Impact of simulated lung fluid components on the solubility of inhaled drugs and predicted in vivo performance

Orally inhaled products (OIPs) are gaining increased attention, as pulmonary delivery is a preferred route for the treatment of various diseases. Yet, the field of inhalation biopharmaceutics is still in development phase. For a successful correlation between various in vitro data obtained during formulation characterization and in vivo performance, it is necessary to understand the impact of parameters such as solubility and dissolution of drugs. In this work, we used in vitro-in silico feedback-feedforward approach to gain a better insight into the biopharmaceutics behavior of inhaled Salbutamol Sulphate (SS) and Budesonide (BUD). The thorough characterization of the in vitro test media and the impact of different in vitro fluid components such as lipids and protein on the solubility of aforementioned drugs was studied. These results were subsequently used as an input into the developed in silico models to investigate potential PK parameter changes in vivo. Results revealed that media comprising lipids and albumin were the most biorelevant and impacted the solubility of BUD the most. On the contrary, no notable impact was seen in case of SS. The use of simple media such as phosphate buffer saline (PBS) might be sufficient to use in solubility studies of the highly soluble and permeable drugs. However, its use for the poorly soluble drugs is limited due to the greater potential for interactions within in vivo environment. The use of in silico tools showed that the model response varies, depending on the used media. Therefore, this work highlights the relevance of carefully selecting the media composition when investigating solubility and dissolution behavior, especially in the early phases of drug development and of poorly soluble drugs.

Prazosin induced lysosomal tubulation interferes with cytokinesis and the endocytic sorting of the tumour antigen CD98hc

The quinazoline based drug prazosin (PRZ) is a potent inducer of apoptosis in human cancer cells. We recently reported that PRZ enters cells via endocytosis and induces tubulation of the endolysosomal system. In a proteomics approach aimed at identifying potential membrane proteins with binding affinity to quinazolines, we detected the oncoprotein CD98hc. We confirmed shuttling of CD98hc towards lysosomes and upregulation of CD98hc expression in PRZ treated cells. Gene knockout (KO) experiments revealed that endocytosis of PRZ still occurs in the absence of CD98hc - suggesting that PRZ does not enter the cell via CD98hc but misroutes the protein towards tubular lysosomes. Lysosomal tubulation interfered with completion of cytokinesis and provoked endoreplication. CD98hc KO cells showed reduced endoreplication capacity and lower sensitivity towards PRZ induced apoptosis than wild type cells. Thus, loss of CD98hc does not affect endocytosis of PRZ and lysosomal tubulation, but the ability for endoreplication and survival of cells. Furthermore, we found that glutamine, lysomototropic agents - namely chloroquine and NH4Cl - as well as inhibition of v-ATPase, interfere with the intracellular transport of CD98hc. In summary, our study further emphasizes lysosomes as target organelles to inhibit proliferation and to induce cell death in cancer. Most importantly, we demonstrate for the first time that the intracellular trafficking of CD98hc can be modulated by small molecules. Since CD98hc is considered as a potential drug target in several types of human malignancies, our study possesses translational significance suggesting, that old drugs are able to act on a novel target.

Zoledronic acid combined with adjuvant endocrine therapy of tamoxifen versus anastrozol plus ovarian function suppression in premenopausal early breast cancer: final analysis of the Austrian Breast and Colorectal Cancer Study Group Trial 12

BACKGROUND

Zoledronic acid (ZOL) plus adjuvant endocrine therapy significantly improved disease-free survival (DFS) at 48- and 62-month follow-up in the ABCSG-12 trial. We present efficacy results of a final additional analysis after 94.4 months.

PATIENTS AND METHODS

Patients were premenopausal women who had undergone primary surgery for stage I/II estrogen-receptor-positive and/or progesterone-receptor-positive breast cancer with <10 positive lymph nodes, and were scheduled for standard goserelin therapy. All 1803 patients received goserelin (3.6 mg every 28 days) and were randomized to tamoxifen (20 mg/days) or anastrozole (1 mg/days), both with or without ZOL (4 mg every 6 months) for 3 years. The primary end point was DFS; recurrence-free survival and overall survival (OS) were secondary end points.

RESULTS

After 94.4-month median follow-up (range, 0-114 months), relative risks of disease progression [hazard ratio (HR) = 0.77; 95% confidence interval (CI) 0.60-0.99; P = 0.042] and of death (HR = 0.66; 95% CI 0.43-1.02; P = 0.064) are still reduced by ZOL although no longer significant at the predefined significance level. Overall, 251 DFS events and 86 deaths were reported. Absolute risk reductions with ZOL were 3.4% for DFS and 2.2% for OS. There was no DFS difference between tamoxifen alone versus anastrozole alone, but there was a pronounced higher risk of death for anastrozole-treated patients (HR = 1.63; 95% CI 1.05-1.45; P = 0.030). Treatments were generally well tolerated, with no reports of renal failure or osteonecrosis of the jaw.

CONCLUSION

These final results from ABCSG 12 suggest that twice-yearly ZOL enhances the efficacy of adjuvant endocrine treatment, and this benefit is maintained long-term.

CLINICALTRIALSGOV

NCT00295646 (http://www.clinicaltrials.gov/ct2/results?term=00295646).

Abstract P5-11-02: The Carry-Over Effect of Adjuvant Zoledronic Acid: Comparison of 48- and 62-Month Analyses of ABCSG-12 Suggests That the Benefits of Combining Zoledronic Acid with Adjuvant Endocrine Therapy Persist Long after Completion of Therapy

Background: ABCSG-12 examined the efficacy of ovarian suppression using goserelin combined with tamoxifen (TAM) or anastrozole (ANA) ± zoledronic acid (ZOL) in premenopausal patients with endocrine-responsive early breast cancer. Results at 48 months and at 62 months show that adding ZOL significantly improved disease-free survival (DFS) and reduced disease recurrence.

