First-cycle Dose-limiting Toxicities Research Articles

Phase 1b study of bavdegalutamide, an androgen receptor PROTACdegrader, combined with abiraterone in patients with metastatic prostate cancer.

TPS5106 Background: Bavdegalutamide (ARV-110) is a novel, oral PROteolysis TArgeting Chimera (PROTAC) protein degrader that targets wild-type androgen receptor (AR) and clinically relevant mutants. Bavdegalutamide demonstrated tumor growth inhibition in multiple xenograft models (eg, AR gene amplification, AR mutation, enzalutamide resistance, and enzalutamide insensitivity). In a phase 1/2 study (NCT03888612), bavdegalutamide showed clinical activity in patients with metastatic castration-resistant prostate cancer (mCRPC) who had previously received 1–2 prior novel hormonal agents (eg, abiraterone and/or enzalutamide), including heavily pretreated patients. Abiraterone is approved, in combination with a corticosteroid, to treat patients with mCRPC or with high-risk castration-sensitive prostate cancer (CSPC). Up to a third of patients treated with abiraterone develop primary resistance to this drug and nearly all patients experience disease progression. Here we describe a phase 1b study that will evaluate the combination of bavdegalutamide with abiraterone at the initiation of progression on abiraterone (prostate-specific antigen [PSA] progression without radiographic progression) to test if the addition of bavdegalutamide will overcome resistance to abiraterone and re-establish the AR pathway blockade in patients with prostate cancer. Methods: Eligible patients are men ≥18 years of age with histologically, pathologically, or cytologically confirmed adenocarcinoma of the prostate and Eastern Cooperative Oncology Group performance status of 0 or 1. Patients must be receiving ongoing treatment with stable doses of abiraterone and a concomitant corticosteroid for mCRPC or CSPC and have PSA progression ≥16 weeks after initiation of abiraterone, ≥2 rising PSA values measured ≥1 week apart, and no radiographic evidence of disease progression while receiving abiraterone. Ongoing androgen deprivation therapy with a gonadotropin-releasing hormone analogue or inhibitor or orchiectomy is required. Prior treatment with enzalutamide, apalutamide, darolutamide, or experimental AR-directed therapies is not permitted. Bavdegalutamide, abiraterone, and a corticosteroid will be administered daily in 28-day cycles. Primary objectives are to evaluate the safety and tolerability of bavdegalutamide plus abiraterone and determine the recommended phase 2 dose and schedule of this combination (based on the incidence of first-cycle dose-limiting toxicities and the frequency and severity of adverse events and laboratory abnormalities). Clinical trial information: NCT05177042.

Abstract P1-19-03: JAVELIN PARP Medley, a phase 1b/2 study of avelumab plus talazoparib: Results from advanced breast cancer cohorts

