Achieving superresolution with illumination-enhanced sparsity.

Recent advances in superresolution fluorescence microscopy have been limited by a belief that surpassing two-fold resolution enhancement of the Rayleigh resolution limit requires stimulated emission or the fluorophore to undergo state transitions. Here we demonstrate a new superresolution method that requires only image acquisitions with a focused illumination spot and computational post-processing. The proposed method utilizes the focused illumination spot to effectively reduce the object size and enhance the object sparsity and consequently increases the resolution and accuracy through nonlinear image post-processing. This method clearly resolves 70nm resolution test objects emitting ~530nm light with a 1.4 numerical aperture (NA) objective, and, when imaging through a 0.5NA objective, exhibits high spatial frequencies comparable to a 1.4NA widefield image, both demonstrating a resolution enhancement above two-fold of the Rayleigh resolution limit. More importantly, we examine how the resolution increases with photon numbers, and show that the more-than-two-fold enhancement is achievable with realistic photon budgets.

Population pharmacokinetics and exposure-response relationship of amatuximab, an anti-mesothelin monoclonal antibody, in patients with malignant pleural mesothelioma and its application in dose selection.

PURPOSE: To characterize amatuximab pharmacokinetics (PK) and the relationship of amatuximab exposure with response in patients with unresectable malignant pleural mesothelioma (MPM) receiving amatuximab with pemetrexed and cisplatin. METHODS: A nonlinear mixed effects PK model was built using data from all of the amatuximab studies conducted to date. Patients received amatuximab alone or in combination with chemotherapy. The influence of demographic, laboratory and disease characteristics on PK parameters was assessed. Exposure-response analyses explored relationships between amatuximab exposure and overall survival (OS), progression-free survival (PFS) and safety. Alternative amatuximab dosing regimens were explored with simulations using population PK and parametric survival models. RESULTS: Amatuximab PK was best described by a two-compartment model with parallel linear and nonlinear elimination pathways. Body weight and an antidrug antibodies reaction with the titer >64 affected volume of distribution and clearance, respectively. Exposure-response analyses demonstrated that the amatuximab exposure (C min) showed a significant effect on OS (log-rank test, P = 0.0202). For patients with amatuximab C min above the median (38.2 µg/mL), the median OS was 583 days (90 % CI 418 -NE). For patients with C min ≤ 38.2 µg/mL, the median OS was 375 days (90 % CI 325-486). The amatuximab exposure showed similar significant effect on PFS. Exposure-response analysis for adverse events did not reveal any relationship. CONCLUSIONS: In patients with MPM, higher amatuximab exposure in combination with chemotherapy was shown to be associated with longer OS, supporting evaluation of more frequent dosing in future trials to achieve higher exposure and subsequently longer OS.

Safety and biodistribution of 111In-amatuximab in patients with mesothelin expressing cancers using single photon emission computed tomography-computed tomography (SPECT-CT) imaging.

Amatuximab is a chimeric high-affinity monoclonal IgG1/k antibody targeting mesothelin that is being developed for treatment of mesothelin-expressing cancers. Considering the ongoing clinical development of amatuximab in these cancers, our objective was to characterize the biodistribution, and dosimetry of 111Indium (111In) radiolabelled amatuximab in mesothelin-expressing cancers. Between October 2011 and February 2013, six patients including four with malignant mesothelioma and two with pancreatic adenocarcinoma underwent Single Photon Emission Computed Tomography-Computed Tomography (SPECT/CT) imaging following administration of 111In amatuximab. SPECT/CT images were obtained at 2-4 hours, 24-48 hours and 96-168 hours after radiotracer injection. In all patients, tumor to background ratios (TBR) consistently met or exceeded an uptake of 1.2 (range 1.2-62.0) which is considered the minimum TBR that can be visualized. TBRs were higher in tumors of patients with mesothelioma than pancreatic adenocarcinoma. 111In-amatuximab uptake was noted in both primary tumors and metastatic sites. The radiotracer dose was generally well-tolerated and demonstrated physiologic uptake in the heart, liver, kidneys and spleen. This is the first study to show tumor localization of an anti-mesothelin antibody in humans. Our results show that 111In-amatuximab was well tolerated with a favorable dosimetry profile. It localizes to mesothelin expressing cancers with a higher uptake in mesothelioma than pancreatic cancer.

