Sunitinib in combination with docetaxel in patients with advanced solid tumors: a phase I dose-escalation study

Purpose

Sunitinib in combination with docetaxel enhances antitumor activity in xenograft models of human breast and non-small cell lung cancer. We assessed the maximum tolerated doses (MTDs), safety, pharmacokinetic profiles, and preliminary efficacy of sunitinib plus docetaxel in patients with advanced solid tumors.

Methods

In this phase I study, successive patient cohorts received sunitinib 25, 37.5, or 50 mg/day for 4 weeks of a 6-week cycle (Schedule 4/2, 4 weeks on, 2 weeks off) or for 2 weeks of a 3-week cycle (Schedule 2/1, 2 weeks on, 1 week off) with docetaxel 60 or 75 mg/m² IV q21d to determine the MTDs of this treatment combination.

Results

Fifty patients enrolled: 10 on Schedule 4/2 and 40 on Schedule 2/1. MTDs were established as sunitinib 25 mg on Schedule 4/2 with docetaxel 60 mg/m² q21d, and as sunitinib 37.5 mg on Schedule 2/1 with docetaxel 75 mg/m² q21d. On Schedule 2/1, the most frequent dose-limiting toxicity was neutropenia (±fever; grade [G]3/4, n = 5) and the most common G3/4 non-hematologic adverse event (AE) was fatigue (G3, n = 8). Hematologic AEs were managed with growth factor support in 11 of 23 (48%) patients treated at Schedule 2/1 MTD. Three patients achieved a partial response at the Schedule 2/1 MTD. There were no pharmacokinetic drug–drug interactions with either schedule.

Conclusions

Oral sunitinib 37.5 mg/day on Schedule 2/1 with docetaxel 75 mg/m² IV q21d is a clinically feasible regimen with a manageable safety profile, no pharmacokinetic drug–drug interactions, and shows antitumor activity in patients with advanced solid tumors.     

A phase I trial of oxaliplatin in combination with docetaxel in patients with advanced solid tumors

The primary objective of this trial was to establish the maximum tolerated dose (MTD) of oxaliplatin 130 mg/m² preceded by escalating doses of docetaxel 60 mg/m² (75, 90, 100 mg/m²) administered every 3 weeks. A total of 11 patients were entered; 10 evaluable for response: 4 stable disease (liver, ovary and esophagus) and 1 partial remission (esophagus). At dose level 1, there was 1 dose-limiting toxicity (DLT) (grade 3 allergic reaction). At dose level 2, there were 3 DLTs (3 grade 4 neutropenia, grade 3 gastritis, diarrhea, hypophosphatemia, neuro-mood). The MTD is docetaxel 60 mg/m² with oxaliplatin 130 mg/m².     

A phase I,dose-escalation study of volasertib combined with nintedanib in advanced solid tumors

BackgroundVolasertib is a potent and selective cell-cycle kinase inhibitor that induces mitotic arrest and apoptosis by targeting Polo-like kinases. This study determined the maximum tolerated dose (MTD) and pharmacokinetics of volasertib combined with nintedanib, a potent and orally bioavailable triple angiokinase inhibitor, in patients with advanced solid tumors.Patients and methodsThis open-label, dose-escalation trial recruited patients with advanced metastatic solid tumors following failure of conventional treatment (NCT01022853; Study 1230.7). Volasertib was administered by intravenous infusion over 2 h, starting at 100 mg in the first dose cohort. Nintedanib was administered orally at a dose of 200 mg twice daily. The first treatment cycle comprised 28 days (days 1–7 and days 9–28: nintedanib; day 8: volasertib). From cycle 2 onwards, volasertib was administered on day 1 of a 21-day cycle and nintedanib was administered days 2–21. The primary objective was the MTD of volasertib in combination with nintedanib.ResultsThirty patients were treated. The MTD of volasertib plus fixed-dose nintedanib was 300 mg once every 3 weeks, the same as the recommended single-agent dose of volasertib in solid tumors. Two of 12 assessable patients treated with the MTD experienced dose-limiting toxicities [grade 3 increased alanine aminotransferase (ALT); grade 3 ALT increase and grade 3 increased aspartate aminotransferase]. Disease control [stable disease (SD)/partial response (PR)/complete response (CR)] was achieved in 18 patients (60%): 1 CR (breast cancer), 1 PR (nonsmall-cell lung cancer), and 16 patients with SD. Volasertib showed that multiexponential pharmacokinetic behavior and co-administration of nintedanib had no significant effects on its exposure.ConclusionsVolasertib could be combined with fixed-dose nintedanib at the recommended single-agent dose. At this dose, the combination had a manageable safety profile without unexpected or overlapping adverse events, and showed antitumor activity.     

