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Selectins are cell adhesion proteins discovered in the 1980s. As C-type lectins, selectins contain an essential calcium ion in the ligand-binding pocket and recognize the isomeric tetrasaccharides sialyl Lewis x (sLe x ) and sialyl Lewis a (sLe a ). Three selectins, E-selectin, P-selectin, and L-selectin, play distinct, complementary roles in inflammation, hematopoiesis, and tumor biology. They have been implicated in the pathology of diverse inflammatory disorders, and several selectin antagonists have been tested clinically. E-selectin plays a unique role in leukocyte activation, making it an attractive target for intervention, for example, in sickle cell disease (SCD). This review summarizes selectin biology and pathology, structure and ligand binding, and selectin antagonists that have reached clinical testing with an emphasis on E-selectin., Competing Interests: Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: John M. Peterson declare(s) employment, a patent, stock/stock options and travel from GlycoMimetics, Inc. Edwin P. Rock declare(s) employment, stock/stock options and travel from GlycoMimetics, Inc. John L. Magnani declare(s) personal fees, employment and stock/stock options from GlycoMimetics, Inc. Theodore A. Smith declare(s) employment, a patent and stock/stock options from GlycoMimetics, Inc. Intellectual property info: All authors are currently or were recently employees of GlycoMimetics Inc. As such, we have been involved in the discovery and development of the E-selectin antagonists uproleselan and GMI-1687, as well as the pan-selectin antagonist rivipansel, which are described in this manuscript. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Peterson et al.)

Background: Patient survival in advanced/metastatic melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC) has improved with immune checkpoint inhibitors (ICI). Biomarkers' role in prognosis and treatment has been limited by conflicting trial results., Methods: This retrospective, observational study analyzed baseline demographic, clinical, laboratory, and treatment data versus outcomes of The US Oncology Network adult outpatients. Patients with advanced/metastatic melanoma, NSCLC, or RCC treated between January 1, 2015 and November 30, 2020 were given ICI monotherapy or combination therapy with ipilimumab, pembrolizumab, nivolumab, or atezolizumab. Treatment outcomes (overall survival [OS], time to treatment discontinuation, time to next treatment) were followed longitudinally until May 31, 2021, last patient record, or date of death. Baseline blood cell counts, including absolute monocyte count (AMC), absolute lymphocyte count (ALC), monocyte-to-lymphocyte ratio (MLR), absolute neutrophil count (ANC), and eosinophil count, were subdivided into quintiles for univariate and multivariable Cox regression analyses., Results: Data from 18,186 patients with advanced/metastatic melanoma (n = 3314), NSCLC (n = 12,416), and RCC (n = 2456) were analyzed. Better OS correlated with increased baseline serum albumin concentration, increased eosinophil and lymphocyte counts, and Western United States physician practice location. Decreased OS correlated with increased AMC, MLR, ANC, age, and worse Eastern Cooperative Oncology Group performance status., Conclusions: To our knowledge, this study is the largest to date to associate baseline survival indicators and outcomes in outpatients with advanced/metastatic melanoma, NSCLC, or RCC and receiving ICIs. Results may inform disease-specific prognostic models and help providers identify patients most likely to benefit from ICI therapy., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Sepsis, a heterogeneous clinical syndrome, features a systemic inflammatory response to tissue injury or infection, followed by a state of reduced immune responsiveness. Measurable alterations occur in both the innate and adaptive immune systems. Immunoparalysis, an immunosuppressed state, associates with worsened outcomes, including multiple organ dysfunction syndrome, secondary infections, and increased mortality. Multiple immune markers to identify sepsis immunoparalysis have been proposed, and some might offer clinical utility. Sepsis immunoparalysis is characterized by reduced lymphocyte numbers and downregulation of class II human leukocyte antigens (HLA) on innate immune monocytes. Class II HLA proteins present peptide antigens for recognition by and activation of antigen-specific T lymphocytes. One monocyte class II protein, mHLA-DR, can be measured by flow cytometry. Downregulated mHLA-DR indicates reduced monocyte responsiveness, as measured by ex-vivo cytokine production in response to endotoxin stimulation. Our literature survey reveals low mHLA-DR expression on peripheral blood monocytes correlates with increased risks for infection and death. For mHLA-DR, 15,000 antibodies/cell appears clinically acceptable as the lower limit of immunocompetence. Values less than 15,000 antibodies/cell are correlated with sepsis severity; and values at or less than 8000 antibodies/cell are identified as severe immunoparalysis. Several experimental immunotherapies have been evaluated for reversal of sepsis immunoparalysis. In particular, sargramostim, a recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF), has demonstrated clinical benefit by reducing hospitalization duration and lowering secondary infection risk. Lowered infection risk correlates with increased mHLA-DR expression on peripheral blood monocytes in these patients. Although mHLA-DR has shown promising utility for identifying sepsis immunoparalysis, absence of a standardized, analytically validated method has thus far prevented widespread adoption. A clinically useful approach for patient inclusion and identification of clinically correlated output parameters could address the persistent high unmet medical need for effective targeted therapies in sepsis., Competing Interests: IJ is an employee of and has stock options for Partner Therapeutics, Inc. WPC is the owner of Walt Carney Biomarkers Consulting and a paid consultant for Partner Therapeutics, Inc. At the time of the drafting of this manuscript, EPR was an employee of Partner Therapeutics, Inc. and has stock options., (Copyright © 2023 Joshi, Carney and Rock.)

