126 Evaluation of topotecan (Hycamtin™) in relapsed small cell lung cancer (SCLC). A multicentre phase II study

A Phase Ib Dose-Escalation Study of LCL161 Plus Oral Topotecan for Patients With Relapsed/Refractory Small Cell Lung Cancer and Select Gynecologic Malignancies

BACKGROUND

This was an open-label, multicenter, single-arm phase Ib dose-escalation study of oral LCL161 administered in combination with oral topotecan in patients with relapsed/refractory small cell lung cancer (SCLC) and select gynecological cancers.

METHODS

Cohorts of 3-6 patients initiated treatment with LCL161 and topotecan in escalating doses. LCL161 was administered orally on days 1, 8, and 15 of each 21-day cycle; topotecan was administered orally for the first 5 days of each 21-day cycle.

RESULTS

A total of 35 patients were enrolled in 6 cohorts; 30 patients were female; 4 patients had SCLC and 19 patients had ovarian cancer. Median prior lines of therapy were 3 (1-10). Median duration of treatment was 7.1 weeks (0.1-174). The most frequent grade 3/4 treatment-related adverse events were thrombocytopenia (51.43%) and anemia (31.43%). ORR was 9.7%; 58% of patients had SD. The study was stopped early before the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) were determined.

CONCLUSION

The addition of LCL161 to oral topotecan caused more myelosuppression when dosed together than what was associated with either drug alone. Moreover, the drug combination did not improve outcomes. The study was terminated early (ClinicalTrials.gov Identifier: NCT02649673).

Prognostic role of hyponatremia in 564 small cell lung cancer patients treated with topotecan

OBJECTIVES

Hyponatremia is reported in about 15% of small cell lung cancer (SCLC). Variable results of the prognostic significance of low plasmatic sodium (Napl) have been reported. Our study was performed to investigate the prognostic role of hyponatremia in SCLC patients treated in second-line with topotecan chemotherapy.

MATERIALS AND METHODS

Data were retrospectively collected from a database including clinical data from 631 patients enrolled in 6 prospective topotecan iv studies. Final data were obtained from 564 patients in which data on baseline Napl were available. Univariate and multivariate analysis were carried out to study the possible correlation between Napl and second-line clinical outcomes.

RESULTS

Hyponatremia (Napl<135mequiv./l) was present in 101 cases (17.9%). Napl was <125mequiv./l in 16 patients (2.8%), 126-130mequiv./l in 11 (2%), 130-134mequiv./l in 74 (13.1%), while 463 patients (82.1%) showed normal values. The median survival was 28.7 weeks in patients with normal Napl, and 21.1 weeks in patients with hyponatremia (p<0.0001, HR=1.67, 95%CI=1.32-2.10). By Cox multivariate analysis, hyponatremia was associated with poorer prognosis (p=0.0024, HR=1.44, 95%CI=1.13-1.82). A not statistically significant trend of correlation between hyponatremia and progression-free survival (p=0.085, HR=1.23, 95%CI 0.97-1.55) and response rate (p=0.5037, OR=0.81, 95%CI 0.44-1.49) was observed.

CONCLUSION

Hyponatremia is an independent prognostic factor for patients with SCLC treated with topotecan in second-line setting. Further studies are needed to prospectically confirm these results and to develop an optimal therapy for hyponatremic patients.

Current and emerging pharmacotherapies for the treatment of relapsed small cell lung cancer

Small cell lung cancer (SCLC) is a very aggressive cancer with poor outcome if left untreated, but it is also one of the most chemotherapy responsive cancers. Overall it has a very poor prognosis especially if it is chemotherapy resistant to first line treatment. Second line chemotherapy has not been very beneficial in SCLC as opposed to breast cancer and lymphoma. In the last few years topotecan is the only drug that has been approved by the food and drug administration (FDA) for the second line treatment of SCLC but in Japan another drug, amrubicin is approved. There are many combinations of different chemotherapies available in moderate to high intensity, in this difficult to treat patient to overcome the chemo resistance, but many of these studies are small or phase II trials. In this article we have reviewed single agent and multidrug regimens that were studied in both chemo sensitive and refractory setting, including the most recent clinical trials.

Clinical relevance of human cancer xenografts as a tool for preclinical assessment: example of in-vivo evaluation of topotecan-based chemotherapy in a panel of human small-cell lung cancer xenografts

Prediction of human tumor response based on preclinical data could reduce the failure rates of subsequent new anticancer drugs clinical development. Human small-cell lung carcinomas (SCLC) are characterized by high initial sensitivity to chemotherapy but a low median survival time because of drug resistance. The aim of this study was to evaluate the therapeutic relevance of a panel of human SCLC xenografts established in our laboratory using one compromising drug in SCLC, topotecan (TPT). Six SCLC xenografts derived from six patients were used: three were sensitive to a combination of etoposide (VP16), cisplatin (CDDP), and ifosfamide (IFO), and three were resistant, as published earlier. Growth inhibition was greater than 84% for five xenografts at doses of 1-2 mg/kg/day. TPT was combined with IFO, etoposide (VP16), and CDDP. IFO improved the efficacy of TPT in three of the five xenografts and complete responses were obtained even with the less TPT-sensitive xenograft. VP16 increased the efficacy of two of four xenografts and complete responses were obtained. The combination of TPT and CDDP did not improve TPT responses for any of the xenografts tested. Semiquantitative reverse transcriptase-PCR of genes involved in drug response, such as topoisomerase I, topoisomerase IIalpha, multidrug resistance 1 (MDR1), multidrug resistance-associated protein (MRP), lung resistance-related protein (LRP), and glutathione S-transferase pi (GSTpi), did not explain the variability in drug sensitivity between SCLC xenografts. In conclusion, these preclinical data mirror those from published clinical studies suggesting that our panel of SCLC xenografts represents a useful tool for preclinical assessment of new treatments.

Randomized Phase II Trial Comparing Amrubicin With Topotecan in Patients With Previously Treated Small-Cell Lung Cancer: North Japan Lung Cancer Study Group Trial 0402

Purpose

Amrubicin, a new anthracycline agent, and topotecan are both active for previously treated small-cell lung cancer (SCLC). No comparative study of these agents has been reported. This randomized phase II study was conducted to select amrubicin or topotecan for future evaluation.

