BACKGROUND

[0001] The present invention pertains to compounds and methods that have utility for treating and/or mitigating the effects of idiopathic pulmonary fibrosis and related interstitial lung diseases.

[0002] Pulmonary fibrosis (PF) is one of a family of related diseases called interstitial lung diseases that can result in lung scarring. As the lung tissue becomes scarred, it interferes with a person's ability to breathe. Idiopathic pulmonary fibrosis (IPF) is a chronic and ultimately fatal disease in which the patient experiences progressive scarring of lung tissue with no apparent source or cause for the scarring. In PF, as scarring progresses, the sufferers can experience increasingly worsening symptom such as shortness of breath, coughing, fatigue and pain as well as concomitant psychological effects. Individuals suffering from pulmonary fibrotic diseases such as IPF can often manifest a histological pattern known as usual interstitial pneumonia (UIP). UIP can also occur due to diseases such as systemic sclerosis, rheumatoid arthritis, and asbestosis. UIP typically progresses to respiratory failure and death with median survival rates currently being between 3 and 4 years.

[0003] IPF is one of a larger group of interstitial lung diseases (ILD), characterized by involvement of the lung interstitium. While such diseases affect the interstitium, there can and is involvement of the air sacs, peripheral airways and various vessels. A disease is typically diagnosed as IPF when no cause can be associated with the onset of the disease. Other interstitial lung diseases include diseases like sarcoidosis, anti synthetase syndrome. In addition to asbestosis, environmentally induced interstitial lung diseases can include exposure to inhaled substances like silicon and beryllium as well as various organic materials. It is also believed that ILDs can be the result of or associated with various autoimmune diseases such as rheumatoid arthritis, systemic sclerosis and systemic lupus.

[0004] In addition to the more chronic manifestations of IPF and associated ILDs, diseases like IPF can exhibit acute exacerbations which are defined as unexplained worsening or development of dyspnea within 30 days with new radiological infiltrates at HRCT abnormality often superimposed on a background consistent with UTP pattern. The yearly incidence of AE- IPF is between 10 and 15% of all patients. The prognosis of AE-IPF is poor, with mortality ranging from 78% to 96%.

[0005] To date there have been few effective treatments for PF, IPF and various associated ILDs. Those that are available or on the horizon, act to reduce or slow the progression the disease. Pirenidone has been employed as a growth factor and precollagen down regulator. Nintedanib has been employed to target fibroblast growth receptors to slow decrease in forced vital capacity. Various monoclonal antibodies such as simfuzumab, tralokimab and lebrikizumab show promise. These latter materials are believed to be directed against several growth factors and cytokynes that play a role in the proliferation, activation or differentiation or inappropriate survival of fibroblasts.

[0006] The various drugs and therapies that have been proposed to date have various side effects, contraindications and effectiveness. It is desirable to provide a compound that can address symptoms and/or sequellae of IPF and/or various ILDs either alone or in combination with previously known compounds and therapies.

[0007] It would be desirable to provide a more effective compound or compounds that target one of more of the physical symptoms and manifestations associated with IPF and/or various ILDs either alone or in combination with previously known compounds and therapies.

SUMMARY

[0008] As disclosed herein, a compound selected from the group consisting of [Met-

OH ^u ]-substance P, [Met-OMe ^u ]-substance P, [Nle ¹¹ ] -sub stance P, [Pro ⁹ ] -sub stance P, [Sar ⁹ ]- substance P, [Tyr ⁸ ]-substance P, Sar ⁹ , Met (O2) ¹ ^Substance P, and [p-Cl-Phe ⁷ ' ⁸ ]-substance P is employed in addressing at least one symptom and/or condition associated with an interstitial lung disease ILD. In certain embodiments, the interstitial lung disease (TLD) can be pulmonary fibrosis (PF) such as idiopathic pulmonary fibrosis (IPF). In certain embodiments, the therapeutic compound is integrated into a dose form that can be administered at least once to a patient to address at least one symptom associated with interstitial lung disease. The therapeutic compound disclosed herein can be administered alone in certain embodiments, or in combination with one or more active agents.