Abstract Background: Avelumab, a human IgG1 anti–PD-L1 monoclonal antibody, has shown antitumor activity and a manageable safety profile in several tumor types. Talazoparib, an orally available PARP inhibitor, is approved for the treatment of patients with deleterious or suspected deleterious germline BRCA1/2-mutated HER2− locally advanced (LA) or metastatic (M) breast cancer (BC). Preclinical data suggest that PARP inhibitors may have synergistic activity when administered in combination with immune checkpoint inhibitors. We report results from patients with LA/MBC enrolled in the phase 1b/2, multicohort JAVELIN PARP Medley study (NCT03330405). Methods: In phase 1b (cohort 1), patients with advanced solid tumors who had received ≥1 prior standard of care chemotherapy (CT) regimen were treated with avelumab 800 mg IV every 2 weeks (Q2W) in combination with talazoparib 1.0 mg orally once daily (QD) (dose de-escalation to 0.75 or 0.5 mg permitted following toxicity). In 2 phase 2 cohorts, eligible patients had either LA/M triple-negative BC (TNBC, cohort 2A) or LA/M hormone receptor positive (HR+), HER2−, DNA damage repair defect-positive BC (cohort 2B). Patients in cohort 2A had received 0 to 2 prior CT regimens (no progression on prior platinum-based CT) and patients in cohort 2B had received prior standard of care hormone therapy in either the adjuvant and/or LA/M setting followed by 0 to 2 prior CT regimens (no progression on prior platinum-based CT). The primary endpoint for phase 1b was first-cycle dose-limiting toxicities (DLTs) and for phase 2 was objective response (investigator assessed per RECIST v1.1). Adverse events (AEs) were characterized using National Cancer Institute Common Terminology Criteria for AEs v4.03. Results: By the data cutoff on December 24, 2018, 34 patients had been treated in cohorts 1 and 2. Twelve patients with advanced solid tumors were treated in cohort 1 (including 2 patients with TNBC); 3 patients (25.0%) had a first-cycle DLT: grade 3 neutropenia, (n=1) and grade 3 thrombocytopenia, (n=2). Best overall response (BOR) was partial response (PR) in 1 patient, stable disease (SD) in 3, progressive disease (PD) in 6, and non-complete response/non-PD in 1 patient with metastatic castration-resistant prostate cancer and non-measurable disease at baseline; 1 patient was not evaluable for response. Both patients with TNBC had a BOR of SD and remained on treatment for ≥9 months. Objective response rate in this pre-treated and heterogenous population was 8.3% (95% CI, 0.2, 38.5). Based on the phase 1b data, the recommended phase 2 dose was avelumab 800 mg Q2W and talazoparib 1 mg QD. By data cutoff, 22 patients had been treated in cohorts 2A (n=19) and 2B (n=3); median age was 56 and 50 years, respectively. In cohort 2A, 12 patients were evaluable for disease assessment; BOR was PR in 1, SD in 6, and PD in 5. All 3 patients in cohort 2B were non-evaluable for response at data cutoff. Treatment-related AEs (TRAEs) of any grade occurred in 11 patients (91.7%) in cohort 1, and 18 (94.7%) patients in cohort 2A. In cohort 2A, the most common TRAEs were anemia (57.9%), nausea (26.3%), fatigue (21.1%) and thrombocytopenia (21.1%); 9 patients (47.4%) had grade ≥3 TRAEs. There were no treatment-related deaths. Safety data from cohort 2B are not reported owing to low patient numbers. Observed pharmacokinetic (PK) data for avelumab 800 mg Q2W were similar to simulated data derived from a population PK model developed using 10 mg/kg dosing. Conclusions: Avelumab 800 mg Q2W administered in combination with talazoparib 1 mg QD in patients with advanced solid tumors, showed preliminary antitumor activity and a manageable safety profile, which was comparable to the safety profiles of the single agents. The study is ongoing; updated safety and efficacy data, and biomarker data will be presented. Citation Format: Timothy A Yap, Panagiotis Konstantinopoulos, Melinda L. Telli, Smita Saraykar, J Thaddeus Beck, Matthew D. Galsky, Jame Abraham, David R. Wise, Mustafa Khasraw, Gabor Rubovszky, Mikhail Dvorkin, Anil A Joy, Mateusz Opyrchal, Daria Stypinski, Colombe Chappey, Ross Stewart, Rossano Cesari, Anita Scheuber, Aditya Bardia. JAVELIN PARP Medley, a phase 1b/2 study of avelumab plus talazoparib: Results from advanced breast cancer cohorts [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-19-03.