A phase I trial of intermittent high-dose gefitinib and fixed-dose docetaxel in patients with advanced solid tumors

PURPOSE: Based on our mouse xenograft model demonstrating that intermittent high-dose gefitinib sensitizes tumors to subsequent treatment with taxanes, we initiated this phase I trial to explore docetaxel in combination with escalating doses of intermittent gefitinib (Iressa) given prior to docetaxel. METHODS: This was a phase I study where patients with advanced cancer were treated with escalating doses of gefitinib (1,000, 1,500, 2,250, 3,000 mg) on days 1 and 2 followed by docetaxel (75 mg/m2) on day 3 of a 21 day cycle. Gefitinib pharmacokinetic data were obtained on days 1, 2, and 3 of cycles 1 and 2 at each dose level. RESULTS: 18 patients were enrolled in this study with the most frequent tumor types being non-small cell lung cancer and head and neck squamous cell cancer. The dose-limiting toxicity was neutropenia (n=1 at dose level 2, n=2 at dose level 4). Rash, diarrhea, and fatigue were the most common grade 1-2 toxicities. Pharmacokinetic data indicated no accumulation of gefitinib between cycles 1 and 2 and no clear correlation between gefitinib plasma levels and toxicity. Partial responses were observed in one patient with head and neck squamous cell carcinoma and one patient with anaplastic thyroid cancer. CONCLUSION: The recommended dose for phase II studies is gefitinib 2,250 mg on days 1 and 2, followed by docetaxel 75 mg/m2 on day 3.     

A phase I trial of perillyl alcohol in patients with advanced solid tumors

PURPOSE: Perillyl alcohol is a plant-derived lipid with preclinical antitumor activity. Its proposed mechanism of action involves inhibition of post-translational isoprenylation of small G proteins, including the proto-oncogene p21- ras, thereby blocking signal transduction. This phase I trial was conducted to determine the optimal dose of perillyl alcohol. METHODS: The study group comprised 21 adults with advanced solid tumors who were treated with perillyl alcohol, delivered orally, four times daily, without interruption. Doses ranged from 4,800 to 11,200 mg/m(2) per day. RESULTS: The maximum tolerated dose (MTD) for this schedule was determined to be 8400 mg/m(2) per day. The dose-limiting toxicities in this trial were nausea and vomiting, encountered in all patients at the highest dose level. No antitumor activity was observed. Pharmacokinetic data suggest dose-dependent increases in C(max) of perillic acid, a metabolite of perillyl alcohol, but with high inter- and intrapatient variability. CONCLUSIONS: The MTD of perillyl alcohol for this schedule was determined to be 8400 mg/m(2) per day. This is higher than the MTDs determined in other similar phase I trials. This may have been due to the fact that the gastrointestinal symptoms caused by perillyl alcohol are highly subjective, with high interpatient variability. Phase II trials of perillyl alcohol in hormone-refractory prostate, breast, ovarian and colorectal cancer using doses in the range 4800-6400 mg/m(2) per day are underway.     

A phase I dose-escalation and pharmacokinetic study of enzastaurin and erlotinib in patients with advanced solid tumors

Purpose  

Enzastaurin, an oral serine/threonine kinase inhibitor, targets the protein kinase C and AKT pathways with anti-tumor and anti-angiogenic effects. Erlotinib, an oral epidermal growth factor receptor (EGFR) inhibitor, has activity in solid tumors. Based on the promising combination of EGFR inhibitors and anti-angiogenic agents, this phase I trial was initiated.     

Phase I trial of bortezomib in combination with docetaxel in patients with advanced solid tumors.

