Frontline treatment of advanced gastric cancer with docetaxel and granulocyte colony-stimulating factor (G-CSF): a phase II trial

Experience with docetaxel in the treatment of gastric cancer

Gastric cancer is the second most common cause of cancer death worldwide. In operable patients, standard care includes surgery with or without adjuvant chemotherapy and radiotherapy; standard care for inoperable disease includes chemotherapy with or without radiotherapy. Docetaxel has shown in vitro and in vivo antitumor effects on human gastric cell lines and gastric cancer xenografts. Phase I through III trials of docetaxel alone and in combination with other chemotherapy agents have subsequently been conducted. This review provides an overview of these studies and suggestions for future directions in the treatment of gastric cancer.

Docetaxel + 5-fluorouracil + cisplatin 3-day combination chemotherapy as a first-line treatment in patients with unresectable gastric cancer

BACKGROUND

Our objective was to verify the efficacy and safety of "docetaxel + 5-fluorouracil + cisplatin" 3-day combination chemotherapy as a first-line treatment in patients with unresectable gastric cancer.

METHODS

Between January and November 2002, we enrolled 43 patients [males 31; median age 55 years (range 24-74)] with inoperable gastric cancer who had not been seen previously in Seoul National University Hospital. The regimen used was docetaxel 70 mg/m(2) on day 1, cisplatin 40 mg/m(2) on days 2 and 3, and 5-fluorouracil 1200 mg/m(2) over 10 h on days 1-3, every 3 weeks.

RESULTS

A total of 168 cycles were administered. Mean cycle number per patient was 3.9. The administered dose intensity of docetaxel was 21.23 mg/m(2)/week, 5-FU 1092.14 mg/m(2)/week and cisplatin 23.82 mg/m(2)/week, which corresponded to 91.1, 91.0 and 89.5% of planned doses. Of the 43 patients, response evaluation was possible in 40 and, of these patients, 17 (42.5%) achieved a partial response, 13 (32.5%) stable disease, and 10 patients (25%) showed progressive disease. The median time to progression was 5.6 months [95% confidence interval (CI) 4.6-6.6 months]. Median overall survival was 9.0 months. (95% CI 4.8-13.2 months). Leukopenia occurred during 21.4% of cycles (36 of 168 cycles); 14.3% grade 1, 5.3% grade 2 and 1.8% grade 3. Anemia occurred in 16.7% (28 of 168 cycles); 11.3% grade 1, 4.8% grade 2 and 0.6% grade 3. Thrombocytopenia was not observed. Diarrhea, stomatitis and hypersensitivity occurred in 4.7% (two out of 43 patients), respectively. Neutropenic fever occurred in two patients (4.7%) and myalgia in three (7.0%).

CONCLUSION

"Docetaxel + 5-fluorouracil + cisplatin" 3-day combination chemotherapy is an active and tolerable regimen as a first-line treatment in patients with unresectable gastric cancer.

Palliative chemotherapy for advanced gastric cancer

BACKGROUND

More than two-thirds of patients diagnosed with gastric cancer will have unresectable disease. They present a difficult problem to clinicians as to whether to choose a strictly supportive approach or expose patients to the side-effects of a potentially ineffective treatment. The objective of this article is to review the clinical trials utilizing cytotoxic chemotherapy in patients with advanced gastric cancer.

METHODS

A computerized (Medline) search was carried out to identify papers published on this topic between 1966 and 2003. Only articles with an English abstract were reviewed, and studies only presented in abstract form were not included in the analysis.

RESULTS

A total of 101 trials were subsequently identified. Four randomized trials compared palliative chemotherapy with best supportive care in 174 patients with advanced gastric cancer. Effectiveness and side-effects were evaluated in 73 phase II studies and 24 randomized phase III trials.

