Phase II Study of Panitumumab Monotherapy in Chemotherapy‐Naïve Frail or Elderly Patients with Unresectable RAS Wild‐Type Colorectal Cancer: OGSG 1602

Lessons Learned

• Panitumumab monotherapy showed favorable efficacy and feasibility in the treatment of frail or elderly patients with RAS wild‐type unresectable colorectal cancer.
• It is especially effective for left‐sided tumors; therefore, panitumumab as first‐line treatment could be an additional therapeutic option for frail elderly patients, particularly in those who are unsuitable for upfront oxaliplatin‐based or irinotecan‐based combination regimens.

BackgroundFirst‐line panitumumab monotherapy is expected to be well tolerated and improve survival in patients ineligible for intensive chemotherapy. However, its safety and efficacy in chemotherapy‐naïve frail or elderly patients with unresectable RAS wild‐type (WT) colorectal cancer (CRC) have not been studied. The aim of this phase II trial was to evaluate the efficacy and safety of panitumumab as first‐line treatment.MethodsWe conducted a multicenter phase II study on patients aged ≥76 years or ≥65 years considered unsuitable for intensive chemotherapy. Panitumumab 6 mg/kg of intravenous infusion was administered every 2 weeks. The primary endpoint was disease control rate (DCR). Secondary endpoints included progression‐free survival (PFS), overall survival (OS), response rate (RR), time to treatment failure (TTF), and incidence of grade 3 or 4 toxicities.ResultsThirty‐six patients (median age: 81 [range, 67–88] years) were enrolled between February 2017 and August 2018. Two patients were excluded from the analysis of efficacy: one from lack of image examination at baseline and the other from lack of a measurable lesion. Thirty‐three (91.6%) patients had a performance status (PS) of 0 or 1, whereas two (5.6%) patients and one (2.8%) patient had a PS of 2 and 3, respectively. Twenty‐eight patients (77.8%) had left‐sided CRC, whereas eight (22.2%) had right‐sided CRC. The RR was 50.0% (95% confidence interval [CI], 32.4–67.6), including three patients (8.8%) who had complete responses. A total of 26.5% had stable diseases, resulting in a DCR of 76.5% (90% CI, 61.5–87.7). The RR of patients with left‐ and right‐sided tumors was 65.4% (95% CI, 44.3–82.8) and 0.0% (95% CI, 0.0–36.9), respectively. Major grade 3 or 4 nonhematologic toxicities were rash (n = 6, 16.7%), hypomagnesemia (n = 4, 11.1%), fatigue (n = 3, 8.3%), paronychia (n = 2, 5.6%), and hyponatremia (n = 2, 5.6%). The only grade 3 hematologic toxicity was neutropenia (n = 1, 2.8%).ConclusionPanitumumab monotherapy showed favorable efficacy and feasibility in frail or elderly patients with RAS WT unresectable CRC. Survival analysis including OS, PFS, and TTF is currently in progress.     

Physiologically-based pharmacokinetic modeling for mirabegron: a multi-elimination pathway mediated by cytochrome P450 3A4, uridine 5'-diphosphate-glucuronosyltransferase 2B7, and butyrylcholinesterase

1. This was the first study to construct a physiologically-based pharmacokinetic (PBPK) model for mirabegron which incorporates the overall elimination pathways of metabolism by cytochrome P450 (CYP) 3A4, uridine 5'-diphosphate-glucuronosyltransferase (UGT) 2B7, and butyrylcholinesterase (BChE) and renal excretion. The objective was to assess the risk of drug-drug interactions (DDIs) by estimating the contribution of each elimination pathway and simulating the magnitude of the DDIs with UGT2B7 inhibitors.

2. A PBPK model for mirabegron was constructed to reproduce the plasma concentration-time curves from a phase 1 study and the magnitude of the DDI with ketoconazole taking into account the overall elimination pathways. The PBPK model was subsequently verified using data from other DDI studies.