Methods: Premenopausal patients with endocrine-responsive early breast cancer (N = 1,803) were randomized to goserelin (3.6 mg q28d) and TAM (20 mg/d) or ANA (1 mg/d) ± ZOL (4 mg q6mo) for 3 years. Endpoints included DFS and overall survival, both analyzed using log-rank test and Cox models.

Results: At 48 months’ median follow-up, ZOL significantly reduced the risk of DFS events by 36% versus no-ZOL (hazard ratio [HR] = 0.64; P = .01); this was maintained at 62 months’ follow-up (HR = 0.68; P = .009). In addition, the trend toward reduced risk of death with ZOL was maintained at both 48 months (HR = 0.60; P = .11) and 62 months (HR = 0.66; P = .10) compared with no-ZOL. Patients receiving ZOL also had fewer distant recurrences compared with no-ZOL: 29 versus 41 events at 48 months, and 44 versus 56 events at 62 months. No significant renal adverse events or confirmed cases of osteonecrosis of the jaw (ONJ) have been reported.

Conclusions: Comparisons of 48- and 62-month data suggest a possible carry-over of the ZOL anticancer benefit 2 years after treatment completion. Additional analyses will be presented, including disease outcomes during therapy and after treatment, as well as overall survival analyses.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-11-02.

The number needed to treat (NNT) as a measure of drug efficacy: the case of zoledronic acid for early hormone-responsive breast cancer in the ABCSG-12 trial

Abstract #2113

Background: Zoledronic acid (ZOL) has demonstrated antitumor and antimetastatic activities in preclinical and early clinical studies in many cancer types. The Austrian Breast and Colorectal Cancer Study Group Trial 12 (ABCSG-12) examined the efficacy of adjuvant therapy in premenopausal women with hormone-responsive early breast cancer receiving goserelin (GOS) + anastrozole (ANA) or tamoxifen (TAM), both ± ZOL. In this trial, ZOL significantly prolonged disease-free survival (DFS) and recurrence-free survival (RFS) versus no ZOL. However, in addition to relative risk reduction, the potential for patients to benefit from a treatment is an important consideration. The number needed to treat (NNT) represents an estimation of the number of patients that have to be treated with an investigational drug for 1 patient to receive clinical benefit within a specific follow-up period. NNT is a powerful, clinically relevant measure of efficacy that can provide a real-world perspective on the efficacy results from clinical trials. Methods: 1,803 patients were randomized to GOS (3.6 mg/28 d SC) + TAM (20 mg/d PO) ± ZOL (4 mg/ 6 mos IV) or GOS + ANA (1 mg/d PO) ± ZOL for 3y. Endpoints at 60 mos for TAM vs ANA and ZOL vs no ZOL were DFS (primary), RFS, overall survival and safety. NNT was calculated for ZOL with respect to DFS and RFS, and compared with other paradigm-changing cancer therapies. Results: After 60 mos median follow-up, ZOL significantly reduced the risk of DFS events by 36% (P = .01) and RFS events by 35% (P = .02) vs no ZOL. For ZOL therapy, NNT = 31 and NNT = 33 to prevent 1 DFS or 1 RFS event respectively at a median follow-up of 60 months. In comparison, the NNT with respect to DFS is 28 for paclitaxel (60-69 months follow-up) and 31 for docetaxel (43-60 months follow-up). Moreover, ZOL was generally well tolerated, and neither ONJ nor renal toxicity was an issue in this setting. Conclusions: The NNT is a simple and effective method to assess clinical trial results that will have relevance to daily practice. In the current comparisons, the NNT for ZOL plus endocrine therapy in ABCSG-12 was similar to the NNTs for taxanes. Therefore the addition of ZOL provides DFS and RFS benefits of magnitudes similar to those from practice-changing chemotherapies like taxanes.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2113.

[Results of surgical treatment of pregnancy-associated pelvic vein thrombosis]

We report the results of surgical treatment of iliofemoral vein thrombosis in 49 pregnant women in a seven years period. The patients mean age was 26.5 years (range 18-41 years). Isolated descending pelvic vein thrombosis (PVT) occurred between the 20th and 36th week of pregnancy and was located predominantly left sided. 89.8% of PVT developed in the late period of gestation, three cases of pelvic vein thrombosis were diagnosed after vaginal delivery. An iliac vein spur in one patient and an AT-III deficiency in two cases were registered as additional risk factors. After venous catheter thrombectomy an arteriovenous fistula between the superficial femoral artery and the femoral vein was performed to increase blood flow and velocity in the pelvic veins. Abdominal delivery was performed simultaneously, if thrombosis occurred after the 34th week of pregnancy. Late re-thrombosis was registered in 4 patients (9.0%) after a mean follow-up of 42 months. We have seen symptoms of mild, not life threatening pulmonary embolism in two patients on the first postoperative day (complication rate 4.0%). Re-occlusion rate was high (3/5) after surgical thrombectomy carried out between the 20th and 26th week of gestation. Risk factors were an AT III deficiency in two cases and the continued compression syndrome of the pelvic veins caused by the enlarging uterus. In the late period of gestation surgical thrombectomy of PVT is the preferential method of treatment in selected patients with good therapeutical results. The operation reduces the risk of future venous insufficiency and post-thrombotic syndrome in the young female patients.