A phase II/III randomized study to compare the efficacy and safety of rigosertib plus gemcitabine versus gemcitabine alone in patients with previously untreated metastatic pancreatic cancer.

BACKGROUND: Rigosertib (ON 01910.Na), a first-in-class Ras mimetic and small-molecule inhibitor of multiple signaling pathways including polo-like kinase 1 (PLK1) and phosphoinositide 3-kinase (PI3K), has shown efficacy in preclinical pancreatic cancer models. In this study, rigosertib was assessed in combination with gemcitabine in patients with treatment-naïve metastatic pancreatic adenocarcinoma. MATERIALS AND METHODS: Patients with metastatic pancreatic adenocarcinoma were randomized in a 2:1 fashion to gemcitabine 1000 mg/m(2) weekly for 3 weeks of a 4-week cycle plus rigosertib 1800 mg/m(2) via 2-h continuous IV infusions given twice weekly for 3 weeks of a 4-week cycle (RIG + GEM) versus gemcitabine 1000 mg/m(2) weekly for 3 weeks in a 4-week cycle (GEM). RESULTS: A total of 160 patients were enrolled globally and randomly assigned to RIG + GEM (106 patients) or GEM (54). The most common grade 3 or higher adverse events were neutropenia (8% in the RIG + GEM group versus 6% in the GEM group), hyponatremia (17% versus 4%), and anemia (8% versus 4%). The median overall survival was 6.1 months for RIG + GEM versus 6.4 months for GEM [hazard ratio (HR), 1.24; 95% confidence interval (CI) 0.85-1.81]. The median progression-free survival was 3.4 months for both groups (HR = 0.96; 95% CI 0.68-1.36). The partial response rate was 19% versus 13% for RIG + GEM versus GEM, respectively. Of 64 tumor samples sent for molecular analysis, 47 were adequate for multiplex genetic testing and 41 were positive for mutations. The majority of cases had KRAS gene mutations (40 cases). Other mutations detected included TP53 (13 cases) and PIK3CA (1 case). No correlation between mutational status and efficacy was detected. CONCLUSIONS: The combination of RIG + GEM failed to demonstrate an improvement in survival or response compared with GEM in patients with metastatic pancreatic adenocarcinoma. Rigosertib showed a similar safety profile to that seen in previous trials using the IV formulation.

Phase II study of iproplatin (CHIP) in previously treated small-cell lung cancer.

Eighteen patients with previously treated extensive small-cell carcinoma of the lung were entered into a Phase II study employing iproplatin (CHIP), a cis-platin analog. Patients had received a mean of two prior chemotherapeutic regimens. Fifty-five percent had received prior cis-platinum and 33% had received prior radiation therapy. CHIP (225 mg/m2) was administered by intermittent intravenous infusion over 30 min for 5 days of a 28-day cycle without prehydration. Sixteen patients with Zubrod performance scores of less than or equal to 3 received 27 courses of therapy (mean 1.7, range 1-6). One partial response of 167 days duration was observed, with complete regression of involved lymph nodes and stabilization of nonevaluable disease in the chest. Six patients had stable disease following one cycle of CHIP, but all progressed following a second cycle of drug. The main toxicity was myelosuppression with prominent thrombocytopenia. Median survival was 75 days from initiation of therapy. In this group of heavily pretreated patients with advanced disease, iproplatin has only minimal activity as a single agent and does not show non-cross-resistance with cis-platinum.

Thrombotic thrombocytopenic purpura: treatment with plasmapheresis.

Twenty-one episodes of thrombotic thrombocytopenic purpura (TTP) were treated with plasmapheresis. Adjunctive agents included corticosteroids, aspirin, dipyridamole, and vincristine. There were 17 patients; 12 were female. The median age was 41 years. Most patients presented with neurologic symptoms. Thrombocytopenia was profound with a mean initial platelet count of 14,900/mm3. The mean hematocrit on presentation was 26.7% and the mean LDH 1300 IU/L. Eighteen episodes responded completely following plasmapheresis/plasma exchange (86%). Response was prompt, the initial rise in platelet count occurred after a mean of four exchanges, and complete response (a platelet count over 150,000/mm3) was obtained after a mean of nine exchanges. Four of the episodes treated were relapses that occurred in three patients. All responders are alive with a median duration of follow-up of 20 months. The three patients who failed to respond have died. This report extends recent observations that the addition of plasmapheresis/plasma exchange to the therapy of TTP has significantly improved the outlook for patients with this disorder.

Acute renal infarction in sickle cell disease.

End organ failure in sickle cell disease has classically been attributed to changes in the microvasculature. A case is reported in which sudden and complete loss of blood flow to the left kidney occurred during a painful crisis in a woman with homozygous SS disease. The findings are most consistent with occlusion of the renal artery.