Patients and Methods

Patients with SCLC previously treated with platinum-containing chemotherapy were randomly assigned to receive amrubicin (40 mg/m2 on days 1 through 3) or topotecan (1.0 mg/m2 on days 1 through 5). Patients were stratified by Eastern Cooperative Oncology Group performance status (0, 1, or 2) and type of relapse (chemotherapy sensitive or refractory). The primary end point was overall response rate (ORR), and secondary end points were progression-free survival (PFS), overall survival, and toxicity profile.

Results

From February 2004 to July 2007, 60 patients were enrolled, and 59 patients (36 patients with sensitive and 23 patients with refractory relapse) were assessable for efficacy and safety evaluation. Neutropenia was severe, and one treatment-related death owing to infection was observed in the amrubicin arm. ORRs were 38% (95% CI, 20% to 56%) for the amrubicin arm and 13% (95% CI, 1% to 25%) for the topotecan arm. In sensitive relapse, ORRs were 53% for the amrubicin arm and 21% for the topotecan arm. In refractory relapse, ORRs were 17% for the amrubicin arm and 0% for the topotecan arm. Median PFS was 3.5 months for patients in the amrubicin arm and 2.2 months for patients in the topotecan arm. Multivariate analysis revealed that amrubicin has more influence than topotecan on overall survival.

Conclusion

Amrubicin may be superior to topotecan with acceptable toxicity for previously treated patients with SCLC. Further evaluation of amrubicin for relapsed SCLC is warranted.

Current status of second-line treatment and novel therapies for small cell lung cancer

Despite high response rates to first-line standard treatment, the great majority of patients with small cell lung cancer (SCLC) will relapse and succumb to their disease rather quickly. In the context of salvage therapy, symptom palliation and quality-of-life improvements, besides survival prolongation, are primary treatment endpoints. A variety of single-agent and multi-agent chemotherapy regimens have been tested with limited success in patients with recurrent SCLC. A number of combination regimens have demonstrated high response rates in second-line settings, but these can be considered only for patients with good performance status. Treatment outcome depends on many factors, including type of response to first-line therapy, treatment-free interval, and performance status. Currently, topotecan represents an effective, tolerable therapeutic option and is the only agent approved for this indication. The management of patients with recurrent disease remains an area of active research. This review provides an update of clinical research on second-line chemotherapy of SCLC and of recent results obtained with novel molecular targeted approaches in both first- and second-line therapy.

Topotecan for the treatment of small-cell lung cancer

Lung cancer is the most prevalent and yet the most preventable malignancy worldwide. Owing to the propensity of small-cell lung cancer to early relapse and its relative resistance to subsequent treatment there is a need to improve currently available therapies. Topotecan has provided an efficacious and tolerable therapeutic option for patients with recurrent small-cell lung cancer, and the oral formulation has also been shown to be beneficial, even in elderly patients of poor performance status. Herein we review the role of topotecan in the treatment of small-cell lung cancer.

Phase III Study of Oral Compared With Intravenous Topotecan As Second-Line Therapy in Small-Cell Lung Cancer

Purpose

Single-agent intravenous (IV) topotecan is an effective treatment for small-cell lung cancer (SCLC) after failure of first-line chemotherapy. This open-label, randomized, phase III study compared oral and IV topotecan in patients with SCLC sensitive to initial chemotherapy.

Patients and Methods

Patients with limited- or extensive-disease SCLC, documented complete or partial response to first-line therapy, Eastern Cooperative Oncology Group performance status ≤ 2, and measurable recurrent disease (WHO criteria) with a treatment-free interval of ≥ 90 days were assigned to treatment with either oral topotecan 2.3 mg/m2/d on days 1 through 5 or IV topotecan 1.5 mg/m2/d on days 1 through 5 every 21 days. Primary end point was response rate as confirmed by an external reviewer blinded to treatment.

Results

A total of 309 patients were randomly assigned. In intent-to-treat analysis, response rates were 18.3% with oral topotecan (n = 153) and 21.9% with IV topotecan (n = 151), with a difference (oral –IV) of −3.6% (95% CI, −12.6% to 5.5%). Median survival time was 33.0 weeks for oral and 35.0 weeks for IV topotecan; 1- and 2-year survival rates were 32.6% and 12.4% for oral topotecan, respectively, and 29.2% and 7.1% for IV topotecan, respectively. Third-line chemotherapy was similar for both groups (33% for oral; 35% for IV). Incidence of grade 4 toxicity in patients who received oral and IV topotecan was as follows: neutropenia in 47% and 64%, thrombocytopenia in 29% and 18%, grade 3 or 4 anemia in 23% and 31%, and sepsis in 3% and 3%, respectively. The most frequent nonhematologic adverse events (all grades) included nausea (43% oral; 42% IV), alopecia (26% oral; 30% IV), fatigue (31% oral; 36% IV), and diarrhea (36% oral; 20% IV).

Conclusion

Oral topotecan demonstrates activity and tolerability similar to IV topotecan in chemotherapy-sensitive SCLC patients and offers patients a convenient alternative to IV therapy.

Topotecan therapy in patients with relapsed small-cell lung cancer and poor performance status

PURPOSE

Topotecan is generally well tolerated and active in patients with relapsed small-cell lung cancer (SCLC) and poor performance status (PS). In this study, we investigated whether treatment with topotecan is associated with improvement in PS as measured by the rate of conversion from PS 2 to PS 0/1.

PATIENTS AND METHODS

A retrospective analysis of data from 7 clinical trials (N = 795) investigating topotecan in patients with relapsed SCLC was performed. All patients received topotecan 1.25-1.5 mg/m2 daily on days 1-5 of a 21-day cycle. Demographics were similar for patients with PS 2 and PS 0/1. A total of 152 patients with PS 2 at baseline received 502 cycles (median, 2 cycles; range, 1-14 cycles) of therapy, and 32 (21%) experienced PS improvement to PS 0/1 that lasted for > or = 2 cycles.

