Lon Smith

Phase II trial of irinotecan in patients with progressive or rapidly recurrent colorectal cancer

PURPOSE To evaluate irinotecan (CPT-11; Yakult Honsha, Tokyo, Japan) in patients with metastatic colorectal carcinoma that had recurred or progressed following fluorouracil (5-FU)-based therapy. PATIENTS AND METHODS Patients were treated with irinotecan 125 to 150 mg/m2 intravenously (IV) every week for 4 weeks, followed by a 2-week rest. Forty-eight patients were entered onto the study and all were assessable for toxicity. Forty-three patients completed one full course of therapy and were assessable for response. RESULTS One complete and nine partial responses were observed (response rate, 23%; 95% confidence interval [CI], 10% to 36%). The median response duration was 6 months (range, 2 to 13). The median survival time was 10.4 months and the 1-year survival rate was 46% (95% CI, 39% to 53%). Grade 4 diarrhea occurred in four of the first nine patients (44%) treated on this study at the 150-mg/m2 dose level. The study was amended to reduce the starting dose of irinotecan to 125 mg/m2. At this dose, nine of 39 patients (23%) developed grade 4 diarrhea. Aggressive administration of loperamide also reduced the incidence of grade 4 diarrhea. Grade 4 neutropenia occurred in eight of 48 patients (17%), but was associated with bacteremia and sepsis in only case. CONCLUSION Irinotecan has significant single-agent activity against colorectal cancer that has progressed during or shortly after treatment with 5-FU-based chemotherapy. The incidence of severe diarrhea is reduced by using a starting dose of irinotecan 125 mg/m2 and by initiating loperamide at the earliest signs of diarrhea. These results warrant further clinical evaluation to define the role of irinotecan in the treatment of individuals with colorectal cancer.

Phase I and pharmacokinetic trial of weekly CPT-11

PURPOSE We conducted a phase I and pharmacokinetic trial of CPT-11 (irinotecan) to characterize the maximum-tolerated dose (MTD), toxicities, pharmacokinetic profile, and antitumor effects in patients with refractory solid malignancies. PATIENTS AND METHODS We treated 32 patients with CPT-11 administered as a 90-minute intravenous infusion every week for 4 consecutive weeks followed by a 2-week rest period. Dose levels ranged from 50 to 180 mg/m2/wk. We determined concentrations of the lactone (active) and total (lactone plus carboxylate) forms of CPT-11 and its metabolite, SN-38, in the plasma and urine of selected patients during and after drug infusion. RESULTS Grade 4 diarrhea was the dose-limiting toxicity (DLT) at the 180-mg/m2/wk dose level. Other toxicities attributed to CPT-11 included dehydration, nausea, vomiting, and asthenia. Hematologic toxicity was mild in most patients. The terminal plasma half-life for CPT-11 (total) was 7.9 +/- 2.8 hours, for CPT-11 (lactone) 6.3 +/- 2.2 hours, for SN-38 (total) 13.0 +/- 5.8 hours, and for SN-38 (lactone) 11.5 +/- 3.8 hours. We observed significant correlations between drug dose and peak plasma concentration (Cpmax) and between drug dose and area under the concentration curve (AUC) for CPT-11, but not for SN-38. CONCLUSION The MTD for CPT-11 in this patient population was 150 mg/m2/wk when administered on a weekly-times-four schedule repeated every 6 weeks. At dose levels greater than 150 mg/m2/wk, diarrhea is dose-limiting.

