US 20140243254A1 (19) United States (12) Patent Application Publication (10) Pub. No.: US 2014/0243254 A1 Hersel et al. (43) Pub. Date: Aug. 28, 2014 (54) POLYMERC HYPER BRANCHED Publication Classification CARRIER-LINKED PRODRUGS (51) Int. Cl. (75) Inventors: Ulrich Hersel, Heidelberg (DE); A647/48 (2006.01) Guillaume Maitro, Mannheim (DE); (52) U.S. Cl. Herald Rau, Dossenheim (DE); Tobias CPC. A61 K47/48338 (2013.01); A61K 47/48215 Voigt, Heidelberg (DE) (2013.01) USPC ............................. 514/1.3; 544/282; 530/331 (73) Assignee: Ascendis Pharma A/S, Hellerup (DK) (21) Appl. No.: 14/237,833 (57) ABSTRACT (22) PCT Fled: Aug. 10, 2012 The present invention relates to water-soluble carrier-linked prodrugs of formula (I), wherein POL is a polymeric moiety, (86) PCT NO.: PCT/EP2012/065736 each Hyp is independently a hyperbranched moiety, each S371 (c)(1), moiety SP is independently a spacer moiety, each L is inde (2), (4) Date: May 13, 2014 pendently a reversible prodrug linker moiety, m is 0 or 1, each n is independently an integer from 2 to 200 and each X is (30) Foreign Application Priority Data independently 0 or 1. It further relates to pharmaceutical compositions comprising said water-soluble carrier-linked Aug. 12, 2011 (EP) .................................. 111774O6.3 prodrugs and methods of treatment. US 2014/0243254 A1 Aug. 28, 2014 POLYMERC HYPER BRANCHED from twofold up to several orders of magnitude. Therefore, CARRIER-LINKED PRODRUGS the cleavage is predominantly controlled by the enzymatic reaction. 0001. The present application claims priority from PCT 0010. A major drawback of predominantly enzymatic Patent Application No. PCT/EP2012/065736 filed on Aug. cleavage is interpatient variability. Enzyme levels may differ 10, 2012, which claims priority from European Patent Appli significantly between individuals resulting in biological cation No. EP 11177406.3 filed on Aug. 12, 2011, the disclo variation of prodrug activation by the enzymatic cleavage. sures of which are incorporated herein by reference in their The enzyme levels may also vary depending on the site of entirety. administration. For instance it is known that in the case of Subcutaneous injection, certain areas of the body yield more FIELD OF THE INVENTION predictable therapeutic effects than others. To reduce this unpredictable effect, non-enzymatic cleavage or intramo 0002. It is noted that citation or identification of any docu lecular catalysis is of particular interest. ment in this application is not an admission that such docu 0011. Therefore, enzyme-independent autocatalytic ment is available as prior art to the present invention. cleavage of carrier and drug is preferred. In most cases this is 0003 Drugs frequently exhibit short plasma half-life due achieved by an appropriately designed linker moiety between to renal and receptor-mediated clearance, aggregation, pro the carrier and the drug, which is directly attached to the teolytic degradation, poor bioavailability and physical prop functional group of a drug via a covalent bond. erties which preclude efficient formulations. This is highly 0012. A number of such enzyme-independent prodrugs undesirable as it leads to the need for frequent and repeated suitable for different classes of biologically active moieties administration of the drug, resulting in increased costs and are known in the art. Examples can be found in the interna inconvenience for the patient. tional patent applications WO-A 2005/099768, WO-A 2006/ 0004 One mechanism for enhancing the availability of 13565869, WO-A 2009/095479, and WO-A 2011/012722. drugs is by conjugating it with derivatizing compounds, 0013 Typically, carrier-linked prodrugs have a stoichiom which include, for example, poly(ethylene glycol) (PEG) and etry of one drug molecule conjugated to one carrier moiety. poly(propylene glycol). Some of these benefits recognized However, for many medical applications such stoichiometry include lowered immunogenicity and antigenicity, increased is disadvantageous as large Volumes of Such conjugates duration of action, and altered pharmacokinetic properties would have to be applied to a patient to ensure a high enough (Veronese, F. M.. “Enzymes for Human Therapy: Surface drug dose, causing undue pain and possibly requiring Structure Modifications.” Chimica Oggi, 7:53-56, 1989). increased amounts of time for the administration process and 0005 To enhance physicochemical or pharmacokinetic thus increasing the costs of the treatment. In Such situations, properties of a drug in vivo, drugs can be bound to carriers in carrier-linked prodrugs in which more than one drug moiety a non-covalent way, using physicochemical formulations of is conjugated to a carrier molecule might be better Suited as drug-solvent-carrier mixtures. However, the non-covalent they provide a higher drug loading and thus require Smaller approach requires a highly efficient drug encapsulation to Volumes of the pharmaceutical composition to be adminis prevent uncontrolled, burst-type release of the drug. Restrain tered to a patient. ing