RESULTS

Overall, 50% of patients who experienced PS conversion also exhibited an objective antitumor response, compared with 8% of patients with PS 2 who had no improvement in PS and achieved a response. Similarly, median overall survival was longer for patients with PS improvement (37 weeks; 95% confidence interval, 29.6-49.4 weeks) compared with patients with PS 2 who had a response but no PS improvement (10.4 weeks; 95% confidence interval, 8.7-13.6 weeks). A substantial proportion of patients with PS 2 and relapsed SCLC experienced PS improvement during topotecan treatment. These patients had a substantially longer median survival and a higher response rate compared with the overall trial population.

CONCLUSION

Improvement in PS appears to be a good indicator of benefit from topotecan therapy.

Phase III trial comparing supportive care alone with supportive care with oral topotecan in patients with relapsed small-cell lung cancer

PURPOSE

For patients with small-cell lung cancer (SCLC), further chemotherapy is routinely considered at relapse after first-line therapy. However, proof of clinical benefit has not been documented.

PATIENTS AND METHODS

This study randomly assigned patients with relapsed SCLC not considered as candidates for standard intravenous therapy to best supportive care (BSC) alone (n = 70) or oral topotecan (2.3 mg/m2/d, days 1 through 5, every 21 days) plus BSC (topotecan; n = 71).

RESULTS

In the intent-to-treat population, survival (primary end point) was prolonged in the topotecan group (log-rank P = .0104). Median survival with BSC was 13.9 weeks (95% CI, 11.1 to 18.6) and with topotecan, 25.9 weeks (95% CI, 18.3 to 31.6). Statistical significance for survival was maintained in a subgroup of patients with a short treatment-free interval (< or = 60 days). Response to topotecan was 7% partial and 44% stable disease. Patients on topotecan had slower quality of life deterioration and greater symptom control. Principal toxicities with topotecan were hematological: grade 4 neutropenia, 33%; grade 4 thrombocytopenia, 7%; and grade 3/4 anemia, 25%. Comparing topotecan with BSC, infection grade 2 was 14% versus 12% and sepsis 4% versus 1%; other grade 3/4 events included vomiting 3% versus 0, diarrhea 6% versus 0, dyspnea 3% versus 9%, and pain 3% versus 6%. Toxic deaths occurred in four patients (6%) in the topotecan arm. All cause mortality within 30 days of random assignment was 13% on BSC and 7% on topotecan.

CONCLUSION

Chemotherapy with oral topotecan is associated with prolongation of survival and quality of life benefit in patients with relapsed SCLC.

Topotecan in the treatment of elderly patients with relapsed small-cell lung cancer

BACKGROUND

Almost 70% of all patients with lung cancer in the United States are>65 years of age, and the incidence of small-cell lung cancer (SCLC) increases with age until the eighth decade of life. However, elderly patients are underrepresented in clinical trials and are often suboptimally treated. The validity of age as a prognostic factor for toxicity or survival remains controversial.

PATIENTS AND METHODS

To investigate the safety and efficacy of topotecan (an approved treatment for relapsed SCLC) in older patients, we performed a retrospective analysis in patients >or= 65 years of age versus patients < 65 years of age from 5 large topotecan trials. In all 5 trials, patients received topotecan 1.5 mg/m2 per day via a 30-minute intravenous infusion on days 1 through 5 of a 21-day cycle. Efficacy and tolerability outcomes were assessed for both age groups.

RESULTS

Topotecan was similarly tolerated in both age groups, with generally manageable hematologic toxicity. The incidence, duration, and onset of severe hematologic toxicities did not vary significantly with age. In the<65 age group, grade 4 neutropenia and leukopenia were reported in 72% and 32% of patients, respectively; in the >or= 65 age group, grade 4 neutropenia and leukopenia were reported in 77% and 31% of patients, respectively. Grade 4 thrombocytopenia was less common in the<65 age group. Nonhematologic toxicities, median time to progression, and overall survival were comparable between groups.

CONCLUSION

This is the first demonstration of the safety and efficacy of topotecan in older patients with recurrent SCLC. Future studies are needed to fully characterize the role of topotecan in the treatment of older patients.

Sequential versus alternating administration of cisplatin/etoposide and topotecan as first-line treatment in extensive-stage small-cell lung cancer: preliminary results of a Phase III Trial of the Hellenic Oncology Research Group

BACKGROUND

This trial was designed to compare the efficacy and toxicity of sequential versus alternating administration of cisplatin/etoposide and topotecan in patients with previously untreated extensive-stage small-cell lung cancer (SCLC).

PATIENTS AND METHODS

Two hundred eighty-four chemotherapy-naive patients were randomized between the sequential therapy arm (n=142; 4 cycles of cisplatin 75 mg/m2 intravenously [I.V.] on day 1 with etoposide 100 mg/m2 per day I.V. on days 1-3 followed by 4 cycles of topotecan 1.5 mg/m2 per day I.V. on days 1-5) and the alternating arm (n=142; same doses of cisplatin/etoposide on cycles 1, 3, 5, and 7 and topotecan on cycles 2, 4, 6, and 8). Treatment cycles for both regimens were administered every 3 weeks.

RESULTS

At this preliminary analysis, no statistically significant difference in the overall response rate, duration of response, time to disease progression, or median survival was observed between the 2 arms. A total of 756 cycles of the sequential therapy and 830 cycles of the alternating therapy were administered, with a median numbers of 6 and 7 cycles per patient, respectively. Topotecan was administered in 85 patients on the sequential arm and 132 patients on the alternating arm. Dose reductions for toxicity were similar in both arms. Grade 3/4 toxicities in the sequential and alternating arms, respectively, included neutropenia (51% and 52%; P=NS), anemia (12% and 11%; P=NS), febrile neutropenia (7% and 9%; P=NS), thrombocytopenia (19% and 20%; P=NS), and asthenia (8% and 2%; P=0.02). There were 4 toxicity-related deaths in the sequential arm versus 3 in the alternating arm.

CONCLUSION

Our preliminary conclusion is that the sequential and alternating regimens resulted in comparable activity and tolerability in previously untreated patients with extensive-stage SCLC.