PURPOSE: Bortezomib (PS-341), a first-in-class proteasome inhibitor, is metabolized by deboronation involving cytochrome P4503A (CYP3A), which also metabolizes docetaxel. Preclinical studies have shown synergy between bortezomib and taxanes. We conducted a phase I study combining bortezomib and docetaxel in refractory solid tumor patients. EXPERIMENTAL DESIGN: Patients received escalating doses of weekly docetaxel (days 1 and 8) and twice weekly bortezomib (days 2, 5, 9, and 12) in 3-week cycles. Two subjects were enrolled at each dose level, with cohort expansion to six for dose-limiting toxicity (DLT). Dose levels 1, 2, and 3 consisted of docetaxel/bortezomib 25/0.8, 25/1.0, and 30/1.0 mg/m(2), respectively. CYP3A activity and docetaxel pharmacokinetic studies were conducted, and proteasome inhibition was assessed. RESULTS: Fourteen patients received a total of 34 cycles of treatment. Dose level 2 was expanded for DLT that occurred in two of six patients consisting of febrile neutropenia in one patient and grade 3 thrombocytopenia in one patient. One patient received two cycles at dose level 3 with dose reduction to dose level 2, where grade 3 thrombocytopenia occurred at cycle 3. Both episodes of grade 3 thrombocytopenia were transient (<7 days). Dose level 1 was then expanded to six patients where no DLTs occurred. CYP3A activity and docetaxel clearance did not change between weeks 1 and 5. CONCLUSIONS: The maximum tolerated dose was docetaxel 25 mg/m(2) (days 1 and 8) with bortezomib 0.8 mg/m(2) (days 2, 5, 9, and 12) given every 21 days. Bortezomib treatment did not alter CYP3A activity and docetaxel clearance.     

A phase I and pharmacokinetic study of exisulind and docetaxel in patients with advanced solid tumors.

PURPOSE: Exisulind (sulindac sulfone, FGN-1, Aptosyn) is a sulindac metabolite that induces apoptosis via inhibition of cyclic GMP-phosphodiesterase. This agent demonstrated tumor growth inhibition in rodent models of colon, breast, prostate, and lung carcinogenesis. In an orthotopic model of human non-small-cell lung cancer, the combination of exisulind and docetaxel prolonged survival in athymic nude rats, forming the basis of this phase I combination study. EXPERIMENTAL DESIGN: This study evaluated the toxicity and pharmacokinetics of combining exisulind (150-250 mg) given orally twice daily and docetaxel (30-36 mg/m2) administered intravenously on days 1, 8, and 15 of a 4-week cycle. RESULTS: Twenty patients with a range of advanced solid tumors (median age, 59 years; age range, 35-77 years; median performance status, 1) received a total of 70 courses. Observed adverse events were mild to moderate, and there was no dose-limiting toxicity at any level. Grade 3 gastrointestinal toxicities were present in 10 of the 70 cycles (10%) and included nausea, vomiting, dyspepsia, and elevated alkaline phosphatase. Neutropenia was present in four cycles in patients treated with a docetaxel dose of 36 mg/m2. Pharmacokinetic analysis did not demonstrate a clear effect of exisulind on docetaxel pharmacokinetics and vice versa. Relationships were evident between the plasma concentration of exisulind and the development of grade 2 or greater toxicities. One third of patients maintained stable disease for 3 to 12 cycles, but no objective responses were observed. CONCLUSIONS: The combination of docetaxel (36 mg/m2, weekly) and exisulind (500 mg/d) was reasonably well tolerated, and it is undergoing phase II testing in patients with non-small-cell lung cancer.     

A phase I trial of gemcitabine in combination with patupilone in patients with advanced solid tumors

INTRODUCTION: Chemotherapy regimens including gemcitabine in combination with microtubule inhibitors such as docetaxel and paclitaxel have wide clinical application. Patupilone is a novel tubulin-polymerizing agent with activity against paclitaxel-resistant cell lines. We conducted a phase I trial to assess the maximum tolerated dose, dose limiting toxicity (DLT) and antitumor activity of gemcitabine and patupilone. METHODS: Patients with refractory solid tumors enrolled in cohorts of three. Cohorts received fixed doses of gemcitabine (1,000 or 750 mg/m(2)) along with escalating doses of patupilone (1.5-3 mg/m(2)) on days 1 and 8 of a 21-day cycle. RESULTS: Twenty-seven patients received a total of 99 courses of treatment on study. Hematologic toxicity in the first cohort required a modification of the protocol to decrease the gemcitabine dose. Subsequent patients received gemcitabine 750 mg/m(2) and escalating doses of patupilone from 1.5 to 3 mg/m(2). DLTs were grade 3 asthenia and grade 3 dehydration. There was also one treatment-related death due to neutropenic infection. Other clinically significant toxicities were persistent asthenia and persistent nausea. Four patients, one each with pancreatic cancer, esophageal carcinoma, cholangiocarcinoma and gallbladder carcinoma, experienced a partial response. CONCLUSIONS: The dose-limiting toxicities of gemcitabine and patupilone were asthenia and dehydration. Dose reductions also occurred due to persistent fatigue that was not dose-limiting. However, patients with advanced malignancies were able to tolerate gemcitabine and patupilone at doses that resulted in clinical benefit. The recommended phase II dose for this schedule is gemcitabine 750 mg/m(2) and patupilone 1.5 mg/m(2) on days 1 and 8 of a 21-day cycle.     

