Patent Description:
The general anti-inflammatory potential of PDE4 inhibition, as exemplified by roflumilast, is well established (<NPL>), and the use of PDE4 inhibitors in various inflammatory and immune-mediated diseases has been broadly investigated (<NPL>; <NPL>). However, in the last decade, it has become increasingly clear that PDE4 may also play an important role in fibrosis, based on animal studies and on in vitro experiments evaluating the functional role of PDE4 inhibitors in fibroblasts. The attenuation of lung fibrosis by PDE4 inhibitors has been demonstrated under various experimental conditions, most widely in bleomycin-induced fibrosis in rodents. In rat models, rolipram was shown to inhibit fibrotic score, hydroxyproline content, and serum tumor necrosis factor-α (TNF-α) (<NPL>). In this initial study, the PDE4 inhibitor was administered from the beginning of bleomycin challenge, so it was not clear whether rolipram was primarily active due to inhibition of initial inflammation or inhibition of secondary fibrosis. A second early study in mice and rats, however, showed that oral roflumilast was active both in preventive and in therapeutic protocols in a dose-dependent manner (<NPL>). In lung extracts, roflumilast inhibited histologically assessed fibrosis, hydroxyproline content, and the mRNA expression of TNF-α, transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), α1 collagen, endothelin-<NUM>, and mucin 5ac. In bronchoalveolar lavage fluid (BALF), the levels of TNF-α, interleukin (IL)-<NUM>, TGF-β, and mucin 5ac, the formation of lipid hydroperoxides, and the influx of inflammatory cells (e.g. neutrophils and macrophages) were inhibited. Besides fibrosis, right ventricular hypertrophy and vascular remodeling (pulmonary arteries) were positively influenced by roflumilast. The same group later on also demonstrated that the metabolome associated with pulmonary fibrosis in bleomycin mice was modulated by roflumilast. Levels of the amino acids (AAs) glycine and proline, involved in collagen formation/structure, were lowered by roflumilast, while lung glutathione and plasma tetrahydrobiopterin were increased, suggesting an alteration in oxidative equilibrium by roflumilast (<NPL>). Another PDE4 inhibitor, cilomilast, was shown to inhibit late-stage lung fibrosis and tended to reduce collagen content in bleomycin mice, although no effect on TGF-β1 and collagen type (Col) 1A1 expression was found (<NPL>).

Improvement of lung fibrosis by PDE4 inhibition was not limited to the bleomycin model. In a murine model of lung fibrosis targeting type II alveolar epithelial cells in transgenic mice expressing the diphtheria toxin receptor under the control of the murine surfactant protein C promoter, roflumilast lowered lung hydroxyproline content and mRNA expression of TNF-α, fibronectin (FN), and CTGF (<NPL>). Interestingly, roflumilast was active both in a preventive and in a therapeutic regimen, and under the latter conditions appeared to be therapeutically equipotent to pirfenidone and nintedanib. Furthermore, in a mouse model of chronic graft-versus-host disease, lung fibrosis was attenuated by oral roflumilast (<NPL>). roflumilast inhibited fibrosis, collagen deposition, hydroxyproline and TGF-β1 content, cell infiltration, and expression of mRNA for IL-<NUM> and IL-1β. In addition, in the BALF inflammatory cells (macrophages, lymphocytes, neutrophils, and eosinophils), expression of mRNA for IL-<NUM>, IL-1β, and monocyte chemotactic protein-<NUM> was inhibited by roflumilast. In a rabbit tuberculosis model, pulmonary damage and fibrosis were shown to be inhibited by two PDE4 inhibitors from Celgene, CC-<NUM> (<NPL>) and CC-<NUM> (<NPL>). PDE4 inhibition improved antibiotic therapy and lung fibrosis by positively influencing collagen deposition and mRNA expression of various matrix metalloproteinases, including metalloproteinase <NUM>.

Besides the lung, beneficial effects of PDE4 inhibition on fibrosis have been demonstrated in several other organs including skin, liver, kidney, and colon. For example, in various preclinical mouse models of SSc, skin fibrosis induced by either bleomycin or topoisomerase I and chronic graft-versus-host disease was inhibited by rolipram and apremilast (<NPL>). This group did not find direct inhibitory effects of PDE4 inhibition on the release of profibrotic cytokines (IL-<NUM>, IL-<NUM>, TGF-β1/β2) in fibroblasts and M2 macrophages purified from peripheral blood of patients with SSc, which may be due to the lack of an exogenous cAMP trigger under the experimental conditions used. In a model of unilateral ureteral obstruction-induced obstructive nephropathy in mice, rolipram was shown to inhibit renal interstitial fibrosis (<NPL>). In mouse primary tubular epithelial cells in vitro, TGF-β up-regulated PDE4A/B, and rolipram inhibited TGF-β-induced damage, FN expression, and deficiency of mitochondrial biogenesis. roflumilast inhibited diethylnitrosamine-induced liver fibrosis, hydroxyproline deposition, and TGF-β1 expression in rats (<NPL>). Similarly, rolipram inhibited collagen deposition, α-smooth muscle actin (α-SMA) staining, and mRNA expression, as well as the expression of TGF-β1 mRNA and TNF-α protein, in a bile duct ligation-induced hepatic fibrosis model in rats, with up-regulation of PDE4A, B, and D (Gobejishvili <NUM>). In hepatic stellate cells in vitro, rolipram inhibited mRNA expression of α-SMA and Col1A2 (<NPL>). With respect to colonic tissue, rolipram inhibited collagen and TGF-β1 in a model of trinitrobenzene sulfonic acid-induced colitis in rats (<NPL>), and apremilast inhibited fibrosis in colon, collagen deposition, and the expression of genes related to fibrosis in a model of dextran sulfate sodium-induced colitis ulcerosa in mice (<NPL>). In a murine cecal abrasion model, rolipram inhibited fibrotic reactions, indicating that PDE4 inhibition has the potential to prevent postoperative intra-abdominal adhesions (<NPL>). Adhesions are assumed to result from laparotomy by abnormal healing. In support of this assumption, rolipram has been shown to be active in a subcutaneous or intraperitoneal polyether-polyurethane sponge implant model in mice by inhibiting intra-implant collagen and TGF-β1 deposition (<NPL>). Thus, in various animal models, the beneficial impact of selective PDE4 inhibition on fibrosis has been proven, most extensively in the lung but also in several other organs. While the specific target(s) of PDE4 inhibitors in fibrotic diseases are largely unknown, it is tempting to speculate that they act either indirectly via inhibition of pro-inflammatory cells and mediators, and/or directly by inhibiting the typical effector cells (fibroblasts, myofibroblasts) mediating fibrosis.