Hematologic Safety and Tolerability of Topotecan in Recurrent Ovarian Cancer and Small Cell Lung Cancer: An Integrated Analysis

The purpose was to conduct an integrated analysis of the cumulative hematologic toxicity of topotecan in patients with relapsed ovarian cancer and small cell lung cancer (SCLC). Data were pooled from eight phase II and phase III clinical studies performed in patients with relapsed stage III/IV ovarian cancer or extensive SCLC treated with topotecan at a dose of 1.5 mg/m(2) per day on days 1-5 of a 21-day course. Quantitative hematologic toxicities were assessed using the National Cancer Institute Common Toxicity Criteria. A total of 4,124 courses of therapy was administered to the 879 patients in the pooled population. Grade 4 neutropenia was experienced by 78% of patients. The lowest nadirs for neutrophils and platelets generally occurred after the first course of therapy, followed by improvement or stabilization in subsequent courses. Neutropenia was noncumulative. During the first course, significant risk factors were identified: renal impairment and advanced age (grade 3/4 thrombocytopenia and grade 4 neutropenia) and prior radiotherapy; performance status score > or =2; SCLC; and exposure to both cisplatin (Platinol; Bristol-Myers Squibb, Princeton, NJ, http://www.bms.com) and carboplatin (Paraplatin; Bristol-Myers Squibb) (grade 3/4 thrombocytopenia only). The most frequent interventions for hematologic toxicities were RBC transfusions, treatment delays, G-CSF support, and dose reductions. Analysis of neutrophil and platelet nadirs and dosing for each course of therapy showed no apparent evidence of cumulative neutropenia or thrombocytopenia. The risk of grade 3 or 4 anemia was higher during the first four courses of therapy and may need to be more aggressively managed with erythropoietin therapy.

A randomised phase II study of the efficacy and safety of intravenous topotecan in combination with either cisplatin or etoposide in patients with untreated extensive disease small-cell lung cancer

PURPOSE

Topotecan (Hycamtin is active in small-cell lung cancer (SCLC). This phase II study investigated the efficacy and safety of topotecan in combination with either cisplatin or etoposide in untreated extensive disease SCLC (ED SCLC).

PATIENTS AND METHODS

Patients with untreated ED SCLC were randomised to treatment with T/C (topotecan 1.25mg/(m(2)day) IV days 1-5, cisplatin 50mg/m(2) IV day 5; 41 patients) or T/E (topotecan 0.75 mg/(m(2)day) IV days 1-- 5, etoposide 60 mg/(m(2)day) IV days 1-5; 41 patients) every 21 days. Response was evaluated by strict radiological criteria.

RESULTS

Response rates were similar for T/C (63.4%, 95% CI: 48.7-78.2%) and T/E (61.0%, 95% CI: 46-76%) with one patient in each arm who underwent complete response. Median survival was 41.6 weeks (9.6 months) for the T/C group and 43.7 weeks (10.1 months) for the T/E group. Toxicity was primarily haematological in both groups. The proportion of patients with grades 3-4 anaemia was significantly higher in the T/C arm (46.4%) versus 20% with the T/E arm (p=0.018). The proportion of patients with grade 4 neutropenia was not significantly lower with T/C (56.1%) than with T/E (65.0%, p=0.41), as was the incidence of associated events such as sepsis (T/C: 0%; T/E: 9.8%, p=0.11). The overall deliverability of either regimen was similar. The most frequent non-haematological adverse experiences of all grades per patient were nausea (T/C: 43.9%; T/E: 36.6%), and alopecia (T/C: 39.0%; T/E: 56.1%). Topotecan did not appear to increase the frequency of adverse events specifically associated with cisplatin.

CONCLUSION

This study showed T/C and T/E to be effective and well tolerated in patients with ED SCLC and further evaluation of topotecan in first line SCLC is warranted.

Combination of topotecan and cisplatin in relapsed patients with small cell lung cancer: a phase II study of the hellenic cooperative oncology group (HeCOG)

PURPOSE

To assess the safety and efficacy of a 3-day schedule of cisplatin and topotecan in patients with recurrent small-cell lung cancer (SCLC).

METHODS

Thirty-four relapsed patients were treated with cisplatin 20 mg/m2 and topotecan 0.9 mg/m2, both given on days 1-3 every 3 weeks, in a phase II study.

RESULTS

Complete response (CR) was achieved in two patients (6%), partial response (PR) in 4 (12%), stable disease in 6 (18%) and progressive disease in 14 (41%). Eight patients (23%) were non-evaluable for response. Among 21 sensitive patients, 2 (9.5%) achieved CR and 3 (14%) PR. Among 13 refractory patients, none achieved CR and only 1 (8%) PR. Median survival was 6.5 months for all patients, 7.8 for sensitive and 6.2 for refractory. Median time to progression (TTP) was 4.4 months for all patients, 5.9 for sensitive and 3.2 for refractory. Grade 3-4 toxicities included anemia (15%), thrombocytopenia (15%), neutropenia (42%), nausea/vomiting (3%), and alopecia (6%). No toxic death occurred.

CONCLUSIONS

This 3-day schedule was well tolerated, produced modest response rates but good survival and TTP both in sensitive and refractory patients with relapsed SCLC.

Topotecan in the treatment of recurrent small cell lung cancer: an update

Small cell lung cancer (SCLC) is an aggressive malignancy with a high propensity for early regional and distant metastasis. Response rates to first-line chemotherapy are typically high, but short lived. The outlook for patients with recurrent SCLC is poor. A variety of single- and multi-agent chemotherapy regimens have met with limited success in patients with recurrent SCLC, and survival is generally measured in weeks. Until recently, further chemotherapy was not widely considered appropriate for patients with relapsed SCLC. The choice of chemotherapy at relapse is dependent on many factors, including type of and response to first-line therapy, the treatment-free interval, and the patient's performance status. Intravenous topotecan (Hycamtin; GlaxoSmithKline; Philadelphia, PA) has provided oncologists and patients in many countries with an effective and tolerable therapeutic option for recurrent SCLC. The clinical profile of topotecan was established in several phase II studies and confirmed in a randomized, phase III trial versus cyclophosphamide, doxorubicin (Adriamycin; Bedford Laboratories; Bedford, OH), and vincristine (Oncovin; Eli Lilly and Company; Indianapolis, IN)--CAV. In those studies, topotecan exhibited antitumor activity in both chemosensitive and refractory disease. Further, topotecan therapy is associated with significant symptom palliation in this patient population. Because the toxicity profile of topotecan is predictable, generally manageable, and noncumulative, the agent also has potential utility in patients with a poor prognosis and/or a poor performance status. Alternative dosing regimens (lower dose, weekly) and the introduction of an oral formulation may expand the use of topotecan as a single agent and in combination therapy in the second- and first-line treatment of this disease.