Introduction: Endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF), identified by its ability to support differentiation of hematopoietic cells into several types of myeloid cells, is now known to support maturation and maintain the metabolic capacity of mononuclear phagocytes including monocytes, macrophages, and dendritic cells. These cells sense and attack potential pathogens, present antigens to adaptive immune cells, and recruit other immune cells. Recombinant human (rhu) GM-CSF (e.g., sargramostim [glycosylated, yeast-derived rhu GM-CSF]) has immune modulating properties and can restore the normal function of mononuclear phagocytes rendered dysfunctional by deficient or insufficient endogenous GM-CSF., Methods: We reviewed the emerging biologic and cellular effects of GM-CSF. Experts in clinical disease areas caused by deficient or insufficient endogenous GM-CSF examined the role of GM-CSF in mononuclear phagocyte disorders including autoimmune pulmonary alveolar proteinosis (aPAP), diverse infections (including COVID-19), wound healing, and anti-cancer immune checkpoint inhibitor therapy., Results: We discuss emerging data for GM-CSF biology including the positive effects on mitochondrial function and cell metabolism, augmentation of phagocytosis and efferocytosis, and immune cell modulation. We further address how giving exogenous rhu GM-CSF may control or treat mononuclear phagocyte dysfunction disorders caused or exacerbated by GM-CSF deficiency or insufficiency. We discuss how rhu GM-CSF may augment the anti-cancer effects of immune checkpoint inhibitor immunotherapy as well as ameliorate immune-related adverse events., Discussion: We identify research gaps, opportunities, and the concept that rhu GM-CSF, by supporting and restoring the metabolic capacity and function of mononuclear phagocytes, can have significant therapeutic effects. rhu GM-CSF (e.g., sargramostim) might ameliorate multiple diseases of GM-CSF deficiency or insufficiency and address a high unmet medical need., Competing Interests: HL is a paid consultant to Partner Therapeutics and has stock options. KP, TB, and CR, are employees of Partner Therapeutics and have stock options. ER at the time of drafting of this manuscript was an employee of Partner Therapeutics and has stock options. TW, EB, MD, RP, and RG received funds from Partner Therapeutics within the past 3 years, but none in relation to this publication. HL is a paid consultant to Pluri-Biotech, Inc. TW acknowledges support from Savara, Kiniksa, Kinevant (for participation on a DSMB or advisory board), the PAP Foundation (serves as the vice president and clinical director of the PAP Foundation) and is a paid consultant to IQVIA. EL acknowledges funding from the NIH, myCME, is a paid consultant to Guidepoint Global, and received support for travel from the PAP Foundation. EB acknowledges support from Genentech, Novartis, and Lilly, and received funds from Apexigen, Shionogi, Bristol Myers Squibb, Nektar, Instilbio, and Xilio for consulting within the past 3 years. MD received funds from Neolukin Therapeutics (and has stock options), Moderna, Aditum, OREC, Tillotts Pharma, SQZ Biotech, AzurRx, and Mallinckrodt for consulting within the past 3 years, and acknowledges support from UpToDate, Sandoz Academy, Experts at Your Fingertips, and WebMD. DA acknowledges funding from the NIH, National Institute of Diabetes and Digestive and Kidney Diseases. RP acknowledges support to his institution from the US Department of Veterans Affairs and the NHLBI. RG is a consultant to NexImmune Inc., Ananexa Pharma Ascentage Pharm Group, Antengene Biotech LLC, and a Medical Director within FFF Enterprises Inc. and AZAC Inc. RG serves on the Board of Directors of the Russian Foundation for Cancer Research Support and is on the Scientific Advisory Board of StemRad Ltd., (Copyright © 2023 Lazarus, Pitts, Wang, Lee, Buchbinder, Dougan, Armstrong, Paine, Ragsdale, Boyd, Rock and Gale.)

