (CR) is the most powerful predictor of survival in extensive-stage small cell lung cancer (SCLC). Improvements in long-term survival in extensive-stage SCLC can be made if the proportion of complete responders to induction therapy can be increased. We performed a phase II trial of the feasibility of adding paclitaxel to standard cisplatin/etoposide (EP regimen) in extensive-stage SCLC. The primary endpoint for this trial is the proportion of patients (pts) obtaining a CR rather than overall response. The null hypothesis for this trial consists of the absence of a CR rate >20%. Paclitaxel was given at doses of 135 (3 pts) or 170 mg/m(2) i.v. over 3 h on day 1. Cisplatin 60 mg/m(2) was given on day 1. On days 1-3 etoposide 80 mg/m(2) per day i.v. was given. G-CSF was used from days 5 to 14 of each cycle. Cycles were repeated q21 days. A two-stage design was used for patient accrual, based on the occurrence of complete responses. Initially, 16 patients were to be accrued. If more than three complete responses were to occur, a further 20 patients would be accrued to the study (Simon's optimal two stage design). Sixteen patients were enrolled. Two patients had a CR (13%) and nine patients had a partial response (56%) for an overall response rate of 69%. The trial was suspended due to the low CR rate. Review of the literature for paclitaxel based front-line treatment combined with EP therapy, in extensive stage SCLC, consistently shows a CR rate <20% but high overall response rate is maintained (thus most responses are partial). As virtually all long-term survivors in extensive-disease SCLC have had a CR to induction therapy and CR remains the strongest predictor of survival for this disease, this may suggest that paclitaxel added to standard EP may improve progression-free survival (and possibly median survival) but is unlikely to significantly improve long-term survival. Initial randomized phase III data confirm the absence of impact on survival for this triple-drug regimen compared to EP therapy alone. Furthermore, other regimens comparing favorably to the EP regimen have all shown consistent CR rates >20% in the phase II setting. In conclusion, consideration should be given to the use of CR rate as a phase II endpoint to determine if a particular regimen should be compared to the standard in a phase III setting for extensive-stage SCLC. A two-stage phase II design based on a minimum required completed responses for further patient accrual is recommended.

Oral combination chemotherapy in conjunction with filgrastim (G-CSF) in the treatment of AIDS-related non-Hodgkin's lymphoma: evaluation of the role of G-CSF; quality-of-life analysis and long-term follow-up.

In 1993 we reported the efficacy and toxicity profile of an oral combination regimen administered to 18 patients with AIDS-related lymphoma (NHL-1 study). We observed a 61% response rate; 39% one-year survival rate; nearly two-thirds of patients developed > or = grade 3 leukopenia; and 28% of cycles were associated with febrile neutropenia. These results prompted us to shorten the duration of therapy and to add G-CSF to ameliorate the myelosuppression. Twenty patients with biopsy-proven AIDS-related lymphoma were treated with three 6-week cycles of oral chemotherapy consisting of lomustine (CCNU) 100 mg/m2 on day 1, cycles no. 1 and 3; etoposide 200 mg/m2 days 1-3; cyclophosphamide and procarbazine both 100 mg/m2 days 22-31; and G-CSF 5 microg/kg subcutaneously days 5-21 and days 33-42 (NHL-2 study). The following analyses were undertaken: (1) evaluation of toxicity and efficacy parameters for patients in the current (NHL-2) study; (2) analysis of the clinical role of G-CSF by (historical) comparison with the NHL-1 study of the same regimen without G-CSF; (3) quality-of-life assessments using the Functional Living Index-Cancer (FLIC) and Brief Symptom Inventory (BSI) instruments for all 38 patients (NHL-1+2); and (4) long-term follow-up for all 38 patients. In the current study the overall objective response using ECOG criteria was 70% (95% CI, 50-90%) with 6 CRs (30%) and 8 PRs (40%). The median survival duration was 7.3 months (range: 0.5-51+ months). One patient developed CNS relapse. There were no significant differences with respect to demographics or prognostic factors between the patient populations of the NHL-1 study and the current study (P > 0.2 for each factor). Myelosuppression was the major toxicity in both studies. In the current study versus the NHL-1 study, although the lower incidences of grade 3/4 myelosuppression (51% vs. 64%) and febrile neutropenia (17% vs. 28%) on a per cycle basis were not statistically significant, fewer patients (40% vs. 60%) were affected. However, the severity of myelotoxicity was lessened with the addition of G-CSF, measured in terms of the discontinuation of therapy, myelotoxic deaths, and freedom from grade 3/4 myelotoxicity ( P < 0.02). The number of hospitalizations for febrile neutropenia (7 in the NHL-2 study vs. 13 in the NHL-1 study) was also significantly different (P < 0.05). Quality-of-life analysis confirmed no significant functional or psychological deterioration during therapy except for patients experiencing febrile neutropenia, whose functional capacity deteriorated (P < 0.04). The 1-year, 18-month, and 2-year survival rates for the combined studies (38 patients) were 32%, 21%, and 13%, respectively. At time of death 49% of patients were free from progression of their lymphoma. Administration of the oral regimen has resulted in 13% of patients surviving two years, and half of patients surviving free from progression of their lymphoma. This regimen is efficacious and considerate of patient quality-of-life issues. The addition of G-CSF to the regimen decreases the frequency of hospitalization for febrile neutropenia.