[0009] According to another aspect of the invention a method is provided for treating individuals at risk for developing usual interstitial pneumonia (UIP) and/or individuals presenting ILDs such as IPF at risk of developing an acute exacerbation (AE). The method includes administering an effective amount of a compound selected from the group consisting of [Met-OH ^u ]-substance P, [Met-OMe ^u ]-substance P, [Nle ^u ]-substance P, [Pro ⁹ ]-substance P, [Sar ⁹ ]-substance P, [Tyr ⁸ ]-substance P, Sar ⁹ , Met (0 ₂ ) 11 -Substance P, and [p-Cl-Phe ^{7 8} ]- substance P is administered to the individual on an as needed or continuing basis as part of a treatment regimen.

DESCRIPTION OF THE DRAWINGS

[0010] In order to facilitate the present disclosure, reference is made to the following illustrative drawing figures in which like reference numerals are employed where appropriate throughout the various views:

[0011] Fig. 1 is a space filling model of Substance P: Arg-Pro-Lys-Pro-Gln-Gln-Phe-Phe-

Gly-Leu-Met- H ₂ ;

[0012] Fig. 2 is a structural depiction of an analog of Substance P as disclosed herein; and

[0013] Fig. 3 is a table depicting the amino acid sequence for Sar ⁹ , Met (0 ₂ ) ⁿ - SP and endogenous tachykinins

DETAILED DESCRIPTION

[0014] It has been discovered unexpectedly that bioactive Substance P analogs including but not limited to Sar ⁹ , Met (0 ₂ ) ¹ ^Substance P, [Met-OH ^u ]-substance P, [Met-OMe ^u ]-substance P, [Nle ^u ]-substance P, [Pro ⁹ ] -sub stance P, [Sar ⁹ ] -sub stance P, [Tyr ⁸ ]-substance P, and [p-Cl- Phe ⁷ ' ⁸ ]-substance P provide therapeutic effect when administered to individuals presenting with various forms of interstitial lung disease (ILD) including, but not limited to, idiopathic pulmonary fibrosis (IPF). Without being bound to any theory, it is believed that individuals so treated exhibit an increased interval before or between development of acute exacerbations (AE) of the underlying ILD, such as acute exacerbations of pulonary fibrosis (PF) or idiopathic pulomnary fibrosis (IPF) ( AE-PF or AE-IPF). It has also been discovered unexpectedly bioactive analogs of Substance P as disclosed herein can be administered to individuals presenting with usual interstitial pneumonia (UIP) and/or AE-IPF to reduce or ameliorate symptoms.

[0015] A bioactive analog of Substance P (RPKPQQFFGLM- H ₂ ; SEQ ID NO: 1) can be administered to treat various forms of interstitial lung disease (ILD) manifesting at least one fibrotic mass including, but not limited to, idiopathic pulmonary fibrosis (IPF). Non-limiting examples of the bioactive analogs of Substance P that can be employed in the present disclosure include [Met-OH ^u ]-substance P, [Met-OMe ^u ]-substance P, [Nle ^u ]-substance P, [Pro ⁹ ] -sub stance P, [Sar ⁹ ]-substance P, [Tyr ⁸ ]-substance P, Sar ⁹ Met (0 ₂ ) ^u -Substance P, and [p-Cl-Phe ^{7 8} ]- substance P. It is also contemplated that other compounds which function in the same way can be identified by their ability to compete with substance P for binding to its receptor (NK-1) or for their ability to agonize the NK-1 receptor can be utilized in the present disclosure in combination with the aforementioned bioactive analogs.

[0016] Where desired or required, the bioactive analogs of Substance P as described herein can be co-administered with Substance P in a suitable treatment regimen.

[0017] The Bioactive analogs of substance P as disclosed herein can be administered by any method known in the art, including via aerosol inhalation. Intravenous, intratracheal, intrabronchial, intramuscular, sublingual, and oral administrations can also be used.