The direct modulation of various fibroblast functions by PDE4 inhibitors has been demonstrated in fibroblast cell lines of human origin. Kohyama et al. demonstrated a direct impact of PDE4 inhibitors on fibroblasts in vitro (<NPL>). In human fetal lung fibroblasts (HFL-<NUM>), rolipram and cilomilast inhibited FN-induced chemotaxis and contraction of collagen gels. Inhibition of fibroblast function by prostaglandin E2 (PGE2) was shifted to the left in the presence of PDE4 inhibitors, and the inhibition of endogenous PGE2 by indomethacin diminished their effects (<NPL>). The inhibition of the fibroblast cell line HFL-<NUM> functions by cilomilast could be modulated by cytokines like IL-1β (which up-regulated PGE2 and shifted the cilomilast curve to the left) or IL-<NUM> (which down-regulated PGE2 and shifted the cilomilast curve to the right). The inhibition of HFL-<NUM> functions (FN-stimulated chemotaxis and collagen gel contraction) by rolipram and roflumilast was dependent on cyclooxygenase-<NUM> expression and subsequent PGE2 synthesis (<NPL>). In addition, TGF-β1-stimulated FN release was inhibited by the PDE4 inhibitors, paralleled by a stimulation of PGE2 release as a positive feedback mechanism (<NPL>. In another human fetal lung fibroblast strain (GM06114), roflumilast N-oxide, the active metabolite of roflumilast, in the presence of PGE2 was shown to inhibit intercellular adhesion molecule-<NUM> and eotaxin release stimulated by TNF-α, proliferation stimulated by basic fibroblast growth factor (bFGF) plus IL-1β, as well as TGF-β1-induced α-SMA, CTGF, and FN mRNA expression in the presence of IL-1β (<NPL>). Importantly, IL-1β up-regulated PDE4 activity.

In normal human lung fibroblasts (NHLFs), the impact of PDE4 inhibitors has been described in several publications. TGF-β-induced fibroblast-to-myofibroblast conversion assessed by α-SMA expression was shown to be inhibited by piclamilast in the presence of PGE2 (<NPL>). In subsequent papers, the same group showed the inhibition of IL-<NUM> plus bFGF-stimulated fibroblast proliferation by piclamilast and the importance of cyclooxygenase-<NUM> and PGE2 (<NPL>). By using PDE4 subtype-specific siRNA, the involvement of PDE4B and PDE4A in this response, as well as the involvement of PDE4B and PDE4D in TGF-β-induced α-SMA expression, were shown (<NPL>). The importance of a cAMP trigger for the modulation of fibroblast functions by PDE4 inhibition was corroborated by the inhibition by roflumilast of TGF-β1-induced CTGF mRNA and α-SMA protein expression, and FN in the presence of the long-acting β2-adrenergic agonist indacaterol (<NPL>). In addition, various other NHLF responses (collagen synthesis, proliferation, reactive oxygen species and F2-isoprostane formation, NADPH oxidase <NUM> expression) stimulated by bleomycin or <NUM>-epi-PGF2α were inhibited by roflumilast N-oxide (<NPL>). In yet another human lung fibroblast model (WI-<NUM>), TGF-β-induced mRNA expression of collagen α1, CTGF, and FN in the presence of the adenyl cyclase activator forskolin were inhibited by roflumilast and another PDE4 inhibitor (compound <NUM>) (<NPL>), as well as a dual-selective PDE4/<NUM> inhibitor (compound A) (<NPL>).

Thus, a multitude of in vitro studies indicate that PDE4 inhibitors are able to directly inhibit various fibroblast functions where either an endogenous or an exogenous cAMP trigger is available in the test system. While the availability of cAMP agonists may be limited under artificial in vitro conditions, it can be expected that in diseased (inflammatory, fibrotic) tissues, cAMP agonists like PGE2, adenosine, histamine, or adrenalin may be formed. The importance of PDE4 under such conditions may be further enhanced by up-regulation of PDE4 activity by cytokines such as IL-1β.

The modulation of another interesting aspect of fibrosis, epithelial-mesenchymal transition, was addressed in the TGF-β1-stimulated A549 human alveolar epithelial cell line in vitro. TGF-β1 stimulated the up-regulation of PDE4 subtypes (PDE4A and 4D), and rolipram and siRNA inhibited epithelial-mesenchymal transition changes like FN and collagen mRNA expression, although not α-SMA mRNA (<NPL>).

