Ponsegromab for the Treatment of Cancer Cachexia.

BACKGROUND: Cachexia is a common complication of cancer and is associated with an increased risk of death. The level of growth differentiation factor 15 (GDF-15), a circulating cytokine, is elevated in cancer cachexia. In a small, open-label, phase 1b study involving patients with cancer cachexia, ponsegromab, a humanized monoclonal antibody inhibiting GDF-15, was associated with improved weight, appetite, and physical activity, along with suppressed serum GDF-15 levels. METHODS: In this phase 2, randomized, double-blind, 12-week trial, we assigned patients with cancer cachexia and an elevated serum GDF-15 level (≥1500 pg per milliliter) in a 1:1:1:1 ratio to receive ponsegromab at a dose of 100 mg, 200 mg, or 400 mg or to receive placebo, administered subcutaneously every 4 weeks for three doses. The primary end point was the change from baseline in body weight at 12 weeks. Key secondary end points were appetite and cachexia symptoms, digital measures of physical activity, and safety. RESULTS: A total of 187 patients underwent randomization. Of these patients, 40% had non-small-cell lung cancer, 32% had pancreatic cancer, and 29% had colorectal cancer. At 12 weeks, patients in the ponsegromab groups had significantly greater weight gain than those in the placebo group, with a median between-group difference of 1.22 kg (95% credible interval, 0.37 to 2.25) in the 100-mg group, 1.92 (95% credible interval, 0.92 to 2.97) in the 200-mg group, and 2.81 (95% credible interval, 1.55 to 4.08) in the 400-mg group. Improvements were observed across measures of appetite and cachexia symptoms, along with physical activity, in the 400-mg ponsegromab group relative to placebo. Adverse events of any cause were reported in 70% of the patients in the ponsegromab group and in 80% of those in the placebo group. CONCLUSIONS: Among patients with cancer cachexia and elevated GDF-15 levels, the inhibition of GDF-15 with ponsegromab resulted in increased weight gain and overall activity level and reduced cachexia symptoms, findings that confirmed the role of GDF-15 as a driver of cachexia. (Funded by Pfizer; ClinicalTrials.gov number, NCT05546476.).

Decreased VMAT2 in the pancreas of humans with type 2 diabetes mellitus measured in vivo by PET imaging.

AIMS/HYPOTHESIS: The progressive loss of beta cell function is part of the natural history of type 2 diabetes. Autopsy studies suggest that this is, in part, due to loss of beta cell mass (BCM), but this has not been confirmed in vivo. Non-invasive methods to quantify BCM may contribute to a better understanding of type 2 diabetes pathophysiology and the development of therapeutic strategies. In humans, the localisation of vesicular monoamine transporter type 2 (VMAT2) in beta cells and pancreatic polypeptide cells, with minimal expression in other exocrine or endocrine pancreatic cells, has led to its development as a measure of BCM. We used the VMAT2 tracer [18F]fluoropropyl-(+)-dihydrotetrabenazine to quantify BCM in humans with impaired glucose tolerance (prediabetes) or type 2 diabetes, and in healthy obese volunteers (HOV). METHODS: Dynamic positron emission tomography (PET) data were obtained for 4 h with metabolite-corrected arterial blood measurement in 16 HOV, five prediabetic and 17 type 2 diabetic participants. Eleven participants (six HOV and five with type 2 diabetes) underwent two abdominal PET/computed tomography (CT) scans for the assessment of test-retest variability. Standardised uptake value ratio (SUVR) was calculated in pancreatic subregions (head, body and tail), with the spleen as a reference region to determine non-specific tracer uptake at 3-4 h. The outcome measure SUVR minus 1 (SUVR-1) accounts for non-specific tracer uptake. Functional beta cell capacity was assessed by C-peptide release following standard (arginine stimulus test [AST]) and acute insulin response to the glucose-enhanced AST (AIRargMAX). Pearson correlation analysis was performed between the binding variables and the C-peptide AUC post-AST and post-AIRargMAX. RESULTS: Absolute test-retest variability (aTRV) was ≤15% for all regions. Variability and overlap of SUVR-1 was measured in all groups; HOV and participants with prediabetes and with type 2 diabetes. SUVR-1 showed significant positive correlations with AIRargMAX (all groups) in all pancreas subregions (whole pancreas p = 0.009 and pancreas head p = 0.009; body p = 0.019 and tail p = 0.023). SUVR-1 inversely correlated with HbA1c (all groups) in the whole pancreas (p = 0.033) and pancreas head (p = 0.008). SUVR-1 also inversely correlated with years since diagnosis of type 2 diabetes in the pancreas head (p = 0.049) and pancreas tail (p = 0.035). CONCLUSIONS/INTERPRETATION: The observed correlations of VMAT2 density in the pancreas and pancreas regions with years since diagnosis of type 2 diabetes, glycaemic control and beta cell function suggest that loss of BCM contributes to deficient insulin secretion in humans with type 2 diabetes.