Update on the role of topotecan in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is an aggressive disease that is generally resistant to chemotherapy. As a result, the prognosis for patients with NSCLC is poor. Currently, platinum-based regimens are the standard of care for patients with advanced NSCLC. However, these regimens are associated with severe and often cumulative hematologic and nonhematologic toxicities, limiting dose intensity. Therefore, novel chemotherapeutic agents and combination regimens may improve the outcome for these patients. A variety of new agents and combinations have been investigated in the treatment of NSCLC. However, to date, no clearly superior single-agent or combination regimen has emerged. Topotecan (Hycamtin; GlaxoSmithKline; Philadelphia, PA), a topoisomerase I inhibitor, is currently approved for the treatment of patients with relapsed small cell lung cancer (SCLC) and is associated with manageable, noncumulative, hematologic toxicities. In addition, topotecan demonstrates a favorable nonhematologic tolerability profile compared with agents currently used in the treatment of patients with NSCLC. The success of topotecan in patients with SCLC has made it an attractive option in the NSCLC setting. Topotecan-based combination regimens in the first-line treatment of NSCLC have demonstrated promising antitumor activities with favorable toxicity profiles. Many topotecan combination regimens have induced stable disease, a response that may offer meaningful clinical benefit in the palliative treatment of patients with advanced disease. Topotecan plus gemcitabine (Gemzar; Eli Lilly and Company; Indianapolis, IN) and single-agent topotecan may be particularly appropriate for patients in the second-line setting, in which palliation of symptoms is an important outcome of chemotherapy. Herein, the future role of topotecan in the first- and second-line treatment of NSCLC and the potential role of resistance mechanisms obtained from in vivo dose-response studies in designing future combination regimens are discussed.

Topotecan in the first-line treatment of small cell lung cancer

Small cell lung cancer (SCLC) is generally sensitive to first-line chemotherapy, but limited disease often recurs and extensive disease is rarely curable. The most common first-line therapy regimen is cisplatin (Platinol; Bristol-Myers Squibb; Princeton, NJ) plus etoposide (Etopophos; Bristol-Myers Squibb)--PE, which is associated with overall response rates >80% in patients with limited SCLC. Although it is associated with median survival times of approximately 18-20 months for limited disease, PE yields median survival times of only approximately 8-12 months in patients with extensive disease, and symptom palliation becomes the primary therapeutic goal. The toxicities of PE may undermine quality of life and leave patients more susceptible to adverse events during subsequent therapies. Topotecan (HYCAMTIN; GlaxoSmithKline; Philadelphia, PA), an established treatment for recurrent SCLC, is being investigated in the first-line setting because of its novel mechanism of action; predictable, noncumulative, and manageable toxicities; and potential synergy with other active agents. Several recent phase II trials have generated promising results for topotecan-based combination regimens, including topotecan/paclitaxel (TAXOL; Bristol-Myers Squibb) (overall response rates 45%-100%), topotecan/etoposide (overall response, 95%), and topotecan, paclitaxel, and platinum agent triplets (overall response rates 51%-93%). The most frequent serious toxicity associated with these regimens was reversible and noncumulative neutropenia, which was generally manageable with supportive care. Additional clinical trials to investigate topotecan-based combination regimens and confirm their role in the first-line treatment of SCLC are under way.

Quality‐of‐Life Considerations in Patients with Advanced Lung Cancer: Effect of Topotecan on Symptom Palliation and Quality of Life

Key goals in the treatment of lung cancer are to improve both survival and quality of life (QOL). While formal techniques are frequently used to evaluate survival and response, such rigor is used less often in assessing the impact of treatment on quality of life. Many patients with lung cancer are elderly and have complex medical histories and a myriad of comorbidities. In these patients, with limited survival expectations, symptom palliation, quality of life, and convenience of therapy are especially important end points. Indeed, clinical trials are now incorporating symptom scores and QOL outcomes in their designs (now combined as "patient reported outcomes" or PROs). Moreover, symptom palliation correlates well with QOL and survival duration, providing further rationale for therapy selection based on these parameters. The potential palliative and QOL benefits of chemotherapy have been investigated for several agents in lung cancer trials. Of these, topotecan (Hycamtin; GlaxoSmithKline; Philadelphia, PA) is the best characterized in relapsed small cell lung cancer (SCLC). In a phase III trial of topotecan versus cyclophosphamide, doxorubicin (Adriamycin; Bedford Laboratories; Bedford, OH), and vincristine (Oncovin; Eli Lilly and Company; Indianapolis, IN) (CAV) in patients with recurrent SCLC, topotecan was associated with statistically significant (p < 0.05) improvements in general symptoms (e.g., fatigue and interference with daily activity) and disease-specific symptoms (e.g., dyspnea and hoarseness). Moreover, the introduction of oral therapies, such as oral topotecan, may increase the convenience of therapy by reducing the time needed for therapy and the need for frequent venipuncture. This review summarizes the role of chemotherapy in symptom palliation, with an emphasis on the impact of topotecan therapy on symptom parameters in patients with relapsed SCLC and the emerging role of oral therapy in this setting.

Emerging Role of Weekly Topotecan in Recurrent Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an aggressive tumor that often metastasizes before the primary cancer is diagnosed. Patients with SCLC are typically elderly and often have comorbidities that may predispose them to adverse events during therapy. Although topotecan (Hycamtin; GlaxoSmithKline; Philadelphia, PA), 1.5 mg/m(2)/day via a 30-minute i.v. infusion on days 1-5 of a 21-day cycle, is a standard therapy for relapsed SCLC, this regimen can result in significant neutropenia, especially in previously treated patients. This hematologic toxicity is noncumulative and reversible, but its management can be challenging in this poor-prognosis population. Therefore, alternate treatment regimens have been investigated. Weekly topotecan (4.0 mg/m(2)) is currently investigational and has shown promising activity and favorable tolerability in patients with relapsed ovarian cancer, another aggressive malignancy with a poor prognosis. Preliminary results from a phase II trial of weekly bolus topotecan (4.0 mg/m(2)) in patients with recurrent SCLC were recently reported, and this regimen was generally well tolerated. Furthermore, weekly topotecan has been successfully included in several combination therapy regimens in patients with a variety of solid tumors. In untreated SCLC patients, a combination regimen of weekly topotecan, paclitaxel (Taxol; Bristol-Myers Squibb; Princeton, NJ), and cisplatin (Platinol; Bristol-Myers Squibb) was explored and found to be well tolerated and active in patients with extensive and limited-stage disease. Further clinical trials of weekly topotecan and regimens that include weekly topotecan in the SCLC setting are warranted.