Interstitial lung diseases (ILDs) comprise a heterogeneous group of lung diseases affecting the interstitium, distinct from obstructive airway diseases such as asthma or chronic obstructive pulmonary disease (COPD). Prolonged ILD may result in pulmonary fibrosis, but this is not always the case. The most extensively studied ILD is idiopathic pulmonary fibrosis (IPF), which is characterized by progressive pulmonary fibrosis. Non-IPF ILDs may include connective tissue disease-related ILDs such as those related to rheumatoid arthritis and other autoimmune diseases, systemic sclerosis associated ILD (SSc-ILD), and polymyositis/dermatomyositis, and ILDs related to chronic sarcoidosis, chronic hypersensitivity pneumonitis, idiopathic non-specific interstitial pneumonia, and exposure-related diseases such as asbestosis and silicosis (<NPL>; <NPL>). Up to <NUM>% of patients with these ILDs may develop a progressing fibrotic phenotype.

Progressive fibrosing ILDs are associated with high mortality, with median post-diagnosis survival in patients with IPF estimated at <NUM>-<NUM> years (<NPL>). Progression of fibrosing ILD is reflected in various parameters, including decline in pulmonary function, decrease in exercise capacity, deterioration in quality of life, worsening of cough and dyspnea, acute exacerbations, and increase of morphologic abnormalities (<NPL>; <NPL>). In patients with IPF, forced vital capacity (FVC) is a well-established predictor of mortality, and acute exacerbations are associated with very high mortality. Although corticosteroids and/or immunosuppressive drugs are sometimes used off-label to treat progressive fibrosing ILDs, currently the only approved treatments to slow disease progression in IPF are nintedanib and pirfenidone (<NPL>). nintedanib has been approved in the US since <NUM> (U. Food & Drug Administration, <NUM>, OFEV® (nintedanib)), and in Europe and Japan since <NUM> (European Medicines Agency, 2021b, OFEV® (nintedanib)), while pirfenidone was approved in Japan in <NUM>, in Europe in <NUM> (European Medicines Agency, 2021a, Esbriet (pirfenidone)), and in the US in <NUM> (U. Food & Drug Administration, <NUM>, ESBRIET® (pirfenidone)). Lung transplantation is the only potentially curative treatment for IPF and the medical need in IPF and other progressive fibrosing ILDs remains high.

However, in patients with IPF having a mild or moderate impairment of FVC (≥<NUM> % predicted), both presently approved medications pirfenidone and nintedanib, can only reduce the decline in FVC, consistent with a slowing of disease progression, but both are not able to stop or even reverse or heal the symptoms of IPF (<NPL>).

Nevertheless, both treatment-options, either with pirfenidone or with nintedanib, show significant beneficial effects in slowing down IPF disease progression.

The most prominent side effects associated with both, nintedanib and pirfenidone, are gastrointestinal events, particularly diarrhea, nausea, vomiting, abdominal pain, decreased appetite and a decreased body weight. In case that gastrointestinal side effects arise, they are usually managed either by treatment interruption, dose reduction or symptomatic treatment of the gastrointestinal side effects (see <NPL>).

Due to these "accumulative gastrointestinal side effects" of pirfenidone on the one hand and of nintedanib on the other hand a combination treatment for IPF by a combination of pirfenidone and nintedanib is not frequently used. Investigations have shown that a combination treatment with pirfenidone and nintedanib leads to increased gastrointestinal side effects, in particular to diarrhoea, nausea, vomiting, and upper abdominal pain (<NPL>, Epub ahead of print).

Consequently, due to the fact that both active agents which are so far approved for the treatment for IPF, pirfenidone and nintedanib, are - when administered alone - not able to stop or to heal IPF, but instead can only slow down the IPF disease progression to a certain percentage (<NPL>), and due to the fact that additionally both nintedanib and pirfenidone show significant gastrointestinal side effects which accumulate when both compounds are combined, there is still a significant medical need for improved methods of treatment of IPF/ PF-ILD, in particular for improved methods of treatment of IPF/PF-ILD which combine an improved therapeutic efficacy (compared to standard of care treatment) with an acceptable tolerability/safety, in particular with regard to gastrointestinal side effects.

<NPL> discloses a clinical trial for the evaluation of the efficacy and safety of Nintedanib over <NUM> weeks in patients with Progressive Fibrosing Interstitial Lung Disease (PF-ILD).

Further, <NPL>discloses the anti-fibrotic effects of Nintedanib in lung fibroblasts derived from patients with idiopathic pulmonary fibrosis.

<NPL> discloses a clinical trial to find out whether a compound called BI <NUM> can slow down the worsening of lung function in IPF patients. However, this document does not disclose the chemical structure of the unknown compound BI <NUM>.

Butera Armand, "<NPL> discloses that a compound called BI <NUM> showed to stabilize the FVC in IPF patients. However, this document does not disclose the chemical structure of the unknown compound BI <NUM>.

Herrmann et al, "<NPL> discloses preclinical studies on a compound called BI <NUM> showing its anti-inflammatory and antifibrotic potential. However, this document does not disclose the chemical structure of the unknown compound BI <NUM>.

Additionally to the approved PDE4 inhibitors roflumilast and apremilast - many further patent applications drawn on other PDE4-inhibitors with improved properties have been published:.

The PDE4-inhibitors of formula I
<CHM>
and of formula II
<CHM>
and in particular of formula III
<CHM>.

<CIT> discloses a combination of nintedanib and of the PDE4-inhibitor of formula III which shows in an in vitro assay using human lung fibroblasts a synergistic overadditive effect with respect to fibroblast proliferation.

Therefore, neither <CIT> nor <CIT> disclose oral compositions and/or dose regimens of the PDE4-inhibitor of formula III which combine both, an excellent therapeutic efficacy (alone and in combination with standard of care treatment which is either nintedanib treatment or pirfenidone treatment) and an acceptable tolerability/safety profile in human PF-ILD/IPF-patients, in particular acceptable gastrointestinal adverse events/side effects.

