Preuse/Poststerilization Integrity Testing (PUPSIT): To Do or Not to Do?

In manufacture of heat labile sterile drug products, the final step involves filtration through sterilizing grade filters. It is the drug manufacturer's responsibility to check whether an integral filter has been used. One method used widely to check the integrity of a filter is the bubble point test. To confirm that the filter used is integral, the postuse integrity test is made obligatory by regulatory bodies. However, preuse/poststerilization integrity testing (PUPSIT) of filters remains debatable for the risks associated in its execution. Although PUPSIT is recommended by regulatory bodies, it poses a risk of compromising downstream sterility and involves high costs to mitigate such risks. This study highlights the impact of filter clogging on bubble point values with the consequent possibility of a nonintegral filter passing postuse integrity testing. The results clearly show an increase in postuse bubble point values, which can camouflage a possible flaw in sterilizing filters. The fluid streams 20% dextrose, 0.001% bentonite, paclitaxel, and 0.05% sodium hyaluronate were selected based not only on the commonality of their clogging propensity but also on the different nature of streams that influence the clogging of sterilizing filters. Paclitaxel is an injectable for oncotherapy, and 0.05% sodium hyaluronate is an ophthalmic. The study was conducted with 0.2 µm sterilizing filters from four different manufacturers. It was observed that some fluid streams show a significant increase in the postuse bubble point test values over the preuse bubble point values. This establishes the necessity of performing PUPSIT in certain cases based on the postfiltration shift in bubble point values. As part of the filter validation studies with specific drug products, additional testing should be carried out to establish the need for PUPSIT on a case-by-case basis.

Dose response to Paclitaxel-coated balloon catheters in the porcine coronary overstretch and stent implantation model.

OBJECTIVE: There is little published information regarding the efficacy of paclitaxel-coated balloon catheters except for the iopromide-containing formulation, and less is known about the kind of toxicity at overdose. The aim of our study was to assess 2 different paclitaxel matrix formulations on angioplasty balloon catheters in vitro, with respect to pharmacokinetics, and efficacy and tolerance to determine the minimum effective dose and local toxicity at extremely high dose which is only achieved in experimental studies. METHODS AND MATERIALS: Adherence of coatings was tested in vitro in dry state and during passage through hemostatic valves, guiding catheters, and blood. Drug release, transfer to the vessel wall during coronary angioplasty, inhibition of neointimal proliferation, and tolerance were investigated in swine. Efficacy and tolerance of balloons were examined for doses ranging from 1 to 9 µg/mm2 and 3 overlapping applications of balloons coated with 3 times the regular dose of 3 µg/mm2. Paclitaxel concentrations were determined by high performance liquid chromatography, efficacy and tolerance by vital signs, clinical observation, quantitative coronary angiography, and histomorphometry 4 weeks after implanting premounted bare stents in coronary arteries applying 1:1.2 overstretch. RESULTS: Under worst-case conditions, drug loss on the way through the guiding catheter and blood was in the range of 30%. After inflation of balloons coated with the clinically tested dose of 3 µg/mm2 in a coronary artery about 10% of drug remained on balloons, 20% to 30% was taken up into the vessel wall (∼200 µg). Neointimal area on cross sections was 6.8 ± 2.2 mm2 (uncoated control); 3.1 ± 1.1 mm2 (iopromide-matrix) and 3.0 ± 0.5 mm2 (urea-matrix) at 1 µg/mm2; 2.0 ± 0.4 mm2 versus 1.7 ± 1.1 mm2 at 3 µg/mm2 with no further decrease at higher doses. Thrombotic occlusions were observed in 3 of 15 vessel segments treated with overlapping inflations of 3 high-dose balloons but without any signs of aneurysms. CONCLUSION: In the animal model, 2 paclitaxel matrix formulations were similar in respect of uptake in the vessel wall, and effective already at a dose of 1 µg/mm2. Except thrombotic events for the intentionally excessive dose, paclitaxel-coated balloons were well tolerated in the animal model.

Sirolimus- vs. paclitaxel-eluting stents in patients undergoing off-label percutaneous coronary intervention.