Phase I and biomarker study of OPB-51602, a novel signal transducer and activator of transcription (STAT) 3 inhibitor, in patients with refractory solid malignancies

The aim of this study was to determine the maximum-tolerated dose (MTD), safety, pharmacokinetics, and pharmacodynamics of OPB-51602, an oral, direct signal transduction activator of transcription 3 (STAT3) inhibitor, in patients with refractory solid tumors. Three cohorts were studied: cohort A, a sequential dose escalation of OPB-51602 administered intermittently (days 1-14 every 21 days); cohort B, an expansion cohort evaluating the dose lower than the MTD; cohort C, evaluating continuous daily dosing. Fifty-one patients were studied at 2, 4, and 5 mg per day dosing. The MTD was 5 mg; first-cycle dose-limiting toxicities (DLTs) were grade 3 hyponatremia in one patient, and grade 3 dehydration in another. Intermittent dosing of both 2 and 4 mg doses were tolerable, and the recommended phase II dose was 4 mg. Cohort B investigated 4 mg intermittently, whereas cohort C investigated 4 mg continuously. Common toxicities included fatigue, nausea/vomiting, diarrhea, anorexia, and early-onset peripheral neuropathy. Drug-induced pneumonitis occurred in two patients in cohort C. Continuous dosing was associated with a higher incidence of peripheral neuropathy and a lower mean relative dose intensity, compared with intermittent dosing. Steady-state pharmacokinetics was characterized by high oral clearance, mean elimination half-life ranging from 44 to 61 h, and a large terminal-phase volume of distribution. An active metabolite, OPB-51822, accumulated to a greater extent than OPB-51602. Flow cytometry of peripheral blood mononuclear cells demonstrated pSTAT3 (Tyr(705)) inhibition following exposure. Two patients achieved partial responses at 5 mg intermittently and 4 mg continuously; both had epidermal growth factor receptor (EGFR) mutation-positive non-small-cell lung cancer (NSCLC) with prior EGFR tyrosine kinase inhibitor exposure. OPB-51602 demonstrates promising antitumor activity, particularly in NSCLC. Its long half-life and poorer tolerability of continuous dosing, compared with intermittent dosing, suggest that less frequent dosing should be explored. NCT01184807.

Phase 1 Dose-Escalation Study of PF-04449913, An Oral Hedgehog (Hh) Inhibitor, in Patients with Select Hematologic Malignancies