However, only oral compositions with dosings and dose regimens that combine both, a satisfying therapeutic efficacy for the treatment of PF-ILD, preferably IPF, on the one hand and an acceptable tolerability/safety on the other hand will lead to sufficient patient compliance and thereby to a successful PF-ILD/IPF- therapy for patient.

Consequently, it was the problem of the invention to provide an oral composition comprising a suitable dose and dose regimen of the PDE4 inhibitor of formula III that will combine both, a satisfying therapeutic efficacy for the treatment of PF-ILD patients, preferably of IPF patients, and an acceptable tolerability/safety profile that will lead to sufficient patient compliance.

This problem of the invention was solved by the results of a clinical trial in IPF patients (phase II) over <NUM> weeks evaluating efficacy, safety and tolerability of the PDE4-inhibitor of formula III either alone or in combination with standard of care IPF-treatment (with either nintedanib or pirfenidone) which led to a new oral pharmaceutical composition comprising the PDE4 inhibitor of formula III
<CHM>
in the dose of <NUM> for use in the treatment of a PF-ILD patient, preferably for use in the treatment of an IPF patient, wherein this oral pharmaceutical composition is administered twice daily (b. ) to the said PF-ILD patient, or preferably IPF patient.

In a first aspect the invention concerns an oral pharmaceutical composition comprising the PDE4B-inhibitor of formula III
<CHM>
in a dose of <NUM> for use in the treatment of one or more progressive fibrosing interstitial lung diseases (PF-ILD), wherein this oral pharmaceutical composition is administered to the patient twice daily.

In a preferred embodiment of the above-mentioned oral pharmaceutical composition the one or more progressive fibrosing interstitial lung disease (PF-ILD) is idiopathic pulmonary fibrosis (IPF).

In a further preferred embodiment of the above-mentioned oral pharmaceutical composition this oral pharmaceutical composition is a film-coated tablet.

In a more preferred embodiment the invention concerns an oral pharmaceutical composition consisting essentially of.

Hereby these oral pharmaceutical compositions consisting essentially of the PDE4B-inhibitor of formula III in the dose of <NUM> and optionally of one or more pharmaceutically acceptable carriers or excipients which are to be administered twice daily are preferably film-coated tablets.

In another preferred embodiment the invention concerns an oral pharmaceutical composition comprising.

Hereby these oral pharmaceutical compositions comprising the PDE4B-inhibitor of formula III in the above mentioned dose of <NUM> as the only active agent and optionally one or more pharmaceutically acceptable carriers or excipients are preferably film-coated tablets.

In a second aspect the invention concerns the use of the PDE4B-inhibitor of formula III
<CHM>
for the manufacture of an oral pharmaceutical composition consisting essentially of <NUM> and optionally of one or more pharmaceutically acceptable carriers or excipients for the treatment of a patient suffering from a progressive fibrosing interstitial pulmonary disease (PF-ILD), wherein said oral pharmaceutical composition is to be administered to said patient twice daily.

In a preferred embodiment of the above-mentioned use the PDE4B-inhibitor of formula III is administered to the PF-ILD patient, preferably to the IPF patient, in the dose of <NUM> twice daily.

In a preferred embodiment of the above-mentioned use of the PDE4B-inhibitor of formula III for the manufacture of the oral pharmaceutical composition consisting essentially of the PDE4B-inhibitor of formula III in the dose of <NUM> and optionally of one or more pharmaceutically acceptable carriers or excipients for the treatment of a patient suffering from a PF-ILD, the progressive fibrosing interstitial pulmonary disease (PF-ILD) is idiopathic pulmonary fibrosis (IPF).

In a further preferred embodiment of the above-mentioned use of the PDE4B-inhibitor of formula III for the manufacture of the oral pharmaceutical composition consisting essentially of the PDE4B-inhibitor of formula III in the dose of <NUM> and optionally of one or more pharmaceutically acceptable carriers or excipients for the treatment of a patient suffering from a PF-ILD the oral pharmaceutical composition is a film-coated tablet.

In a preferred embodiment, the above-mentioned oral medicaments are used for the treatment of idiopathic pulmonary fibrosis (IPF).

The study was open to adults with idiopathic pulmonary fibrosis (IPF) who were at the time of recruitment at least <NUM> years old. People taking standard medicines for IPF, including antifibrotic medicines, were allowed to continue taking them throughout the study.

The purpose of the study was to find out whether the PDE4 inhibitor of formula III
<CHM>
could slow down the worsening of lung function. Participants were in the study for about <NUM> months. During this time, they visited the study site about <NUM> times. At the beginning, they visited the study site every <NUM> weeks. After <NUM> month of treatment, they visited the study site every <NUM> weeks.

The participants were divided into <NUM> groups by chance (the "active agent group" and the "placebo group"). One tablet comprising <NUM> of the compound of formula III and one tablet comprising <NUM> of the compound of formula III (,,the active agent tablets" resulting in a <NUM> single dose, see Table <NUM>) was administered orally to the patients of the first group twice daily (b. One <NUM> placebo tablet and one <NUM> placebo tablet (both containing no active ingredient, see Table <NUM>) was administered orally to the patients of the second group twice daily (b. The placebo tablets looked like the tablets of the active ingredient (=the compound of formula III).