Studies of percutaneous coronary intervention (PCI) with drug-eluting stents in high-risk scenarios are often limited by short follow up and use definitions of "off-label" PCI which do not entirely mirror insert packages recommendations. We analyzed the incidence of cardiovascular events in 1050 consecutive patients undergoing off-label PCI with sirolimus- (n=581) or paclitaxel- (n=469) eluting stents. At 3 years, there were no differences between groups in terms of major cardiovascular events (adjusted hazard ratio 0.991; 95% CI, 0.758 to 1.295; p=0.945), despite slightly higher rates of myocardial infarction and late stent thrombosis seen among patients who received paclitaxel-eluting stents.

Randomized phase II trial of weekly paclitaxel combined with carboplatin versus standard paclitaxel combined with carboplatin for elderly patients with advanced non-small-cell lung cancer.

BACKGROUND: The optimal platinum doublet regimen in elderly patients with non-small-cell lung cancer (NSCLC) is still uncertain. We conducted a randomized phase II study to compare the efficacy and safety of weekly paclitaxel combined with carboplatin with those of the standard schedule. PATIENTS AND METHODS: Elderly patients (age > or =70 years) with advanced NSCLC were randomly assigned to either the weekly arm {70 mg/m(2) paclitaxel on days 1, 8, and 15 and carboplatin [area under the curve (AUC) = 6] on day 1} or the standard arm [200 mg/m(2) paclitaxel and carboplatin (AUC = 6) on day 1]. The primary end point was the overall response rate (ORR). RESULTS: Eighty-two patients were enrolled. The ORR and median progression-free survival were 55% and 6.0 months for the weekly arm and 53% and 5.6 months for the standard arm. Grade 3/4 neutropenia and peripheral neuropathy were observed in 41% and 0% of the patients in the weekly arm and in 88% and 25% in the standard arm, respectively. CONCLUSIONS: This is the first randomized study that compares the platinum doublet designed specifically for the elderly. Regarding the safety, the weekly regimen was less toxic than the standard regimen and seems to be preferable for elderly patients with advanced NSCLC.

Effect of induction chemotherapy and tandem cycles of high-dose chemotherapy on outcomes in autologous stem cell transplant for metastatic breast cancer.

We assessed the effect standard-dose induction chemotherapy and tandem cycles of high-dose chemotherapy (HDC) have on outcomes in metastatic breast cancer. One hundred and one women with metastatic breast cancer were enrolled in two non-randomized phase II studies. The first group of 64 patients (induction group) received four cycles of docetaxel 75 mg/m2 and doxorubicin 50 mg/m2. The next 37 patients did not receive induction (no induction group). Both groups received two (tandem) cycles of HDC. Blood-derived stem cells were collected after the first HDC cycle, processed using CD34+ cell selection and then reinfused after the second HDC cycle. Outcomes were compared between the two groups and also to patients participating in the Philadelphia (inter-group) randomized metastatic breast cancer transplant trial (PBT-01). Intent-to-treat analysis revealed no significant differences in complete response rates (37.5% vs 27%; P = 0.20), overall response (75% vs 71%), median progression free survival (PFS) (11.9 vs 8 months; P = 0.24) and overall survival (OS) (>36 vs 25 months; P = 0.16), in the induction vs no induction groups, respectively. Adjusting for differences in known baseline characteristics, induction group patients were found to have significantly longer PFS (P = 0.002), OS (P = 0.01) and more frequent conversion from a partial to complete response (58% vs < or = 13%, P < or = 0.0002) when compared with PBT-01 patients. Induction chemotherapy administered prior to tandem cycles of HDC does not appear to adversely affect outcomes in metastatic breast cancer patients. Outcomes in our induction group also compare favorably with those observed in PBT-01 and warrant further clinical investigation.

A phase II trial of docetaxel for peripheral blood stem cell mobilization for patients with breast cancer and ovarian cancer.