Several therapeutic monoclonal antibodies (mAbs), including those targeting epidermal growth factor receptor, human epidermal growth factor receptor 2 (HER2), and CD20, mediate fragment crystallizable gamma receptor (FcγR)-dependent activities as part of their mechanism of action. These activities include induction of antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), which are innate immune mechanisms of cancer cell elimination. FcγRs are distinguished by their affinity for the Fc fragment, cell distribution, and type of immune response they induce. Activating FcγRIIIa (CD16A) on natural killer cells plays a crucial role in mediating ADCC, and activating FcγRIIa (CD32A) and FcγRIIIa on macrophages are important for mediating ADCP. Polymorphisms in FcγRIIIa and FcγRIIa generate variants that bind to the Fc portion of antibodies with different affinities. This results in differential FcγR-mediated activities associated with differential therapeutic outcomes across multiple clinical settings, from early stage to metastatic disease, in patients with HER2+ breast cancer treated with the anti-HER2 mAb trastuzumab. Trastuzumab has, nonetheless, revolutionized HER2+ breast cancer treatment, and several HER2-directed mAbs have been developed using Fc glyco-engineering or Fc protein-engineering to enhance FcγR-mediated functions. An example of an approved anti-HER2 Fc-engineered chimeric mAb is margetuximab, which targets the same epitope as trastuzumab, but features five amino acid substitutions in the IgG 1 Fc domain that were deliberately introduced to increase binding to activating FcγRIIIa and decrease binding to inhibitory FcγRIIb (CD32B). Margetuximab enhances Fc-dependent ADCC in vitro more potently than the combination of pertuzumab (another approved mAb directed against an alternate HER2 epitope) and trastuzumab. Margetuximab administration also enhances HER2-specific B cell and T cell-mediated responses ex vivo in samples from patients treated with prior lines of HER2 antibody-based therapies. Stemming from these observations, a worthwhile future goal in the treatment of HER2+ breast cancer is to promote combinatorial approaches that better eradicate HER2+ cancer cells via enhanced immunological mechanisms., Competing Interests: Competing interests: AM reports grants from Roche and Eisai; personal fees from MacroGenics, Roche, Eisai, Novartis, and Lilly; participation in advisory boards from MacroGenics, Roche, Eisai, Novartis, Lilly. WJG has nothing to disclose. HSR reports personal fees for short-term consulting from Puma and Samsung; institutional grants for clinical research study activities from MacroGenics, Roche, Pfizer, Novartis, Lilly, Merck, Seattle Genetics, Odonate Therapeutics, Eisai, Sermonix, and Immunomedics, Daiichi Sankyo. MDP reports personal consulting fees from MacroGenics, AstraZeneca/Daiichi Sankyo, Pfizer, and Roche/Genentech, and grant support on this topic from the Parker Institute for Cancer Immunotherapy and the Mary Kay Foundation. JLN is an employee of MacroGenics. EPR was an employee of MacroGenics and is now an employee of Partner Therapeutics. FA was an employee of MacroGenics and is now an employee of AstraZeneca., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Importance: ERRB2 (formerly HER2)-positive advanced breast cancer (ABC) remains typically incurable with optimal treatment undefined in later lines of therapy. The chimeric antibody margetuximab shares ERBB2 specificity with trastuzumab but incorporates an engineered Fc region to increase immune activation., Objective: To compare the clinical efficacy of margetuximab vs trastuzumab, each with chemotherapy, in patients with pretreated ERBB2-positive ABC., Design, Setting, and Participants: The SOPHIA phase 3 randomized open-label trial of margetuximab plus chemotherapy vs trastuzumab plus chemotherapy enrolled 536 patients from August 26, 2015, to October 10, 2018, at 166 sites in 17 countries. Eligible patients had disease progression on 2 or more prior anti-ERBB2 therapies and 1 to 3 lines of therapy for metastatic disease. Data were analyzed from February 2019 to October 2019., Interventions: Investigators selected chemotherapy before 1:1 randomization to margetuximab, 15 mg/kg, or trastuzumab, 6 mg/kg (loading dose, 8 mg/kg), each in 3-week cycles. Stratification factors were metastatic sites (≤2, >2), lines of therapy (≤2, >2), and chemotherapy choice., Main Outcomes and Measures: Sequential primary end points were progression-free survival (PFS) by central blinded analysis and overall survival (OS). All α was allocated to PFS, followed by OS. Secondary end points were investigator-assessed PFS and objective response rate by central blinded analysis., Results: A total of 536 patients were randomized to receive margetuximab (n = 266) or trastuzumab (n = 270). The median age was 56 (27-86) years; 266 (100%) women were in the margetuximab group, while 267 (98.9%) women were in the trastuzumab group. Groups were balanced. All but 1 patient had received prior pertuzumab, and 489 (91.2%) had received prior ado-trastuzumab emtansine. Margetuximab improved primary PFS over trastuzumab with 24% relative risk reduction (hazard ratio [HR], 0.76; 95% CI, 0.59-0.98; P = .03; median, 5.8 [95% CI, 5.5-7.0] months vs 4.9 [95% CI, 4.2-5.6] months; October 10, 2018). After the second planned interim analysis of 270 deaths, median OS was 21.6 months with margetuximab vs 19.8 months with trastuzumab (HR, 0.89; 95% CI, 0.69-1.13; P = .33; September 10, 2019), and investigator-assessed PFS showed 29% relative risk reduction favoring margetuximab (HR, 0.71; 95% CI, 0.58-0.86; P < .001; median, 5.7 vs 4.4 months; September 10, 2019). Margetuximab improved objective response rate over trastuzumab: 22% vs 16% (P = .06; October 10, 2018), and 25% vs 14% (P < .001; September 10, 2019). Incidence of infusion-related reactions, mostly in cycle 1, was higher with margetuximab (35 [13.3%] vs 9 [3.4%]); otherwise, safety was comparable., Conclusions and Relevance: In this phase 3 randomized clinical trial, margetuximab plus chemotherapy had acceptable safety and a statistically significant improvement in PFS compared with trastuzumab plus chemotherapy in ERBB2-positive ABC after progression on 2 or more prior anti-ERBB2 therapies. Final OS analysis is expected in 2021., Trial Registration: ClinicalTrials.gov Identifier: NCT02492711.