Pharmacokinetics and pharmacodynamics of PF-05231023, a novel long-acting FGF21 mimetic, in a first-in-human study.

AIMS: The aim of the present study was to evaluate the pharmacokinetics/pharmacodynamics (PK/PD), safety and tolerability of single intravenous (IV) doses of PF-05231023, a long acting fibroblast growth factor 21 (FGF21) analogue being developed for the treatment of type 2 diabetes mellitus (T2DM). METHODS: T2DM subjects (glycosylated haemoglobin: 7.0-10.5%; on stable metformin therapy and/or diet and exercise) were randomized to receive a single dose of placebo or PF-05231023 (0.5-200 mg). Safety evaluations were performed up to 14 days after dosing. PK and PD endpoints were measured and a PK/PD model was developed for triglyceride - an early marker of drug activity. RESULTS: No antidrug antibody or serious adverse events (AEs) were observed. The most frequent AEs were gastrointestinal but were generally mild. Plasma PF-05231023 levels peaked immediately post-IV dosing, with mean terminal half-lives of 6.5-7.7 h and 66.5- 96.6 h for intact C- and N-termini, respectively. Intact C-terminus exposures increased proportionally with increasing dose, whereas N-terminus exposures appeared to trend higher than dose-proportionally. Although no apparent effect on plasma glucose was seen, dose-dependent decreases in triglyceride were observed, with a maximum reduction of 48.5 ± 10.0% (mean ± standard deviation) for the 200 mg dose compared with a reduction of 19.1 ± 26.4% for placebo, demonstrating proof of pharmacology. Moreover, a reduction in total cholesterol and low-density lipoprotein cholesterol and an increase in high-density lipoprotein cholesterol were observed in the high-dose groups. CONCLUSIONS: Single IV doses of PF-05231023 up to 200 mg were generally safe and well tolerated by subjects with T2DM. The observed early sign of pharmacology supports further clinical testing of PF-05231023 upon repeated administration.

The mortality burden of cachexia or weight loss in patients with colorectal or pancreatic cancer: A systematic literature review.

Cancer-associated cachexia is a multifactorial wasting disorder characterized by anorexia, unintentional weight loss (skeletal muscle mass with or without loss of fat mass), progressive functional impairment, and poor prognosis. This systematic literature review (SLR) examined the relationship between cachexia and survival in patients with colorectal or pancreatic cancer in recent literature. The SLR was conducted following PRISMA guidelines. Embase® and PubMed were searched to identify articles published in English between 1 January 2016 and 10 October 2021 reporting survival in adults with cancer and cachexia or at risk of cachexia, defined by international consensus (IC) diagnostic criteria or a broader definition of any weight loss. Included publications were studies in ≥100 patients with colorectal or pancreatic cancer. Thirteen publications in patients with colorectal cancer and 13 with pancreatic cancer met eligibility criteria. Included studies were observational and primarily from Europe and the United States. Eleven studies (42%) reported cachexia using IC criteria and 15 (58%) reported any weight loss. An association between survival and cachexia or weight loss was assessed across studies using multivariate (n = 23) or univariate (n = 3) analyses and within each study across multiple weight loss categories. Cachexia/weight loss was associated with a statistically significantly poorer survival in at least one weight loss category in 16 of 23 studies that used multivariate analyses and in 1 of 3 studies (33%) that used univariate analyses. Of the 17 studies demonstrating a significant association, 9 were in patients with colorectal cancer and 8 were in patients with pancreatic cancer. Cachexia or weight loss was associated with significantly poorer survival in patients with colorectal or pancreatic cancer in nearly two-thirds of the studies. The classification of weight loss varied across and within studies (multiple categories were evaluated) and may have contributed to variability. Nonetheless, awareness of cachexia and routine assessment of weight change in clinical practice in patients with colorectal or pancreatic cancer could help inform prognosis and influence early disease management strategies.