As docetaxel is known to have significant antineoplastic activity against breast and ovarian cancer, we explored its application as a peripheral blood stem cell mobilizing agent in 33 women with stage lll-IV ovarian carcinoma (n = 10) or stage ll-lV breast cancer (n = 23) who were in preparation for high-dose chemotherapy. Eleven patients had bone and/or bone marrow involvement with their disease. The median number of prior regimens received before mobilization was two (range 1-3). The three dose levels administered were 100 mg/m(2), 110 mg/m(2) and 120 mg/m(2). Patients received one dose of docetaxel in the outpatient setting followed by G-CSF (10 microg/kg/day) starting 4 days after docetaxel administration. Leukapheresis commenced when WBC >1.0 x 10(9)/l or when the WBC began to rise after reaching a nadir. Ninety-seven percent of patients began leukapheresis within 7-9 days after receiving docetaxel (range 7-10 days). The collection goal was >/=2 x 10(6) CD34(+) cells/kg. Twenty-seven (82%) patients reached this goal in a median of 2 leukapheresis days (range 1-3). No grade 2-4 nonhematologic toxicities were noted. Thirteen patients (55%) showed a WBC nadir >1.0 x 10(9)/l. None of the patients experienced neutropenic fever or required blood or platelet transfusion support. In conclusion, docetaxel + G-CSF is an effective, well-tolerated regimen for PBPC mobilization which can be safely administered in the outpatient setting with minimal toxicity.

A short course of induction chemotherapy followed by two cycles of high-dose chemotherapy with stem cell rescue for chemotherapy naive metastatic breast cancer.

A single cycle of high-dose chemotherapy with stem cell support (HDC) in women with responsive metastatic breast cancer (BC) consistently achieves over 50% complete and near complete response (CR/nCR). This significant cytoreduction results in a median event-free survival (EFS) of 8 months, and approximately 20% 3-year and 16% 5-year EFS in selected patients. To improve long-term outcomes, new strategies to treat minimal residual tumor burden are needed. Increased total dose delivered can be achieved with two cycles of HDC. Critical design issues include shortening induction chemotherapy to avoid development of drug resistance and the use of different agents for each HDC cycle. We have determined the maximum tolerated dose (MTD) for paclitaxel combined with high-dose melphalan in the context of a double transplant and explored the impact of a short induction phase. Between June 1994 and August 1996, we enrolled 32 women with metastatic BC on to this phase I double transplant trial. Induction consisted of doxorubicin 30 mg/m2/day days 1-3 given for 2 cycles every 14 days with G-CSF 5 microg/kg s.c. days 4-12. Stem cell collection was performed by leukapheresis in each cycle when the WBC recovered to above 1000/microl. Patients with stable disease or better response to induction were eligible to proceed with HDC. HDC regimen I (TxM) included paclitaxel with dose escalation from 0 to 300 mg/m2 given on day 1 and melphalan 180 mg/m2 in two divided doses given on day 3. HDC regimen II was CTCb (cyclophosphamide 6 g/m2, thiotepa 500 mg/m2, and carboplatin 800 mg/m2 total doses) delivered by 96-h continuous infusion. At the first dose level of 150 mg/m2 paclitaxel by 3 h infusion, four of five patients developed dose-limiting toxicity consisting of diffuse skin erythema and capillary leak syndrome. Only two of these five completed the second transplant. Subsequently, paclitaxel was delivered by 24-h continuous infusion together with 96 h of dexamethasone and histamine receptor blockade. This particular toxicity was not observed again. No toxic deaths occurred and dose-limiting toxicity was not encountered. Three patients were removed from study prior to transplant: one for insurance refusal and two for disease progression. All others completed both cycles of transplant. Complete and near complete response (CR/nCR) after completion of therapy was achieved in 23 (72%) of 32 patients. The median EFS is 26 months. The median overall survival has not yet been reached. At a median follow-up of 58 months, EFS and overall survival are 41% and 53%, respectively. This double transplant approach is feasible, safe, and tolerable. Treatment duration is only 14 weeks and eliminates lengthy induction chemotherapy. The observed event-free and overall survivals are promising and are better than expected following a single transplant. Whilst selection biases may in part contribute to this effect, a much larger phase II double transplant trial is warranted in preparation for a potential randomized comparison of standard therapy vs single vs double transplant.

Mobilization of peripheral blood stem cells in high-risk breast cancer patients using G-CSF after standard dose docetaxel.