The Clinical Effect of the Dual-Targeting Strategy Involving PI3K/AKT/mTOR and RAS/MEK/ERK Pathways in Patients with Advanced Cancer

Purpose: This study evaluated the clinical relevance of the dual-targeting strategy involving PI3K/AKT/mTOR and RAF/MEK/ERK pathways. Experimental Design: We investigated safety, efficacy, and correlations between tumor genetic alterations and clinical benefit in 236 patients with advanced cancers treated with phase I study drugs targeting phosphoinositide 3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways in our Phase I Clinical Trials Program. Results: Seventy-six (32.2%) patients received a PI3K pathway inhibitor in combination with a MAPK pathway inhibitor (D), whereas 124 (52.5%) and 36 (15.3%), respectively, received an inhibitor of either the PI3K or MAPK pathways (S). The rates of drug-related grade >III adverse events were 18.1% for (S) and 53.9% for (D; P < 0.001); the rates of dose-limiting toxicities were 9.4% for (S) and 18.4% for (D; P = 0.06). The most frequent grade >III adverse events were transaminase elevations, skin rash, and mucositis. In our comprehensive tumor genomic analysis, of 9 patients who harbored coactivation of both pathways (colorectal cancer, n = 7; melanoma, n = 2), all 5 patients treated with (D) had tumor regression ranging from 2% to 64%. Conclusions: These results suggest that dual inhibition of both pathways may potentially exhibit favorable efficacy compared with inhibition of either pathway, at the expense of greater toxicity. Furthermore, this parallel pathway targeting strategy may be especially important in patients with coexisting PI3K pathway genetic alterations and KRAS or BRAF mutations and suggests that molecular profiling and matching patients with combinations of these targeted drugs will need to be investigated in depth. Clin Cancer Res; 18(8); 2316–25. ©2012 AACR.

Cantuzumab Mertansine, a Maytansinoid Immunoconjugate Directed to the CanAg Antigen: A Phase I, Pharmacokinetic, and Biologic Correlative Study

PURPOSE To determine the maximum tolerated dose and pharmacokinetics of cantuzumab mertansine, an immunoconjugate of the potent maytansine derivative (DM1) and the humanized monoclonal antibody (huC242) directed to CanAg, intravenously (i.v.) once every 3 weeks and to seek evidence of antitumor activity. PATIENTS AND METHODS Patients with CanAg-expressing solid malignancies were treated with escalating doses of cantuzumab mertansine administered i.v. every 3 weeks. The pharmacokinetic parameters of cantuzumab mertansine, the presence of plasma-shed CanAg, and the development of both human antihuman and human anti-DM1 conjugate antibodies also were characterized. RESULTS Thirty-seven patients received 110 courses of cantuzumab mertansine at doses ranging from 22 to 295 mg/m2. Acute, transient, and reversible elevations of hepatic transaminases were the principal toxic effects. Nausea, vomiting, fatigue, and diarrhea were common but rarely severe at the highest dose levels. Dose, peak concentration, and area under the concentration-time curve correlated with the severity of transaminase elevation. The mean (+/- SD) clearance and terminal elimination half-life values for cantuzumab mertansine averaged 39.5 (+/-13.1) mL/h/m2 and 41.1 (+/-16.1) hours, respectively. Strong expression (3+) of CanAg was documented in 68% of patients. Two patients with chemotherapy-refractory colorectal carcinoma had minor regressions, and four patients had persistently stable disease for more than six courses. CONCLUSION The recommended dose for cantuzumab mertansine is 235 mg/m2 i.v. every 3 weeks. The absence of severe hematologic toxic effects, preliminary evidence of cantuzumab mertansine tumor localization, and encouraging biologic activity in chemotherapy-refractory patients warrant further broad clinical development of this immunoconjugate in CanAg-expressing tumors.

Phase I clinical trial of taxotere administered as either a 2-hour or 6-hour intravenous infusion.