The "active agent group" and the "placebo group" were further distributed to two different groups regarding background medication: the "AF-group" ("antifibrotic background medication group") and the "Non-AF-group" ("no antifibrotic background medication group"). The patients that were part of the "Non-AF group" did not obtain an antifibrotic background medication of either nintedanib or pirfenidone (in doses and dose regimens as authorized) during the trial (that means either the PDE4B inhibitor of formula III in the <NUM> dose b. d (= twice daily) or placebo b. d (twice daily) was administered alone) and the patients that were part of the "AF-group" obtained an antifibrotic background medication of either nintedanib or pirfenidone during the trial (that means either the PDE4B inhibitor of formula III in the <NUM> dose b. d (= twice daily) or placebo b. d (twice daily) was administered in combination with either nintedanib or with pirfenidone. The combination of both nintedanib and pirfenidone as background medication was not allowed in the "AF-group".

The participants performed lung function tests at study visits ("Forced Vital Capacity (FVC)"). The results of the changes in lung function tests were compared between the "active agent group" and the "placebo group" (both within the "AF-group and within the "Non AF-group"). The doctors also regularly checked the general health of the participants.

For the study <NUM> IPF patients with the following inclusion criteria have been recruited:.

For the participating IPF patients the following exclusion criteria were applied:.

The trial was a randomised, double-blind, placebo-controlled parallel group study. During the <NUM> weeks of the study the lung function of all participating IPF patients has been monitored by measuring the change from baseline in Forced Vital Capacity (FVC) ("primary outcome measure"). During the <NUM> weeks of the treatment period and one week after the treatment period (time frame: up to <NUM> weeks) the Treatment Emergent Adverse Events (TEAE) have been monitored for all participating IPF patients ("secondary outcome measures").

Out of the <NUM> patients, all who prematurely discontinued from the trial medication were from the "active agent group" for both, the "AF-group" <NUM>/<NUM> (<NUM>%) and the "Non-AF-group" <NUM>/<NUM> (<NUM>%).

The most frequent reason for premature discontinuation was an adverse event which accounts for <NUM>% of the discontinuations in the "AF-group" <NUM>/<NUM> and for <NUM>% of the discontinuations in the "Non-AF-group" <NUM>/<NUM> (see Table <NUM>).

Table <NUM> shows that the time since diagnosis of IPF was longer in the "AF-group" (<NUM> yrs. ) vs. in the "Non-AF-group" (<NUM> yrs. ) and was balanced between placebo control and active agent arms.

Table <NUM> shows that the IPF patients in the "AF-group" used more nintedanib as background medication than pirfenidone (in the "active agent group" <NUM> % nintedanib and <NUM>% pirfenidone, in the "placebo group" <NUM> % nintedanib and <NUM> % pirfenidone). Furthermore, Table <NUM> shows that for the IPF-patients from the "AF-group" the passed time since IPF-diagnosis was longer (<NUM> years for the "active agent group" and <NUM> years for the "placebo group") than for the patients of the "Non-AF-group" (<NUM> years for the "active agent group" and <NUM> years for the "placebo group").

The IPF patients of the "Non AF-group" obtained either tablets containing <NUM> of the compound of formula III twice daily (="active agent group") or placebo tablets without active ingredient twice daily (hereby the "Placebo-tablets" were with respect to look, smell, taste etc. not distinguishable from the "active agent tablets" containing <NUM> of the compound of formula III). The patients of the "Non-AF-group" obtained no standard of care background medication for the treatment of IPF during the study period of <NUM> weeks (that means no nintedanib background medication and no pirfenidone background medication). Each tested patient performed lung function tests in regular intervals at each study visit. From the results of these lung function tests the change from baseline in FVC (in ml) was determined for the different time points in the study (see <FIG>). The patient data from the lung function tests at the different time points within the study period of <NUM> weeks was analyzed by Mixed Model Repeated Measures (MMRM). MMRM is an established method of analyzing longitudinal data allowing to use a set of repeated measurements of a patient in the estimation process (<NPL>)).

The change from baseline in FVC from the beginning of the study to week <NUM> was - <NUM> for the "Placebo group" and + <NUM> for the "Active agent group" resulting in a difference in the change from baseline in FVC from the beginning of the study to week <NUM> between "active agent group" and "Placebo group" of <NUM> (see Table <NUM>, <FIG> and <FIG>). Whereas the change from baseline in FVC substantially decreased in the "Placebo group" during the <NUM> weeks long study period (which means that the IPF disease progressed substantially in these untreated patients), the change from baseline in FVC in the "active agent group" (that had obtained the PDE4-inhibitor of formula III in the <NUM> dose twice daily) stayed stable or was even slightly increased during the same <NUM> weeks long study period (see <FIG> and <FIG>). Consequently, the PDE4-inhibitor of formula III in the <NUM> dose twice daily shows an impressive therapeutic efficacy in IPF-patients over the treatment period of <NUM> weeks without standard of care background medication of either nintedanib or pirfenidone.

The IPF patients of the "AF-group" obtained either tablets containing <NUM> of the compound of formula III twice daily (= "active agent group") or similar looking placebo tablets without active ingredient twice daily (= "Placebo group"). Additionally, the patients of the "AF-group" obtained standard of care background medication for the treatment of IPF during the study period of <NUM> weeks (that means either nintedanib background medication at doses/dose regimen as authorized or pirfenidone background medication at doses/dose regimen as authorized, the combination of both nintedanib and pirfenidone as background medication was not allowed). Each tested patient performed lung function tests in regular intervals at each study visit. From the results of these lung function tests the change from baseline in FVC (in ml) was determined for the different time points in the study (see <FIG>). The patient data from the lung function tests at the different time points within the study period of <NUM> weeks was analyzed by Mixed Model Repeated Measures (MMRM).

The change from baseline in FVC from the beginning of the study to week <NUM> was - <NUM> for the "Placebo group" and + <NUM> for the "Active agent group" (see Table <NUM>, <FIG> and <FIG>) resulting in a difference in the change from baseline in FVC from the beginning of the study to week <NUM> between "active agent group" and "Placebo group" of <NUM>.