Background: The hypomethylating drugs azacitidine and decitabine have shown efficacy in myelodysplastic syndromes and acute myeloid leukaemia, but complete tumour responses are infrequent and of short duration, possibly because of the short half-lives and suboptimal bone marrow exposure of the drugs. Guadecitabine, a next-generation hypomethylating drug, has a longer half-life and exposure than its active metabolite decitabine. A phase 1 study established 60 mg/m 2 guadecitabine for 5 days as an effective treatment schedule. In this phase 2 study, we aimed to assess the safety and activity of two doses and schedules of guadecitabine in older (≥65 years) patients with treatment-naive acute myeloid leukaemia who were not candidates for intensive chemotherapy., Methods: We did a multicentre, randomised, open-label, phase 1/2 study of guadecitabine in cohorts of patients with treatment-naive acute myeloid leukaemia, relapsed or refractory acute myeloid leukaemia, and myelodysplastic syndromes; here we report the phase 2 results from the cohort of treatment-naive patients with acute myeloid leukaemia. We included patients aged at least 65 years from 14 US medical centres (hospitals and specialist cancer clinics) who were not candidates for intensive chemotherapy and randomly assigned them (1:1) using a computer algorithm (for dynamic randomisation) to guadecitabine 60 or 90 mg/m 2 on days 1-5 (5-day schedule) of a 28-day treatment cycle. Treatment allocation was not masked. We also assigned additional patients to guadecitabine 60 mg/m 2 in a 10-day schedule in a 28-day treatment cycle after a protocol amendment. The primary endpoint was composite complete response (complete response, complete response with incomplete platelet recovery, or complete response with incomplete neutrophil recovery regardless of platelets). Response was assessed in all patients (as-treated) who received at least one dose of guadecitabine. We present the final analysis, although at the time of the database lock, 15 patients were still in follow-up for overall survival. This study is registered with ClinicalTrials.gov, number NCT01261312., Findings: Between Aug 24, 2012, and Sept 15, 2014, 107 patients were enrolled: 54 on the 5-day schedule (26 randomly assigned to 60 mg/m 2 and 28 to 90 mg/m 2 ) and 53 were assigned to the 10-day schedule. Median age was 77 years (range 62-92), and median follow-up was 953 days (IQR 721-1040). All treated patients were assessable for a response. The number of patients who achieved a composite complete response did not differ between dose groups or schedules (13 [54%, 95% CI 32·8-74·4] with 60 mg/m 2 on the 5-day schedule; 16 [59%; 38·8-77·6] with 90 mg/m 2 on the 5-day schedule; and 26 [50%, 35·8-64·2] with 60 mg/m 2 on the 10-day schedule). The most frequent grade 3 or worse adverse events, regardless of relationship to treatment, were febrile neutropenia (31 [61%] of 51 patients on the 5-day schedule vs 36 [69%] of 52 patients on the 10-day schedule), thrombocytopenia (25 [49%] vs 22 [42%]), neutropenia (20 [39%] vs 18 [35%]), pneumonia (15 [29%] vs 19 [37%]), anaemia (15 [29%] vs 12 [23%]), and sepsis (eight [16%] vs 14 [27%]). The most common serious adverse events, regardless of relationship to treatment, for the 5-day and 10-day schedules, respectively, were febrile neutropenia (27 [53%] vs 25 [48%]), pneumonia (14 [27%] vs 16 [31%]), and sepsis (eight [16%] vs 14 [27%]). 23 (22%) patients died because of adverse events (mainly from sepsis, eight [8%]; and pneumonia, five [5%]); four deaths were from adverse events deemed treatment-related (pneumonia, two [2%]; multiorgan failure, one [1%]; and sepsis, one [1%], all in the 10-day cohort)., Interpretation: More than half of older treatment-naive patients with acute myeloid leukaemia achieved a composite complete response with guadecitabine at all drug doses and schedules investigated, with tolerable toxicity. The recommended guadecitabine regimen for this population is 60 mg/m 2 in a 5-day schedule. A phase 3 study in this patient population is ongoing (NCT02348489) to assess guadecitabine 60 mg/m 2 in a 5-day schedule versus standard of care., Funding: Astex Pharmaceuticals and Stand Up To Cancer., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Purpose: To determine the maximum tolerated dose (MTD) and biologic activity of OPB-31121, an oral inhibitor of STAT3, administered twice daily (BID) to subjects with advanced solid tumors., Methods: Subjects received escalating doses of OPB-31121 BID for the first 21 days of each 28-day cycle in a standard 3 + 3 design. Dose-limiting toxicities (DLTs), safety, pharmacokinetics, and antitumor activity were assessed., Results: Thirty subjects were treated twice daily with OPB-31121 at 6 dose levels: 50 mg (n = 4); 70 mg (n = 3); 140 mg (n = 3); 200 mg (n = 4); 300 mg (n = 9); 350 mg (n = 7). There were no DLTs observed until 300 mg BID (Grade 3 lactic acidosis). At the next dose level (350 mg BID), two subjects had DLTs (Grade 3 vomiting and Grade 3 diarrhea). Thus, 300 mg BID was declared the MTD. OPB-31121-related adverse events included nausea (80 %), vomiting (73 %), diarrhea (63 %), and fatigue (33 %), all of which were primarily grade 1/2. Pharmacokinetics demonstrated high inter-subject variability with exposures 146- to 4,788-fold lower than target concentrations from tumor-bearing mouse models. No objective responses were observed, and all subjects who completed two cycles of treatment had disease progression at their first assessment., Conclusions: Twice-daily administration of OPB-31121 was feasible up to doses of 300 mg. The pharmacokinetic profile was unfavorable, and no objective responses were observed.

As targeted therapies advance treatment for brain tumors, standard clinical trial endpoints of survival, progression free survival and radiographic response have become insufficient to capture clinical benefit. Brain cancer is a malignancy with neurodegenerative features. In this setting prolongation of life and/or radiographic stability are less clinically meaningful if neurocognitive function substantially declines. Hence evaluation of new therapeutic strategies should routinely include periodic assessment of neurocognitive function.

Good Clinical Practice (GCP) provides an internationally accepted standard to ensure subject safety and data quality in clinical trials. Much of GCP parallels ethical considerations that have accumulated in successive versions of the World Medical Association's Declaration of Helsinki. This document advocates for preservation of rights, safety, and well-being of human study participants. By contrast, GCP data quality provisions follow from evolution in the United States drug regulatory system during the 1960s. Evidence of fraudulent or otherwise biased data-gathering ultimately led to U.S. Food and Drug Administration (FDA) data integrity regulations that were subsequently embraced as GCP principles in the Declaration of Helsinki. This manuscript summarizes GCP data quality provisions and describes practices that clinical site investigators can adopt to comply with these principles and to prevent adverse audit findings in the event of a regulatory inspection.

Assessing the potential for a new drug to cause life-threatening arrhythmias is now an integral component of premarketing safety assessment. International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use Guideline (ICH) E14 recommends the "Thorough QT Study" (TQT) to assess clinical QT risk. Such a study calls for careful evaluation of drug effects on the electrocardiographic QT interval at multiples of therapeutic exposure and with a positive control to confirm assay sensitivity. Yet for some drugs and diseases, elements of the TQT Study may be impractical or unethical. In these instances, alternative approaches to QT risk assessment must be considered. This article presents points to consider for evaluation of QT risk when alternative approaches are needed.