Contemplated intravenous dosages include 0.05 to 5 nanomolar compound for intravenous administration. In certain intravenous applications a dose concentration of 0.1 to 2 nanomolar may be employed; while in other applications 0.5 to 1.5 nanomolar concentrations can be used. For aerosol administration contemplated dosages include 0.05 to 5.0 micromolar substance P or analog with dosages from 0.1 to 2 micromolar employed in certain applications and dosages from 0.5 to 1.5 micromolar employed in others. Typical concentration ranges of substance P or its bioactive analog in the aerosol administered is between 0.001 and 10 μΜ. It can be advantageously administered as a liquid at a concentration between about 0.1 and 10 μΜ.

[0018] Bioactive analogs, according to the present disclosure are those which act as competitive inhibitors of Substance P by binding to the Substance P receptor (NK-1 receptor). The analogs may be agonists of the NK-1 receptor. Other derivatives as are known in the art and commercially available (e.g., from Sigma) can be used. In addition, substance P fragments and derivatized substance P fragments may also be used. Substitution, deletion, or insertion of one to eight amino acid residues, and preferably from one to three amino acid residues, will lead to analogs which can be routinely tested for biological activity. In addition, functional groups may be modified on SP while retaining the same amino acid backbone. Again, routine testing will determine which of such modifications do not adversely affect biological activity.

[0019] Without being bound to any theory, it is believed that Substance P, the parent compound for the various analogs disclosed herein, is a relatively small (1,348 Daltons), endogenous peptide first discovered in 1931 and characterized chemically about 40 years later. Neuropeptides, such as Substacne P, were originally discovered as being distributed throughout the peripheral and central nervous systems. However, Substance P has since been shown to be produced in non-neuronal cells such as human endothelial cells, Leydig cells, enterochromaffin cells, epithelial cells, fibroblasts, keratinocytes, intestinal and airway smooth muscle cells, inflammatory and immune cells, and in cells of the female reproductive system.

[0020] Historically, Substance P has been recognized as a mediator of nonadrenergic, noncholinergic (NANC) excitatory neurotransmission, and as playing a role in the transmission of pain.

[0021] It is believed that the analogs of Substance P as disclosed herein bind to one or more of the three neurokinin receptors (NK-1, NK-2 and NK-3), with preferentially interaction at the NK-1R to mediate its biological effects. The neurokinin receptors belong to "family 1" (rhodopsin-like) of the G protein-coupled receptors. Like many G protein-coupled receptors, the NK-1R consists of seven putative a-helical transmembrane segments, an intracellular carboxyl tail, and an extracellular amino-terminus. At the extracellular amino terminus there is an N- glycosylation site, while many serine and threonine residues at the intracellular carboxyl terminus are potential phosphorylation sites.

[0022] The Neurokinin-1 receptor has been identified in stem cell lines as well as cells derived from human placental cord blood, rich in hematopoietic stem and progenitor cells. The NK-1R has been identified in a various tissues and cell type and is expressed in immune cells such as T and B lymphocytes, monocytes/macrophages, neutrophils, and mast cells. Non- immune cells like vascular endothelial cells, bone marrow stromal cells, muscle cells, astrocytes, adipocytes, keratinocytes, and fibroblasts also express the K-1R. The NK-1R receptor is appears to be involved in a number of physiological systems that may be of significance to the immune system, and the cells that support the immune system.

[0023] The primary amino acid sequences of Substance P analogs including but not limited to Sar ⁹ , Met (02) ^U -SP are distinct from the tachykinins Neurokinin A (NKA) and Neurokinin B (NKB) at the N-terminus (referenced by the start of the amino acid sequence as seen in FIG 3. These differences result in NKA and NKB binding with significantly less affinity to the Neurokinin-1 receptor (NK-1R) than do compounds such as Sar ⁹ , Met (02) ^U -SP, which share an identical N-terminal sequence. The C-terminal penta-peptide, Phe-Phe/Val-Gly-Leu- Met-NH ₂ , is conserved between all natural tachykinins and is required for receptor activation. Amidation of the C-terminal methionine is vital for peptide function as without this modification tachykinins are unable to activate their corresponding mammalian receptors. It is believed that the specific C-terminal modifications that separate Sar ⁹ , Met (0 ₂ ) ^u -SP from endogenous SP contribute to differences in bioactivity and confer NK-1 receptor specificity (via the modification of the Gly ⁹ ), as the ligand-receptor interactions are changed as depicted in FIG. 2.