Phase II clinical trial of amatuximab, a chimeric antimesothelin antibody with pemetrexed and cisplatin in advanced unresectable pleural mesothelioma.

PURPOSE: Amatuximab is a chimeric monoclonal antibody to mesothelin, a cell surface glycoprotein highly expressed in malignant pleural mesothelioma (MPM). On the basis of its synergy with chemotherapy in preclinical studies, we evaluated the antitumor activity of amatuximab plus pemetrexed and cisplatin in patients with unresectable MPM. EXPERIMENTAL DESIGN: In a single-arm phase II study, amatuximab (5 mg/kg) was administered on days 1 and 8 with pemetrexed (500 mg/m(2)) and cisplatin (75 mg/m(2)) on day 1 of 21-day cycles for up to six cycles. Patients with response or stable disease received amatuximab maintenance until disease progression. Primary endpoint was progression-free survival (PFS) at 6 months. Secondary endpoints were overall survival (OS), response rate, and safety. RESULTS: Eighty-nine patients were enrolled at 26 centers. Median of five cycles (range, 1-6) of combination treatment was administered, and 56 (63%) patients received amatuximab maintenance. Combination therapy resulted in no overlapping toxicities. Eleven patients (12.4%) had amatuximab-related hypersensitivity reactions. Responses included partial responses in 33 (40%) and stable disease in 42 (51%). Six-month PFS rate was 51% [95% confidence interval (CI), 39.1-62.3)], median PFS was 6.1 months (95% CI, 5.8-6.4), and median OS was 14.8 months (95% CI, 12.4-18.5) with 29 patients alive at data cut-off. CONCLUSIONS: Amatuximab with pemetrexed and cisplatin was well tolerated with objective tumor response or stable disease rate of 90% by independent radiologic review. Although PFS was not significantly different from historical controls, the median OS was 14.8 months with a third of patients alive and 5 continuing to receive amatuximab at the time of analysis.

Alvimopan, for postoperative ileus following bowel resection: a pooled analysis of phase III studies.

OBJECTIVE: To obtain further analysis regarding specific outcomes and alvimopan doses in bowel resection (BR) patients. SUMMARY BACKGROUND DATA: Although postoperative ileus (POI) is common after BR, there is currently no recognized treatment or prevention available. Alvimopan, a novel, peripherally active mu-opioid receptor antagonist, accelerated GI recovery after BR or hysterectomy in 3 phase III trials. METHODS: A pooled retrospective subset analysis of BR patients in alvimopan phase III trials was performed. Randomized BR patients received alvimopan 6 mg (n = 397), 12 mg (n = 413), or placebo (n = 402) >or=2 hours before surgery and twice daily until hospital discharge for

A double-blind, randomized, placebo-controlled phase III study of the safety of alvimopan in patients who undergo simple total abdominal hysterectomy.

OBJECTIVE: The purpose of this study was to investigate the safety and efficacy of alvimopan, a novel peripherally acting mu-opioid receptor antagonist, in patients who undergo simple total abdominal hysterectomy. STUDY DESIGN: Women (n = 519) were randomized (4:1) to receive alvimopan 12 mg (n = 413) or placebo (n = 106) > or = 2 hours before the operation then twice daily for 7 days (hospital and home). Adverse events were monitored up to 30 days after the last dose of study drug was administered. Efficacy was assessed for 7 postoperative days. RESULTS: Overall, the most common adverse events were nausea, vomiting, and constipation; < 5% of patients discontinued use because of adverse events. Alvimopan significantly accelerated the time to first bowel movement (hazard ratio, 2.33; P <.001). Average time to first bowel movement was reduced by 22 hours, with more frequent bowel movement and better bowel movement quality found in the treatment cohort. CONCLUSION: Alvimopan has a safety profile that is similar to that of placebo and provides significantly improved lower gastrointestinal recovery in women who undergo simple total abdominal hysterectomy.