To evaluate and improve the use of cancer trial end points that reflect the patient's own perspective, the National Cancer Institute organized an international conference, Patient-Reported Outcomes Assessment in Cancer Trials (PROACT), in 2006. The 13 preceding articles in this special issue of the Journal were commissioned in preparation for or in response to the PROACT conference, which was cosponsored by the American Cancer Society. Drawing from these articles and also commentary from the conference itself, this concluding report takes stock of what has been learned to date about the successes and challenges in patient-reported outcome (PRO) assessment in phase III, phase II, and symptom management trials in cancer and identifies ways to improve the scientific soundness, feasibility, and policy relevance of PROs in trials. Building on this synthesis of lessons learned, this article discusses specific administrative policies and management procedures to improve PRO data collection, analysis, and dissemination of findings; opportunities afforded by recent methodologic and technologic advances in PRO data collection and analysis to enhance the scientific soundness and cost efficiency of PRO use in trials; and the importance of better understanding the usefulness of PRO data to the full spectrum of cancer decision makers, including patients and families, health providers, public and private payers, regulatory agencies, and standards-setting organizations.

In 2006, the US Food and Drug Administration (FDA) published draft guidance to provide recommendations for development, validation, implementation, and interpretation of patient-reported outcome (PRO) measures that can support treatment benefit claims in product labeling. Here, we summarize and discuss FDA approvals of anticancer products in the context of the draft guidance. We identified anticancer product approvals having efficacy claim(s) based at least in part on a PRO. In addition, we collated limitations of PRO instruments commonly submitted for regulatory review over the period from October 1, 2004 to September 30, 2006. From 1995 onward, nine indications were approved for seven anticancer products based at least in part on a PRO. In eight of nine approvals, PRO data supplemented other evidence of clinical benefit. In seven approvals, the PRO measured a single symptom or functional domain that was directly attributable to the treatment benefit observed in the disease. The FDA's draft PRO guidance describes principles that have been used in anticancer product approvals for more than a decade. PRO end points typically support treatment benefit claims that refer to a patient's symptoms or ability to function. Single-item PROs may be acceptable. PRO data should be both internally consistent and aligned with other evidence of clinical benefit. The FDA encourages sponsors to consult with the FDA early in the process of PRO development.

This article concerns development and use of patient-reported outcomes (PROs) in clinical trials to evaluate medical products. A PRO is any report coming directly from patients, without interpretation by physicians or others, about how they function or feel in relation to a health condition and its therapy. PRO instruments are used to measure these patient reports. PROs provide a unique perspective on medical therapy, because some effects of a health condition and its therapy are known only to patients. Properly developed and evaluated PRO instruments also have the potential to provide more sensitive and specific measurements of the effects of medical therapies, thereby increasing the efficiency of clinical trials that attempt to measure the meaningful treatment benefits of those therapies. Poorly developed and evaluated instruments may provide misleading conclusions or data that cannot be used to support product labeling claims. We review selected major challenges from Food and Drug Administration's perspective in using PRO instruments, measures, and end points to support treatment benefit claims in product labeling. These challenges highlight the need for sponsors to formulate desired labeling claim(s) prospectively, to acquire and document information needed to support these claim(s), and to identify existing instruments or develop new and more appropriate PRO instruments for evaluating treatment benefit in the defined population in which they will seek claims.

Purpose: To describe the Food and Drug Administration (FDA) review and approval of sunitinib malate (Sutent). Sunitinib received regular approval for the treatment of gastrointestinal stromal tumor (GIST) after disease progression or intolerance to imatinib mesylate (Gleevec). Additionally, sunitinib received accelerated approval for the treatment of advanced renal cell carcinoma., Experimental Design: For the GIST indication, FDA reviewed data from a randomized, placebo-controlled trial with supportive evidence from a single-arm study. For the advanced renal cell carcinoma indication, FDA reviewed data from two single-arm studies of patients with cytokine-refractory metastatic renal cell carcinoma., Results: In patients with imatinib refractory or intolerant GIST, time-to-tumor progression of sunitinib-treated patients was superior to that of placebo-treated patients. Median time-to-tumor progression of sunitinib-treated patients was 27.3 weeks, compared with 6.4 weeks for placebo-treated patients (P < 0.0001). Partial responses were observed in 6.8% of sunitinib-treated patients. In patients with metastatic renal cell carcinoma, partial responses were observed in 25.5% (95% confidence interval, 17.5, 34.9) and 36.5% (95% confidence interval, 24.7, 49.6) of patients treated with sunitinib. Median response durations were 27.1 and 54 weeks. The most common adverse events attributed to sunitinib included diarrhea, mucositis, skin abnormalities, and altered taste. Reductions in left ventricular ejection fraction and severe hypertension were also more common in sunitinib-treated patients., Conclusions: On January 26, 2006, the FDA approved sunitinib for the treatment of patients with imatinib refractory or intolerant GIST. Accelerated approval was granted for the treatment of advanced renal cell carcinoma.

The U.S. Food and Drug Administration (FDA) approves labeling claims of drug efficacy based on substantial evidence of clinical benefit demonstrated in adequate and well-controlled investigations. Patient-reported outcomes (PROs) may support marketing claims of clinical benefit, either alone or with other study endpoints. Health-related quality of life (HRQL) is a PRO that comprehensively measures patients' reported health status. We present an overview of why HRQL-based efficacy claims have not to date been accepted by the FDA for inclusion in anticancer product labels. Persistent challenges to allowance of such claims include shortcomings in randomization and blinding of clinical trials, missing data, statistical multiplicity, and unclear intrinsic meaning of selected HRQL findings.