PURPOSE To determine the potential efficacy and dose-limiting toxicity of taxotere, a hemisynthetic inhibitor of tubulin depolymerization. PATIENTS AND METHODS Fifty-eight patients were administered taxotere in this phase I clinical trial as a 6-hour or a 2-hour infusion repeated every 21 days. Forty patients received 181 courses on the 6-hour infusion schedule, and 18 patients received 105 courses on the 2-hour infusion schedule. RESULTS Neutropenia was the dose-limiting toxicity on both schedules. The maximally tolerated dose was 100 mg/m2 on the 6-hour infusion schedule and 115 mg/m2 on the 2-hour infusion schedule. The most prominent nonhematologic toxicities included mucositis (more prominent on the 6-hour infusion schedule), transient rash (more common on the 2-hour infusion schedule), and alopecia. Hypersensitivity reactions were seen in five patients. There was no evidence of neurotoxicity or cardiotoxicity. One partial response was noted on the 6-hour infusion schedule (one in refractory breast cancer) and four additional partial responses were noted on the 2-hour infusion schedule (two in adenocarcinoma of the lung, one in refractory breast cancer, one in cholangio-carcinoma). In addition, 10 patients had minor responses. Pharmacokinetic studies showed plasma concentrations of taxotere declined in a triexponential manner, with a terminal half-life of 11.8 hours. CONCLUSION The recommended starting dose for phase II taxotere trials is 100 mg/m2 administered as a 2-hour infusion, repeated every 21 days. Taxotere is a promising antineoplastic agent worthy of extensive phase II testing in patients with a variety of malignancies.

Phase I and Pharmacologic Study of the Specific Matrix Metalloproteinase Inhibitor BAY 12-9566 on a Protracted Oral Daily Dosing Schedule in Patients With Solid Malignancies

PURPOSE To evaluate the feasibility of administering BAY 12-9566, a matrix metalloproteinase (MMP) inhibitor with relative specificity against MMP-2, MMP-3, and MMP-9, on a protracted oral daily dosing schedule in patients with advanced solid malignancies. The study also sought to determine the principal toxicities of BAY 12-9566, whether plasma BAY 12-9566 steady state concentrations (C(ss)) of biologic relevance could be sustained for prolonged periods, and whether BAY 12-9566 affected plasma concentrations of MMP-2, MMP-9, and tissue inhibitor of MMP-2 (TIMP-2). PATIENTS AND METHODS Patients with solid malignancies were treated with BAY 12-9566 at daily oral doses ranging from 100 to 1,600 mg. BAY 12-9566 dose schedules included 100 mg once daily, 400 mg once daily, 400 mg twice daily, 400 mg three times daily, 400 mg four times daily, and 800 mg twice daily. Plasma was collected to study the range of BAY 12-9566 C(ss) values achieved, and exploratory studies were performed to assess the effects of BAY 12-9566 on plasma concentrations of MMP-2, MMP-9, and TIMP-2. RESULTS Twenty-one patients were treated with 47 28-day courses of BAY 12-9566. The most common side effects were headache, nausea, vomiting, abnormalities in hepatic functions, and thrombocytopenia, which were rarely clinically significant. BAY 12-9566 was well tolerated on all dose schedules, and there was no consistent dose-limiting toxicity that precluded treatment in the range of dose schedules evaluated. Instead, dose escalation was terminated because BAY 12-9566 plasma C(ss) values increased less than proportionately and plateaued as the daily dose was increased within the dose range of 100 to 1,600 mg/d, suggesting saturable drug absorption. Mean plasma C(ss) values achieved with all dose schedules exceeded BAY 12-9566 concentrations required to inhibit MMPs in vitro and in vascular invasion and tumor proliferation in vivo models. There were no consistent effects of BAY 12-9566 on the plasma concentrations of MMP-2 and MMP-9 over the continuous dosing period at any dose schedule level. However, plasma levels of TIMP-2 seemed to increase in a dose-dependent manner (r(2) =.50, P =.046). CONCLUSIONS The recommended dose of BAY 12-9566 for subsequent disease directed studies is 800 mg twice daily, which resulted in biologically relevant plasma C(ss) values and an acceptable toxicity profile. Although exploratory studies of MMPs in plasma were not revealing, it is conceivable that some tumor types and disease settings are more likely to produce more readily quantifiable levels of activated MMPs than others. Therefore, attempts to identify and quantify surrogate markers of MMP inhibitory effects should continue to be performed in disease-directed studies in more homogenous patient populations.