Phase I clinical trial of weekly combined paclitaxel plus docetaxel in patients with solid tumors

BACKGROUND: A Phase I and feasibility study of combined docetaxel (D) plus paclitaxel (P) was undertaken to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) for each analogue delivered concomitantly on a weekly schedule. METHODS: Patients were accrued in 3-6 patient cohorts to P administered over a course of 45-60 minutes followed by D infused over a course of 30 minutes for 4 consecutive weeks with the cycles repeated at 6 weeks. The MTD was defined as the dose of each agent administered with at least Grade 3 (according to National Cancer Institute standard criteria) hematologic toxicity in 50% of the patients but without Grade 4 toxicity. RESULTS: Twenty patients received D plus P weekly for 4 weeks at 4 dose levels. At the highest P dose (80 mg/m2; total dose per cycle, 320 mg/m2) 2 of 6 patients received treatment for 4 consecutive weeks but 5 of 6 patients developed hematologic and/or nonhematologic (skin) DLTs. The recommended treatment doses for this combined taxane regimen is D, 35 mg/m2/week, plus P, 65 mg/m2/week, for 4 weeks. An unusual cutaneous syndrome was observed in four patients that was manifested as erythema and blistering on the dorsum of the hands. CONCLUSIONS: The lack of complete cross-resistance for D and P in experimental systems and the clinical observation that tumor resistance to one taxane does not necessarily convey resistance to the alternative taxane was the basis for exploring the use of both analogues administered simultaneously. This Phase I trial establishes the optimal weekly dose for each taxane when administered in combination.     

A phase I trial of docetaxel and gemcitabine in patients with advanced cancer

Background:Docetaxel and gemcitabine are active in a broad rangeof malignancies. The objective of this phase I trial was to determine themaximally tolerated doses of the combination of docetaxel and gemcitabine. Patients and methods:Patients with advanced cancer, WHOperformance status 0–2, who had received up to one prior chemotherapyregimen were treated with gemcitabine on days 1 and 8 and docetaxel on day 8repeated every 21 days. Prophylactic ciprofloxacin was commenced on day 11 ofeach cycle and continued until the neutrophil count reached 1.0 ×10⁹/l. G-CSF was not administered. Dose levels studied weredocetaxel/gemcitabine: 60/800, 60/1000, 75/1000, 75/1200, 85/1200 and 100/1200mg/m². Results:Thirty-nine patients were entered and all were assessablefor toxicity. The highest administered dose level was 100 mg/m²docetaxel and 1200 mg/m² gemcitabine with dose limiting toxicitiesof febrile neutropenia, grade 4 neutropenia 7 days, grade 4thrombocytopenia, grade 3 stomatitis and/or grade 3 fatigue in three out ofsix patients. Treatment was well tolerated (40 cycles) in the 10 patientstreated at the recommended dose level (85/1200) with only a single episode offebrile neutropenia and grade 3 or 4 non-hematologic toxicity was infrequent.There was no significant pulmonary toxicity. Responses were seen in a rangeof malignancies including non-small-cell lung cancer. Conclusions:The recommended dose level of 85 mg/m²docetaxel and 1200 mg/m² gemcitabine has a favourable toxicityprofile and is suitable for further investigation in phase II trials. Thisnon-platinum containing regimen warrants further investigation as a potentialalternative to platinum containing regimens in non-small-cell lung cancer andother malignancies.     

A phase 1 study of pralatrexate in combination with paclitaxel or docetaxel in patients with advanced solid tumors.

