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Articles by I Okamoto
Total Records ( 4 ) for I Okamoto
  T Satoh , I Okamoto , M Miyazaki , R Morinaga , A Tsuya , Y Hasegawa , M Terashima , S Ueda , M Fukuoka , Y Ariyoshi , T Saito , N Masuda , H Watanabe , T Taguchi , T Kakihara , Y Aoyama , Y Hashimoto and K. Nakagawa
 

Purpose: YM155, a novel molecular targeted agent, suppresses survivin, a member of the inhibitor of apoptosis protein family that is overexpressed in many tumor types. The aim of this study was to determine the maximum tolerated dose (MTD) and to assess the safety, pharmacokinetics, and antitumor activity of YM155 in patients with advanced refractory solid tumors.

Experimental Design: Patients with advanced refractory solid tumors were treated with escalating doses of YM155 administered by continuous i.v. infusion for 168 hours in 21-day cycles.

Results: Of the 34 patients enrolled, 33 (median age, 59 years) received at least 1 dose of YM155 (range, 1-19 cycles). The dose levels studied were 1.8, 3.6, 4.8, 6.0, 8.0, and 10.6 mg/m2/d. The MTD was determined to be 8.0 mg/m2/d, based on a dose-limiting toxicity of increased blood creatinine observed in 2 patients receiving 10.6 mg/m2/d. The most common adverse reactions judged to be related to YM155 were urine microalbumin present; fever; injection-site phlebitis; fatigue; and decreased hemoglobin/anemia, blood albumin, and lymphocyte count. The pharmacokinetic profile was almost linear over the dosing range and was similar between cycles 1 and 2. Urinary excretion of YM155 showed no definite difference among doses. Stable disease was achieved in nine patients.

Conclusions: YM155 was safely administered to patients with advanced refractory solid tumors by 168-hour continuous i.v. infusion in 21-day cycles. The MTD was determined to be 8.0 mg/m2/d. The safety profile, plasma concentrations achieved, and antitumor activity observed merit further studies with this survivin suppressant, alone and in combination regimens.

  I Okamoto , T Doi , A Ohtsu , M Miyazaki , A Tsuya , K Kurei , K Kobayashi and K. Nakagawa
  Objective

To determine the pharmacokinetics and safety of RAD001 (everolimus) in Japanese patients with advanced solid tumors.

Methods

An open-label, non-randomized, dose-escalation Phase I study of RAD001 administered continuously once daily in a 28-day cycle was performed. The study had a ‘3 + 3’ design, with three patients recruited to each of three successive cohorts treated with RAD001 at 2.5, 5.0 or 10.0 mg/day.

Results

The pharmacokinetics of RAD001 in Japanese patients were similar to those previously determined in Caucasians. The drug safety profile was consistent with that of a mammalian target of rapamycin inhibitor. No dose-limiting toxicities were observed. One patient with esophageal cancer and one with gastric cancer treated with RAD001 at 10 mg/day showed marked tumor responses.

Conclusions

Treatment of Japanese cancer patients with RAD001 may be undertaken with the expectation that previously determined pharmacokinetic and safety profiles apply. The drug may hold promise for treatment of esophageal and gastric cancer.

  K Okamoto , I Okamoto , K Takezawa , I Tachibana , M Fukuoka , Y Nishimura and K. Nakagawa
  Objective

The optimal management of elderly patients with limited-disease small cell lung cancer (LD-SCLC) has not been established.

Methods

The records of elderly (≥70 years of age) patients with LD-SCLC who had been treated with etoposide and cisplatin chemotherapy with early concurrent twice-daily thoracic radiotherapy (TRT) were reviewed retrospectively.

Results

Of the 25 elderly patients with LD-SCLC identified, 12 (48%) individuals received etoposide–cisplatin chemotherapy with early concurrent twice-daily TRT. The main toxicities of this treatment regimen were hematologic, with neutropenia of Grade 4 being observed in all patients and febrile neutropenia of Grade 3 in eight patients during the first cycle of chemoradiotherapy. The toxicity of TRT was acceptable, with all patients completing the planned radiotherapy within a median of 29 days (range, 19–33). No treatment-related deaths were observed. The median progression-free survival and overall survival times were 14.2 months (95% confidence interval, 4.3–18.2) and 24.1 months (95% confidence interval, 11.3–27.2), respectively.

Conclusions

Etoposide–cisplatin chemotherapy with early concurrent twice-daily TRT was highly myelotoxic in elderly patients with LD-SCLC, although no treatment-related deaths were observed in our cohort. Prospective studies are required to establish the optimal schedule and dose of chemotherapy and TRT in such patients.

  I Okamoto , M Munakata , M Miyazaki , T Satoh , T Takahata , Y Takamatsu , O Muto , K Koike , K Ishitani , T Mukaiyama , Y Sakata , K Nakagawa and K. Tamura
  Objective

Hormonal imbalance characterized by excessive production of growth hormone (GH) and a low circulating concentration of insulin-like growth factor (IGF)-1 has been demonstrated in individuals with various serious conditions. However, little is known about changes in the GH–IGF-1 axis in cancer patients.

Methods

We prospectively examined the circulating levels of several hormones in 58 patients with solid tumors who were classified according to Eastern Cooperative Oncology Group performance status (PS): PS 0–1, n = 15; PS 2, n = 15; PS 3, n = 15; and PS 4, n = 13. The relations of hormone concentrations, with a focus on the GH–IGF-1 system, to PS were evaluated by Spearman's rank correlation test and regression analysis.

Results

The circulating levels of IGF-1, IGF-binding protein-3 and thyroid hormones (total T3 and T4) were inversely correlated with PS score. The concentration of GH was increased irrespective of PS but not statistically significant. The ratio of IGF-I to GH was inversely correlated with PS. The levels of GH and IGF-1 in all patients were also inversely correlated.

Conclusions

The present study suggests that the GH–IGF-1 axis is disturbed in patients with cancer.

 
 
 
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