Phase I and Pharmacologic Study of the Tyrosine Kinase Inhibitor SU101 in Patients With Advanced Solid Tumors

PURPOSE To evaluate the clinical feasibility and pharmacologic behavior of the platelet-derived growth factor (PDGF) tyrosine kinase inhibitor SU101, administered on a prolonged, intermittent dosing schedule to patients with advanced solid malignancies. PATIENTS AND METHODS Twenty-six patients were treated with SU101 doses ranging from 15 to 443 mg/m(2) as a 24-hour continuous intravenous (IV) infusion weekly for 4 weeks, repeated every 6 weeks. Pharmacokinetic studies were performed to characterize the disposition of SU101 and its major active metabolite, SU0020. Immunohistochemical staining of PDGF-alpha and -beta receptors was performed on malignant tumor specimens obtained at diagnosis. RESULTS Twenty-six patients were treated with 52 courses (187 infusions) of SU101. The most common toxicities were mild to moderate nausea, vomiting, and fever. Two patients experienced one episode each of grade 3 neutropenia at the 333 and 443 mg/m(2) dose levels. Dose escalation of SU101 above 443 mg/m(2)/wk was precluded by the total volume of infusate required, 2.5 to 3.0 L. Individual plasma SU101 and SU0020 concentrations were described by a one-compartment model that incorporates both first-order formation and elimination of SU0020. SU101 was rapidly converted to SU0020, which exhibited a long elimination half-life averaging 19 +/- 12 days. At the 443 mg/m(2)/wk dose level, trough plasma SU0020 concentrations during weeks 2 and 4 ranged from 54 to 522 micromol/L. Immunohistochemical studies revealed PDGF-alpha and -beta receptor staining in the majority (15 of 19) of malignant neoplasms. CONCLUSION SU101 was well tolerated as a 24-hour continuous IV infusion at doses of up to 443 mg/m(2)/wk for 4 consecutive weeks every 6 weeks. Although further dose escalation was precluded by infusate volume constraints, this SU101 dose schedule resulted in the achievement and maintenance of substantial plasma concentrations of the major metabolite, SU0020, for the entire treatment period.

A phase 1b study of trametinib, an oral Mitogen-activated protein kinase kinase (MEK) inhibitor, in combination with gemcitabine in advanced solid tumours

PURPOSE This phase 1b study determined the safety, tolerability, and recommended phase 2 dose (RP2D) and schedule of trametinib in combination with gemcitabine. Secondary objectives included assessment of clinical activity and steady-state pharmacokinetics. METHODS Adults with advanced solid tumours, adequate organ function and Eastern Co-operative Oncology Group performance status (ECOG PS) ⩽ 1 were eligible. Once-daily oral trametinib (1mg, 2mg, 2.5mg) was escalated in a 3+3 design with standard gemcitabine dosing (1000 mg/m(2) IV Days 1, 8, and 15 of 28-day cycles). During expansion, trametinib 2mg was combined with gemcitabine. Pharmacokinetics samples were collected on Day 15 pre-dose and 1, 2, 4 and 6h post-dose; tumour assessments were repeated every two cycles. RESULTS Between 8/2009 and 11/2010, 31 patients (pancreas = 11, breast = 6, non-small cell lung cancer (NSCLC) = 4, other = 10) were treated. Dose-limiting toxicities (DLTs) occurred in each cohort, and included febrile neutropenia, transaminase elevation and uveitis. The RP2D was declared as trametinib 2mg daily with standard gemcitabine dosing. Common grade 3/4 toxicities at the RP2D included: neutropenia (38%), thrombocytopenia (19%) and transaminase elevation (14%). Of 10 patients with measurable pancreatic cancer, three partial responses (30%) were documented; two additional patients achieved objective responses (breast, complete response (CR); salivary glands, partial response (PR)). Pharmacokinetics suggested no change in exposures of either drug in combination. CONCLUSION Administration of trametinib at its full monotherapy dose of 2mg daily in combination with standard gemcitabine dosing (1000 mg/m(2) IV Days 1, 8, and 15 every 28 days) was feasible. Though most toxicities were manageable, the addition of trametinib may increase gemcitabine-associated myelosuppression. Future studies of this combination will require monitoring to maintain dose and schedule.