the diffusion of an unbound, water Soluble drug molecule (0014 U.S. Pat. No. 7,744,861 B2 discloses multi-arm pro requires strong van der Waals contacts, frequently mediated drugs in which at least three arms extend from a branching through hydrophobic moieties. Many conformationally sen core and each of these arms carries one drug moiety. Simi sitive drugs, such as proteins or peptides, are rendered dys larly, WO-A 2010/019233 discloses multi-arm prodrugs of functional during the encapsulation process and/or during which each arm of a carrier moiety is conjugated to one drug Subsequent storage of the encapsulated drug. In addition, moiety. Despite the multi-arm backbone structure. Such car Such amino-containing drugs readily undergo side reactions rier-linked prodrugs still have a relatively low drug load. with carrier degradation products. Furthermore, dependence 00.15 More carrier-linked prodrugs with two polymer of the release mechanism of the drug upon biodegradation based arms are disclosed in WO-A 2008/034119, wherein may cause interpatient variability. each arm is attached to a drug moiety, diagnostic agent or 0006 Alternatively, the drugs may be conjugated to a car targeting moiety. rier via a transient linker molecule, resulting in carrier-linked 0016 Prodrugs of the anti-malaria drug artelinic acid are prodrugs. This approach is applied to various classes of mol disclosed in U.S. Pat. No. 6,461,603 B2. The polymeric pro ecules, from So-called Small molecules, through natural prod drugs are also based on a backbone moiety from which arms ucts up to larger peptides and proteins. extend which each carry one drug moiety at their terminus. 0007 Prodrug activation may occur by enzymatic or non 0017. Another approach to high-loading carrier-linked enzymatic cleavage of the bond between the carrier and the prodrugs involves the use of dendrimers. Dendrimers are drug molecule, or a sequential combination of both, i.e. an repeatedly branched, roughly spherical, large molecules. enzymatic step followed by a non-enzymatic rearrangement. Dendrimers have been used to non-covalently embed drug moieties and for covalent attachment of drug moieties to the 0008 Enzymatically induced prodrug activation is char termini of the dendrimer. acterized in that the cleavage in enzyme-free in vitro environ (0018 Taite & West (J. Biomater. Sci. Polymer Edn, 2006, ment such as an aqueous buffer Solution, of e.g., an ester or 17, 1159–1172) describe lysine-based dendrimer moieties in amide may occur, but the corresponding rate of hydrolysis which free amines have been converted to diazeniumdiolate may be much too slow and not therapeutically useful. NO-donors through the reaction with NO gas. The dendrim 0009. In an in-vivo environment, esterases oramidases are ers released NO over a period of 60 days. However, this typically present and the esterases and amidases may cause approach does not allow for the adjustment of release speed as significant catalytic acceleration of the kinetics of hydrolysis no reversible prodrug linkers have been used to attach the NO US 2014/0243254 A1 Aug. 28, 2014 to the termini of the dendrimer and this approach is also not high drug loading due to the presence of the hyperbranched transferable to other drug moieties. moieties. In addition, the polymeric moiety allows for 00.19 US 2010/0160299 A1 discloses dendrimers to increased water-solubility. which therapeutic agents for the reduction and/or elimination of pain are connected in a reversible manner. Similarly, DETAILED DESCRIPTION OF EMBODIMENTS WO-A 2010/075423 discloses modular dendrimer platforms 0035. It is to be understood that the figures and descrip suitable for the delivery of therapeutic agents, for example. tions of the present invention have been simplified to illustrate 0020. However, dendrimers typically exhibit a low degree elements that are relevant for a clear understanding of the of water-solubility. When poorly water-soluble drug moieties present invention, while eliminating, for purposes of clarity, are coupled to the functional groups of Such dendrimers the many other elements which are conventional in this art. Those resulting conjugates are even less water-soluble. Therefore, of ordinary skill in the art will recognize that other elements although dendrimers provide a high drug loading, their appli are desirable for implementing the present invention. How cability for prodrug approaches is limited. ever, because Such elements are well known in the art, and 0021. It is noted that in this disclosure and particularly in because they do not facilitate a better understanding of the the claims and/or paragraphs, terms such as "comprises'. present invention, a discussion of Such elements is not pro “comprised', 'comprising and the like can have the meaning vided herein. attributed to it in U.S. patent law; e.g., they can mean “includes”, “included”, “including, and the like; and that 0036. The present invention will now be described in terms such as "consisting essentially of and "consists essen detail on the basis of exemplary embodiments.