Abstract 424 Background:Hh signaling is activated in a variety of human cancers and is required for maintenance of leukemic stem cell (LSC) populations in several hematologic malignancies. PF-04449913 selectively inhibits Hh signaling by binding Smoothened, a membrane protein that regulates the Hh pathway. PF-04449913 significantly reduced LSC burden following xenotransplantation of patient-derived CD34+ imatinib-resistant chronic myeloid leukemia (CML) cells in preclinical models. Methods:This first-in-patient Phase 1a dose-escalation study is assessing first-cycle dose-limiting toxicities (DLTs) and the recommended Phase 2 dose (RP2D) of PF-04449913 in patients with select hematologic malignancies (primary endpoint). Secondary endpoints include safety, pharmacokinetics (PK), pharmacodynamics, and preliminary signs of efficacy as defined by disease-specific guidelines. Patients had refractory, resistant, or intolerant select hematologic malignancies and could be previously untreated but not candidates for standard therapies: CML including T315I mutations (any phase), acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), myelofibrosis (MF), or chronic myelomonocytic leukemia (CMML). Cohorts of ≥3 patients received PF-04449913 alone, administered continuously in 28-day cycles, starting at a dose of 5 mg orally once daily. Results:Thirty-two patients have been enrolled at doses up to 270 mg: 18 males/14 females; AML, 18; MF, 6; CML, 5; MDS, 3; with a median age of 68.5 (35–79) years. ECOG PS was 0/1/2: n=11/16/5. Treatment duration ranged from 1 to 387 days (AML: 1–266; CML: 1–281; MDS: 2–335; MF: 44–387 days). One patient discontinued the study due to a treatment-related adverse event (AE) after 137 days of therapy at the 10 mg dose level (grade [G] 3 hemorrhagic gastritis in the setting of chronic proton pump inhibitor administration prior to and during the study). One AML patient evolved from CMML on 80 mg had a DLT comprising G3 hypoxia and G3 pleural effusion. The majority of AEs were of G1/2 severity; the most frequent treatment-related AEs included dysguesia (16%), alopecia (6%), arthralgia (6%), decreased appetite (6%), nausea (6%), and vomiting (6%). Preliminary indications of efficacy were observed across all hematologic diseases studied. One patient with AML (evolved from CMML and with a concurrent diagnosis of systemic mastocytosis) achieved a complete remission with incomplete blood count recovery; bone marrow blast count decreased from 92% to 1%. Five AML patients had a ≥50% reduction in bone marrow blast counts (20% to 10%, 70% to 20%, 44% to 8%, 14% to 7%, 40% to 10%). One patient with low-risk MDS, currently remaining on study after 335 days, achieved significant reduction in spleen size and a hematologic improvement in platelets (from 98.5 to 369 ×109/L) and neutrophils (ANC from 410 to 5490), and is no longer granulocyte colony-stimulating factor (G-CSF) dependent. Five patients with MF attained stable disease; an additional MF patient, currently remaining on study after 385 days, achieved clinical improvement with a >50% reduction in extramedullary disease (spleen size decreased from 10 cm to 3.5 cm sustained over 8 weeks). One patient with T3151 lymphoid blast crisis CML on study for 115 days achieved a major cytogenetic response with loss of their T3151 mutation. PF-04449913 PK data (5–180 mg) indicated a dose-proportional profile, with a median time to maximum concentration (Tmax) of 1–2 hours, a mean half-life ranging from 17 to 35 hours, and a large volume of distribution (mean range 250–480 L). Following daily dosing, steady state was achieved by Day 8 and the median accumulation ratio ranged from 1.3 to 2.9. Conclusions:PF-04449913 was safe and well tolerated, with early signs of efficacy observed in all hematologic diseases studied. Several patients with aggressive malignancies remained on trial for prolonged durations with improved quality of life; some exhibited cellular differentiation as determined by flow cytometry. On-target AEs (e.g. dysgeusia and alopecia) were observed at multiple dose levels. Pharmacokinetics were linear, predictable, and compatible with once-daily dosing. On the basis of these encouraging results, a Phase 1b study of PF-04449913 in combination with bosutinib and dasatinib is planned in patients with CML. Disclosures:Jamieson:Pfizer Oncology: Research Funding; Celgene: Research Funding; Novartis: Honoraria; Wintherix: Equity Ownership. Cortes:Pfizer Oncology: Consultancy; Novartis: Consultancy; BMS: Consultancy; Pfizer Oncology: Research Funding; Novartis: Research Funding; BMS: Research Funding; Infinity: Research Funding. Oehler:Pfizer Oncology: Research Funding. Baccarani:Pfizer Oncology: Consultancy; Novartis: Consultancy; BMS: Consultancy; Ariad: Consultancy; Novartis: Research Funding; Pfizer Oncology: Honoraria; Novartis: Honoraria; BMS: Honoraria; Ariad: Honoraria; Novartis: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees; Ariad: Membership on an entity's Board of Directors or advisory committees. Zhang:Pfizer Oncology: Employment; Pfizer Oncology: Equity Ownership. Shaik:Pfizer Oncology: Employment; Pfizer Oncology: Equity Ownership. Courtney:Pfizer Oncology: Employment; Pfizer Oncology: Equity Ownership. Levin:Pfizer Oncology: Employment; Pfizer Oncology: Equity Ownership. Martinelli:Novartis: Membership on an entity's Board of Directors or advisory committees; BMS: Membership on an entity's Board of Directors or advisory committees.

Abstract C18: A phase I study of enavatuzumab (PDL192, ABT-361), a first-in-class human monoclonal antibody targeting TWEAK (tumor necrosis factor-like inducer of apoptosis) receptor, in patients (Pts) with advanced solid tumors.