Postoperative upper and lower gastrointestinal recovery and gastrointestinal morbidity in patients undergoing bowel resection: pooled analysis of placebo data from 3 randomized controlled trials.

BACKGROUND: This analysis examines gastrointestinal recovery in patients who underwent bowel resection (BR) in 3 recent trials. METHODS: Patients who underwent BR in the placebo groups of 3 randomized, double-blind, phase III, parallel-group, multicenter alvimopan efficacy trials were analyzed. RESULTS: Most patients tolerated solid food and had a bowel movement by postoperative day 4. The majority of patients were discharged from the hospital by day 6, but 24.4% required a prolonged hospital stay or readmission. The incidence of nausea was highest on the day of surgery and decreased thereafter, whereas vomiting was uncommon on the day of surgery but increased slightly on postoperative days 1 to 6. The incidence of postoperative nasogastric tube insertion was highest (12%) on day 2. CONCLUSIONS: This analysis provides valuable clinical insight into gastrointestinal recovery after BR in a large homogenous patient population receiving multimodal care.

Effect of alvimopan and codeine on gastrointestinal transit: a randomized controlled study.

UNLABELLED: background & aims: Opiate bowel dysfunction is a significant clinical problem. Our aim was to evaluate the ability of a peripheral mu-opioid antagonist, alvimopan, to reverse the effect of codeine on gastric, small-bowel, and colonic transit time in healthy volunteers. METHODS: Seventy-four healthy participants (43 women) were randomized in a double-blind, placebo-controlled manner to 1 of 4 groups: alvimopan 12 mg twice daily in the presence and absence of codeine sulfate 30 mg 4 times/day, or codeine or placebo alone. Gastric emptying, small-bowel, and colonic transit were measured by scintigraphy using a 99m-labeled technetium egg meal and 111-labeled indium charcoal delivered to the proximal colon via a delayed-release capsule. The primary end points for colonic transit were geometric center of the colonic counts at 24 hours and time for 50% ascending colon emptying. Analysis of covariance was used to assess the significance of the primary and secondary end points. RESULTS: Codeine delayed gastric, small-bowel, proximal, and overall colonic transit (P < .05). Alvimopan reversed codeine's effect on small bowel and colon (ascending colon and overall colonic transit). Alvimopan also accelerated overall colonic transit compared with placebo. Thus, the mean colonic geometric center at 24 hours was 2.33 with placebo/placebo, 3.25 with alvimopan/placebo (P < .05), 1.5 with placebo/codeine (P < .05), and 2.63 with alvimopan/codeine. Alvimopan did not reverse codeine's delay of gastric emptying. CONCLUSIONS: Alvimopan reverses codeine's inhibitory effect on small-bowel and colon transit and has potential for treatment of opiate bowel dysfunction. Alvimopan alone accelerates colonic transit, suggesting that mu-opiate mechanisms participate in the physiologic control of colonic transit.

Phase III trial of alvimopan, a novel, peripherally acting, mu opioid antagonist, for postoperative ileus after major abdominal surgery.

PURPOSE: Postoperative ileus presents significant clinical challenges that potentially prolong hospital stay, contribute to readmission, and increase morbidity. There is no approved treatment for postoperative ileus. Alvimopan is a novel, peripherally acting, mu opioid receptor antagonist currently in development for the management of postoperative ileus. METHODS: Patients undergoing partial colectomy or simple or radical hysterectomy were randomized to receive alvimopan 6 mg (n = 152), alvimopan 12 mg (n = 146), or placebo (n = 153) orally 2 hours before surgery and twice daily thereafter until discharge or for up to seven days. The primary efficacy end point, time to return of gastrointestinal function, was a composite measure of passage of flatus or stool and tolerating solid food. Secondary end points included time to the hospital discharge order written. Adverse events were monitored throughout the study. RESULTS: Mean time to gastrointestinal recovery was significantly reduced in patients treated with alvimopan 6 mg vs. placebo (hazard ratio = 1.45; P = 0.003), with a smaller reduction seen with alvimopan 12 mg (hazard ratio = 1.28; P = 0.059). Mean time to the hospital discharge order written was significantly accelerated in patients treated with alvimopan 6 mg (hazard ratio = 1.50; P < 0.001). The most common treatment-emergent adverse events across all treatment groups were nausea, vomiting, and hypotension; the incidence of nausea and vomiting was reduced by 53 percent in the alvimopan 12-mg group. CONCLUSIONS: In patients undergoing major abdominal surgery, alvimopan accelerated gastrointestinal recovery and time to the hospital discharge order written compared with placebo and was well tolerated.