[0024] By way of non-limiting example, one particular analog that has been found to be particularly efficacious in treatment is created by modifying two of the eleven amino acids in the Substance P sequence. These modifications included replacing glycine (Gly) with sarcosine (Sar or N-methyl glycine) at the ninth position and introducing an oxidized form of methionine

[Met(0 ₂ )j at the eleventh position (as seen in FIGS 2 and resulting in the peptide Sar ⁹ Met (0 ₂ ) ^u -SP (1,393.6 Daltons)

[0025] Without being bound to any theory, it is believed that materials such as Sar ⁹ Met

(0 ₂ ) ^u -SP and the analogs disclosed herein mediate predominately through interactions with the Neurokinin-1 receptor located on the plasma membrane of many cell types. Substance P analog binds to all three neurokinin receptors (NK-1, NK-2 and NK-3), though SP preferentially interacts at the NK-IR to mediate its biological effects. Compounds such as Sar ⁹ Met (0 ₂ ) ^u -SP, [Met-OH ^u ]-SP, [Met-OMe ^u ]-SP, [Nle ^u ]-SP, [Pro ⁹ ]-SP, [Sar ⁹ ]-SP, [Tyr ⁸ ] -sub stance P, [p-Cl- Phe ⁷ ' ⁸ ]-SP and the like are believed to be highly selective for NK-IR while demonstrating little or no activity in NK-2 and NK-3 receptor biological activity assays while eliciting greater than 3-times the biological activity as SP in K-lR-specific tissues. The two-fold greater binding affinity for analogs such as Sar ⁹ Met (02) ^U -SP shows for the K-1R compared to SP (0.8 ± 0.3 nM vs. 1.6 ± 0.4 nM, respectively) is evidence of increases in biological activity

[0026] It is believed that the interaction of both Sar ⁹ Met (0 ₂ ) ^u -SP and SP with the NK-

1R induces secondary messenger signaling events, which originate from the activated receptor and then rapidly cascade throughout the cell. Water-soluble messengers, like Ca ²⁺ and cyclic AMP (cAMP), diffuse throughout the cytosol, while the hydrophobic lipid-soluble messengers like diacylglycerol (DAG) diffuse into the plasma membrane. In some tissues, activation of water-soluble messengers can lead to signaling events in adjacent cells via gap junctions, thus leading to a broad multi -cellular response from the stimulation of a single cell

[0027] SP analogs disclosed herein such as Sar ⁹ Met (0 ₂ ) ^u -SP are capable of utilizing both phosphatidylinositol (PI) hydrolysis and cAMP as second messenger signaling systems (mediating changes in intracellular Ca ²⁺ mobilization), and do so with high potency. Using an in vitro model (Chinese Hamster Ovary cells transfected with human K-1R) Sagan et al. have reported an EC50 of 1.0 ± 0.6 nM for SP in stimulating phosphatidylinositol (PI) hydrolysis whereas Sar ⁹ Met (0 ₂ ) ^u -SP was reported to have an EC50 of 0.40 ± 0.01 nM in stimulating PI hydrolysis, Sagan, S. et al., J. Pharmacology and Experimental Therapeutics 276 (1996) 1039- 1048. The same group reported an EC50 of 8 ± 4 nM for SP in stimulating cAMP formation whereas Sar ⁹ , Met (0 ₂ ) ^u -SP was reported to have an EC50 of 16 ± 7 nM.

[0028] The Substance P analog, Sar ⁹ Met (0 ₂ ) ^u -SP is a 1393 Da, 11-amino acid, synthetically-manufactured analog of Substance P (SP). Sar ⁹ Met (0 ₂ ) ^u -SP is modified at the 9th [N-Methyl glycine (or Sarcosine) instead of glycine] and 11th (addition of a Sulphone) positions. These modifications render Sar ⁹ Met (O2) ¹¹ - Sub stance P receptor-specific for the Neurokinin-1 receptor, and also make Sar ⁹ Met (0 ₂ ) ^u -SP more resistant to proteolytic degradation relative to the endogenous peptide, Substance P.