Phase I study of daily times five topotecan and single injection of cisplatin in patients with previously untreated non-small-cell lung carcinoma

BACKGROUND The objectives were to determine the dose-limiting toxicity of topotecan in combination with cisplatin, to describe the principal toxicities, and to define the maximally-tolerated doses of the drugs in previously untreated patients with advanced non-small-cell lung carcinoma. PATIENTS AND METHODS The study was designed to evaluate escalated doses of topotecan (starting at 0.75 mg/m2/day) as a 30-minute infusion daily for five consecutive days with a fixed clinically-relevant dose of 75 mg/m2 cisplatin given on day 1, every three weeks. RESULTS Fifteen chemotherapy-naive patients entered the study and 14 were evaluable for toxicity. All 11 patients treated at the first topotecan/cisplatin dose level of 0.75/75 mg/m2, experienced at least one episode of grade 4 neutropenia. For six patients, absolute neutrophil counts were below 500/ml for more than five days, and two of them developed a grade 4 thrombocytopenia. At the next higher topotecan/cisplatin dose level (1.0/75 mg/m2), grade 4 neutropenia lasting longer than five days occurred in all three evaluable patients, including one patient who expired due to a severe neutropenia associated with sepsis. Non-hematologic toxicities, predominantly nausea and vomiting, were mild to moderate in severity and manageable. Four patients had partial responses (30.7%; 95% confidence interval (9%-61%) of relatively short duration. CONCLUSION Both severe neutropenia and thrombocytopenia precluded dose escalation of topotecan and cisplatin administered on this schedule. In previously untreated patients, the first topotecan/cisplatin dose level (0.75/75 mg/m2), was associated with intolerable myelosuppression, and, therefore, the dose levels evaluated in this study cannot be recommended for subsequent phase II investigations. The high toxicity of this schedule and the recent understanding of the pharmacokinetic interaction between those drugs may encourage the investigation of the alternate sequence of cisplatin after TPT in phase II studies.

Phase I and Pharmacokinetic Study of BMS-184476, a Taxane With Greater Potency and Solubility Than Paclitaxel

PURPOSE To assess the feasibility, toxicity, pharmacokinetics, and preliminary activity of BMS-184476 administered as a 1-hour intravenous (IV) infusion every 3 weeks. PATIENTS AND METHODS Patients with advanced solid malignancies were treated with escalating doses of BMS-184476 as a 1-hour IV infusion every 3 weeks without premedication to prevent hypersensitivity reactions (HSR). Plasma sampling and urine collections were performed to characterize the pharmacokinetics and pharmacodynamics of BMS-184474. RESULTS Thirty-four patients were treated with 78 courses of BMS-184476 at five dose levels ranging from 20 to 80 mg/m2. Dose-limiting toxicity (DLT), consisting of severe neutropenia with fever, severe diarrhea, and/or severe mucositis, was experienced during course 1 by six of nine minimally pretreated patients treated at the 70 and 80 mg/m2 dose level. In contrast, of 15 assessable patients treated at the 60 mg/m2 dose level, which is the maximum-tolerated dose (MTD) of BMS-184476 on this administration schedule, only one heavily pretreated patient developed DLT (grade 4 neutropenia with fever and grade 3 diarrhea). One patient developed a grade 2 HSR during a second course of BMS-184476 at the 40 mg/m2 dose level. A previously untreated patient with an advanced cholangiocarcinoma experienced a partial response, and a patient with an untreated carcinoma of the gastroesophageal junction had a minor response. The pharmacokinetics of BMS-184476 seemed linear in the dose range studied. Mean +/- SD values for clearance, volume of distribution at steady-state, and terminal half-life were 220 +/- 89 mL/min/m2, 402 +/- 231 L/m2, and 40.8 +/- 21.8 hours, respectively. CONCLUSION The MTD and recommended dose for phase II evaluations of BMS-184476 is 60 mg/m2 as a 1-hour IV infusion every 3 weeks. The results of this study suggest that BMS-184476 may have several advantages compared with paclitaxel in terms of toxicity, pharmacokinetics, pharmaceutics, and administration and warrants further clinical development.