CONCLUSION

Analysis of results shows chemotherapy to be superior to best supportive care alone. Combination chemotherapy compared with monochemotherapy is associated with significantly higher overall (complete plus partial) response rates but nevertheless results in similar survival. ECF (epirubicin, cisplatin and 5-fluorouracil) currently represents one of the most effective regimens for advanced gastric cancer, whereas among the newer combinations, irinotecan- or taxane-based regimens have also given promising results. In patients with a poor performance status, consideration could be given to leucovorin-modulated 5-fluorouracil alone. Prognosis for the majority of patients, however, remains poor, as increases in survival were moderate at best.

Docetaxel in the Treatment of Esophageal Cancer

Esophageal cancer is the ninth most common malignancy in the world and the seventh leading cause of death in American men. Because symptoms are often intermittent and vague, patients typically present at an advanced stage, with limited survival. In operable patients, standard care includes surgery with or without adjuvant chemotherapy and radiotherapy; chemotherapy and radiotherapy is the standard care for inoperable disease. Docetaxel, a taxane that promotes polymerization of tubules and inhibits depolymerization of microtubules, has shown in vitro and in vivo antitumor effects on human gastric cell lines and gastric cancer xenografts. These antitumor effects have led to the evaluation of docetaxel as a single agent and in combination with other agents and modalities in patients with esophageal cancer. Results of relevant trials are reviewed herein.

Docetaxel and continuous-infusion fluorouracil versus epirubicin, cisplatin, and fluorouracil for advanced gastric adenocarcinoma: a randomized phase II study

PURPOSE

A combination of docetaxel and fluorouracil (DF) was evaluated in an outpatient setting and compared with epirubicin, cisplatin, and fluorouracil (ECF), which served as an internal control arm to avoid selection bias.

PATIENTS AND METHODS

Patients with metastatic or locally advanced gastric adenocarcinoma without prior chemotherapy were randomly assigned to receive either ECF (epirubicin 50 mg/m(2) day 1, cisplatin 60 mg/m(2) day 1, and fluorouracil 200 mg/m(2) days 1 through 21, every 3 weeks) or DF (docetaxel 75 mg/m(2) day 1, and fluorouracil 200 mg/m(2) days 1 through 21, every 3 weeks).

RESULTS

Ninety patients were randomly assigned. Toxicity was rarely severe. Major toxic effects included diarrhea, stomatitis, and leukopenia in the DF arm and nausea, vomiting, and leukopenia in the ECF arm. Forty-three of 45 patients in each arm were assessable. In the DF arm, two patients (4.4%, intent to treat) experienced a confirmed complete tumor remission as best response, and 15 patients (33.3%) experienced a confirmed partial remission (overall response rate [ORR], 37.8%; 95% CI, 25.9% to 51.9%). Two patients (4.4%) in the ECF arm showed confirmed complete remission, and 14 (31.1%) showed confirmed partial remission (ORR, 35.6%; 95% CI, 24.8% to 48.7%). For the DF and ECF arms, the median survival was 9.5 and 9.7 months, and the median time to tumor progression 5.5 and 5.3 months, respectively.

CONCLUSION

DF can be safely given in an ambulant setting. Compared with ECF, the dual combination of DF shows promising efficacy and may be an alternative treatment option that avoids cisplatin.

A cost-benefit analysis of chemotherapy for gastric cancer

Gastric cancer is the second most common cause of cancer-related deaths worldwide. Surgery remains the mainstay of any curative treatment; however, those patients who are considered not amenable of curative resection generally receive chemotherapy, in order to obtain palliation of symptoms and improved survival. Many drugs have been tested in several combination regimens yielding higher response rates. In spite of the fact that chemotherapy has been extensively used in advanced gastrointestinal cancer, there are few studies that focus on its economic costs. The aim of this paper is to review the results of the main studies regarding the relationship between the cost of chemotherapy and its effectiveness in advanced gastric and gastrointestinal cancer patients.