[0029] The differences in the degradation characteristics between Substance P and Sar ⁹

Met (0 ₂ ) ^u -SP have recently been found to result in different biological effects. Ligands that signal via G protein-coupled receptors elicit downstream cellular signals (e.g. CAMP F-KB, etc.), which consequently produce a physiological effect. Once the ligand binds the receptor (the K1 receptor in the case of Sar ⁹ Met (O2) ¹¹ - Sub stance P and Substance P), downstream cellular signals are elicited and the ligand-receptor complex is internalized from the plasma membrane into an early endosome, where the ligand is degraded. Recently Cattaruzza et al. reported that the endopeptidase called endothelin-converting enzyme-1 (ECE-1) is responsible for the degradation of internalized neuropeptides within early endosomes, Cattaruzza, F. et al., Br J Pharmacol. 2009 Mar; 156(5):730-9. ECE-1 shares considerable sequence homology with Neprilysin (a.k.a. Neutral Endopeptidase or CD 10), which is recognized for degrading neuropeptides extracellularly. Indeed, the CDIO/CALLA (common acute lymphoblastic leukemia antigen) nomenclature reflects the historical localization of the enzyme's activity on the surface of intact cells. ECE-1 hydrolyzes SP at Gln ⁶ -Phe ⁷ and Gly ⁹ -Leu ¹⁰ linkages and degradation of endocytosed neuropeptides regulates trafficking and signaling of internalized receptors. This enzyme facilitates the release of the receptor from the ligand-receptor complex and allows for the receptor to be recycled back to the cell surface, which mediates resensitization.

[0030] It is believed that the ability of the ligand to be degraded by ECE-1 is contributes to the resensitization of the cell following activation. In the case of Substance P, this occurs rapidly and efficiently. However, in the case of Sar ⁹ Met (02) ^U -SP this process is considerably less efficient. It is believed that Sar ⁹ Met (02) ^U -SP is degraded significantly slower and less efficiently than the endogenous tachykinin Substance P: within 100 minutes of incubation in a solution containing 195nM ECE-1, nearly 100% of the Substance P present is degraded.

However, at this same concentration of ECE-1 only about 20% of the Sar ⁹ Met (02) ^U -SP present is degraded. In fact, it takes nearly 300 minutes for 50% of the Sar ⁹ Met (02) ^U -SP present to become degraded and no additional degradation occurs even at 1200 minutes post-incubation. It is believed that within NK1-R expressing cells ECE-1 degradation of Substance P disrupted the SP-NK1R association with β-arrest in-Src complexes and the resultant ERK1/2 activation. Thus the effect of a slower degradation of Sar ⁹ , Met (02) ^U -SP and its complex with internalized NK1R might result in prolonged activation of intracellular ERKs (extracellular signal-regulated kinases) and a different (prolonged ERK activation but delayed receptor resensitization), perhaps enhanced cellular response compared to that elicited by SP

[0031] Without being bound to any theory, it is believed that Sar ⁹ Met (02) ^U -SP may induce cellular responses that differ from those elicited by SP and reduce the rate at which NK1 receptor recycling and resensitization occurs. The physiological implications of this recent finding are many, and could include a greater initial stimulatory response to K1R stimulation due to the prolonged intracellular kinase activation followed by a prolonged resistance to endogenous SP due to the inhibition of NK1R recycling.

[0032] As disclosed herein, bioactive Substance P analogs as disclosed herein have particular applicability and efficiency as a primary or adjunct therapeutic material for treatment of interstitial lung disease (ILD) such as fibrosis, idiopathic pulmonary fibrosis, as well as prodromal conditions which present prior to the onset of ILD. It has also been discovered that a therapy regimen that includes administration of the compounds disclosed herein can reduce the incidence and severity of acute exacerbations of PF or IPE It is also contemplated that one or more of the compounds disclosed herein can be used as an intervention material, alone or in combination with other therapeutic agents in addressing and ameliorating episodes of acute respiratory distress. Suitable analogues include but are not limited to [Met-OH ^u ]-substance P, [Met-OMe ^u ]-substance P, [Nle ^u ]-substance P, [Pro ⁹ ] -sub stance P, [Sar ⁹ ]-substance P, [Tyr ⁸ ]- substance P, Sar ⁹ , Met (02) ^U -Substance P, and [p-Cl-Phe ⁷ ' ⁸ ]-substance P.