Abstract Background: TWEAK receptor (TweakR, TNFRSF12A, CD266) is a member of the TNF receptor superfamily and is expressed on a range of solid tumors. Enavatuzumab is a humanized IgG1 antibody to TweakR that exhibits anti-tumor activity in preclinical models through two mechanisms: direct signaling through TweakR and antibody-dependent cellular cytotoxicity. Methods: This phase I, multicenter study was designed to determine the maximum tolerated dose (MTD) and to evaluate the safety and pharmacokinetic (PK) profiles of enavatuzumab, given intravenously over 60 minutes on days 1 and 15 of each 28-day cycle. Pts with advanced solid tumors; ECOG ≤1; adequate hematologic, renal, and hepatic function; no brain metastasis; no history of cirrhosis or pancreatitis; no recent history of acute cholecystitis; and not on immunosuppressive drugs were enrolled. Cohorts of 3–6 pts were treated at escalating dose levels of enavatuzumab ranging from 0.1 mg/kg to 1.5 mg/kg. Dose limiting toxicity (DLT) was defined as grade (G) 3 AST or ALT lasting >14 days or associated with clinical hepatitis and/or bilirubin ≥G2; G3 amylase or lipase lasting >14 days; ≥G3 bilirubin; any G4 AST, ALT, amylase, or lipase; acute pancreatitis; ≥G3 hematologic and non-hematologic toxicities; G4 cytokine release syndrome (CRS) or G3 CRS despite premedication. MTD was defined as the highest dose level with 0/3 or ≤1 of 6 pts experiencing a first-cycle DLT. PK sampling was performed on cycle 1 day 1 (C1D1), C1D2, C1D8, Day 15 of all cycles, C1D16, C2D1, and C3D1. Response was assessed by RECIST every 8 weeks. Results: Thirty pts [12 male, 18 female; median age 64.5 (range 36–82)] were enrolled at 6 dose levels: 0.1, 0.3, 0.5, 0.7, 1.0, and 1.5 mg/kg. Tumor types included colorectal (15); pancreas (4); ovarian (4); and tongue, cervical, prostate, endometrial, breast, hepatocellular, and thyroid (1 each). Sixteen pts had liver metastases. DLTs included G4 lipase and G3 bilirubin in 1 of 6 pts at the 1.0 mg/kg level and G4 lipase and G4 amylase in 1 pt at the 1.5 mg/kg level. Grade 3/4 toxicities in ≥5% of subjects included fatigue, pneumonia, hyponatremia, hypoxia, dyspnea, and elevated AST, ALT, GGT, lipase, and amylase. There was no apparent correlation of liver or pancreatic enzyme elevation with tumor type or presence of liver metastases. Of the disease evaluable pts, 11 had disease progression as their best response and 2 had stable disease (2 and 4 month duration). Enavatuzumab followed a two-compartment linear PK model. The estimated clearance was 23–33 mL/hr and elimination half-life was 7–18 days. The mean Cmax after the first dose was 2.0 mcg/mL and 28.1 mcg/mL for the 0.1 mg/kg and 1.0 mg/kg cohorts, respectively. Mean Css was reached following the second dose and was within the target efficacious peak and trough levels for the 1.0 mg/kg cohort. Conclusions: The MTD for this first-in-class drug was reached at 1.0 mg/kg. Six of 7 pts at 1.0 mg/kg and 1 of 1 pts at 1.5 mg/kg had ≥G3 liver and/or pancreatic enzyme elevations; therefore higher doses are not being tested. The mechanisms of liver and pancreatic enzyme toxicity are currently being investigated and preclinical studies are ongoing to assess potential combination strategies. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C18.

