A phase I study to characterize the safety, tolerability, and pharmacokinetics of topotecan at 4 mg/m2 administered weekly as a 30-minute intravenous infusion in patients with cancer

Adverse Effects and Safety of Etirinotecan Pegol, a Novel Topoisomerase Inhibitor, in Cancer Treatment: A Systematic Review

Background:

Due to the increasing prevalence of cancer and the inadequacy of current therapies, the development of novel antitumor pharmaceutics with higher efficacies and lower adverse effects is considered a fundamental tenet of contemporary cancer management. Poly-Ethylene-Glycol (PEG) attachment is a novel pharmaceutical technology to improve the efficacy and safety of chemotherapies. Etirinotecan Pegol (EP), also known as NKTR-102, is the PEGylated form of Irinotecan (CPT-11), which causes cancer cell apoptosis by inhibiting the topoisomerase I enzyme.

Objectives:

The present study reviews and evaluates various reports of the EP’s anti-tumor activity in various cancers.

Data Sources:

Studies were identified using the Scopus database, with no exclusions. The search terms included Etirinotecan Pegol and NKTR-102, which yielded 125 articles (66 and 59 articles, respectively). In addition, the clinicaltrials.gov website was used to find ongoing studies, which resulted in the addition of two studies.

Study Eligibility Criteria:

Subsequently, we excluded studies that were published in languages other than English, duplicate articles, and studies with no data.

Results:

This systematic review clarifies that EP possesses numerous advantages over many other medications, such as safety, efficacy, increased half-life, increased health-related quality of life, increased overall survival, increased progression-free survival, and decreasing the adverse events in the treatment of various cancers.

Conclusion:

Therefore, Etirinotecan Pegol may represent a major contribution to the treatment of various cancers in the future.

Oral topotecan: Bioavailability, pharmacokinetics and impact of ABCG2 genotyping in Chinese patients with advanced cancers

Oral topotecan (Hycamtin(®)) has been recently approved for the treatment of relapsed small cell lung cancer (SCLC) in 2007, however, the bioavailability and pharmacokinetic data of topotecan for Chinese patients is still limited. Xinze(®) is a new and the only capsule formulation of topotecan used in China that is similar to Hycamtin(®). The current study aimed to investigate the absolute bioavailability and pharmacokinetics of Xinze(®) in Chinese patients with advanced cancers. On day 1, an IV dose of 1.5 mg/m(2)/d as a 30 min continuous infusion was administered. Patients took the oral topotecan at one of two dose levels: 1.5 mg/m(2)/d (six patients) or 1.9 mg/m(2)/d (seven patients) on day 2. Plasma pharmacokinetics of total topotecan and topotecan in the lactone form were performed on both days using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Single-nucleotide polymorphisms (SNPs) identified in exon 5 (421C>A) and in exon 2 (34G>A) in ATP-binding cassette sub-family G member 2 (ABCG2) were analyzed by direct sequencing. Safety assessments were performed throughout the study. The maximum plasma concentration (Cmax) reached at 1-2 h and the elimination half-life time (T1/2) was approximately 4.2 h after oral administration. The absolute bioavailability of total topotecan in the 1.5 mg/m(2)/d and 1.9 mg/m(2)/d groups averaged 41.23 ± 11.8% and 36.00 ± 14.8%, respectively. The patients with heterozygous SNPs had essentially the same bioavailability and pharmacokinetics. The bioavailability of topotecan after oral administration illustrates good systemic exposure at dosages of 1.5 mg/m(2)/d and 1.9 mg/m(2)/d over a five-day schedule in Chinese patients. On a dose-normalized basis, the values of Cmax and AUC0-t for total topotecan in Chinese patients were higher than in Caucasians following oral and intravenous administration, while the T1/2 was consistent.

The chemotherapeutic agent topotecan differentially modulates the phenotype and function of dendritic cells

The camptothecin analogue topotecan (TPT) induces tumor cell apoptosis due to interference with topoisomerase I and is clinically used as a second-line chemotherapeutic in the treatment for metastasizing ovarian and small cell lung carcinoma. Based on the more recent finding of TPT-mediated inhibition of the transcription factor hypoxia-induced factor-1α, a hallmark of solid tumors, TPT, is currently tested in clinical trials for its suitability as a first-line chemotherapeutic for the treatment for various types of tumors. Due to the gained clinical interest in TPT and in light of its modulatory effect on signaling pathways, which are also of importance for immune cell functions, we asked for potential effects of TPT on dendritic cells (DCs), the main antigen-presenting cell population of the immune system. Here, we show that TPT at a therapeutically relevant dose partially activated monocyte-derived DCs as reflected by enhanced migratory activity, elevated expression of HLA-DR and costimulatory/maturation markers, and accordingly an increased allogenic CD4(+) T cell stimulation. In marked contrast, TPT prevented full maturation of DCs stimulated with a cocktail of proinflammatory mediators, accompanied by somewhat lower upregulation of NF-κB factors p65 and RelB.