[0033] The material can be administered in a concentration sufficient to achieve at least one bioactive effect in the patient. Bioactive affect, as the term is employed herein, is taken to mean a dose response exhibited in an average of 50% of the symptomatic or pre-symptomatic patients treated. Dose response as defined herein can include at least one of the following:

reduction in symptoms, stopping disease progression, reduction in acute exacerbations, prolonged survival. Short term dose response can be determined based on one or more of the following: increased lung capacity expressed as vital capacity or forced vital capacity, improved static lung volume, improved lung histopathology expressed as interstitial pathology and/or alveolitis; decreased dyspnea on exertion and increases in functional exercise tolerance, increase in the diffusing capacity for carbon monoxide (DLco), decreased evidence of oxygen

desaturation with exercise as measure by tests such as the six-minute walk test..

[0034] As used herein, the term "vital capacity" is defined as the maximum amount of air a person can expel from the lungs after a maximum inhalation. It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. "Forced vital capacity" (FVC) is defined as the amount of air that can be forcibly exhaled from the lungs after taking the deepest breath possible and is typically measure by spirometry. "Static lung volume" is defined as the measurement of total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), and vital capacity (VC). Functional exercise tolerance in humans can be measured using a six-minute walk test (6MWT) as developed by Balke and promulgated by the American College of Rheumatology. "Diffusing capacity of the lungs for carbon monoxide" as used herein is a determination of how much oxygen travels from the alveoli of the lungs to the blood stream.

[0035] In various embodiments, the material disclosed herein can be formulated as an aerosolizable fluid with active component present in an amount between 0.1 and 10 μΜ. It is also contemplated that the active component can be formulated as a solid dose form as a pill or tablet or as a powder or granular material. In certain applications in which the dose form employed is a pill or powder, it is contemplated that the bioactive analog of Substance P disclosed herein can be present in the dose form at a concentration between 0.05 to 7 nanomolar. In certain applications, it is contemplated that the active compound disclosed herein can be present at suitable therapeutic concentrations, for example 0.05 to 5 nanomolar.

[0036] Suitable devices for administering an aerosol as disclosed herein may include nebulizers as well as hand-held aerosol "puffer" devices. Suitable treatment regimens for treatment according to the present invention include daily or multiple daily treatment by aerosol .

[0037] Other modes of treatment include continual transdermal infusion, intravenous injection, intramuscular, sublingual, subcutaneous injection, and oral administration. Suitable formulations of bioactive analogs of substance P for administration are any which are pharmaceutically acceptable and in which bioactive analogs of substance P retains its biological activity. Generally, such formulations include bioactive analogs of substance P dissolved in normal sterile saline. Other formulations for changing absorption and half-life characteristics can be used, including liposomal formulations and slow-release formulations,

EXAMPLE I

[0038] The degradation characteristics of Sar ⁹ Met (O2) ¹¹ - Sub stance P relative to unmodified Substance P were studied. Samples Substance P and Sar ⁹ Met (O2) ¹¹ - Sub stance P were incubated at equivalent concentrations in FMDM media with 2.5% fetal bovine serum for 72 hours. Only 24% of the initial concentration of Substance P was recovered at this time whereas 59% of the initial concentration of NAS911 was recovered - 146% greater than the amount of Substance P recovered. This demonstrates that the Sar ⁹ Met (O2) ¹ ^Substance P is significantly less prone to degradation than Substance P.