On January 26, 2006, sunitinib (Sutent) received regular approval as monotherapy for the treatment of patients with gastrointestinal stromal tumor after disease progression on or intolerance to imatinib mesylate (Gleevec). Time-to-tumor progression (TTP) of sunitinib-treated patients was superior to that of placebo-treated patients. Median TTP of sunitinib-treated patients was 27.3 weeks, compared with 6.4 weeks for placebo-treated patients (p < .0001). Partial responses were observed in 6.8% of sunitinib-treated patients and no placebo-treated patients. Sunitinib also received accelerated approval on January 26, 2006, as monotherapy for treatment of advanced renal cell carcinoma (RCC). In two single-arm trials of sunitinib in patients with metastatic RCC, partial responses were observed in 25.5% (95% confidence interval [CI], 17.5, 34.9) and 36.5% (95% CI, 24.7, 49.6) of patients. Median response durations in the two trials were 27.1 weeks (95% CI, 24.4, incalculable) and 54 weeks (95% CI, 34.3, 70.1). Treatment-emergent adverse events in sunitinib-treated patients included diarrhea, mucositis, skin abnormalities, altered taste, electrolyte abnormalities, hypertension, and diminution in left ventricular ejection fraction. Cardiac safety of sunitinib in patients with preexisting cardiac abnormalities remains unknown. Based on nonclinical findings, physicians prescribing sunitinib should monitor for adrenal insufficiency in patients who undergo stressors such as surgery, trauma, or severe infection. Caution should be exercised when administering sunitinib in combination with known CYP3A4 inducers or inhibitors.

Human chorionic gonadotropin (hCG) is currently under investigation as an antigenic target in both anti-cancer and anti-fertility vaccines. Formulations studied to date show promise in clinical trials for both applications yet are expensive to produce and require frequented administration in order to maintain an effective antibody titer. We have engineered a fusion protein consisting of Escherichia coli heat-labile enterotoxin subunit B (LTB) genetically linked at its C terminus via a nine amino acid linker to the 37 amino acid carboxyl terminal peptide (CTP) of the hCG beta chain. This LTB-CTP fusion protein is stably expressed in bacteria and forms pentamers of full-length protein subunits. Purified LTB-CTP protein hCG-specific antibodies in mice without additional adjuvants.

Problem: Vaccines that target human chorionic gonadotropin (hCG) might be made more effective through greater understanding of the solution three-dimensional structure and behavior of the hormone., Method: A 37-amino acid carboxyl terminal peptide of the hCG beta subunit was synthesized, purified, and analyzed by two-dimensional nuclear magnetic resonance spectroscopy., Results: Double-quantum filtered correlated spectroscopy data on the peptide in water at 4 degrees C reveals 27 multiplets in the peptide fingerprint region, as expected. A nuclear Overhauser effect spectroscopy spectrum shows several intraresidual peaks in the amide region but lacks clearly assignable interresidual signals., Conclusion: By itself in water the carboxyl terminal peptide of hCG lacks defined secondary structure elements and is thus likely a random coil. The presence of beta turns appears possible although neither their existence nor their localization can be confirmed.

In both immunoglobulins (Ig) and T cell receptors (TCR), the rearrangement of V, D, and J region sequence elements during lymphocyte maturation creates an enormous degree of diversity in an area referred to as the complementarity determining region 3 (CDR3) loop. Variations in the particular V, D, and J elements used, precise points of recombination, and random nucleotide addition all lead to extensive length and sequence heterogeneity. CDR3 loops are often critical for antigen binding in Igs and appear to provide the principal peptide binding residues in TCRs. To better understand the physical and selective constraints on these sequences, we have compiled information on CDR3 size variation for Ig H, L (kappa and lambda) and TCR alpha, beta, gamma, and delta. Ig H and TCR delta CDR3s are the most variable in size and are significantly longer than L and gamma chains, respectively. In contrast, TCR alpha and beta chain distributions are highly constrained, with nearly identical average CDR3 lengths, and their length distributions are not altered by thymic selection. Perhaps most significantly, these CDR3 length profiles suggest that gamma/delta TCRs are more similar to Igs than to alpha/beta TCRs in their putative ligand binding region, and thus gamma/delta and alpha/beta T cells may have fundamentally different recognition properties.

Background: The structures of proteins that undergo significant main-chain conformational change are reported with increasing frequency. Three-dimensional atomic models are often available for two alternative conformational states of the same molecule. Inspection has shown these states to be varied in nature, arising by mechanisms that include hinge-facilitated closure between domains and smaller-scale loop motions within domains; these movements are often induced by metal ion binding or ligand binding. Polypeptides that display flexible segments are also observed in different crystal conformations or as alternatively packed subunits. Although subjective visual inspection has been previously used to compare structures and analyze conformational changes, there is a need for an objective method., Results: We have developed a straightforward, robust, and objective algorithm that can locate the residues that mediate and participate in the changes between the two conformational states. Our method does not require initial superpositioning. We illustrate the method by considering several test cases. The first example is maltose binding protein, a polypeptide that exhibits rigid-body domain closure involving multiple hinges. The second is lactate dehydrogenase, which undergoes both loop and subdomain movement; we accurately describe the location and relative magnitude of these deformations. Finally, in the example of aspartate transcarbamoylase, both hinge-mediated domain movement and functionally relevant loop rearrangements are described. In the instances in which domain closure occurs, the residues that serve as hinges between the domains involved are accurately predicted. In addition, our technique successfully identifies the exact residues that undergo intra-domain loop movements, even for movements that are accompanied by larger scale inter-domain rearrangements., Conclusions: Our algorithm is successful in its comprehensive analysis and description of complex hinge-mediated domain motion for all structures displaying rigid-body movement and is accurate in identifying the location of any independent intra-domain rearrangements.