Whereas the change from baseline in FVC decreased in the "Placebo group" (the "Placebo group" of the "AF-group" obtained antifibrotic background medication only, that means nintedanib only or pirfenidone only) during the <NUM> weeks long study period (which means that the IPF disease progressed in these patients on antifibrotic background medication alone), the change from baseline in FVC in the "active agent group" (that had obtained the PDE4-inhibitor of formula III in the <NUM> dose twice daily in combination with antifibrotic background medication of either nintedanib or pirfenidone) stayed stable or was even slightly increased during the same <NUM> weeks long study period (see <FIG> and <FIG>). Consequently the PDE4-inhibitor of formula III in the <NUM> dose twice daily shows in combination with antifibrotic background medication (either nintedanib or pirfenidone) an impressively improved therapeutic efficacy in IPF-patients over the treatment period of <NUM> weeks compared to the therapeutic effect in IPF-patients that had been treated by the same antifibrotic background medication alone.

This change from baseline in FVC to week <NUM> compared between "active agent group" and "Placebo group" of <NUM> for the "AF-group" is smaller than the <NUM> for the "Non-AF-group". However, this is understandable, since in the "AF-group" also the antifibrotic background medication with nintedanib or pirfenidone should be responsible for a certain therapeutic base effect.

However, when the results from the "AF-group" were analyzed separately by the type of antifibrotic background medication that was administered to the patient (that means separation of the "nintedanib background medication group" from the "pirfenidone background medication group" within the "AF-group"), a trend to a higher therapeutic efficacy in combination with <NUM> of the PDE4-inhibitor of formula III administered twice daily was observed for the group that had obtained nintedanib as background medication compared to the group that had obtained pirfenidone as background medication.

This trend can be concluded from the data as summarized in Table <NUM>: here for the group that had obtained nintedanib as background medication an adjusted mean difference between changes from baseline to week <NUM> between the "active agent group" and the "Placebo group" of <NUM> was calculated from the trial data, whereas for the group that had obtained pirfenidone as background medication an adjusted mean difference between changes from baseline to week <NUM> between the "active agent group" and the "Placebo group" of only <NUM> was calculated from the trial data (see Table <NUM>).

In case you do not differentiate between nintedanib or pirfenidone as background medication an adjusted mean difference between changes from baseline to week <NUM> between the "active agent group" and the "Placebo group" of <NUM> was determined (see Table <NUM> in comparison) - a value that lies more or less in between.

The course of development for the change from baseline in FVC over the <NUM> weeks of treatment can be derived from <FIG> for the "nintedanib as background medication group" and from <FIG> for the "pirfenidone as background medication group".

Consequently, the data from the clinical trial indicate that the combination of <NUM> of the PDE4-inhibitor of formula III administered twice daily and of nintedanib (in doses and dose regimens as authorized) might have even a better therapeutic efficacy than the combination of <NUM> of the PDE4-inhibitor of formula III administered twice daily and of pirfenidone (in doses and dose regimens as authorized).

The combined results for the "Non-AF-group" and the "AF-group" led to the results as shown in <FIG> or as summarized in Table <NUM>.

Whereas the change from baseline in FVC steadily decreased in the "Placebo group" (that had obtained either antifibrotic background medication or not, depending whether the patient was in the "Non-AF-group" or in the "AF-group") during the <NUM> weeks long study period, the change from baseline in FVC in the "active agent group" (that had obtained the PDE4-inhibitor of formula III in the <NUM> dose twice daily either alone or in combination with antifibrotic background medication of either nintedanib or pirfenidone, depending on whether the patient was in the "Non AF-group" or in the "AF-group") stayed stable or was even slightly increased during the same <NUM> weeks long study period (see <FIG>).

The change from baseline in FVC to week <NUM> was for the "active agent group" -<NUM> and for the "Placebo group" -<NUM>, if you consider all results (that means the results for "Non-AF-group" + "AF-group"). The Change from baseline in FVC to week <NUM> compared between "active agent group" and "Placebo group" was calculated to be <NUM>, if you consider all results (that means the results for "Non-AF-group" + "AF-group").

In the "active agent group" <NUM> % of the patients experienced an adverse event (AE): <NUM> % in the "Non-AF-group" and <NUM>% in the "AF-group". In the "Placebo group" <NUM>% of the patients experienced an AE: <NUM> % in the "Non-AF-group" and <NUM> % in the "AF-group" (see Table <NUM>). Within all tested groups only <NUM> % of the patients experienced an AE leading to the discontinuation of the trial drug, <NUM> % of the patients experienced a serious adverse event (see Table <NUM>) and <NUM> patients (that means <NUM> %) of the patients experienced an AE resulting in death (both in the "active agent group", one due to a Covid-<NUM> pneumonitis, one due to an unconfirmed case of vasculitis).

The most frequently reported adverse events (AE) were gastrointestinal disorders, of which diarrhoea was the most frequent AE (in more than <NUM> % of all patients diarrhoea was observed (see Table <NUM>).

Within both groups, the "AF-group" and the "Non-AF-group", for the corresponding "active agent groups" (wherein the compound of formula III was administered either in combination with antifibrotic background medication or alone) an increased frequency of the adverse event diarrhoea compared to the respective "Placebo groups" was observed. Three patients from the "active agent group" discontinued treatment due to AE diarrhoea, all male of ≥ <NUM> years of age from the "AF-group" under nintedanib background treatment.