[0039] It has been found, quite unexpectedly that the bioactive analogs of Substance P described herein function as pleotropic agent to reverse the pathologies associated with interstitial lung disease (ILD) particularly fibrotic development as evidenced in idiopathic pulmonary fibrosis as well as pulmonary fibrosis

EXAMPLE II

[0040] The reactions produced by administration of Sar ⁹ Met (O2) ¹ ^Substance P to mammals presenting with fibrotic lung tissue are studied. In order to produce an animal model for pulmonary fibrosis that is predictive of the human disease cohorts of mice cotton rats and ferrets are exposed to 5Gy of ionizing radiation with an additional lung dose added of 10 Gy. At 26 weeks post irradiation, the lungs of the irradiated animals reveal areas of consolidated fibrosis originating from the pleural surface. This is compared to fibrosis induction methods involving intratracheal instillation and intratracheal aerosol instillation of bleomycyn as outlined in the method by Braun, et al at Comparative Haemotological International (1996), pp 142 et seq. When examined, the pathologies induced by irradiation are found to be closer to pathologies found in human pulmonary fibrosis.

EXAMPLE III

[0041] Animals (six C57B1 mice) are subjected to 5 Gy of whole body radiation and with an additional lung dose added of 10 Gy. At 26 weeks post-irradiation, the lungs of the irradiated animals are inspected and revealed areas of consolidated fibrosis originating from pleural surfaces. Also prominent are a large number of activated macrophages and lymphocytes.

EXAMPLE IV

[0042] Twelve animals (C571B1 mice) are subjected to 5 Gy of whole body radiation and with an additional lung dose added of 10 Gy. Exposed animals are sorted into three groups. One group of three is held as a control; another group of three is dosed immediately and for 14 consecutive days following acute radiation exposure with an aerosolized solution containing 5.0 μΜ concentration of Sar ⁹ Met (O2) ¹¹ - Sub stance P . An additional cohort of three animals are permitted to develop symptoms for twelve weeks before the fifteen-day treatment cycle involving administration an aerosolized solution containing 5.0 μΜ concentration of Sar ⁹ Met (O2) ¹ ^Substance P is commenced. A fourth cohort of three animals is similarly treated at 26 weeks post irradiation.

[0043] Microscopic examination of multiple lung sections of the exposed and treated animals indicates that administration of Sar ⁹ Met (O2) ¹ ^Substance P caused a reduction in the area and degree of consolidated fibrosis relative to the untreated irradiated control.

[0044] Of significance, the increased number of activated macrophages (associated in wound healing) that is evident in the control group as well as the increased number of immune- active lymphocytes (associated with inflammation) is greatly reduced in treated cohorts.

[0045] Acute exposure to Sar ⁹ Met (O2) ¹ ^Substance P alone immediately post radiation exposure treatment 20 weeks after radiation exposure appears to have little or no noticeable impact on the pulmonary profibrotic processes. This suggests that there is no single early seed event that triggers long term sequelae. A 'point of no return' may exist regarding rescue and potentially recovery from the pulmonary injury.

EXAMPLE V

[0046] In order to ascertain radiation exposure sequellae, a cohort of animals (C571B1 mice) are lethally irradiated by exposure to LD50 gamma radiation doses (7.75 GY whole body), in which half of the exposed animals die. In acute survival studies, animals treated with Sar ⁹ Met (O2) ¹ ^Substance P dosing as outlined in previous examples promptly after exposure will yield survival of at least 75% of the animals so exposed. This is similar efficacy in an acute treatment paradigm as seen with GCSF (granulocyte colony stimulating factor, or Neupogen®), and is consistent with prior evidence supporting NAS911 as an acute radiation protectant of the hematopoietic stem cell population.

EXAMPLE VI

[0047] In order to further assess the efficacy of bioactive analogs of substance P such as

Sar ⁹ Met (O2) ¹ ^Substance P, cohorts of irradiated animals received a supplementary lOGy lung- -only radiation dose. Animals that received Sar ⁹ Met (O2) ¹¹ - Sub stance P in an amount of 2mg/kg prior to subsequent exposure, show enhanced preservation of airway progenitor cells, as revealed by expression of the marker protein Club Cell Secretory Protein (CCSP). It is known that CCSP expression is reduced by lung irradiation, so preservation elicited by Sar ⁹ Met (O2) ¹ ^Substance P treatment prior to irradiation is consistent with mitigation of the progenitor cell damage induced by radiation exposure. In contrast animals treated with GCSF, following radiation exposure, demonstrate some protection from the resultant neutropenia typically following acute irradiation, but fail to show the preservative effect on CCSP expression.

[0048] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.