New chemotherapeutic advances in pancreatic, colorectal, and gastric cancers

Pancreatic, gastric, and colorectal cancers are major causes of morbidity and mortality worldwide. When curative surgical resection is not an option, these malignancies tend to respond very poorly to chemotherapy and carry a dismal prognosis. There is, therefore, an urgent need for novel treatment strategies for these cancers. Great strides have been made in colon cancer treatment with the recent introduction of several novel agents, including capecitabine, irinotecan, and oxaliplatin either alone or in combination regimens. Treatment of advanced colon cancer, however, remains essentially palliative, and treatment-related toxicity remains a significant problem. The treatment of advanced gastric and pancreatic cancer has also seen the introduction of new agents, such as gemcitabine and irinotecan; however, the impact of these agents on survival has been small, and toxicity continues to be a major obstacle. The search for new chemotherapeutic agents and treatment strategies will need to focus on improving outcomes and safety and tolerability profiles. To date, several new agents have shown promise, including pemetrexed, G17DT, bevacizumab, and other targeted agents. Further research into their optimal use either alone or in combination regimens should be a priority.

A phase II study of escalated-dose docetaxel with granulocyte colony-stimulating factor support in patients with advanced breast cancer

PURPOSE

Docetaxel is highly active in the treatment of patients with breast cancer. The principal dose-limiting toxicities of the 3-weekly regimen are neutropenia and febrile neutropenia. In a previous phase I dose-escalation study with granulocyte colony-stimulating factor (G-CSF) support, the recommended dose was determined to be docetaxel 160 mg/m(2) 3-weekly. The objectives of this phase II study were to determine the response rate and toxicity of this dose and schedule, given as first-line in patients with advanced breast cancer. Mobilisation of peripheral blood stem cells (PBSCs) was also investigated.

PATIENTS AND METHODS

Eligible women had metastatic breast cancer and were aged 18-75 years with ECOG performance status < or =2. Strict criteria for liver function were followed, and adjuvant chemotherapy must have been completed at least 6 months previously. Treatment was docetaxel 160 mg/m(2) over 60-90 min every 21 days with G-CSF 5 micro g/kg/day until neutrophil recovery, for up to six cycles. A 3-day corticosteroid prophylaxis was given. Bloods samples to determine PBSC levels [CD34+, granulocyte-macrophage colony-forming cells (GM-CFC) and burst-forming units-erythroid (BFU-E)] were taken on days 6, 8, 9 and 11 following docetaxel.

RESULTS

Twenty-five women with median age 50 years (range 35-66) were included. Seventeen (68%) had previously received adjuvant chemotherapy. In total, 112 cycles were delivered (median four per patient), with dose reductions required in 12.5% of cycles. G-CSF was given for a median of 6 days. The median neutrophil nadir was 0.5 x 10(9)/l and occurred a median 5 days after treatment. The median duration of grade 3 or 4 neutropenia was 2 days (range 1-7). Grade 4 neutropenia occurred in 44% of patients, but there was only one episode of febrile neutropenia. Five patients were taken off study due to toxicities that included oedema, neurosensory toxicity and asthenia. Confirmed partial response was seen in nine patients (37.5%; 95% confidence interval 19% to 59%). CD34+ cells, GM-CFC and BFU-E levels peaked at day 8 following docetaxel administration. The median CD34+ cell peak was 6.5 x 10(4)/ml, with only 20% of patients <2 x 10(4)/ml, a level below which leukapheresis is not usually attempted.

CONCLUSIONS

Docetaxel 160 mg/m(2) was delivered with G-CSF support with a very low rate of febrile neutropenia. Non-haematological toxicity was significant, causing five patients to go off study. Effective mobilisation of PBSCs was seen. The response rate of 37.5% was less than that obtained in first-line studies using standard-dose docetaxel 100 mg/m(2), suggesting that there is no additional benefit in dose escalation of this cytotoxic agent in breast cancer patients using this schedule.

Recent developments in chemotherapy of advanced gastric cancer

Approximately 1 million individuals develop gastric cancer every year and the mortality of gastric cancer is only second to lung cancer. The poor prognosis is caused by late diagnosis of most cancers in advanced stages and the limited therapeutic options in these stages. Apart from the elucidation of underlying molecular and genetic changes in the development and progression of gastric cancers, the development of new treatment strategies is critical for the improvement of the treatment and prognosis of these patients. In this review we have summarized and critically assessed recent studies dealing with the chemotherapy of advanced gastric cancer. While the efficacy of most treatment regimens is only limited, new developments may indicate that treatment with chemotherapy may confer some benefit in the future.