A phase I study with an expanded cohort to assess the feasibility of intraperitoneal carboplatin and intravenous paclitaxel in untreated ovarian, fallopian tube, and primary peritoneal carcinoma: A Gynecologic Oncology Group study

ObjectiveThis study aimed to determine the first-cycle maximum tolerated dose (MTD) of intraperitoneal carboplatin in combination with intravenous paclitaxel and then assess the feasibility of this dose over multiple cycles. MethodsBeginning at an intraperitoneal (IP) carboplatin dose area under the curve (AUC) of 5 and a fixed intravenous dose of 175mg/m2 paclitaxel, patients were entered on a dose-escalating phase evaluating first-cycle dose-limiting toxicity (DLT). After estimating the MTD, cohorts of 20 patients were then entered in an expanded phase to evaluate DLT over four cycles. ResultsTwenty-one patients were entered on the dose-escalating phase. A first-cycle MTD of carboplatin at AUC 8 was tolerated although thrombocytopenia was dose-limiting over multiple cycles. An additional 69 patients were treated in expanded cohorts. Only 5/90 (5.6%) patients discontinued treatment because of a port problem. Four-cycle DLT required de-escalation to a carboplatin AUC of 6, and even at that dose, there were 14 dose-limiting toxic effects in 40 patients (35%). Seven dose-limiting toxicities were due to neutropenia, and 6 were due to grade 3/4 thrombocytopenia. Six cycles of therapy were completed in 75% of eligible patients, but dose adjustments were required. ConclusionsThe first-cycle MTD did not predict the tolerability of this regimen over multiple cycles. Using an IP carboplatin dose of AUC 6 in combination with paclitaxel, the regimen can be administered with a high completion rate over multiple cycles. Because neutropenia is a frequent DLT, the addition of hematopoietic growth factors may permit a high completion rate while maintaining this dose.

A Phase I Study of PD 0332991: Complete CDK4/6 Inhibition and Tumor Response In Sequential Combination with Bortezomib and Dexamethasone for Relapsed and Refractory Multiple Myeloma

A Phase I Study of PD 0332991: Complete CDK4/6 Inhibition and Tumor Response In Sequential Combination with Bortezomib and Dexamethasone for Relapsed and Refractory Multiple Myeloma

Phase I trial of weekly cisplatin, irinotecan and paclitaxel in patients with advanced gastrointestinal cancer

To determine the maximum tolerated dose (MTD), toxicities, and suitable dose for weekly 1-h paclitaxel combined with weekly cisplatin and irinotecan to treat advanced gastrointestinal malignancies. Thirty patients with metastatic or locally advanced (unresectable or recurrent) gastrointestinal solid tumors were enrolled on this single-center, phase I study. Patients were treated with paclitaxel given over 1h at 1 of 4 dose levels (40, 50, 65, or 80 mg/m(2)). Paclitaxel was followed by fixed doses of cisplatin (30 mg/m(2)) and irinotecan (50 mg/m(2)). All treatment was administered sequentially, once a week, in 6-week cycles (4 weeks on, 2 weeks off). Dose-limiting toxicity (DLT) was defined as a 2-week delay in treatment for grade 3 or 4 non-hematologic toxicity, neutropenic fever, a 1-week delay for grade 4 hematologic toxicity, or a 2-week delay for grade 3 hematologic toxicity. Thirty patients were recruited; 28 patients were assessable for safety. Most of the patients (70%) had no prior chemotherapy. The primary first-cycle DLTs were neutropenia, diarrhea, and nausea. Paclitaxel at 65 mg/m(2) was defined as the MTD. The most common grade 3-4 toxicities observed during all cycles were neutropenia (57%), febrile neutropenia (11%), diarrhea (29%), fatigue (29%), and nausea (18%). No patients had G-CSF (Neupogen, Amgen Inc., Thousand Oaks, CA) support. Responses were observed in gastric, esophageal, and pancreatic cancers. Paclitaxel at 65 mg/m(2), cisplatin (30 mg/m(2)), and irinotecan (50 mg/m(2)) given weekly can be safely administered to patients with solid tumor malignancies. To improve cumulative toxicities, a schedule modification was required (3-week cycle; 2-on, 1-off) Neutropenia was the most common DLT. This combination showed substantial activity, particularly in patients with gastric and esophageal adenocarcinoma, and phase II evaluation could be considered.