Alvimopan: an oral, peripherally acting, mu-opioid receptor antagonist for the treatment of opioid-induced bowel dysfunction--a 21-day treatment-randomized clinical trial.

Alvimopan has been shown to reverse the inhibitory effect of opioids on gastrointestinal transit without affecting analgesia. We evaluated oral alvimopan, 0.5 or 1 mg, versus placebo, once daily for 21 days, in 168 patients with opioid-induced bowel dysfunction (OBD) who were receiving chronic opioid therapy (minimum, 1 month) for nonmalignant pain (n = 148) or opioid dependence (n = 20). The primary outcome was the proportion of patients having at least one bowel movement (BM) within 8 hours of study drug on each day during the 21-day treatment period. Averaged over the 21-day treatment period, 54%, 43%, and 29% of patients had a BM within 8 hours after alvimopan 1 mg, 0.5 mg, or placebo, respectively (P < .001). Secondary outcomes of median times to first BM were 3, 7, and 21 hours after initial doses of 1 mg, 0.5 mg, and placebo, respectively (P < .001; 1 mg vs placebo). Weekly BMs and overall patient satisfaction were increased after the 1-mg dose (P < .001 at weeks 1 and 2 vs placebo, and P = .046, respectively). Treatment-emergent adverse events were primarily bowel-related, occurred during the first week of treatment, and were of mild to moderate severity. Alvimopan was generally well tolerated and did not antagonize opioid analgesia. Patients treated with chronic opioid therapy often experience opioid-induced bowel dysfunction as a result of undesirable effects on peripheral opioid receptors located in the gastrointestinal tract. Alvimopan, a novel peripheral opioid mu-receptor antagonist, has demonstrated significant efficacy for the management of opioid-induced bowel dysfunction without compromise of centrally mediated opioid-induced analgesia.

Alvimopan, a novel, peripherally acting mu opioid antagonist: results of a multicenter, randomized, double-blind, placebo-controlled, phase III trial of major abdominal surgery and postoperative ileus.

OBJECTIVE: To demonstrate that alvimopan (6 or 12 mg) accelerates recovery of gastrointestinal (GI) function in patients undergoing laparotomy for bowel resection or radical hysterectomy. SUMMARY BACKGROUND DATA: Postoperative ileus (POI) following laparotomy may increase morbidity and extend hospitalization. Opioids can contribute to the duration of POI. Alvimopan is a novel opioid receptor antagonist in development for the management of POI. METHODS: A total of 510 patients scheduled for bowel resection or radical hysterectomy were randomized (1:1:1) to receive alvimopan 6 mg, alvimopan 12 mg, or placebo orally > or =2 hours before surgery, then twice a day (b.i.d.) until hospital discharge or for up to 7 days. The primary efficacy end point was a composite of time to recovery of upper and lower GI function. An associated secondary end point was time to hospital discharge order written. RESULTS: The modified intent-to-treat population included 469 patients (451 bowel resection and 18 radical hysterectomy patients). Time to recovery of GI function was accelerated for the alvimopan 6 mg (hazard ratio [HR] = 1.28; P < 0.05) and 12 mg (HR = 1.54; P < 0.001) groups with a mean difference of 15 and 22 hours, respectively, compared with placebo. The time to hospital discharge order written was also accelerated in the alvimopan 12 mg group (HR = 1.42; P = 0.003) with a mean difference of 20 hours compared with placebo. The incidence of adverse events was similar among treatment groups. CONCLUSIONS: Alvimopan accelerated GI recovery and time to hospital discharge order written compared with placebo in patients undergoing laparotomy and was well tolerated.