Update on Intraperitoneal Chemotherapy for the Treatment of Epithelial Ovarian Cancer

Surgical treatment and chemotherapy administration in women with epithelial ovarian cancer is more controversial today than at any point in the last 3 decades. The use of chemotherapy administered intraperitoneally has been particularly contentious. Three large randomized phase III studies, multiple meta-analyses, and now real-world data have demonstrated substantial outcome benefit for the use of chemotherapy administered intraperitoneally versus intravenously for first-line postoperative treatment of optimally debulked advanced ovarian cancer. Unfortunately, for each of these randomized studies, there was scope to either criticize the design or otherwise refute adoption of this route of administration. As a result, the uptake has been variable in North America, although in Europe it has been practically nonexistent. Reasons for this include unquestionable additional toxicity, more inconvenience, and extra cost. However, 10-year follow up of these studies demonstrates unprecedented survival in the intraperitoneal arm (median survival 110 months in patients with completely debulked stage III), raising the possibility that by combining maximal debulking surgery with postoperative intraperitoneal chemotherapy it may be possible to bring about a step change in the outcomes for these patients. In this review, we discuss the rationale for administering chemotherapy intraperitoneally, the merits of the main randomized clinical trials, the evidence regarding optimal regimes, issues of toxicity, port considerations, and reasons for lack of universal adoption. We also explore potential clinical and biologic factors that may be useful for patient selection in the future.

Intraperitoneal clearance as a potential biomarker of cisplatin after intraperitoneal perioperative chemotherapy: a population pharmacokinetic study

Background:

Intraperitoneal (IP) perioperative chemotherapy with cisplatin is an interesting option in ovarian cancer treatment. A combination of cisplatin with IP epinephrine (already shown to improve IP and decrease systemic platinum (Pt) exposure) was evaluated using a population pharmacokinetic analysis.

Methods:

Data from 55 patients treated with cisplatin-based IP perioperative chemotherapy with (n=26) or without (n=29) epinephrine were analysed using NONMEM.

Results:

Epinephrine halves clearance between peritoneum and serum (IPCL) and increases the Pt central volume of distribution, IP exposure and penetration in tissue. IPCL has a better predictive value than any other parameter with respect to renal toxicity.

Conclusion:

This confirms that IPCL could be useful in assessing renal toxicity. As IPCL is also linked to tissue penetration and IP exposure, it may be proposed as biomarker. In addition to a Bayesian estimation, we propose a single-sample calculation-way to assess it. Prospective studies are needed to validate IPCL as a biomarker in this context.

Optimal sampling strategy development methodology using maximum a posteriori Bayesian estimation

Maximum a posteriori Bayesian (MAPB) pharmacokinetic parameter estimation is an accurate and flexible method of estimating individual pharmacokinetic parameters using individual blood concentrations and prior information. In the past decade, many studies have developed optimal sampling strategies to estimate pharmacokinetic parameters as accurately as possible using either multiple regression analysis or MAPB estimation. This has been done for many drugs, especially immunosuppressants and anticancer agents. Methods of development for optimal sampling strategies (OSS) are diverse and heterogeneous. This review provides a comprehensive overview of OSS development methodology using MAPB pharmacokinetic parameter estimation, determines the transferability of published OSSs, and compares sampling strategies determined by MAPB estimation and multiple regression analysis. OSS development has the following components: 1) prior distributions; 2) reference value determination; 3) optimal sampling time identification; and 4) validation of the OSS. Published OSSs often lack all data necessary for the OSS to be clinically transferable. MAPB estimation is similar to multiple regression analysis in terms of predictive performance but superior in flexibility.

Reducing excessive toxicity in ovarian cancer treatment: a personalized approach

The management of ovarian cancer is not only multifactorial, but also patient-specific. Different treatment modalities lead to varying levels of toxicity and individual patient responses, necessitating a personalized approach to each treatment plan. Surgical treatment along with first-line and salvage chemotherapies, are standard modalities but recent innovations in chemotherapy delivery and innovative therapy with mechanism of action are reviewed in this article. Extensive experience with standard chemotherapy has outlined algorithms for managing various toxicities. The focus of treatment may ultimately point towards palliative care and clinicians must be comfortable and well versed in addressing this important option. Overall, management of ovarian cancer requires a multi-faceted approach, keeping the patients’ overall health, curative goals and well-being at the forefront. It is nearly impossible to detail exact management plans for every possible toxicity for every patient; formulating personalized treatment plans should be based on evidence and clinician experience, all part of the art of medicine. The objective of this article is to highlight the most frequently encountered and most limiting toxicities of current standard therapies for epithelial ovarian cancer.

Population pharmacokinetics of the humanised monoclonal antibody, HuHMFG1 (AS1402), derived from a phase I study on breast cancer

Background:

HuHMFG1 (AS1402) is a humanised monoclonal antibody that has undergone a phase I trial in metastatic breast cancer. The aim of this study was to characterise the pharmacokinetics (PKs) of HuHMFG1 using a population PK model.

Method:

Data were derived from a phase I study of 26 patients receiving HuHMFG1 at doses ranging from 1 to 16 mg kg⁻¹. Data were analysed using NONMEM software and covariates were included. A limited sampling strategy (LSS) was developed using training and a validation data set.

Results:

A linear two-compartment model was shown to be adequate to describe data. Covariate analysis indicated that weight was not related to clearance. An LSS was successfully developed on the basis of the model, in which one sample is collected immediately before the start of an infusion and the second is taken at the end of infusion.

Conclusion:

A two-compartment population PK model successfully describes HuHMFG1 behaviour. The model suggests using a fixed dose of HuHMFG1, which would simplify dosing. The model could be used to optimise dose level and dosing schedule if more data on the correlation between exposure and efficacy become available from future studies. The derived LSS could optimise further PK assessment of this antibody.