PURPOSE: Pralatrexate is a rationally designed antifolate with greater preclinical antitumor activity than methotrexate. Pralatrexate was synergistic with paclitaxel and with docetaxel in mouse xenograft experiments. This phase 1 study was designed to determine the maximum tolerated dose and toxicity of pralatrexate plus paclitaxel or docetaxel in patients with advanced cancer. EXPERIMENTAL DESIGN: Pralatrexate was administered i.v. every 2 weeks (days 1 and 15) in a 4-week cycle. Depending on the taxane used and dose being tested, the taxane was administered on days 1 and 15; days 2 and 16; or days 1, 8, and 15. In the latter part of the study, patients in the docetaxel arm were treated with vitamin B(12) and folic acid supplementation to mitigate toxicity and allow pralatrexate dose escalation. RESULTS: For the combination of pralatrexate plus paclitaxel without vitamin supplementation, dose-limiting stomatitis and peripheral neuropathy were encountered at the lowest dose levels tested. For pralatrexate plus docetaxel plus vitamin supplementation, pralatrexate 120 mg/m(2) plus docetaxel 35 mg/m(2) administered on the same day every other week was defined as the maximum tolerated dose and schedule, with dose-limiting toxicities at higher dose combinations including stomatitis and asthenia. Significant antitumor activity was observed for this combination in patients with non-small-cell lung cancer. CONCLUSIONS: Pralatrexate (120 mg/m(2)) plus docetaxel (35 mg/m(2)) plus vitamin supplementation is well tolerated with signs of efficacy against non-small-cell lung cancer that merit phase 2 testing.     

A first in man phase I trial of the oral immunomodulator,indoximod, combined with docetaxel in patients with metastatic solid tumors

Background

Indoleamine 2,3-dioxygenase (IDO) is an enzyme that tumors use to create a state of immunosuppression. Indoximod is an IDO pathway inhibitor. Preclinical studies demonstrated that indoximod combined with chemotherapy was synergistic in a mouse model of breast cancer. A phase I 3+3 trial was designed to study the combination of docetaxel and indoximod.

Methods

Docetaxel was administered at 60 mg/m² intravenously every 3 weeks dose levels 1-4 and 75 mg/m² for dose level 5. Indoximod was given at 300, 600, 1000, 2000, and 1200 mg PO twice daily continuously for levels 1-5, respectively. Serum drug levels were measured.

Results

Twenty-seven patients were treated, with 22 evaluable for response. DLTs included grade 3 dehydration (level 1), hypotension(level 4), mucositis (level 4) and grade 5 enterocolitis (level 2). Dose level 5 is the recommended phase II dose. The most frequent adverse events were fatigue (58.6%), anemia (51.7%), hyperglycemia (48.3%), infection (44.8%), and nausea (41.4%). There were 4 partial responses (2 breast, 1 NSCLC, 1 thymic tumor). No drug-drug interactions were noted.

Conclusions

Docetaxel plus indoximod was well tolerated with no increase in expected toxicities or pharmacokinetic interactions. It was active in a pretreated population of patients with metastatic solid tumors.     

A phase I dose-escalation study of docetaxel with granulocyte colony-stimulating factor support in patients with solid tumours.

BACKGROUND: Docetaxel is a widely active cytotoxic agent. The principal dose-limiting toxicities (DLTs) of the 3-weekly regimen are neutropenia and febrile neutropenia. Use of prophylactic granulocyte colony-stimulating factor (G-CSF) may allow higher doses of docetaxel to be administered with potentially greater anticancer efficacy. The objectives of this study were to determine the maximum tolerated dose (MTD) and toxicity profile of docetaxel given with G-CSF support. PATIENTS AND METHODS: Eligible patients had solid tumours and were aged 18-75 years with a WHO performance status of up to 2. Strict criteria for liver function were followed. Patients may have received one previous regimen of chemotherapy in addition to adjuvant chemotherapy. Cohorts of three to six patients received docetaxel over 60-90 min every 3 weeks, commencing at 110 mg/m(2) and escalating at 10 mg/m(2) increments. Patients also received G-CSF 5 micro g/kg/day until neutrophil recovery. A 3-day corticosteroid prophylaxis was given. RESULTS: Twenty-nine patients with median age 55 years (range 29-75) were included. Fourteen (48%) had previously received chemotherapy. At the 170 mg/m(2) dose level (the MTD), two of three patients had DLTs and 160 mg/m(2) was determined to be the recommended dose. The principal DLTs were skin and neurosensory toxicity. Asthenia was frequent, especially at dose levels >/=140 mg/m(2). Grade 4 neutropenia occurred in only 10 patients (35%) and was not dose related, with febrile neutropenia in three patients (10%). CONCLUSIONS: Docetaxel may be escalated considerably above standard doses when administered with G-CSF support. The recommended dose for phase II studies is 160 mg/m(2). With escalated-dose docetaxel, DLTs were non-haematological and qualitatively similar to the toxicity profile at standard doses.     