Association between growth differentiation factor-15 and adverse outcomes among patients with heart failure: A systematic literature review.

Growth differentiation factor-15 (GDF-15) is an emerging biomarker in several conditions. This SLR, conducted following PRISMA guidelines, examined the association between GDF-15 concentration and range of adverse outcomes in patients with heart failure (HF). Publications were identified from Embase® and Medline® bibliographic databases between January 1, 2014, and August 23, 2022 (congress abstracts: January 1, 2020, to August 23, 2022). Sixty-three publications met the eligibility criteria (55 manuscripts and 8 abstracts; 45 observational studies and 18 post hoc analyses of randomized controlled trials [RCTs]). Of the 19 outcomes identified, the most frequently reported longitudinal outcomes were mortality (n = 32 studies; all-cause [n = 27] or cardiovascular-related [n = 6]), composite outcomes (n = 28; most commonly mortality ± hospitalization/rehospitalization [n = 19]), and hospitalization/re-hospitalization (n = 11). The most common cross-sectional outcome was renal function (n = 22). Among longitudinal studies assessing independent relationships with outcomes using multivariate analyses (MVA), a significant increase in risk associated with higher baseline GDF-15 concentration was found in 22/24 (92 %) studies assessing all-cause mortality, 4/5 (80 %) assessing cardiovascular-related mortality, 13/19 (68 %) assessing composite outcomes, and 4/8 (50 %) assessing hospitalization/rehospitalization. All (7/7; 100 %) of the cross-sectional studies assessing the relationship with renal function by MVA, and 3/4 (75 %) assessing exercise capacity, found poorer outcomes associated with higher baseline GDF-15 concentrations. This SLR suggests GDF-15 is an independent predictor of mortality and other adverse but nonfatal outcomes in patients with HF. A better understanding of the prognostic role of GDF-15 in HF could improve clinical risk prediction models and potentially help optimize treatment regimens.

A Phase Ib First-In-Patient Study Assessing the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of Ponsegromab in Participants with Cancer and Cachexia.

PURPOSE: Cachexia is common in patients with advanced cancer and is associated with elevated serum growth differentiation factor 15 (GDF-15) concentrations. This first-in-patient (phase Ib), 24-week study assessed use of ponsegromab, a mAb against GDF-15, in adults with advanced cancer, cachexia, and elevated GDF-15 serum concentration. PATIENTS AND METHODS: Participants (n = 10) received open-label ponsegromab subcutaneous 200 mg every 3 weeks for 12 weeks in addition to standard-of-care anticancer treatment. Ponsegromab safety, tolerability, and pharmacokinetics were assessed in addition to serum GDF-15 concentrations and exploratory measures of efficacy. RESULTS: No treatment-related treatment-emergent adverse events, injection site reactions, or adverse trends in clinical laboratory tests, vital signs, or electrocardiogram parameters attributable to ponsegromab were identified. Median serum unbound GDF-15 concentration at baseline was 2.269 ng/mL. Following initiation of study treatment, median unbound GDF-15 concentrations were below the lower limit of quantification (0.0424 ng/mL) from day 1 (3 hours postdose) through week 15. Increases in body weight were observed at all time points during the treatment and follow-up periods. A least-squares mean (SE) increase of 4.63 (1.98) kg was observed at week 12, an increase of approximately 6.6% relative to baseline. Ponsegromab-mediated improvements in actigraphy-based assessments of physical activity and in quality of life, including appetite as assessed by Functional Assessment of Anorexia-Cachexia Therapy total and subscale scores, were also observed. CONCLUSIONS: Ponsegromab was well tolerated, suppressed serum GDF-15 concentrations, and demonstrated preliminary evidence of efficacy. These findings support the continued development of ponsegromab for the treatment of cachexia.

Mortality burden of pre-treatment weight loss in patients with non-small-cell lung cancer: A systematic literature review and meta-analysis.