The role of topotecan in the treatment of brain metastases

Despite advances in the treatment of systemic malignancies, the prognosis for patients with brain metastases continues to be dismal. Because the majority of cytotoxic agents seem to be unable to penetrate the blood-brain barrier, the role of chemotherapy in the treatment of brain metastases remains controversial. However, growing amounts of both laboratory and clinical data suggest that a few of the newly developed cytotoxic agents can cross the blood-brain barrier and may have a role in the treatment of patients with brain metastases. Topotecan, a novel topoisomerase I inhibitor, freely crosses the blood-brain barrier and may be clinically effective in both the therapeutic and prophylactic settings in patients with brain metastases. Recent studies have demonstrated the antitumor activity of topotecan against brain metastases, with objective response rates ranging from 33%-63% in patients with various solid tumors. The antitumor response in the central nervous system was often greater and occurred more quickly than the systemic antitumor response to topotecan treatment. This result may be explained by the lack of exposure of brain metastases to previous cytotoxic agents, suggesting a role for topotecan in patients with brain metastases. Early studies have also suggested that topotecan, an apparent radiosensitizer, may be particularly effective in combination with radiotherapy, the current standard of care for patients with brain metastases. In addition, preliminary data suggest that topotecan in combination with temozolomide (another cytotoxic agent that can cross the blood-brain barrier) may have synergistic antitumor activity against brain metastases. This review summarizes the available preclinical and clinical evidence for the role of topotecan in the treatment of brain metastases and concludes with three case studies.

Topotecan in the Treatment of Relapsed Small Cell Lung Cancer Patients with Poor Performance Status

Topotecan is the only single-agent therapy approved by the U.S. Food and Drug Administration for the treatment of patients with recurrent small cell lung cancer (SCLC). Poor performance status (PS) at the time of relapse can hinder the ability of a patient to tolerate second-line chemotherapy. To investigate the feasibility of topotecan in the treatment of relapsed SCLC patients with PS 2 scores, we retrospectively analyzed data from five clinical trials that included 479 patients who were treated with single-agent topotecan at a dose of 1.5 mg/m2/day on days 1-5 of a 21-day course. Of these patients, 381 had a PS 0 or 1 and 98 had a PS 2. Topotecan was well tolerated by both patient groups. Hematologic toxicities were generally manageable, and neutropenia was noncumulative. With the exception of grade 3/4 anemia, the incidences of severe hematologic toxicities were not statistically different between the two groups. The nonhematologic toxicity profiles were also similar in the two patient groups. Treatment provided similar benefits, including antitumor response rates and symptom palliation, in PS 0/1 and PS 2 patients. As expected, the median overall survival time was shorter in patients with worse PS scores; the median overall survival times were 36.3 weeks, 25.4 weeks, and 16 weeks for PS 0, PS 1, and PS 2 patients, respectively. In conclusion, treatment with topotecan is feasible and well tolerated in patients with relapsed SCLC with suboptimal PS scores.

Ex vivo analysis of topotecan: advancing the application of laboratory-based clinical therapeutics

Topotecan is currently approved for relapsed small-cell lung cancer and ovarian cancer. Topotecan's efficacy in the second-line setting and novel mechanism of action suggest broad antitumour activity. We utilised a clinically validated, cell-death, ex vivo assay in human tumour explants to examine the activity profile of topotecan alone and in combination with other antitumour agents. Serial dilutions of topotecan alone and in combination with other cytotoxic agents were applied to biopsy specimens of non-small-cell lung cancer (NSCLC) and breast, colon, and prostate cancers. Dose-response curves were interpolated to provide 50% lethal concentrations (LC(50)). The degree of synergy (by median effect) and normalised Z-scores (raw scores converted to relative activity distributed around the mean) were then computed. Single-agent activity was observed for topotecan in all four tumour types. In 57 chemotherapy-naive specimens, NSCLC revealed the highest activity, demonstrated by the lowest LC(50) value (0.26+/-0.06 microg ml(-1); P=0.002). Overall, previously treated and chemotherapy-naive specimens revealed no significant differences in mean LC(50)'s. Synergy was observed for several combinations, including topotecan plus cisplatin in prostate and for topotecan plus 5-fluorouracil in breast cancers. The Z-score analyses conducted suggest activity for previously unexplored drug regimens, including topotecan plus 5-fluorouracil, vinorelbine, and mitomycin-C in NSCLC and breast cancer. Phase II studies are underway to determine the degree to which these ex vivo findings will translate into improved clinical results.

The role of topotecan in treating small cell lung cancer: second-line treatment

Small-cell lung cancer (SCLC) is highly chemosensitive but up to 70% of patients with limited disease and more than 90% of patients with extensive disease will relapse after first-line treatment. There are several standard chemotherapy regimens used for second-line treatment yet the prognosis for patients requiring this treatment remains poor. The topoisomerase-I inhibitor, topotecan, has achieved response rates of up to 22% in previously treated patients with SCLC and survival almost double that achieved with other single agents. Compared with cyclophosphamide/doxorubicin/vincristine (CAV), single-agent topotecan achieved a higher response rate, longer survival and statistically significant improvements in dyspnea, hoarseness, fatigue, anorexia and interference with daily activities. Brain metastases are common in SCLC. Topotecan crosses the blood-brain barrier and shows promise for the management of brain metastases.