Chemotherapy, in addition to recombinant growth factors, has been effective in mobilizing stem cells. Unfortunately, the use of chemotherapy for this purpose has resulted in profound myelosuppression and increased morbidity. Docetaxel, the single most active agent in the treatment of advanced breast cancer, was evaluated for its potential to mobilize stem cells when given at conventional doses followed by granulocyte colony-stimulating factor (G-CSF). Sixteen high-risk breast cancer patients were mobilized with a regimen consisting of docetaxel (100 mg/m2) followed by daily G-CSF (10 microg/kg), beginning 72 h after the docetaxel, and continuing until completion of the apheresis. The median white blood cell count (WBC) nadir was 1,000/microl (range 500 to 4000/microl ) occurring a median of 6 days (range 4 to 9 days) after the docetaxel. No patient experienced a neutropenic febrile episode due to the mobilization regimen. The median time interval for initiating the apheresis was 8 days (range 6 to 11 days) following the docetaxel. The median number of apheresis was 2 (range 1 to 3) in each patient. Stem cell recovery as measured by the CD34 cell count x 10(6)/kg was a median of 5.2 (range 1.4 to 15.1). A significant correlation was found between CFU-GM, BFU-E, and CFU-GEMM/kg and CD34 cells/kg (r = 0.891, 0.945, and 0.749, respectively, p < 0.001). When our results were compared to a matched cohort receiving G-CSF alone, the docetaxel group demonstrated a superior CD34 cells/kg yield (p = <0.001). Following myeloablative chemotherapy consisting of thiotepa and cyclophosphamide with or without carboplatinum, the hematopoetic recovery determined by an absolute neutrophil count (ANC) of greater than 500/microl and an unsupported platelet count of > or =20,000/microl for 48 h, was a median of 10 days (range 9 to 14 days) and 10 days (range 8 to 30 days), respectively. The results demonstrate that conventional dose docetaxel, combined with G-CSF, is an effective mobilization regimen with minimal toxicity in high-risk breast cancer patients.

[What has been done for international harmonization and what remains to be solved?].

With the idea of expediting drug development and increasing the availability of new medicines to patients, the International Conference on Harmonization (ICH) was organized more than five years ago. Since then, significant progress has been made toward harmonizing preclinical and clinical requirements for the development of medicinal products. For companies whose drug development strategy is global and ongoing in different countries, international harmonization has been an important subject for R&D strategy as well as a critical target that must be achieved. Rhône-Poulenc Rorer, a multi national pharmaceutical company, has globally developed an anti cancer drug, docetaxel, in midstream of international harmonization efforts, and faced various difficulties related to international harmonization. In this paper, based on the author's preclinical experience obtained from the development of docetaxel, various approaches in addressing ICH related difficulties/problems and pending issues are described. In conclusion, the author acknowledges that ICH has made a significant achievement in harmonizing the requirements in certain areas of drug development. However, it seems that even a joint effort of ICH participants, pharmaceutical industry and regulatory agencies may not be enough to address social difficulties associated with drug development rather than scientific discipline. Among many other classes of drugs, the relationship with society appears to be most complicated in anti-cancer drug development, specifically at the clinical level, in which cancer patients are recruited for Phase I study. Finally, as a future target of ICH, harmonization efforts on the way NDA dossiers are appraised and processed across tri-partite regulatory authorities is of great interest for international pharmaceutical enterprises.

Comparative studies of taxol and taxotere on tumor growth and lymphocyte functions.

Taxotere, a semisynthetic derivative similar to taxol, has shown promising results in vitro and in preliminary in vivo studies. We have previously reported that taxol at 10 micrograms/ml suppressed the cytotoxic function and activation of natural killer cells and major histocompatibility nonrestricted (MHC-NR) T cells against the ovarian cell line OV-2774 and the erythroleukemia cell line K-562. In this paper, we investigated the effect of taxotere on lymphocyte function and found that a suppression of MHC-NR cytotoxicity of naive lymphocytes is only seen at higher doses of taxotere (50 micrograms/ml). At the concentrations of 10 and 50 micrograms/ml, taxotere did not have any effect on the cytotoxic function of IL-2-preactivated lymphocytes. On the contrary, both taxol and taxotere caused a significant suppression of lymphocyte growth and activation with IL-2 at 10 and 50 micrograms/ml. Both drugs (at the concentration of 10 micrograms/ml) were potent inhibitors of the growth of the tumor cell lines OV-2774 and K-562. In conclusion, despite the fact that taxotere shares with taxol a potent antitumor effect, it seems to be less suppressive for lymphocyte cytotoxicity, an effect clearly desirable in cancer therapy.