PURPOSE Pemetrexed or bevacizumab is used for maintenance therapy of advanced nonsquamous non–small-cell lung cancer (NSCLC). The combination of bevacizumab and pemetrexed has also demonstrated efficacy. We conducted a randomized study to determine the optimal maintenance therapy. PATIENTS AND METHODS Patients with advanced nonsquamous NSCLC and no prior systemic therapy received carboplatin (area under the curve, 6), paclitaxel (200 mg/m2), and bevacizumab (15 mg/kg) for up to four cycles. Patients without progression after four cycles were randomly assigned to maintenance therapy with bevacizumab (15 mg/kg), pemetrexed (500 mg/m2), or a combination of the two agents. The primary end point was overall survival, with bevacizumab serving as the control group. RESULTS Of the 1,516 patients enrolled, 874 (57%) were randomly assigned after induction therapy to one of the three maintenance therapy groups. With a median follow-up of 50.6 months, median survival with pemetrexed was 15.9 months, compared with 14.4 months with bevacizumab (hazard ratio [HR], 0.86; P = .12); median survival with pemetrexed and bevacizumab was 16.4 months (HR, 0.9; P = .28); median progression-free survival was 4.2, 5.1 (HR, 0.85; P = .06), and 7.5 months (HR, 0.67; P < .001) for the three groups, respectively. Incidence of worst grade 3 to 4 toxicity was 29%, 37%, and 51%, respectively, for bevacizumab, pemetrexed, and the combination regimen. CONCLUSION Single-agent bevacizumab or pemetrexed is efficacious as maintenance therapy for advanced nonsquamous NSCLC. Because of a lack of survival benefit and higher toxicity, the combination of bevacizumab and pemetrexed cannot be recommended.

9085 Background: Capecitabine is an oral fluoropyrimidine that is used to treat various malignancies. Hand and Foot Syndrome (HFS) is a dose limiting toxicity of capecitabine and can limit the use of this agent in some patients. Some investigators have observed that pyridoxine (vitamin B6) can ameliorate HFS caused by capecitabine. We designed a prospective trial to determine if pyridoxine can prevent HFS in patients receiving capecitabine. Methods: In our double-blind, placebo controlled trial, we randomly assigned eligible patients treated with capecitabine to receive either daily pyridoxine 100 mg or placebo along with their capecitabine-containing chemotherapy regimen. Patients were observed during the first four cycles of capecitabine treatment. The primary end point was the incidence and grade of HFS that occurred in both arms. Results: Between 2008 and 2011, 77 patients were randomly assigned to receive either pyridoxine (n=38) or placebo (n=39). Both arms were matched in baseline characteristics. The median age was 53.5 years. The ethnic composition of the study population was African American 53%, Caucasian 22%, Hispanic 18%, and Asian 7%. The daily doses of capecitabine were: 2000 mg/m2 (69 pts), 1650 mg/m2 (5 pts), 1400 mg/m2 (2 pts) and 1000 mg/m2 (1 pt). Dosages of capecitabine were equally matched between the two arms of the study. HFS occurred after a median of 2 chemotherapy cycles in both groups. HFS developed in 10/38 (26%) patients in the pyridoxine group and in 8/39 (20%) patients in the placebo group (p=0.547). Therefore, the risk of HFS was 6 percentage points higher in pyridoxine group (95% CI for difference: -13 percentage points to +25 percentage points). Given our study results, we can be confident of excluding a true benefit from pyridoxine larger than 13 percentage points. No difference in HFS grades was observed. Conclusions: Prophylactic pyridoxine (vitamin B6), given concomitantly with capecitabine-containing chemotherapy, was not effective for the prevention of HFS. [Table: see text]

Mass vaccination campaigns are being run all over the globe to combat the ongoing COVID-19 pandemic. There have been several reports of immune thrombocytopenic purpura (ITP) occurrence following COVID-19 vaccination. However, ITP due to the Pfizer-BioNTech vaccine has been rarely reported, and a causal link has not been identified. The pathophysiology behind immune thrombocytopenia is similar to heparininduced thrombocytopenia. The management is also similar to other secondary immune thrombocytopenia. We present a case of a 67-year old female diagnosed with immune thrombocytopenia following Pfizer-BioNTech vaccination. The treatment was resistant to high-dose steroids, intravenous immunoglobulin (IVIG), and rituximab and eventually responded to a thrombopoietin-stimulating agent.

1779 Introduction: Tumor Lysis Syndrome (TLS) is an oncologic emergency that leads to a host of metabolic disturbances which can ultimately result in acute renal failure and death. Currently rasburicase, Elitek™, is FDA approved for the treatment of TLS in patients with leukemia, lymphoma, and solid tumor malignancies which have risk factors for TLS. The approved adult dose is 0.2mg/kg/day over 30 minutes for up to 5 days. Chemotherapy should be initiated within 24 hours of rasburicase administration. Since rasburicase's introduction to the market, various studies have examined single dose use (3mg and 6mg) in the adult population, trying to resolve the dilemma of determining a dosing regimen for adults that is as effective as the FDA approved dosing regimen, while minimizing cost. This study was aimed at determining if a single 4.5mg dose of rasburicase would be adequate in reducing uric acid levels (UAL) as compared to the FDA approved conventional weight based approach; it also sought to determine the cost-effectiveness of this approach. Method: This is a retrospective study of the John H. Stroger Jr. Hospital of Cook County (JHS) patients who were administered a single dose of 4.5 mg rasburicase for TLS from 12/2007 to 06/2010. We included patients ≥ 18 years old, with a hematologic malignancy and on chemotherapy or about to start receiving chemotherapy within 24 hours of rasburicase administration. Patients with low risk for TLS or an indication other than prevention and management of TLS were excluded. Result: Demographics: Characteristics: Responders are defined as patients that achieved more than 50% reduction in the UAL at 24 hours, 48 hours or 96 hours or a decrease of UAL to normal levels. Two patients required a second dose to achieve response. The non-responders did not receive any additional doses for unclear reasons. No adverse events were noted. Conclusion: This retrospective study provides evidence that a single 4.5mg dose of rasburicase effectively reduced plasma UAL to within normal limits. In addition, decrease in plasma UAL was observed within 24 hours after administration. No effect on electrolytes and serum creatinine was noted. The cost-effectiveness of a single 4.5mg dose of rasburicase was evaluated based on dose and drug cost. The potential cost saving was substantial when compared with the FDA approved dose. In our opinion, this study validates the use of a single dose of 4.5mg rasburicase in the treatment and prophylaxis of TLS. This dose can be considered as a possible alternative to the FDA approved adult dosing regimen. Disclosures: No relevant conflicts of interest to declare.

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