[Clinical trial of chemotherapy identified according to chemosensitivity assay for oral cancer patients with unresectable recurrent lesions]

Identification of the optimal cetuximab concentration that is effective against oral squamous cell carcinoma in collagen gel droplet embedded culture drug sensitivity testing

Anticancer drug sensitivity testing using the collagen gel droplet embedded culture drug sensitivity test (CD-DST) on oral squamous cell carcinoma (OSCC) samples beginning from 2010 has been conducted. The present study investigated the effect of adding cetuximab (Erbitux^®), a molecularly targeted drug, on anticancer drug activity against clinical OSCC specimens. A total of 25 specimens were obtained from 25 patients with OSCC between October 2013 and December 2017. The present study conducted anticancer drug sensitivity testing for cisplatin (CDDP), 5-fluorouracil (5-FU), cetuximab, three-drug combination, single agent and multi drug combinations, and cetuximab addition to the aforementioned regimens using CD-DST. In addition, the optimum concentration of each drug was evaluated. The overall evaluation success rate of the CD-DST method for OSCC specimens was 84.0% (21 of 25 cases); sensitivity to anticancer drugs and cetuximab could be evaluated. The in vitro efficacy rate of a cetuximab single agent and CDDP + 5-FU (PF) at a cut-off value of 50% was similar to the known clinical response rate. However, at a cut-off value of 50%, the in vitro efficacy of PF + cetuximab was calculated to be 40%, which was higher than the clinical response rate. The CD-DST method could be used to evaluate cetuximab, a molecularly targeted drug. Furthermore, its additive effect on conventional chemotherapy could be evaluated. The CD-DST method is suitable for evaluating and selecting chemotherapy regimens, including molecularly targeted drugs. Future studies are required to generate and evaluate relevant clinical data.

Collagen gel droplet-embedded culture drug sensitivity testing in squamous cell carcinoma cell lines derived from human oral cancers: Optimal contact concentrations of cisplatin and fluorouracil

The collagen gel droplet-embedded culture drug sensitivity test (CD-DST) is an anticancer drug sensitivity test that uses a method of three-dimensional culture of extremely small samples, and it is suited to primary cultures of human cancer cells. It is a useful method for oral squamous cell carcinoma (OSCC), in which the cancer tissues available for testing are limited. However, since the optimal contact concentrations of anticancer drugs have yet to be established in OSCC, CD-DST for detecting drug sensitivities of OSCC is currently performed by applying the optimal contact concentrations for stomach cancer. In the present study, squamous carcinoma cell lines from human oral cancer were used to investigate the optimal contact concentrations of cisplatin (CDDP) and fluorouracil (5-FU) during CD-DST for OSCC. CD-DST was performed in 7 squamous cell carcinoma cell lines derived from human oral cancers (Ca9-22, HSC-3, HSC-4, HO-1-N-1, KON, OSC-19 and SAS) using CDDP (0.15, 0.3, 1.25, 2.5, 5.0 and 10.0 µg/ml) and 5-FU (0.4, 0.9, 1.8, 3.8, 7.5, 15.0 and 30.0 µg/ml), and the optimal contact concentrations were calculated from the clinical response rate of OSCC to single-drug treatment and the in vitro efficacy rate curve. The optimal concentrations were 0.5 µg/ml for CDDP and 0.7 µg/ml for 5-FU. The antitumor efficacy of CDDP at this optimal contact concentration in CD-DST was compared to the antitumor efficacy in the nude mouse method. The T/C values, which were calculated as the ratio of the colony volume of the treatment group and the colony volume of the control group, at the optimal contact concentration of CDDP and of the nude mouse method were almost in agreement (P<0.05) and predicted clinical efficacy, indicating that the calculated optimal contact concentration is valid. Therefore, chemotherapy for OSCC based on anticancer drug sensitivity tests offers patients a greater freedom of choice and is likely to assume a greater importance in the selection of treatment from the perspectives of function preservation and quality of life, as well as representing a treatment option for unresectable, intractable or recurrent cases.

Formulation design and pharmaceutical development of a novel controlled release form of azithromycin for single-dose therapy

BACKGROUND

Azithromycin's long serum half-life (approximately 68 hours) allows for a short 5-day, 3-day, and now 1-day course therapy with a large 2-g dose. Although the single-dose, 1-day therapy offers the advantage of 100% patient compliance, tolerance of such large dose becomes an issue.

METHODS

The dosage form discussed in this article employed a melt-congealing process to produce matrix microspheres with a 3-hour, first-order release. The vehicle blend included alkalizing agents to minimize GI side effects, minimize loss of bioavailability, and mask the bitter taste of azithromycin.

RESULTS

Azithromycin microspheres are small (approximately 200 microm) with a narrow particle size distribution. Drug release was optimized by controlling the amount of dissolution enhancer in the microspheres and by the addition of proper amount of alkalizing agents in the vehicle blend. The final formulation was selected based on a balance between bioavailability and tolerability.

CONCLUSIONS

Drug release from the microspheres was shown to occur via diffusion through the larger pores formed by dissolution of azithromycin crystals and the smaller interconnected pores formed by dissolution of poloxamer. Several clinical studies have been conducted with the formulation to evaluate its pharmacokinetics and to demonstrate its safety and efficacy. The combined suspension formulation for a 2-g dose of azithromycin provided taste-masking and good tolerability.