Docetaxel-based chemotherapy in the treatment of gastric cancer

Docetaxel-based chemotherapy appears to have considerable promise in advanced gastric cancer. In phase II studies of single agent docetaxel, response rates (RRs) of 17% to 24% have been achieved in previously untreated patients. Importantly, RRs of 20% to 22% are seen in second-line treatment. Work by a Swiss and Italian collaborative group has shown that the combination of docetaxel 85 mg/m(2) with cisplatin 75 mg/m(2) every 3 weeks is quite active, achieving an RR of 55% and median survival of 9 months. Hematotoxicity was the main adverse event but was manageable. In other respects the docetaxel/cisplatin doublet (TC) was relatively well tolerated. The same group demonstrated that continuous infusion of 5-fluorouracil (5-FU) 300 mg/m(2) can be given on 2 weeks out of 3 to patients receiving TC. The addition of 5-FU, by this schedule, to TC (TCF) does not increase hematological toxicity, and does not compromise the tolerability of TC. An overall RR of 55% has been reported with TCF. A randomized phase II comparison of TC or TCF versus an ECF (epirubicin/cisplatin/5-FU) control arm is ongoing and should lead to a randomized phase III trial comparing TC or TCF with ECF. In an already completed international randomized phase II comparison of TC versus TCF (TAX-325), the three-drug combination proved significantly more active (RR 54% versus 32% with TC, among patients treated per protocol). Time to progression was also longer for TCF. Gastrointestinal (but not hematological) toxicity was less with TC. TCF was chosen for ongoing phase III comparison against a control 5-FU/cisplatin arm. It is possible that data from these randomized studies will confirm the value of docetaxel-based chemotherapy in advanced gastric cancer and that docetaxel combinations will also be effective in the multidisciplinary efforts to cure earlier stage cancer.

Current treatments and future perspectives in colorectal and gastric cancer

Given the high rate of distant spread, effective systemic therapy is key to improving survival in patients with colorectal cancer (CRC). The past 40 years have seen progress. The addition of folinic acid (FA) to 5-fluorouracil (5-FU), the use of infusional rather than bolus 5-FU, and the combination of new active agents such as irinotecan and oxaliplatin with 5-FU/FA have each led to an increase in activity. In trials of current combination regimens first-line, response rates (RRs) in excess of 50% and median survival durations longer than 16 months are seen. A recent controlled trial suggests that overall time to progression is maximized and toxicity minimized when an irinotecan/5-FU/FA combination is used first-line, followed by an oxaliplatin/ 5-FU/FA combination on progression. In the adjuvant setting, 5-FU/FA is the standard of care in stage III disease but of uncertain value in stage II patients. The role of new agents such as irinotecan in adjuvant regimens is being assessed. Use of highly active chemotherapy in patients with unresectable disease (particularly liver metastases) achieves responses that allow a subset of patients to proceed to potentially curative surgery. The emergence of novel agents targeted at processes such as tumor angiogenesis will complement cytotoxic chemotherapy, while improved understanding of tumor biology should enable agents to be selected according to the likely sensitivity of the disease in a particular patient. In gastric cancer also, surgery remains the only potentially curative treatment. The extent of dissection required is debated, as is the potential benefit of adjuvant chemoradiotherapy (indeed the degree of resection may interact with the effect of adjuvant treatment). In untreated metastatic gastric cancer, median survival is 3-4 months. This can be increased to around 10 months using chemotherapy. Quality of life is also enhanced. There is no clearly defined standard of care. However, some form of cisplatin/5-FU combination can serve as a reference regimen. As single agents, both irinotecan and docetaxel achieve RRs of around 20% in metastatic CRC. In combination with cisplatin and/or 5-FU a very high and promising RR is achieved. The promise of these agents in combination with 5-FU and 5-FU plus cisplatin is currently being tested in phase III trials.

