Elamipretide (MTP-131) is a mitochondria-targeting peptide compound with therapeutic potential for treating diseases associated with mitochondrial dysfunction. Elamipretide contains four-amino acid residues and has been synthesized according to typical linear and convergent solution phase peptide synthesis methods. The synthetic routes to generate elamipretide that have been used to date require the preparation of various differentially protected peptides, such that certain protecting groups are selectively removed in order to subject the deprotected compound to peptide coupling, while other protecting groups remain to prevent unwanted side reactions. Even with protecting groups such coupling reactions and related steps generate impurities. Thus, there exists a need to develop new methods to purify elamipretide that allow the purification after coupling reactions. Crystallization of the desired reaction products are one method of achieving the necessary purification.
Disclosed are crystalline forms of L-Lys(Boc)-Phe-NH2 and Boc-D-Arg-DMT, wherein DMT is an abbreviation for dimethyltyrosine, which are intermediates in the synthesis of elamipretide.
Elamipretide has been shown to have various therapeutic effects in diseases related to mitochondrial dysfunction. Previous synthetic routes to elamipretide presented challenges with respect to scale-up due to reliance on chromatographic separations to enrich levels of desired intermediates. Herein are disclosed crystalline forms of L-Lys(Boc)-Phe-NH2 and Boc-D-Arg-DMT, which can be used as purified intermediates in the synthesis of elamipretide.
One aspect of the present invention relates to crystalline forms of Compound (I):
which compound is also known as L-Lys(Boc)-Phe-NH2.
A crystalline form of Compound (I) can be used in the synthesis of elamipretide.
In certain embodiments, a polymorph of the crystalline form is characterized by powder X-ray diffraction (XRD). θ represents the diffraction angle, measured in degrees. In certain embodiments, the diffractometer used in XRD measures the diffraction angle as two times the diffraction angle θ. Thus, in certain embodiments, the diffraction patterns described herein refer to X-ray intensity measured against angle 2θ.
In certain embodiments, a crystalline form of Compound (I) is not solvated (e.g., the crystal lattice does not comprise molecules of a solvent). In certain alternative embodiments, a crystalline form of Compound (I) is solvated. In some cases, the solvent is water.
In one aspect, the invention features a crystalline form of Compound (I) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern as shown in
In another aspect, the invention features a crystalline form of Compound (I) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) as shown in Table 1.
In another aspect, the invention features a crystalline form of Compound (I) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) of: 4.7, 6.2, 12.4, 15.8, 16.5, 18.0, 18.2, 18.8, and 19.8.
In another aspect, the invention features a crystalline form of Compound (I) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) of: 4.7, 6.2, 11.3, 12.4, 13.3, 15.0, 15.8, 16.5, 17.0, 17.7, 18.0, 18.2, 18.8, 19.8, 22.0, and 22.8.
The relative intensity, as well as the two theta value, of each peak in Table 1, as well as in
One aspect of the present invention relates to a crystalline form of Compound (II):
which compound is also known as Boc-D-Arg-DMT, and may also be drawn in the form of a zwitterion.
A crystalline form of Compound (II) can be used in the synthesis of elamipretide.
In certain embodiments, a polymorph of the crystalline form is characterized by powder X-ray diffraction (XRD). θ represents the diffraction angle, measured in degrees. In certain embodiments, the diffractometer used in XRD measures the diffraction angle as two times the diffraction angle θ. Thus, in certain embodiments, the diffraction patterns described herein refer to X-ray intensity measured against angle 2θ.
In certain embodiments, a crystalline form of Compound (II) is not solvated (e.g., the crystal lattice does not comprise molecules of a solvent). In certain alternative embodiments, a crystalline form of Compound (II) is solvated. In some cases, the solvent is water.
In one aspect, the invention features a crystalline form of Compound (II) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern as shown in
In another aspect, the invention features a crystalline form of Compound (II) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) as shown in Table 2.
In another aspect, the invention features a crystalline form of Compound (II) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) of: 9.3, 12.1, 16.6, 17.6, 18.0, 18.8, and 19.4.
In another aspect, the invention features a crystalline form of Compound (II) which has characteristic peaks in the powder X-ray diffraction (XRPD) pattern at values of two theta (° 2θ) of: 9.3, 12.1, 13.7, 16.3, 16.6, 17.6, 18.0, 18.8, 19.4, 21.3, 23.0, 24.2, and 25.1.
The relative intensity, as well as the two theta value, of each peak in Table 2, as well as in
Materials and Methods
Exemplary Synthetic Route
Synthesis of Compound 3
Synthesis of Compound I
Preliminary Single-Solvent Solubility of Compound I:
ASolubility was determined by HPLC (response curve).
Preliminary Precipitation Studies (MeOH/Water) of Compound I:
AExperiments were conducted on 500 mg scale where the initial solution in MeOH (via 2447-41) was concentrated to a residue followed by charging MeOH/water at 25° C.
BExperiment was conducted on 40 mg scale where the initial solution in MeOH (via 2447-41) was charged directly to water. An additional charge of water was required to enable precipitation.
In Process Precipitation Results (MeOH/Water) of Compound I:
Manufacturing Process to Produce Compound 8
Manufacturing Process to Produce the HCl Salt of Compound II
Preparation of the Zwitterionic Form of Compound II
Formation of zwitterionic compound led to high purity material that was stable, easily handled, and highly crystalline.
All U.S. patents and U.S. and PCT published patent applications mentioned in the description above are incorporated by reference herein in their entirety.
Having now fully described the present invention in some detail by way of illustration and examples for the purposes of clarity of understanding, it will be obvious to one of ordinary skill in the art that the same can be performed by modifying or changing the invention within a range of conditions, formulations and other parameters without affecting the scope of the invention or any specific embodiment thereof, and that such modifications or changes are intended to be encompassed within the scope of the appended claims.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 62/651,430, filed Apr. 2, 2018.
Filing Document | Filing Date | Country | Kind |
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PCT/US19/24617 | 3/28/2019 | WO | 00 |
Number | Date | Country | |
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62651430 | Apr 2018 | US |