A phase I study of gemcitabine and docetaxel for advanced stage solid tumors

Background: We conducted a phase I study to determine the maximum tolerated dose of docetaxel in combination with gemcitabine for patients with refractory solid tumors. Methods: From January 1998 to November 1999, we treated 28 patients on a phase I protocol with gemcitabine given at a constant dose of 800 mg/m² IV over 30 minutes on days 1, 8, and 15. Docetaxel was administered by a phase I schedule over 1 hour on day 1 of a 28-day cycle with a starting dose of 50 mg/m² and increased by increments of 10 mg/m² based on dose-limiting toxicity (DLT) that occurred in the first cycle. Results: Neutropenia and thrombocytopenia were the dose-limiting toxicities. The maximum tolerated dose was 60 mg/m². The most significant nonhematologic toxicities included fatigue, nausea, vomiting, mucositis, and hypersensitivity reactions. There was one partial response at 15 months in a patient with gastric cancer and six patients with stable disease for 4.0 to 15.0 months. Conclusions: The maximum tolerated dose of docetaxel with gemcitabine is 60 mg/m². A phase II study in selected primary sites is planned.     

A phase I study of gemcitabine and docetaxel in patients with metastatic solid tumors

BACKGROUND: A Phase I study was initiated to determine the maximum tolerated dose of weekly gemcitabine combined with monthly, fixed-dose docetaxel. METHODS: Patients with metastatic solid tumors were treated with docetaxel, 60 mg/m(2), on Day 1 every 28 days. Gemcitabine was administered on Days 1, 8, and 15 and underwent dose adjustment in cohorts of 3-6 patients. At the maximum tolerated dose, 11 additional patients were enrolled. RESULTS: Twenty-six patients received 85 cycles of therapy. At the first dose level, the planned gemcitabine dose on Days 1, 8, and 15 was 800 mg/m(2). Two of the 6 patients treated at this dose level experienced dose-limiting toxicities (DLTs) requiring the reduction of gemcitabine to 600 mg/m(2) per dose and the administration of ciprofloxacin, 500 mg orally twice daily, on Days 8-18. At the second dose level the first 3 patients experienced no DLTs and the dose of gemcitabine was increased to 700 mg/m(2). Two of the 6 patients treated at the 700 mg/m(2) dose level experienced DLTs. Eleven additional patients were enrolled at the recommended Phase II dose of gemcitabine (600 mg/m(2)). At this dose level, Grade 3/4 (according the National Cancer Institute's common toxicity criteria) neutropenia and thrombocytopenia occurred in 12.5% and 2.1% of cycles, respectively. Grade 3 and 4 nonhematologic toxicities were uncommon. Three of seven evaluable patients with pancreatic carcinoma had evidence of significant antineoplastic activity (three partial responses). In addition, two complete responses (one patient with gastric carcinoma and one patient with ovarian carcinoma) and one partial response (patient with hepatocellular carcinoma) were noted in patients with other solid tumors. CONCLUSIONS: The regimen comprised of docetaxel, 60 mg/m(2), on Day 1 and gemcitabine, 600 mg/m(2), on Days 1, 8, and 15 with ciprofloxacin on Days 8-18 every 28 days is safe, well tolerated, and active.     

A phase I dose-escalation study to evaluate safety and tolerability of sorafenib combined with sirolimus in patients with advanced solid cancer

Background:

The combination of sorafenib (vascular endothelial growth factor receptor 2 inhibitor) and sirolimus (mammalian target of rapamycin inhibitor) might work synergistically.

Methods:

A phase I dose-escalation study with sorafenib twice a day (b.i.d.) and sirolimus once daily (q.d.) was performed to determine the recommended dose of the combination in patients with solid tumours. Secondary objectives were to determine the safety profile and maximum tolerated dose (MTD), and to evaluate the pharmacokinetics (PK) of the combination.

Results:

Dose-limiting toxicities were transaminitis and cutaneous toxicity. The most frequently reported adverse events were elevated transaminases, hypophosphatemia, fatigue, anorexia, diarrhoea, nausea, rash and palmar–plantar erythrodysaesthesia. Sirolimus did not change the PK of sorafenib; in contrast, sorafenib reduced the AUC₍₀₋₉₆₎ and C_max of sirolimus. No objective responses were observed; eight patients showed stable disease for a median of 16.3 weeks (range 8–24). The MTD of the combination was sorafenib 200 mg b.i.d. with sirolimus 1 mg q.d.

Conclusion:

The combination of sorafenib and sirolimus showed enhanced toxicity, which could not be explained by the PK of both drugs. The relative low doses at the MTD, in combination with the PK results, do not warrant further development of this combination.