Within in the "Non-AF-group", diarrhoea was reported approximately twice as frequently for the "active agent group" (<NUM> %) than for the corresponding "Placebo group" (<NUM> %) (see Table <NUM>). Within the "AF-group", diarrhoea was also reported approximately twice as frequently for the "active agent group" (<NUM> %) than for the corresponding "Placebo group" (<NUM> %) (see Table <NUM>).

However, the overall level of reported diarrhoea within the "AF-group" was also increased compared to the "Non-AF-group" (see Table <NUM>, within the "Placebo-group" <NUM>% of diarrhoea in the "AF-group" compared to <NUM>% diarrhoea in the "Non-AF-group"; within the "Comp. III-group" <NUM>% of diarrhoea in the "AF-group" compared to <NUM>% diarrhoea in the "Non-AF-group").

Consequently, the PDE4-inhibitor of formula III administered bid in a dose of <NUM> seems to lead to an increased frequency of the AE diarrhoea, but also the antifibrotic background medication, in particular background medication with nintedanib, seems to contribute significantly to the increased frequency of reported cases of diarrhoea in the "AF-group" (compared to the "Non-AF-group").

Nevertheless, all cases of reported diarrhoea within the "AF-group" and within the "Non-AF-group" were non-serious adverse events (see Table <NUM>).

The majority of reported diarrhoea events were mild with the exception of two moderate cases of diarrhoea (<NUM> %) and one severe case of diarrhoea (<NUM> %), which all occured in males and in the "active agent group" of the "AF-group" under nintedanib background therapy. Additionally one severe case of diarrhoea occured in a <NUM>-year-old female in the "Placebo-group" of the "AF-group" under nintedanib background therapy.

Overall, the most frequently reported AE leading to discontinuation was diarrhoea (n=<NUM>) whereby all these cases were part of the "AF-group" and were on nintedanib background medication.

In none of the cases of reported diarrhoea within all treatment arms a case of dehydration associated with diarrhoea had been observed.

In all treatment arms, no cases of hypokalaemia had been reported.

Apart from gastrointestinal disorders (in particular diarrhoea) only single adverse events have been reported over all treatment arms (in the "AF-group" and in the "Non-AF-group", in the "active agent groups" and in the "Placebo-groups") without any specific pattern (see Table <NUM>).

If you compare the results with regard to the frequency of the AE "gastrointestinal disorders" - and in particular with regard to the frequency of the AE "diarrhoea" - for the complete "AF-group" (as shown in Table <NUM>) on the one hand and for that part of the "AF-group" that had obtained nintedanib as antifibrotic background medication ("nintedanib background medication group") and for that part of the "AF-group" that had obtained pirfenidone as antifibrotic background medication ("pirfenidone background medication group") on the other hand (as shown in Table <NUM>), it becomes evident that the "pirfenidone background medication group" shows a clearly lower frequency of the AE "gastrointestinal disorders":.

in the "Comp. III-arm" for the "pirfenidone background medication sub-group" only <NUM>% of the patients experienced a gastrointestinal disorder (see Table <NUM>).

Comparable results could be found from the respective "Placebo groups" of the "AF-group":.

in the "Placebo-arm" for the "pirfenidone background medication sub-group" only <NUM>% of the patients experienced a gastrointestinal disorder (see Table <NUM>).

The very same trend can be observed, if you analyze the situation for the AE "diarrhoea" for the "Comp. III - arm":.

in the "Comp. III-arm" for the "pirfenidone background medication sub-group" only <NUM>% of the patients experienced a diarrhoea (see Table <NUM>)
and for the respective "Placebo arm":.

in the "Placebo-arm" for the "pirfenidone background medication sub-group" even <NUM>% of the patients experienced diarrhoea (see Table <NUM>).

This trend of a lower tendency to the AE gastrointestinal disorders, in particular to the AE diarrhoea, in case that pirfenidone is used as antifibrotic background medication (compared to nintedanib as antifibrotic background medication) is also supported from Table <NUM>, wherein the frequencies/percentages of adverse events leading to a discontinuation of the trial medication is shown. From Table <NUM> it is evident that within the "AF-group" in the "active agent arm" ("Compound of Formula III") the combination of <NUM> b. of the compound of formula III with nintedanib as background medication leads to.

whereas the combination of <NUM> b. of the compound of formula III with pirfenidone as background medication leads to no discontinuations of the trial treatment at all (see Table <NUM>). In all treatment arms, wherein pirfenidone was used as background medication (that means in the respective "active agent group" and "Placebo group") no single case of discontinuation of the trial treatment due to any gastrointestinal AEs was recorded (see Table <NUM>). Therefore the combination treatment with <NUM> b. of the compound of formula III and pirfenidone (in doses as authorized) as background treatment might be associated with a reduced frequency and a reduced severity of the AE gastrointestinal disorder, in particular to a a reduced frequency and a reduced severity of the AE diarrhoea in comparison to the combination treatment with <NUM> b. of the compound of formula III and nintedanib (in doses as authorized) as background treatment.

The results of the "Non-AF-group" of the clinical trial support the hypothesis that the PDE4-inhibitor of formula III administered twice daily (b. ) in the dose of <NUM> without antifibrotic background medication substantially slows down FVC decline in IPF-patients for the treatment period of <NUM> weeks ("Non-AF-group": for the "Comp. III (= active agent)-group" the change from baseline in FVC after <NUM> weeks is + <NUM>; for the respective "Placebo-group" the change from baseline in FVC after <NUM> weeks is -<NUM>, (see Table <NUM>, <FIG>)).

For the "Non-AF-group" this leads to an adjusted mean difference between changes from baseline in FVC to week <NUM> between the "active agent group" and the "Placebo group" of <NUM> which supports the hypothesis that the PDE4-inhibitor of formula III administered in a dose of <NUM> twice daily to PF-ILD/IPF patients without antifibotic background treatment shows a high therapeutic efficacy for the treatment of PF-ILD patients, preferably of IPF patients (see Table <NUM>, <FIG>).