Phase I clinical and pharmacokinetic study of rebeccamycin analog NSC 655649 given daily for five consecutive days.

PURPOSE: Rebeccamycin analog (NSC 655649) is active against a variety of both solid and nonsolid tumor cell lines. We performed a phase I trial to determine the maximum-tolerated dose (MTD) of rebeccamycin analog when given on a daily x 5 schedule repeated every 3 weeks, characterize the toxicity profile using this schedule, observe patients for antitumor response, and determine the pharmacokinetics of the agent and pharmacodynamic interactions. PATIENTS AND METHODS: Thirty assessable patients received a total of 153 cycles according to the following dose escalation schema: 60, 80, 106, 141, and 188 mg/m(2)/d x 5 days. RESULTS: Grade 2 phlebitis occurred in all patients before the use of central venous access, placed at dose level 4 and higher. Dose-limiting toxicity (DLT), grade 4 neutropenia, occurred at 188 mg/m(2)/d x 5 days in both previously treated and chemotherapy-naive patients. Pharmacokinetic analysis revealed a three-compartmental model of drug elimination and a long terminal half-life (154 +/- 55 hours). The percentage drop in absolute neutrophil count correlates with the area under the curve infinity. The presence of a second peak during the elimination phase as well as a high concentration of NSC 655649 in biliary fluid compared with the corresponding plasma measurement (one patient) is suggestive of enterohepatic circulation. Two partial responses, two minor responses, and six prolonged (> 6 months) cases of stable disease were observed. Of these, three patients with gallbladder cancer and one patient with cholangiocarcinoma experienced either a minor response or a significant period of freedom from progression. CONCLUSION: The recommended phase II dose for NSC 665649 on a daily x 5 every 3 weeks schedule is 141 and 165 mg/m(2)/d for patients with prior and no prior therapy, respectively, with DLT being neutropenia. During this phase I trial, encouraging antitumor activity was been observed.

Phase II and pharmacokinetic/pharmacodynamic trial of sequential topoisomerase I and II inhibition with topotecan and etoposide in advanced non-small-cell lung cancer.

PURPOSE: In vitro and in vivo preclinical models have demonstrated synergistic activity when topoisomerase I and II inhibitors are administered sequentially. Topoisomerase I inhibitors increase topoisomerase II levels and increase cell kill induced by topoisomerase II poisons. We evaluated this hypothesis in a cohort of patients with advanced non-small-cell lung cancer (NSCLC). METHODS: A group of 19 patients with advanced NSCLC (70% adenocarcinoma) received topotecan at a dose of 0.85 mg/m2 per day as a continuous 72-h infusion from days 1 to 3. Etoposide was administered orally at a dose of 100 mg twice daily for 3 days on days 7-9 (schedule and dose derived from prior phase I trials). Total and lactone topotecan concentrations were measured at the end of the 72-h infusion. Blood samples were obtained immediately after each 72-h topotecan infusion in order to measure the mutational frequency at the hypoxanthine phosphoribosyl transferase (HPRT) locus in peripheral lymphocytes. RESULTS: A total of 55 cycles were administered. Toxicity was mainly hematologic with grade 4 neutropenia occurring in 7% of courses. Only one partial response and two stable diseases were observed. The 1-year survival rate was 33%. There was a statistically significant difference between steady-state lactone concentrations between cycle 1 and cycle 2 with decreasing concentrations with cycle 2 (P = 0.02). This was explained by a statistically significant increase in the clearance of topotecan lactone during cycle 2 (P = 0.03). Total but not lactone concentrations correlated with nadir WBC, ANC and platelet levels. Steady-state plasma lactone levels correlated with the mutational frequency at the HPRT locus (P = 0.06). In the one patient with a partial response a sixfold increase in HPRT mutational frequency was observed, which was not seen in patients with progressive disease. CONCLUSION: The combination of topotecan and etoposide in this schedule of administration has minimal activity in adenocarcinoma of the lung. This lack of activity may be due to the delay in administration of etoposide after the topotecan as studies have shown that the compensatory increase in topoisomerase II levels after treatment with topoisomerase I inhibitors is shortlived (<24 h). The HPRT mutational frequency results suggest that the lack of clinical response may be associated with failure to achieve sufficient cytotoxic dose as indicated by a lack of increase in mutational frequency in those patients with progressive disease. HPRT mutational frequency may correlate with plasma steady-state topotecan lactone levels. Future studies should be directed toward earlier administration of topoisomerase II inhibitors after topoisomerase I inhibition.