Single-agent chemotherapy for non-small cell lung cancer

The survival and quality of life benefits of combination chemotherapy in patients with non-small cell lung cancer (NSCLC) are now well recognized. Since many clinical trials have been conducted in relatively young patients with good performance status, many elderly patients and patients with poor performance status are not offered chemotherapy because of concerns about higher risks of toxicity. The newer agents, including topotecan, are active as single agents in NSCLC, achieving response rates of up to 30%. Overall survival and symptoms may be improved when these agents are added to best supportive care. They are well tolerated in both elderly patients and patients with poor performance status. The major toxicity with the standard 5-day administration schedule of topotecan is myelosuppression, but weekly schedules may offer reduced toxicity while maintaining efficacy. Thus, single-agent therapy with newer agents is generally considered in elderly and poor performance status patients. However, combination chemotherapy may also be appropriate for some patients in these subgroups. Future studies of chemotherapy in NSCLC should not exclude elderly patients and patients with poor performance status.

Treatment of relapsed small-cell lung cancer--a focus on the evolving role of topotecan

Despite the high response rates to chemotherapy, small-cell lung cancer (SCLC) is among the most lethal malignancies. Long-term survival is anecdotal for patients with extensive disease; 5-years survival is < or =5% for those with limited disease. All patients with extensive disease and most patients with limited disease will experience disease progression and become candidates for second-line therapy. Although a number of agents have demonstrated antitumor activity in relapsed SCLC, including paclitaxel, docetaxel, etoposide, cisplatin, and carboplatin, topotecan is the only single agent currently approved in the United States for the treatment of recurrent disease. Topotecan is a novel topoisomerase I inhibitor with established antitumor activity in recurrent SCLC and has a predictable, noncumulative toxicity profile. Furthermore, topotecan has been shown to provide symptom improvement in this predominantly palliative setting. Evidence also suggests that topotecan readily penetrates the blood-brain barrier and might be active in the relatively large subset of SCLC patients who experience brain metastases. This article reviews the clinical utility of topotecan in recurrent SCLC, including its efficacy, tolerability, and quality-of-life effect, when used as monotherapy and in novel combination regimens.

Phase I study of paclitaxel and topotecan for the first-line treatment of extensive-stage small cell lung cancer

Extensive-stage small cell lung cancer (SCLC) is an aggressive disease with a median survival of approximately 8 months. Although current combination chemotherapy regimens provide high initial tumor response rates, they have not translated into large gains in survival. Topotecan and paclitaxel have nonoverlapping mechanisms of action and are active agents in SCLC. Additionally, these two agents demonstrate in vitro synergy in animal and human tumor models. We investigated the maximum tolerated dose of 3-day topotecan in combination with paclitaxel in previously untreated patients with extensive SCLC. Seventeen patients were enrolled in an open-label, phase I, dose-escalation study and were treated with intravenous paclitaxel 135-175 mg/m(2) over 1 hour on day 1, followed by intravenous topotecan 1.25-1.5 mg/m(2) over 30 minutes on days 1-3 of a 21-day course. Sixty-nine courses of therapy were administered with no delays due to hematologic toxicity. Prophylactic hematologic support was required for 24% of patients. The topotecan/paclitaxel combination was well tolerated, with 24%, 12%, and 6% of patients experiencing grade 3/4 neutropenia, anemia, or thrombocytopenia, respectively. Dose-limiting neutropenia was seen in three of five patients treated with topotecan 1.5 mg/m(2) and paclitaxel 175 mg/m(2). Therefore, topotecan 1.5 mg/m(2) with paclitaxel 135 mg/m(2) was determined to be the maximum tolerated dose. Of the 17 evaluable patients, 53% achieved a partial response and 18% achieved stable disease. In summary, we have identified a regimen of topotecan 1.5 mg/m(2) and paclitaxel 135 mg/m(2) that was well tolerated and active in this patient group. Additional studies of topotecan and paclitaxel at these dose levels are needed to fully elucidate the efficacy of this combination in extensive SCLC.

Emerging Role of Topotecan in First-Line Therapy of Small-Cell Lung Cancer

Topotecan, a novel topoisomerase I inhibitor, is an established treatment for patients with recurrent small-cell lung cancer (SCLC), with antitumor response rates of approximately 20% and median survival of approximately 32 weeks in patients with extensive-stage disease. Topotecan's comparable activity relative to other agents used in SCLC and its novel mechanism of action, noncumulative toxicity, and in vitro synergy with other active agents have provided the rationale for investigating topotecan in first-line therapy. Furthermore, topotecan penetrates the blood-brain barrier and is potentially useful for the relatively large subset of patients with SCLC and brain metastases. In early studies of topotecan in brain metastases, encouraging antitumor activity has been observed. In several feasibility and phase II studies of topotecan as single-agent therapy in patients with extensive- and limited-stage tumors and as part of novel first-line combination regimens, overall response rates have ranged from 42% to 100%. Complete responses of 3%-67% and partial responses of 33%-80% have been observed in first-line therapy. Furthermore, the median overall survival in patients receiving topotecan in first-line therapy has ranged from approximately 8 months (extensive-stage disease) to 20 months (limited-stage disease). The most frequent adverse events associated with topotecan-based regimens include grade 3/4 neutropenia and thrombocytopenia that often require the incorporation of growth factor support into the treatment regimen. Nonhematologic adverse events associated with topotecan-based combination regimens have been mild or primarily attributed to other agents in the combination. Alternative doses and schedules (3 consecutive days and weekly) are being explored because they appear to be associated with considerably less myelosuppression. Although several trials have established the feasibility and activity of topotecan in first-line therapy of patients with SCLC, randomized phase III studies with comparison to standard therapy will be required to confirm a potential role for this active agent and to determine the optimal dosing regimen.

A pilot trial of G3139, a bcl-2 antisense oligonucleotide, and paclitaxel in patients with chemorefractory small-cell lung cancer

BACKGROUND

Chemorefractory small-cell lung cancer (SCLC) is defined as disease that progresses during primary therapy or within 3 months of completion of primary therapy. Patients with chemorefractory SCLC have a very poor prognosis, and no treatment has been shown to be of significant clinical benefit. Elevated expression of Bcl-2 is found in the majority of SCLCs and has been associated with therapeutic resistance. Suppression of Bcl-2 levels through the use of G3139, an antisense oligonucleotide complementary to the mRNA encoding Bcl-2, might increase the antitumor efficacy of cytotoxic therapy.