While recent evidence strongly suggests that the third complementarity determining regions (CDR3s) of T cell receptors (TCRs) directly contact antigenic peptides bound to major histocompatibility complex (MHC) molecules, the nature of other TCR contact(s) is less clear. Here we probe the extent to which different antigens can affect this interaction by comparing the responses of T cells bearing structurally related TCRs to cytochrome c peptides and staphylococcal enterotoxin A (SEA) presented by 13 mutant antigen-presenting cell (APC) lines. Each APC expresses a class II MHC molecule (I-Ek) with a single substitution of an amino acid residue predicted to be located on the MHC alpha helices and to point "up" towards the TCR. We find that very limited changes (even a single amino acid) in either a CDR3 loop of the TCR or in a contact residue of the antigenic peptide can have a profound effect on relatively distant TCR/MHC interactions. The extent of these effects can be as great as that observed between T cells bearing entirely different TCRs and recognizing different peptides. We also find that superantigen presentation entails a distinct mode of TCR/MHC interaction compared with peptide presentation. These data suggest that TCR/MHC contacts can be made in a variety of ways between the same TCR and MHC, with the final configuration apparently dominated by the antigen. These observations suggest a molecular basis for recent reports in which either peptide analogues or superantigens trigger distinct pathways of T cell activation.

We have used multiple-amino acid replacement mutagenesis to examine the roles of the TCR homologues of Ig complementarity-determining regions (CDR) and framework sequences in Ag-MHC and Staphylococcus aureus enterotoxin reactivity. In the three cases examined, transplantation of Ig CDR3 homologues between I-Ek-restricted TCR that recognize distinct peptides did not result in transfer of peptide reactivity. Thus the structural context of the CDR3 loops, e.g., both neighboring CDR and the V beta structure, must play a crucial, albeit supporting, role in ligand recognition. The extreme lability of this context was also shown by the fact that transplantation of the CDR1, -2, and -3 loops from the beta chain of 5C.C7 onto a V beta 1 framework failed to transfer MHC-peptide specificity even when the TCR-alpha chains were identical. In contrast, superantigen reactivity was readily transferred in several cases, with CDR2 transplants conferring strong staphylococcal enterotoxin B and A reactivity and CDR1 transplants yielding weak reactivities. This suggests that bacterial (and perhaps other) superantigens bind to many of the same regions of the TCR V beta that are believed to interact with MHC molecules. These regions of V beta may be ideal targets for superantigen binding precisely because they interact with MHC molecules and thus may be relatively conserved.

Six culture-adapted knob-positive Plasmodium falciparum parasites, four of which were nonbinding in an in vitro cytoadherence assay, were tested for the presence of the knob-associated histidine-rich protein PfHRP1. Two knob-positive, strongly cytoadherence-positive P. falciparum strains from Aotus monkeys were also examined. All parasites expressed PfHRP1, suggesting that it plays a structural or functional role related to knobs but is not by itself sufficient for cytoadherence of P. falciparum-infected erythrocytes.

An investigation of antigens accessible to lactoperoxidase-catalysed cell surface iodination on intact Plasmodium falciparum-infected red blood cells (RBC) has identified a 125I-labelled antigen with an apparent size of about 155 kD. This labelled protein was specifically immunoprecipitated by the following antibodies: a rabbit antiserum and a mouse monoclonal antibody raised against a synthetic peptide comprising the 3',8-mer repeat EENVEHDA of the Pf155/RESA protein; a rabbit antiserum raised against a synthetic octapeptide comprising two copies of the 3',4-mer repeat EENV of the Pf155/RESA protein; and rabbit antisera against another synthetic peptide C(MYSNNNVED)2. The last antibody shows a strong reaction in asexual blood stage parasites with the Pf155/RESA antigen. While this antigen has been described previously as a submembrane component of the outer membrane of infected RBC, this report shows that at least part of its is accessible to the surface of both ring and late trophozoite-infected erythrocytes.

Two very large Plasmodium falciparum proteins are identified as constituents of the infected erythrocyte membrane. Sera were obtained from Aotus monkeys that had been repeatedly infected with asexual P. falciparum from one of four strains. The capacity of these sera to block in vitro cytoadherence of infected erythrocytes and agglutinate intact infected cells was determined. The sera were also used to immunoprecipitate protein antigens from detergent extracts of 125I-surface labeled or biosynthetically radiolabeled infected erythrocytes. For each serum/antigen combination, precipitation of only one protein correlated with the ability of the serum to interfere with cytoadherence and agglutinate infected cells. This malarial protein, denoted Pf EMP 1 (P. falciparum-erythrocyte-membrane-protein 1) bore strain-specific epitope(s) on the cell surface and displayed size heterogeneity (Mr approximately 220,000-350,000). Pf EMP 1 was strongly labeled by cell-surface radioiodination but was a quantitatively very minor malarial protein. Pf EMP 1 was distinguished by its size, surface accessibility and antigenic properties from a more predominant malarial protein in the same size range (Pf EMP 2) that is under the infected erythrocyte membrane at knobs. Monoclonal antibodies and rabbit antisera raised against Pf EMP 2 were used to show that this size heterogeneous antigen was indistinguishable from the previously described MESA (mature parasite infected erythrocyte surface antigen), identified by precipitation with rabbit antisera raised against the MESA hexapeptide repeats. Antibodies raised against Pf EMP 2/MESA did not precipitate Pf EMP 1. We conclude that Pf EMP 1 is either directly responsible for the cytoadherence phenomenon, or is very closely associated with another as yet unidentified functional molecule. Pf EMP 2/MESA must have a structural property/function that is important under the host cell membrane.

This report describes the fine structure of the erythrocytic stages of Plasmodium malariae. Erythrocytic parasites from a naturally acquired human infection and an experimentally infected chimpanzee were morphologically indistinguishable and structurally similar to other primate malarias. New findings included observations of highly structured arrays of merozoite surface coat proteins in the cytoplasm of early schizonts and on the surface of budding merozoites and the presence of knobs in the membranes of Maurer's clefts. Morphological evidence is presented suggesting that proteins are transported between the erythrocyte surface and intracellular parasites via two routes: one associated with Maurer's clefts for transport of membrane-associated knob material and a second associated with caveolae in the host cell membrane for the import or export of host- or parasite-derived substances through the erythrocyte cytoplasm.