Chemotherapy in gastric cancer: a review and updated meta-analysis

The five years survival rate for patients with gastric cancer is 15-25%. With the aim of improving survival, chemotherapy has been used in different adjuvant settings. Similarly, but with the aim of improving quality of life and prolonging life, chemotherapy has been used extensively in metastatic disease. In this review we have included studies of systemic and intraperitoneal chemotherapy given before, during or after operation and for advanced disease. A meta-analysis has been made on the 21 randomised studies that used adjuvant systemic chemotherapy postoperatively. A significant survival benefit for the patients treated postoperatively compared with controls was identified (odds ratio (OR) 0.84, 95% confidence interval (CI) 0.74 to 0.96). When western and Asian studies were analysed separately we found no survival benefit for the treated patients in the western groups (OR 0.96 (95 CI 0.83 to 1.12)). Flaws in the conduct of several trials made it difficult to draw firm conclusions, including the exclusion of a small but clinically meaningful survival benefit. Preoperative or neoadjuvant chemotherapy has shown effects in some patients, but no significant benefit was found in the few randomised studies. The few studies that reported intraperitoneal therapy showed no detectable survival benefit either. In patients with advanced disease, four small randomised studies found significantly longer survival in the treated patients. The survival benefit is in the range of 3-9 months, and there were also improvements of the quality of life. Several drug combinations have been tested, however, with no confirmed superiority for a particular regimen.

CONCLUSIONS

Adjuvant chemotherapy cannot be recommended as a routine because of the lack of confirmed beneficial effects. Some patients with advanced disease will have a clinically important benefit from palliative chemotherapy, so this can be recommended for patients who are otherwise in good health.

Docetaxel in combination for advanced gastric cancer

Docetaxel is considered to be active in untreated and previously treated patients with gastric carcinoma. In a multinational phase II trial (TAX 325), 158 untreated patients with advanced gastric cancer (99% without prior chemotherapy) were randomized to receive, every 3 weeks, either docetaxel 85 mg/m2 plus cisplatin 75 mg/m2 (TC) or docetaxel 75 mg/m2 plus cisplatin 75 mg/m2, plus a 5-day continuous infusion of 750 mg/m2 5-fluorouracil (FU; TCF). By intent-to-treat analysis, patients receiving TCF had a significantly higher response rate and longer time to progression. Overall survival in the two arms was not significantly different. Toxicity (particularly gastrointestinal toxicity) was greater with the TCF combination than in the TC arm, and there was a greater need for dose reduction. However, adverse events in both arms were manageable and there were no deaths associated with either regimen. Following these findings, a phase III trial comparing a control arm of cisplatin plus 5-FU against an experimental arm consisting of the TAX 325 phase II docetaxel/cisplatin/5-FU regimen is now in progress.

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.

Status of treatment for advanced gastric carcinoma

Gastric cancer is the second most common cause of cancer death worldwide. Advanced gastric cancer is incurable. The most widely investigated single-agent chemotherapy is 5-fluorouracil (5-FU), with partial response rates up to 20%. Pilot phase II studies investigating combinations of 5-FU, anthracyclines, mitomycin, methotrexate, and platinums achieved higher response rates; however, the response rates declined in subsequent larger trials. Furthermore, toxicity was substantially higher in confirmatory trials, emphasizing the need to develop well-tolerated regimens prior to multi-institutional testing. Although phase III studies of combination regimens have not achieved a clear worldwide standard, the regimen of epirubicin, cisplatin, and continuous-infusion 5-FU achieved a survival benefit, possibly through the increased activity of infusional 5-FU combined with cisplatin. The taxanes, irinotecan and oxaliplatin, have recently shown important activity in gastric cancer. Patient accrual to a phase III trial comparing a docetaxel-based combination regimen with the regimen of cisplatin and 5-FU has completed accrual. Whether patients with adenocarcinomas of the proximal stomach and gastroesophageal junction will have the same response rates to these new agents as did patients with classical body and distal gastric cancers is unknown. It is anticipated that the development of these active new agents will ultimately improve survival for patients with advanced gastric cancer.