Cachexia, with weight loss (WL) as a major component, is highly prevalent in patients with cancer and indicates a poor prognosis. The primary objective of this study was to conduct a meta-analysis to estimate the risk of mortality associated with cachexia (using established WL criteria prior to treatment initiation) in patients with non-small-cell lung cancer (NSCLC) in studies identified through a systematic literature review. The review was conducted according to PRISMA guidelines. Embase® and PubMed were searched to identify articles on survival outcomes in adult patients with NSCLC (any stage) and cachexia published in English between 1 January 2016 and 10 October 2021. Two independent reviewers screened titles, abstracts and full texts of identified records against predefined inclusion/exclusion criteria. Following a feasibility assessment, a meta-analysis evaluating the impact of cachexia, defined per the international consensus criteria (ICC), or of pre-treatment WL ≥ 5% without a specified time interval, on overall survival in patients with NSCLC was conducted using a random-effects model that included the identified studies as the base case. The impact of heterogeneity was evaluated through sensitivity and subgroup analyses. The standard measures of statistical heterogeneity were calculated. Of the 40 NSCLC publications identified in the review, 20 studies that used the ICC for cachexia or reported WL ≥ 5% and that performed multivariate analyses with hazard ratios (HRs) or Kaplan-Meier curves were included in the feasibility assessment. Of these, 16 studies (80%; n = 6225 patients; published 2016-2021) met the criteria for inclusion in the meta-analysis: 11 studies (69%) used the ICC and 5 studies (31%) used WL ≥ 5%. Combined criteria (ICC plus WL ≥ 5%) were associated with an 82% higher mortality risk versus no cachexia or WL < 5% (pooled HR [95% confidence interval, CI]: 1.82 [1.47, 2.25]). Although statistical heterogeneity was high (I2 = 88%), individual study HRs were directionally aligned with the pooled estimate, and there was considerable overlap in CIs across included studies. A subgroup analysis of studies using the ICC (HR [95% CI]: 2.26 [1.80, 2.83]) or WL ≥ 5% (HR [95% CI]: 1.28 [1.12, 1.46]) showed consistent findings. Assessments of methodological, clinical and statistical heterogeneity indicated that the meta-analysis was robust. Overall, this analysis found that ICC-defined cachexia or WL ≥ 5% was associated with inferior survival in patients with NSCLC. Routine assessment of both weight and weight changes in the oncology clinic may help identify patients with NSCLC at risk for worse survival, better inform clinical decision-making and assess eligibility for cachexia clinical trials.

Phase 2 study of the efficacy and safety of ponsegromab in patients with cancer cachexia: PROACC-1 study design.

BACKGROUND: Cancer cachexia is a multifactorial metabolic wasting syndrome characterized by anorexia, unintentional loss of weight involving both skeletal muscle and adipose tissues, progressive functional impairment and reduced survival. Therapeutic strategies for this serious condition are very limited. Growth differentiation factor 15 (GDF-15) is a cytokine that is implicated in cancer cachexia and may represent both a biomarker of cancer cachexia and a potential therapeutic target. Ponsegromab is a potent and selective humanized monoclonal antibody that inhibits GDF-15-mediated signalling. Preclinical and preliminary phase 1 data suggest that ponsegromab-mediated inactivation of circulating GDF-15 may lead to improvement in key characteristics of cachexia. The primary objective of this phase 2 study is to assess the effect of ponsegromab on body weight in patients with cancer, cachexia and elevated GDF-15 concentrations. Secondary objectives include assessing physical activity, physical function, actigraphy, appetite, nausea and vomiting, fatigue and safety. Exploratory objectives include evaluating pharmacokinetics, pharmacodynamics, immunogenicity, lumbar skeletal muscle index and Response Evaluation Criteria in Solid Tumors. METHODS: Approximately 168 adults with non-small-cell lung, pancreatic or colorectal cancers who have cachexia and elevated GDF-15 concentrations will be randomized in a double-blind, placebo-controlled study (NCT05546476). Participants meeting eligibility criteria will be randomized 1:1:1:1 to one of three dose groups of ponsegromab (100, 200 or 400 mg) or matching placebo administered subcutaneously every 4 weeks for an initial 12-week treatment period. This is followed by optional open-label treatment with ponsegromab of 400 mg administered every 4 weeks for up to 1 year. The primary endpoint is mean change from baseline in body weight at Week 12. A mixed model for repeated measures followed by a Bayesian Emax model will be used for the primary analysis. Secondary endpoints include physical activity, physical function and actigraphy measured by remote digital sensors; patient-reported appetite-related symptoms assessed by Functional Assessment of Anorexia-Cachexia Therapy subscale scores; anorexia/appetite, nausea and vomiting, and fatigue evaluated according to questions from the Cancer-Related Cachexia Symptom Diary; and incidence of adverse events, safety laboratory tests, vital signs and electrocardiogram abnormalities. PERSPECTIVE: Cancer-related cachexia is an area of significant unmet medical need. This study will support the clinical development of ponsegromab as a novel inhibitor of GDF-15, which may ameliorate key pathologies of cancer cachexia to improve patient symptoms, functionality and quality of life. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT05546476.