PATIENTS AND METHODS

Twelve patients with chemorefractory SCLC participated in this pilot trial of paclitaxel combined with G3139. G3139 was given by continuous i.v. infusion over 7 days at a fixed dose of 3 mg/kg/day. Paclitaxel dose was initially 175 mg/m2 on day 6, but was decreased to 150 mg/m2 due to myelosuppression observed in two of the three patients treated in the first dose cohort.

RESULTS

The combination of paclitaxel at 150 mg/m2 and G3139 at 3 mg/kg/day was found to be feasible and well tolerated. No objective responses were observed, but two patients had stable disease, one remaining stable on therapy for >30 weeks. Plasma G3139 levels were determined, and were found to be highest in the patient with prolonged stable disease, suggesting that individual variation in metabolism and clearance of the antisense oligonucleotide may influence activity.

CONCLUSIONS

This study demonstrates that G3139 can be combined with paclitaxel in a cytotoxic dose range, and suggests that a similar combination be tested for activity in the context of chemoresponsive disease.

Treatment of extensive stage small cell lung cancer

Over the past twenty years combination chemotherapy has continued to produce small survival gains for patients with SCLC. We enter the next century enthusiastic about the array of new chemotherapeutic agents to evaluate and fascinated by the biological agents with the hope of achieving dramatic improvements in survival for our patients with SCLC.

Phase ii comparator study of oral versus intravenous topotecan in patients with chemosensitive small-cell lung cancer

PURPOSE

Topotecan, administered intravenously, is active in small-cell lung cancer (SCLC). In this study, the comparability of oral topotecan to IV topotecan was investigated.

PATIENTS AND METHODS

Patients with SCLC that had relapsed 90 days or more after cessation of initial chemotherapy were randomized to receive either oral topotecan (Hycamtin) 2.3 mg/m(2)/d x 5 (52 patients) or IV topotecan 1.5 mg/m(2)/d x 5 (54 patients), every 21 days.

RESULTS

Response rates in this phase II randomized study were 23% (12/52) in the oral topotecan arm and 15% (8/54) in the IV topotecan arm. All radiological responses were confirmed by an independent radiologist. Median survival was 32 weeks (oral) and 25 weeks (IV). Good symptom control, defined as sustained improvement or no deterioration, was evident in both treatment groups. Topotecan was generally well tolerated, with myelosuppression being the major toxicity. Grade 4 neutropenia occurred in 35.3% of patients on oral topotecan and in 67.3% of patients on IV topotecan, which was statistically significant (P =.001). Fever/infection more than or equal to grade 2 associated with grade 4 neutropenia, together with sepsis, occurred in only 5.1% of courses (oral) and 3.3% of courses (IV). Non-hematological toxicity consisted mainly of vomiting (oral: 36.5% of patients; IV: 31.5% of patients) and nausea (oral: 26.9% of patients; IV: 40.7% of patients).

CONCLUSION

This study found oral topotecan to be similar in efficacy to IV topotecan in the treatment of patients with relapsed SCLC, sensitive to first-line chemotherapy, with less grade 4 neutropenia and greater convenience of administration.

New chemotherapy agents for small cell lung cancer

BACKGROUND

Approximately 45,000 new cases of small cell lung cancer (SCLC) will be diagnosed in the United States this year. Combination chemotherapy is the cornerstone of treatment for all stages of this disease and results in high response rates (65 to 85%), leading to a meaningful survival advantage for these patients. Patients with limited-stage disease enjoy a median survival of 10 to 15 months with chemotherapy, as compared to 3 months without drug therapy. With addition of chest radiotherapy, survival is further prolonged to 12 to 20 months. Patients with extensive-stage disease experience an average survival of 1.5 months without chemotherapy and 7 to 11 months with chemotherapy. However, no further improvement in survival has been demonstrated since combination chemotherapy regimens were introduced in the late 1970s and early 1980s, despite evaluating numerous strategies; the 5-year survival for all patients remains dismal at 5%. Clearly, new chemotherapy agents with novel mechanisms of action are needed.

FOCUS

This article will review the experience to date with six new agents that are active against SCLC. It includes two taxanes (paclitaxel and docetaxel), vinorelbine, two camptothecin derivatives (topotecan and irinotecan), and gemcitabine. Single-agent activity as well as combination regimens with other agents and radiotherapy will be discussed. The role of maintenance therapy with oral matrix metalloproteinase inhibitors also is evaluated.

Topotecan versus cyclophosphamide, doxorubicin, and vincristine for the treatment of recurrent small-cell lung cancer

PURPOSE

Topotecan and cyclophosphamide, doxorubicin, and vincristine (CAV) were evaluated in a randomized, multicenter study of patients with small-cell lung cancer (SCLC) who had relapsed at least 60 days after completion of first-line therapy.

PATIENTS AND METHODS

Patients received either topotecan (1.5 mg/m2) as a 30-minute infusion daily for 5 days every 21 days (n = 107) or CAV (cyclophosphamide 1,000 mg/m2, doxorubicin 45 mg/m2, and vincristine 2 mg) infused on day 1 every 21 days (n = 104). Eligibility included the following: bidimensionally measurable disease, Eastern Cooperative Oncology Group performance status of less than or equal to 2, and adequate marrow, liver, and renal function. Response was confirmed by blinded independent radiologic review.

RESULTS

Response rate was 26 of 107 patients (24.3%) treated with topotecan and 19 of 104 patients (18.3%) treated with CAV (P = .285). Median times to progression were 13.3 weeks (topotecan) and 12.3 weeks (CAV) (P = .552). Median survival was 25.0 weeks for topotecan and 24.7 weeks for CAV (P = .795). The proportion of patients who experienced symptom improvement was greater in the topotecan group than in the CAV group for four of eight symptoms evaluated, including dyspnea, anorexia, hoarseness, and fatigue, as well as interference with daily activity (P< or =.043). Grade 4 neutropenia occurred in 37.8% of topotecan courses versus 51.4% of CAV courses (P<.001). Grade 4 thrombocytopenia and grade 3/4 anemia occurred more frequently with topotecan, occurring in 9.8% and 17.7% of topotecan courses versus 1.4% and 7.2% of CAV courses, respectively (P<.001 for both). Nonhematologic toxicities were generally grade 1 to 2 for both regimens.

CONCLUSION

Topotecan was at least as effective as CAV in the treatment of patients with recurrent SCLC and resulted in improved control of several symptoms.