Docetaxel in advanced gastric cancer

Standard chemotherapy for advanced gastric cancer remains undefined. Two of the most popular regimens-ECF [epirubicin-cisplatin-5-fluorouracil (5-FU)] and PELF (cisplatin-epirubicin-5-FU-leucovorin)-have been shown to be active, but each has limitations. Phase II trials show that single-agent docetaxel is an active agent in advanced gastric cancer, producing overall response rates (ORRs) of 17.5-24%. Docetaxel has also been shown to lack cross-resistance with other drugs in gastric cancer, and is likely to be at least additive to cisplatin and 5-FU. Phase II results of docetaxel combinations in advanced gastric cancer are encouraging. Docetaxel-cisplatin has yielded response rates similar to those achieved by ECF and PELF. Adding 5-FU to docetaxel-cisplatin has achieved an ORR of 52 versus 45% for docetaxel-cisplatin in a randomized phase II trial. Docetaxel-based regimens demonstrate acceptable tolerability despite predictable hematotoxicity. Neutropenia, the major toxicity, is manageable by dose modification or by using prophylactic granulocyte colony stimulating factor. Several phase III trials are now ongoing, including a large-scale trial of docetaxel-cisplatin-5-FU versus cisplatin-5-FU. Results will show whether docetaxel improves overall response and survival, as suggested in the phase II setting.

Recent developments in the treatment of gastric carcinoma

Surgery remains the mainstay for the curative treatment of gastric carcinoma. However, despite adequate surgery, survival remains poor. The use of adjuvant chemotherapy and radiotherapy has been examined in multiple previous clinical trials without convincing evidence of efficacy. However, recently, a large randomized controlled Intergroup trial, INT 116, demonstrated a survival advantage with chemoradiotherapy following curative surgery for gastric cancer. This review discusses the merits of the Intergroup trial and the ways in which it should affect the treatment of gastric cancer in the United States. INT 116 provides a foundation on which we can build to improve the care of patients with gastric cancer. With the evaluation of potentially better chemotherapeutic agents and the advent of molecularly directed therapy, there is increasing hope for improving the care of patients with gastric carcinoma.

Infusional 5-fluorouracil, cisplatin and mitomycin C in advanced gastric cancer: a low cost effective regimen

Recently, we reported a highly active regimen in advanced gastric cancer including a weekly administration of cisplatin, epidoxorubicin, leucovorin, 5-fluorouracil with the support of filgrastim. In order to simplify the administration and to decrease the toxicity of these drugs, mainly epidoxorubicin-induced alopecia, we designed a regimen including an infusional 5-fluorouracil schedule according to the de Gramont regimen, cisplatin and mitomycin C replacing epidoxorubicin. Forty-five patients with advanced or metastatic gastric cancer were treated with cisplatin 50 mg m(-2) i.v. on day 1, every 2 weeks, 6S-stereoisomer-leucovorin 100 mg m(-2) i.v. followed by 5-fluorouracil 400 mg m(-2) i.v. bolus and 600 mg m(-2) i.v. in a 22-h infusion, on days 1 and 2, every 2 weeks, and mitomycin C 7 mg m(-2) i.v. bolus on day 2, every 6 weeks. Grades 3-4 toxicities (National Cancer Institute-Common Toxicity Criteria) consisted mainly of neutropenia and thrombocytopenia. Five patients had a complete response and 16 had a partial response for an overall response rate of 46.7% (95% confidence interval, 32.1-61.2%). The median survival was 11 months. The combination of cisplatin, 5-fluorouracil and leucovorin according to de Gramont, and mitomycin C seems to be an active and safe regimen in the treatment of advanced gastric cancer. Because of its low cost it may be suggested for patients not enrolled into clinical trials.