Topotecan (Hycamtin™) in small cell lung cancer (SCLC) after failure of first line therapy: Multicentre phase II study

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.

Second-line treatment of small-cell lung cancer

Approximately 45,000 new cases of small-cell lung cancer were diagnosed in 2005 in the United States. Although response to first-time therapy is up to 90%, the majority of patients will ultimately relapse. Therefore, active second-line therapy is needed for this patient population. The only second-line treatment for small-cell lung cancer approved by the US Food and Drug Administration is topotecan. Other agents have been investigated and have shown modest efficacy. These include vinorelbine, irinotecan, etoposide, paclitaxel, and gemcitabine. Novel "targeted therapies" have shown disappointing results in this disease. Much of the recent work has focused on investigating alternative dosing and scheduling of topotecan. Combination therapies have also been investigated, and some have been shown to increase activity over single agents, but toxicity and quality of life variables are imperative in the treatment of this patient population.

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.

Topotecan and etoposide as first-line therapy for extensive disease small cell lung cancer: a phase II trial of a platinum-free regimen

In the treatment of extensive disease of small cell lung cancer (ED SCLC) there is an urgent need for more effective and better-tolerated drug regimens. We report on a prospective phase II trial performed to evaluate the efficacy and safety of a platinum-free regimen--containing topotecan and etoposide--in the first-line treatment of ED SCLC. Between December 1999 and July 2001, 28 chemotherapy-naive patients with ED SCLC were recruited; 9 patients had stage IIIB disease and 19 patients had stage IV disease. Based on phase I results, patients received treatment with intravenous topotecan 1 mg/m2 (days 1-5) followed by intravenous etoposide 75 mg/m2 (days 8-10). Treatment courses were repeated every 28 days for a maximum of 6 cycles. A confirmed response rate of 46.4% with 1 complete response (CR) and 12 partial responses (PR) (95% CI=27.5-66.1%) was observed. Stable disease (SD) was observed in 18% of patients. The median time to response was 7.9 weeks (range: 7.7-15.1 weeks) and median survival was 29.9 weeks (range from 3.3 to 91.4 weeks). Main toxicities encountered were haematological with Grade III/IV neutropenia in 2.6/1.5% of courses and Grade III/IV thrombocytopenia in 1.8%/0.7% of courses. These toxicities were manageable and were not associated with clinical sequels. Non-haematological toxicities were generally mild with no Grade III/IV toxicities reported apart from Grade III alopecia. The combination therapy of topotecan and etoposide is active in first-line chemotherapy for patients with ED SCLC. The regimen showed a tolerable safety profile. Since drug scheduling plays a critical role in the combination of topoisomerase I and II inhibitors, concurrent administration of topotecan and etoposide might increase the efficacy.

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.

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.

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.

Response to topotecan of symptomatic brain metastases of small-cell lung cancer also after whole-brain irradiation. a multicentre phase II study

The purpose of this multicentre phase II study was to evaluate the efficacy and toxicity of topotecan in pretreated patients with small-cell lung cancer (SCLC) who relapsed with symptomatic brain metastases. 30 patients with a median age of 62 years were entered into the study. 22 patients received the initially planned dose of 1.5 mg/m(2) topotecan as a 30-min intravenous (i.v.) infusion for 5 consecutive days every 3 weeks. Due to the observed thrombocytopenia, the dose was reduced to 1.25 mg/m(2) in the last 8 patients. All 30 patients were pretreated with chemotherapy: 14 with one and 16 with at least two protocols. 8 patients had prior whole-brain iradiation (WBI): 7 in the prophylactic and 1 in the palliative setting. Concomitant systemic metastases were recorded in 24 patients at the time of brain relapse. Cerebral metastases responded in 33% of patients (10/30; three complete responses (CR) and seven partial responses (PR)). Noteworthy is the fact that response was achieved in 4 of 8 patients pretreated by WBI (3 in prophylactic and 1 in palliative setting). The systemic response rate was 29% (7/24). Median time to progression was 3.1 months (range 0.25-14.2+ months), median survival from the beginning of this study was 3.6 months (range 0.25-14.2+ months). Therapy was generally well tolerated, with myelotoxicity being the most common adverse event. Grade 3 leucocytopenia according to the Common Toxicity Criteria (CTC) occurred in 28% (23/83) of the courses and grade 4 in 22% (18/83). Grade 3 thrombocytopenia was observed in 17% of the courses (14/83) and grade 4 in 11% (9/83). 17% of patients (5/30) had a documented grade 3 infection. These results using topotecan are promising in heavily pretreated patients with SCLC brain metastases and merit further evaluation.

The role of systemic chemotherapy in the treatment of brain metastases from small-cell lung cancer

Brain is the most common site of metastatic spread in small-cell lung cancer (SCLC). Approximately 10% of SCLC patients have brain metastases (BM) already at diagnosis and an additional 40% will develop central nervous system (CNS) involvement during their disease course. Although whole brain radiotherapy and corticosteroids is considered the treatment of choice, accumulating evidence suggests that systemic chemotherapy may also play an important role. The concept of the brain as a pharmacologic sanctuary site for established metastases is in contrast with recent clinical observations of frequent BM responses with systemic chemotherapy. During the last decade, several reports about the effect of systemic chemotherapy on BM from SCLC have been published. Pooled data from five studies report 66% response rate (RR) in 64 patients with initial BM. In addition, an average RR of 36% is derived from five studies including 135 patients with delayed BM treated with systemic single agent chemotherapy. Among new drugs with activity in patients with SCLC brain metastases, camptothecin analog topotecan is one of the most promising with a 52% RR. Although whole brain radiation remains the standard treatment of established BM in SCLC there is an emerging role for systemic chemotherapy, particularly with the use of new active drugs as part of combined modality treatments.