3. The constructed PBPK model estimated the contribution for each elimination pathway: 44% and 29% for CYP3A4 and UGT2B7 in the liver, 1.6% for UGT2B7 in the kidney, 3.2% for BChE in plasma, and 22% for renal excretion.

4. Co-administration of probenecid (an UGT2B7 inhibitor) or fluconazole (an UGT2B7 and CYP3A4 inhibitor) was predicted to increase area under the curve for mirabegron to 115% or 174%, respectively.

5. In conclusion, PBPK modeling and simulation revealed a low DDI risk for mirabegron following co-administration with BChE or UGT2B7 inhibitors.

     

Evaluation of apremilast,an oral phosphodiesterase 4 inhibitor,for refractory cutaneous dermatomyositis: A phase 1b clinical trial

Dermatomyositis, an idiopathic inflammatory myopathy, is characterized by cutaneous itchy manifestations, which are frequently refractory and recurrent even after intensive immunosuppressive treatments. To evaluate the effectiveness and safety of apremilast, an oral phosphodiesterase 4 inhibitor, in treating skin-dominant dermatomyositis in which myositis and interstitial lung disease are absent or in remission, we performed this prospective, single-arm, interventional study. A total of five Japanese patients (one male and four females, median [range] age, 64 [37–71] years) with refractory dermatomyositis-associated cutaneous manifestations were recruited and treated with a 12-week course of oral apremilast. Among five enrolled patients, three experienced diarrhea with full-dose apremilast (30 mg twice daily), two of whom withdrew from the study and recovered quickly afterwards. A total of three evaluable female patients (median [range] age, 65 [64–71] years) received apremilast treatment for 12 weeks. A 39.4% reduction from baseline Cutaneous Dermatomyositis Disease Area and Severity Index total activity score, but not the damage score, at week 12 was observed in all three patients. Visual analog scale of itching, and quality of life by Dermatology Life Quality Index were slightly improved in one and two apremilast-treated patients, respectively. As apremilast was effective, with expected and recoverable digestive adverse events (diarrhea), in patients with refractory and recurrent dermatomyositis-associated cutaneous manifestations in this first phase Ib study, it can be suggested as a possible treatment when aggressive immunosuppressive therapies with high-dose systemic corticosteroid and/or immunosuppressive agents for other manifestations, myositis, and interstitial lung disease, are not required.     

TRPV2 Promotes Cell Migration and Invasion in Gastric Cancer via the Transforming Growth Factor-β Signaling Pathway

Annals of Surgical Oncology - Transient receptor potential vanilloid 2 (TRPV2) is a highly Ca2+-permeable ion channel that is involved in a number of cellular processes. It is expressed in various...     

Chronic kidney disease and clinical outcomes in patients with COVID-19 in Japan

Clinical and Experimental Nephrology - Identifying predictive factors for coronavirus disease 2019 (COVID-19) is crucial for risk stratification and intervention. Kidney dysfunction contributes to...     

Image-guided laparoscopic surgery in an open MRI operating theater

Background

The recent development of open magnetic resonance imaging (MRI) has provided an opportunity for the next stage of image-guided surgical and interventional procedures. The purpose of this study was to evaluate the feasibility of laparoscopic surgery under the pneumoperitoneum with the system of an open MRI operating theater.

Methods

Five patients underwent laparoscopic surgery with a real-time augmented reality navigation system that we previously developed in a horizontal-type 0.4-T open MRI operating theater.

Results

All procedures were performed in an open MRI operating theater. During the operations, the laparoscopic monitor clearly showed the augmented reality models of the intraperitoneal structures, such as the common bile ducts and the urinary bladder, as well as the proper positions of the prosthesis. The navigation frame rate was 8 frames per min. The mean fiducial registration error was 6.88 ± 6.18 mm in navigated cases. We were able to use magnetic resonance–incompatible surgical instruments out of the 5-Gs restriction area, as well as conventional laparoscopic surgery, and we developed a real-time augmented reality navigation system using open MRI.

Conclusions

Laparoscopic surgery with our real-time augmented reality navigation system in the open MRI operating theater is a feasible option.