Four distinct T-cell antigen-receptor gene loci have now been identified and partly characterized: alpha, beta, gamma and delta. All of these loci can rearrange in an immunoglobulin-like fashion and express polypeptides that contribute to either alpha:beta or gamma:delta T-cell receptor-CD3 complexes. Surprisingly, the T-cell receptor (TCR) delta coding regions are located entirely, or almost entirely, within the TCR alpha locus and share at least some of the V region gene segments, thus at least partly linking the two different types of receptor heterodimers. Analysis of potential T-cell receptor diversity, particularly that of the delta chain, indicates a striking concentration of somatic polymorphism in the V-J junctional region of the two heterodimers, four to six orders of magnitude higher than similar calculations for immunoglobulin light- and heavy-chain combinations. In contrast, the number of possible V region combinations in T-cell receptors is one hundredth to one thousandth that of immunoglobulins. TCR alpha: beta heterodimers are known to recognize many possible fragments of antigens embedded in the peptide-binding clefts of a relatively small number of major histocompatibility complex (MHC) molecules. Thus it is attractive to speculate that the V-J junctional portions of both types of T-cell receptor contact peptide antigens, whereas the remaining diversity regions contact the MHC. This contention is supported by molecular modelling studies and has interesting implications for the evolution of antigen-receptor genes.

T lymphocytes recognize foreign molecules using the T-cell receptor (TCR), a disulphide-linked heterodimer closely associated with the CD3 polypeptide complex on the cell surface. The TCR alpha beta heterodimers seem largely responsible for the recognition properties of both helper (TH) and cytotoxic (TC) T cells. Recently, a second CD3-associated T-cell receptor heterodimer, gamma delta, has been described. Cells bearing the gamma delta receptor appear before those bearing alpha beta during thymic ontogeny and persist as a minor component (1-10%) of mature peripheral T cells. Their function is unknown. As there are a limited number of functional TCR V gamma gene segments, the size and potential diversity of the V delta repertoire is important for the number of different antigens that may be recognized by gamma delta heterodimers. The delta-chain locus is located 75 kilobases (kb) 5' to the TCR C alpha coding region, raising the possibility that the alpha and delta V-region repertoires may overlap. Also, analysis of rearrangements at the delta-chain locus in developing thymocytes shows distinct fetal and adult patterns indicating that there may be differences between the fetal and adult V delta repertoires. To address these questions, we have characterized a large number of delta-containing complementary DNA clones from adult double-negative thymocytes (CD4-8-), an immature population that is enriched for gamma delta-bearing cells. We find that a limited number of V delta sequences are used, showing little overlap with known adult V alpha s and differing significantly from fetal V delta s. But as two D elements may participate simultaneously in V delta gene assembly, and random nucleotides may be added at any one of three junctional points, the potential number of different delta chains that can be made in the adult thymus is very large (approximately 10(13)).

Salmonella are intracellular parasites which enter their hosts by penetrating the intestinal epithelial barrier. We examined the interaction of S. choleraesuis and S. typhimurium with Madin Darby canine kidney (MDCK) and human larynx (HEp-2) epithelial cells to characterize bacterial adherence, invasion and penetration through epithelial monolayers. Epithelial cell microfilaments were required for bacterial internalization and surrounded the bacteria as they were internalized. The bacteria entered membrane-bound vacuoles inside epithelial cells where they replicated. When polarized MDCK cell monolayers were infected, we found that Salmonella could pass through this barrier and enter medium bathing the opposite surface, although most bacteria remained within the monolayer. Synthesis of several Salmonella proteins was induced by the presence of epithelial cell surfaces, and these proteins were required for bacterial adherence and invasion. This induction was stimulated by trypsin- and neuraminidase-sensitive structures on epithelial cells.

Plasmodium falciparum-infected erythrocytes (IRBC) synthesize 3 histidine-rich proteins: HRP-I or the knob-associated HRP, HRP-II and HRP-III or SHARP. In order to distinguish these proteins immunochemically we prepared monoclonal antibodies which react with HRP-I, HRP-II and HRP-III, and rabbit antisera against synthetic peptides derived from the HRP-II and HRP-III sequences. A comparative analysis of diverse P. falciparum parasites was made using these antibodies and immunoprecipitation or Western blotting. HRP-I (Mr 80,000-115,000) was identified in all knob-positive P. falciparum parasites including isolates examined directly from Gambian patients. However, this protein was of lower abundance in these isolates and in 6 knob-positive, culture-adapted parasites compared to Aotus monkey-adapted parasites or culture-adapted parasites studied previously. HRP-II (Mr 60,000-105,000) was identified in all P. falciparum parasites regardless of knob-phenotype, and was recovered from culture supernatants as a secreted water-soluble protein. Within IRBC, HRP-II was found as a complex of several closely spaced bands. Cell surface radio-iodination of IRBC from several isolates and immunoprecipitation with a rabbit antiserum against the HRP-II repeat sequence identified HRP-II as a surface-exposed protein. Like HRP-I, the abundance of HRP-II was lower in the Gambian isolates than with Aotus monkey-adapted parasites studied earlier. Neither HRP-I nor HRP-II were identified in a knob-positive isolate of P. malariae collected from a Gambian patient. Analogues of these HRP were also absent from asexual parasites of diverse primate and murine malaria species screened with this panel of antibodies. HRP-III (Mr 40,000-55,000) was distinguished by its lower apparent size and by specific reaction with rabbit antibody against its 5-mer repeat sequence. HRP-III was of lowest abundance compared with the other two HRP. These antibody reagents and distinguishing properties should prove useful in studies on the separate functions of the 3 P. falciparum HRP.