Different porcine reproductive and respiratory syndrome (PRRS) vaccine regimes and its effect on pig immunity status at Southeast Asia pig farms

Porcine reproductive and respiratory syndrome (PRRS) is a disease characterised by late-term reproductive failure in sows and gilts, and respiratory problems in piglets and growing pigs. In this study, 240 sera were collected from four farms that had been practicing different PRRS vaccination regime for more than a year and vaccinations were done at 2 months before sampling. Fifteen sera samples from four age groups: sows, growers, weaners and piglets were collected from each farm and analysed using IDEXX PRRS X3 ELISA for PRRSV antibodies. Pooled serum samples were tested by using nested-PCR that enable the differentiation of Type I and Type II PRRSV. Out of 80 pooled serum samples, none were positive for PRRSV indicating all age groups were not viraemic after vaccination. Results by ELISA test showed all the farms were seropositive for PRRS. ELISA testing showed no significant difference between the farms except for Farm B which practised whole herd US MLV vaccination. Farm B showed significantly lower (p<0.05) S/P ratio in their piglet, grower and sow groups which suggest there was low virus circulation in herd. Farm A which practised US MLV on sow was the only farm found to have seronegative status in their weaners. Data indicates PRRS MLV vaccination will not cause viraemia post four weeks vaccination and whole herd MLV vaccination may help to reduce virus circulation in PRRS endemic farm.

A phase I study of palifosfamide in combination with doxorubicin: Safety and preliminary efficacy

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Background: Palifosfamide, a bi-functional DNA alkylator is the active metabolite of ifosfamide (IFOS), that lacks the toxicity associated with non-active IFOS metabolites and does not require activation. Recent phase II data shows single agent activity in advanced refractory sarcoma. Marked preclinical synergistic efficacy of palifosfamide in combination with doxorubicin provides a strong rationale for clinical evaluation of this combination regimen. Methods: Eligible subjects with advanced refractory tumors were included if no standard therapy exists and if doxorubicin treatment is medically acceptable. Palifosfamide was administered on days 1 - 3 of a 21 day cycle, starting dose of 100 mg/m2. Doxorubicin was administered on day 1 of 21 day cycle, starting dose of 60 mg/m2. Dose was escalated up to MTD or palifosfamide 150 mg/mg2, doxorubicin 75 mg/m2. Pharmacokinetics (PK) for palifosfamide were determined and compared to those obtained in murine PK/efficacy studies. Results: 13 patients with advanced tumors (8 with soft tissue sarcoma - STS, 5 with SCLC, neuroendocrine and osteosarcoma) have been treated with 8 patients still on treatment. All had ECOG PS <2, median age was 58, and 3 had received prior IFOS. With 51 cycles administered, the combination has been well tolerated, with no dose-limiting toxicities reported. Pts did not receive Mesna or hydration. Study-related Grade 3/4 adverse events include neutropenia and thrombocytopenia. PK evaluation indicates that palifosfamide exposure and Cmax at clinically well-tolerated doses are comparable with those in murine models resulting in marked synergy with doxorubicin. Efficacy in 12 evaluable pts: 3/12 PRs, (2/8 PRs for STS); PFS median duration 20 weeks and ongoing. Conclusions: Palifosfamide in combination with doxorubicin is easy to administer, and has been very well tolerated with no encephalopathy, no hemorrhagic cystitis and no renal toxicity. Early efficacy data has prompted an ongoing randomized phase II study in STS comparing doxorubicin 75 mg/m2 to palifosfamide 150 mg/m2 + doxorubicin 75 mg/m2.

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Aprepitant in adolescent patients for prevention of chemotherapy-induced nausea and vomiting: a randomized, double-blind, placebo-controlled study of efficacy and tolerability

BACKGROUND

The neurokinin-1 receptor antagonist aprepitant, plus a 5HT3 antagonist and corticosteroid is well-tolerated and effective in preventing chemotherapy-induced nausea and vomiting in adults but has not been formally assessed in adolescents.

PROCEDURE

Patients age 11-19 years old receiving emetogenic chemotherapy were randomized 2:1 to aprepitant triple therapy (aprepitant [A] 125 mg p.o., dexamethasone [D] 8 mg p.o., and ondansetron [O] 0.15 mg/kg i.v. t.i.d. day 1; A 80 mg, D 4 mg, and O 0.15 mg/kg t.i.d. day 2; A 80 mg and D 4 mg day 3; and D 4 mg day 4) or a control regimen (D 16 mg and O 0.15 mg/kg t.i.d. day 1; D 8 mg and O 0.15 mg/kg t.i.d. day 2; and D 8 mg days 3 and 4). The primary endpoint was the difference in drug-related adverse events during and for 14 days following treatment. Efficacy and aprepitant pharmacokinetics were assessed.

RESULTS

Baseline characteristics were similar between aprepitant (N = 28) and control (N = 18) groups. Febrile neutropenia was more frequent in the aprepitant group (25% vs. 11.1%). Complete response (CR) rates were 35.7% for aprepitant triple therapy versus 5.6% for the control group. Mean plasma aprepitant AUC(0-24 hr) and C(max) on day 1 and mean trough concentrations on days 2 and 3 were consistently lower compared to historical data obtained from healthy adults; however, the differences were not clinically significant.

CONCLUSION

Aprepitant triple therapy was generally well tolerated; CR were greater with aprepitant, although not statistically significant. Pharmacokinetics suggest that the adult dosing regimen is appropriate for adolescents.