A phase I clinical trial of weekly oral topotecan for relapsed small cell lung cancer

PURPOSE

To determine the dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD) of oral topotecan administered weekly in patients with relapsed small cell lung cancer (SCLC).

PATIENTS AND METHODS

Patients were treated with oral topotecan on days 1, 8, and 15, every 28 days. The dose was escalated by 0.5 mg/m² increments from the starting dose of 3 mg/m² until the MTD was reached. DLTs were defined as grade 4 neutropenia, febrile neutropenia, grade 4 thrombocytopenia, non-hematologic toxicity ≥grade 3, any toxicity precluding the treatment on days 8 or 15 of the first cycle, or delay of the second cycle for more than 7 days.

RESULTS

Eighteen patients were enrolled. Thirteen patients received oral topotecan as second-line and five as third- or further-line treatment. The DLT level was reached at 4.5 mg/m², and the MTD was determined to be 4 mg/m². DLTs consisted of grade 2/3 neutropenia and grade 2 thrombocytopenia precluding treatment on day 15 of the first cycle or on day 1 of the second cycle. The most frequent toxicities were grade 2-3 neutropenia (27.8 % of patients), grade 2-3 anemia (33.3 %), grade 2 thrombocytopenia (16.7 %), and grade 2-3 fatigue (44.4 %). The response rate was 11.1 %, the median progression-free survival 2.3 months, and the median overall survival 5.1 months.

CONCLUSION

The recommended phase II dose of weekly oral topotecan in pretreated patients with SCLC is 4 mg/m² on days 1, 8, and 15 every 28 days.

Toxicity of weekly oral topotecan in relation to dosage for gynecologic malignancies: a phase I study

The aim of this study was to determine the dose of weekly oral topotecan that allows safe administration and to evaluate the pharmacokinetics of this dose in patients with recurrent gynecologic malignancies. The first cohort of patients received oral topotecan 6 mg/week administered orally on days 1, 8, and 15 of a 28-day regimen. A standard 3+3 dose-escalating phase design was used for dose levels II-V (8, 10, 12 and 14 mg/week). Toxicity was scored according to the Common Terminology Criteria for Adverse Events. Cumulative toxicity was summarized in the 6-12 mg/week combined cohort and 14 mg/week cohort separately. Pharmacokinetic samples were obtained for day 1, cycle 1 only in the expansion cohort (dose level V). Twenty-five patients received a total of 88 cycles of therapy. Hematologic toxicities of grade 3 (6-12 mg dose) were neutropenia (25%) and anemia (8.3%). Gastrointestinal toxicities of grade 3 were diarrhea (16.7%) and obstruction (8.3%, disease-related). Grade 3 or 4 (14 mg/week) hematologic toxicities consisted of neutropenia (38.5%), platelets (15.4%), anemia (15.4%), infection with neutropenia (7.7%), and thrombosis (7.7%). Gastrointestinal toxicities of grade 3 were diarrhea (7.7%), obstruction (7.7%), and vomiting (7.7%). One patient died secondary to neutropenic sepsis. One patient (4%; 95% confidence interval: 2.1, 22.3) showed a partial response and five patients (20%; 95% confidence interval: 7.6, 41.3) had stable disease. An oral topotecan dose of 14 mg/week for 3 consecutive weeks out of 4 is mostly associated with acceptable toxicities and may be considered for use in future single-agent phase II trials.

Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress

SIGNIFICANCE

Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity.

RECENT ADVANCES

Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction.

CRITICAL ISSUES

These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress.

FUTURE DIRECTIONS

Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.

Phase I and pharmacologic study of weekly bolus topotecan for advanced non-small-cell lung cancer

PURPOSE

We conducted a phase I trial of the topoisomerase I inhibitor topotecan for the purpose of determining the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of topotecan when administered weekly to patients with advanced non-small-cell lung cancer.

PATIENTS AND METHODS

Twelve patients with stage IIIB or IV disease were treated with topotecan by 30-minute intravenous infusion on days 1, 8, and 15 every 4 weeks. The dose was escalated in 2-mg/m2 increments from the starting dose of 4 mg/m2 until the MTD was reached. After the MTD had been reached in previously treated patients, chemotherapy-naive patients were enrolled for treatment at that dose, and the dose was escalated to estimate the MTD in the treatment-naive group.

RESULTS

The MTD of topotecan was determined to be 6 mg/m2 in the previously treated group and 8 mg/m2 in the chemotherapy-naive group. All 3 previously treated patients experienced DLT at the 6-mg/m2 dose level. Although only 1 of the 3 previously treated patients experienced DLT (grade 4 neutropenia for > or = 3 days) at the 8-mg/m2 dose level, skipping the topotecan dose on day 15 because of neutropenia was reported in 2 patients. Anorexia and general fatigue were the common nonhematologic toxicities.

CONCLUSION

The recommended dose of topotecan for phase II studies in previously untreated patients is 6 mg/m2 on days 1, 8, and 15, every 28 days, and 4 mg/m2 appears to be a suitable dose for use in previously treated patients with this schedule.