On the other hand only <NUM> patient (<NUM> %) of the "active agent group" compared to no patient (<NUM>%) of the "placebo-group" of the "Non-AF-arm" experienced a gastrointestinal disorder leading to a discontinuation of the trial (see Table <NUM>).

The results of that part of the "AF-group that had obtained nintedanib as antifibrotic background medication" support the hypothesis that the PDE4-inhibitor of formula III administered twice daily (b. ) in the dose of <NUM> in combination with nintedanib as antifibrotic background medication substantially slows down FVC decline in IPF-patients for the treatment period of <NUM> weeks compared to the treatment with nintedanib alone ("AF-group with nintedanib as background medication": for the "Comp. III (= active agent)-group" the change from baseline in FVC after <NUM> weeks is + <NUM>; for the respective "Placebo-group" the change from baseline in FVC after <NUM> weeks is -<NUM> (see Table <NUM>, <FIG>)).

This results in an adjusted mean difference between changes from baseline in FVC to week <NUM> between the "active agent group" and the "Placebo group" of <NUM> for the "AF-group that had obtained nintedanib as antifibrotic background medication" (see Table <NUM>, <FIG>).

This supports the hypothesis that the combination of <NUM> of the PDE4-inhibitor of formula III administered twice daily and of nintedanib (administered in doses and dose regimens as authorized) may lead to an extraordinarily high therapeutic efficacy.

On the other hand, <NUM> patients (<NUM> %) of the "active agent group" compared to no patient (<NUM>%) of the "placebo-group" of the "AF-arm with nintedanib as antifibrotic background medication" experienced a gastrointestinal disorder as AE leading to a discontinuation of the trial treatement, <NUM> of these <NUM> patients experienced the AE diarrhoea leading to a discontinuation of the trial treatment (see Table <NUM>).

The results of the "AF-group that had obtained pirfenidone as antifibrotic background medication" support the hypothesis that <NUM> of the PDE4-inhibitor of formula III administered twice daily (b. ) in combination with pirfenidone as antifibrotic background medication substantially slows down FVC decline in IPF-patients for the treatment period of <NUM> weeks compared to the treatment with pirfenidone alone ("AF-group with pirfenidone as background medication": for the "Comp. III (= active agent)-group" the change from baseline in FVC after <NUM> weeks is - <NUM>; for the respective "Placebo-group" the change from baseline in FVC after <NUM> weeks is -<NUM> (see Table <NUM>, <FIG>)).

This results in an adjusted mean difference between changes from baseline in FVC to week <NUM> between the "active agent group" and the "Placebo group" of <NUM> for the "AF-group that had obtained pirfenidone as antifibrotic background medication" (see Table <NUM>, <FIG>).

On the other hand, not a single patient of the "active agent group" nor of the "placebo-group" of the "AF-arm with pirfenidone as antifibrotic background medication" experienced a gastrointestinal disorder leading to a discontinuation of the trial (see Table <NUM>).

On the same time, the administration of <NUM> of the PDE4-inhibitor of formula III twice daily (b. ) increased the frequency of the adverse event "gastrointestinal disorders" and in particular the frequency of the AE "diarrhoea" in all treatment arms (in the "Non-AF-group" and in the "AF-group").

However, within the "AF-group" the frequency and severity of the reported adverse events of gastrointestinal disorders - and in particular the frequency and severity of the reported adverse events of diarrhoea - were strongly dependent from the kind of antifibrotic background medication that was used. In IPF-patients that had obtained pirfenidone as antifibrotic background medication adverse events of gastrointestinal disorders, in particular adverse events of diarrhoea, were less frequently recorded and less frequently lead to the discontinuation of trial treatment (see Tables <NUM> and <NUM>) compared to IPF-patients that had obtained nintedanib as antifibrotic background treatment.

In IPF-patients that had obtained nintedanib as antifibrotic background medication adverse events of gastrointestinal disorders, in particular adverse events of diarrhoea, were recorded more frequently and in some cases also lead to the discontinuation of trial treatment (see Tables <NUM> and <NUM>). However, the IPF-patients that had obtained nintedanib as antifibrotic background medication showed better therapeutic efficacy than the IPF-patients that had obtained pirfenidone as antifibrotic background treatment.

Consequently, the results for the "AF-group with nintedanib as antifibrotic background treatment" of the presented phase II trial support the hypothesis that the PDE4-inhibitor of formula III in the dose of <NUM> twice daily combined with nintedanib background treatment (in doses and dose regimens as authorized for nintedanib (preferably <NUM> b. or <NUM> b. ) may lead to an excellent therapeutic efficacy combined with an acceptable tolerability and safety profile (leading to an acceptable patient compliance). The combination of nintedanib and of the PDE4-inhibitor of formula III in the dose of <NUM> administered twice daily might therefore in particular be suitable for PF-ILD/IPF-patients that have no tendency or predisposition to gastrointestinal disorders, in particular to diarrhoea, or that have experienced in their PF-ILD/IPF treatment history so far no problems due to gastrointestinal disorders, in particular due to diarrhoea.

Claim 1:
An oral pharmaceutical composition comprising
• the PDE4B-inhibitor of formula III
<CHM>
in the dose of <NUM> as the only active agent and
• optionally one or more pharmaceutically acceptable carriers or excipients for use in treating a progressive fibrosing interstitial lung disease (PF-ILD) in a patient suffering from that PF-ILD, wherein this oral pharmaceutical composition is to be administered to said patient twice daily.