Patient Willingness to Use Digital Health Technologies: A Quantitative and Qualitative Survey in Patients with Cancer Cachexia.

Purpose: The objective of this study was to gain insights into the patients' perspectives on the impact of cancer cachexia on physical activity and their willingness to wear digital health technology (DHT) devices in clinical trials. Patients and Methods: We administered a quantitative 20-minute online survey on aspects of physical activity (on a 0-100 scale) to 50 patients with cancer cachexia recruited through Rare Patient Voice, LLC. A subset of 10 patients took part in qualitative 45-minute web-based interviews with a demonstration of DHT devices. Survey questions related to the impact of weight loss (a key characteristic in Fearon's cachexia definition) on physical activity, patients' expectations regarding desired improvements and their level of meaningful activities, as well as preferences for DHT. Results: Seventy-eight percent of patients reported that their physical activity was impacted by cachexia, and for 77% of them, such impact was consistent over time. Patients perceived most impact of weight loss on walking distance, time and speed, and on level of activity during the day. Sleep, activity level, walking quality and distance were identified as the most meaningful activities to improve. Patients would like to see a moderate improvement of activity levels and consider it meaningful to perform physical activity of moderate intensity (eg, walk at normal pace) on a regular basis. The wrist was the preferred location for wearing a DHT device, followed by arm, ankle, and waist. Conclusion: Most patients reported physical activity limitations since the occurrence of weight loss compatible with cancer-associated cachexia. Walking distance, sleep and quality of walk were the most meaningful activities to moderately improve, and patients consider moderate physical activity as meaningful. Finally, this study population found the proposed wear of DHT devices on the wrist and around the waist acceptable for the duration of clinical studies.

Preclinical characterization of an intravenous coronavirus 3CL protease inhibitor for the potential treatment of COVID19.

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. PF-00835231, a 3CL protease inhibitor, has exhibited potent in vitro antiviral activity against SARS-CoV-2 as a single agent. Here we report, the design and characterization of a phosphate prodrug PF-07304814 to enable the delivery and projected sustained systemic exposure in human of PF-00835231 to inhibit coronavirus family 3CL protease activity with selectivity over human host protease targets. Furthermore, we show that PF-00835231 has additive/synergistic activity in combination with remdesivir. We present the ADME, safety, in vitro, and in vivo antiviral activity data that supports the clinical evaluation of PF-07304814 as a potential COVID-19 treatment.

Discovery of a Novel Inhibitor of Coronavirus 3CL Protease for the Potential Treatment of COVID-19.

COVID-19 caused by the SARS-CoV-2 virus has become a global pandemic. 3CL protease is a virally encoded protein that is essential across a broad spectrum of coronaviruses with no close human analogs. The designed phosphate prodrug PF-07304814 is metabolized to PF-00835321 which is a potent inhibitor in vitro of the coronavirus family 3CL pro, with selectivity over human host protease targets. Furthermore, PF-00835231 exhibits potent in vitro antiviral activity against SARS-CoV-2 as a single agent and it is additive/synergistic in combination with remdesivir. We present the ADME, safety, in vitro , and in vivo antiviral activity data that supports the clinical evaluation of this compound as a potential COVID-19 treatment.

GDF-15 Neutralization Alleviates Platinum-Based Chemotherapy-Induced Emesis, Anorexia, and Weight Loss in Mice and Nonhuman Primates.