Phase I and Pharmacokinetic Study of Oral Irinotecan Given Once Daily for 5 Days Every 3 Weeks in Combination With Capecitabine in Patients With Solid Tumors

To assess the maximum tolerated dose, dose-limiting toxicity, pharmacokinetics, and preliminary antitumor activity of oral irinotecan given in combination with capecitabine to patients with advanced, refractory solid tumors. Patients were treated from day 1 with irinotecan capsules given once daily for 5 consecutive days (50 to 60 mg/m2/d) concomitantly with capecitabine given twice daily for 14 consecutive days (800 to 1,000 mg/m2); cycles were repeated every 21 days. Twenty-eight patients were enrolled and received 155 cycles of therapy (median, five cycles; range, one to 18 cycles). With irinotecan 60 mg/m2/d and capecitabine 2 x 800 mg/m2/d, grade 3 delayed diarrhea in combination with grade 2 nausea (despite maximal antiemetic support) and grade 3 anorexia and colitis, were the first-cycle dose-limiting toxicities in two of six patients, respectively. At the recommended doses (irinotecan 50 mg/m2/d; capecitabine 2 x 1,000 mg/m2/d), side effects were mostly mild to moderate and uniformly reversible. Pharmacokinetic analysis showed that there was no interaction between oral irinotecan and capecitabine, and that body-surface area was not significantly contributing to the observed pharmacokinetic variability. Confirmed partial responses were observed in two patients with gallbladder carcinoma and in one patient with melanoma. Disease stabilization was noted in 16 patients. The recommended phase II doses for oral irinotecan and capecitabine are 50 mg/m2/d for 5 consecutive days, and 2 x 1,000 mg/m2/d for 14 consecutive days repeated every 3 weeks, respectively.

Irinotecan (CPT-11) in triplet combinations in patients with advanced non small-cell lung cancer: a review and report of a phase I/II trial.

The objectives of this phase I/II trial were to determine the maximum tolerated dose, toxicities, and the dose suitable for phase II/III trials of irinotecan (CPT-11) combined with paclitaxel and carboplatin in patients with advanced non small-cell lung cancer (NSCLC). Seventy-three patients with stage IIIB/IV NSCLC were enrolled in this multicenter, phase I/II study. The initial regimen was paclitaxel 225 mg/m2 over 3 hours, followed by carboplatin at an area under the curve (AUC) of 6 over 30 minutes on day 1 and CPT-11 starting at 40 mg/m2 over 90 minutes on days 1 and 8, every 3 weeks. Dose-limiting toxicity occurred in three of the original seven patients. The regimen was amended with doses reduced to paclitaxel 175 mg/m2 over 3 hours, carboplatin AUC = 5, and CPT-11 at 40 mg/m2, all on day 1 every 3 weeks. Dose escalation of CPT-11 proceeded to 80 mg/m2 and 125 mg/m2 before dose-limiting toxicities were experienced. Subsequent patients received an intermediate CPT-11 dose of 100 mg/m2. Doses suitable for phase II study were determined to be paclitaxel 175 mg/m2 over 3 hours, carboplatin AUC = 5, and CPT-11 100 mg/m2. The pri-mary first-cycle dose-limiting toxicities were neutropenia and diarrhea. The most common grade 3/4 toxicity observed during all cycles was neutropenia. On the phase I portion of the study, objective tumor response was observed in 39% (12 of 31, 95% confidence interval: 22%-58%). The median time to tumor progression was 6.8 months, median survival was 11.0 months, and 1-year survival probability was 0.46. These data were confirmed in the phase II portion with a 30% objective response rate, median time to progression of 5.6 months, median survival of 12.5 months, and a 1-year survival probability of 0.50. In conclusion, CPT-11 100 mg/m2, paclitaxel 175 mg/m2, and carboplatin AUC = 5 given every 3 weeks can be safely administered in patients with advanced NSCLC. Neutropenia and diarrhea are the dose-limiting toxicities. The combination shows appreciable activity, and survival data are favorable, warranting further study of this regimen. A review of other irinotecan-containing triplet combinations is presented.