Platinum-based cancer therapy is restricted by dose-limiting side effects and is associated with elevation of growth differentiation factor 15 (GDF-15). But whether this elevation contributes to such side effects has been unclear. Here, we explored the effects of GDF-15 blockade on platinum-based chemotherapy-induced emesis, anorexia, and weight loss in mice and/or nonhuman primate models. We found that circulating GDF-15 is higher in subjects with cancer receiving platinum-based chemotherapy and is positively associated with weight loss in colorectal cancer (NCT00609622). Further, chemotherapy agents associated with high clinical emetic score induce circulating GDF-15 and weight loss in mice. Platinum-based treatment-induced anorexia and weight loss are attenuated in GDF-15 knockout mice, while GDF-15 neutralization with the monoclonal antibody mAB1 improves survival. In nonhuman primates, mAB1 treatment attenuates anorexia and emesis. These results suggest that GDF-15 neutralization is a potential therapeutic approach to alleviate chemotherapy-induced side effects and improve the quality of life.

Metabolism, pharmacokinetics, and excretion of a cholesteryl ester transfer protein inhibitor, torcetrapib, in rats, monkeys, and mice: characterization of unusual and novel metabolites by high-resolution liquid chromatography-tandem mass spectrometry and 1H nuclear magnetic resonance.

The disposition of torcetrapib {(-)-[2R,4S] 4-[(3,5-bis-trifluoromethylbenzyl)-methoxycarbonyl-amino]-2-ethyl-6-trifluoromethyl-3,4-dihydro-2H-quinoline-1-carboxylic acid ethyl ester}, a cholesteryl ester transfer protein inhibitor, was studied in rats, monkeys, and mice after oral administration of a single dose of [14C]torcetrapib. Total mean recoveries of the radiocarbon were 90.9, 93.4, and 86.8% from mice, rats, and monkeys, respectively. Excretion of radioactivity was rapid and nearly complete within 48 h after dosing, with a majority excreted in the feces in all species. Torcetrapib was not detected in the urine and/or bile across species, suggesting that it is primarily cleared by metabolism in these species. More than 28 metabolites were identified in all species and were products of oxidation and conjugation pathways. The primary metabolic pathways of torcetrapib involved hydrolysis of the carbamate ester (M2) and the oxidation of the ethyl moieties. M2 was subsequently metabolized in parallel by oxidative cleavage to novel and unusual quinoline metabolites (M3, M4, M5, M9, and M17), M1 (bis trifluoromethyl benzoic acid), and M28 [3,5-bis(trifluoromethyl)phenyl-(methoxycarbonyl)methanesulfonic acid]. The structures of several metabolites were established by high-resolution liquid chromatography-tandem mass spectrometry and 1H NMR. The major circulating and excretory metabolites in mice, rats and monkeys were species-dependent; however, several common metabolites were observed in more than one species. In addition to parent torcetrapib, M1, M3, and M4 in rats, M4 and M17 in mice, and M3 and M8 in monkeys were detected as the major circulating metabolites. A mechanism for the formation of an unusual metabolite M28 has been proposed.

A Long-Acting FGF21 Molecule, PF-05231023, Decreases Body Weight and Improves Lipid Profile in Non-human Primates and Type 2 Diabetic Subjects.

FGF21 plays a central role in energy, lipid, and glucose homeostasis. To characterize the pharmacologic effects of FGF21, we administered a long-acting FGF21 analog, PF-05231023, to obese cynomolgus monkeys. PF-05231023 caused a marked decrease in food intake that led to reduced body weight. To assess the effects of PF-05231023 in humans, we conducted a placebo-controlled, multiple ascending-dose study in overweight/obese subjects with type 2 diabetes. PF-05231023 treatment resulted in a significant decrease in body weight, improved plasma lipoprotein profile, and increased adiponectin levels. Importantly, there were no significant effects of PF-05231023 on glycemic control. PF-05231023 treatment led to dose-dependent changes in multiple markers of bone formation and resorption and elevated insulin-like growth factor 1. The favorable effects of PF-05231023 on body weight support further evaluation of this molecule for the treatment of obesity. Longer studies are needed to assess potential direct effects of FGF21 on bone in humans.

Novel CCR1 antagonists with improved metabolic stability.

The synthesis, biological activity, and pharmacokinetic profile of novel CCR1 antagonists are described.