Odevixibat

Odevixibat is a highly potent, non-systemic ileal bile acid transport inhibitor (IBATi) that has has minimal systemic exposure and acts locally in the small intestine. Albireo is developing odevixibat to treat rare pediatric cholestatic liver diseases, including progressive familial intrahepatic cholestasis, biliary atresia and Alagille syndrome.

With normal function, approximately 95 percent of bile acids released from the liver into the bile ducts to aid in liver function are recirculated to the liver via the IBAT in a process called enterohepatic circulation. In people with cholestatic liver diseases, the bile flow is interrupted, resulting in elevated levels of toxic bile acids accumulating in the liver and serum. Accordingly, a product capable of inhibiting the IBAT could lead to a reduction in bile acids returning to the liver and may represent a promising approach for treating cholestatic liver diseases.

The randomized, double-blind, placebo-controlled, global multicenter PEDFIC 1 Phase 3 clinical trial of odevixibat in 62 patients, ages 6 months to 15.9 years, with PFIC type 1 or type 2 met its two primary endpoints demonstrating that odevixibat reduced serum bile acids (sBAs) (p=0.003) and improved pruritus (p=0.004), and was well tolerated with a low single digit diarrhea rate. These topline data substantiate the potential for odevixibat to be first drug for PFIC patients. The Company intends to complete regulatory filings in the EU and U.S. no later than early 2021, in anticipation of regulatory approval, issuance of a rare pediatric disease priority review voucher and launch in the second half of 2021.

Odevixibat is being evaluated in the ongoing PEDFIC 2 open-label trial (NCT03659916) designed to assess long-term safety and durability of response in a cohort of patients rolled over from PEDFIC 1 and a second cohort of PFIC patients who are not eligible for PEDFIC 1.

Odevixibat is also currently being evaluated in a second Phase 3 clinical trial, BOLD (NCT04336722), in patients with biliary atresia. BOLD, the largest prospective intervention trial ever conducted in biliary atresia, is a double-blind, randomized, placebo-controlled trial which will enroll approximately 200 patients at up to 75 sites globally to evaluate the efficacy and safety of odevixibat in children with biliary atresia who have undergone a Kasai procedure before age three months. The company also anticipates initiating a pivotal trial of odevixibat for Alagille syndrome by the end of 2020.

For more information about the PEDFIC 2 or BOLD studies, please visit ClinicalTrials.gov or contact medinfo@albireopharma.com.

The odevixibat PFIC program, or elements of it, have received fast track, rare pediatric disease and orphan drug designations in the United States. In addition, the FDA has granted orphan drug designation to odevixibat for the treatment of Alagille syndrome, biliary atresia and primary biliary cholangitis. The EMA has granted odevixibat orphan designation, as well as access to the PRIority MEdicines (PRIME) scheme for the treatment of PFIC. Its Paediatric Committee has agreed to Albireo’s odevixibat Pediatric Investigation Plan for PFIC. EMA has also granted orphan designation to odevixibat for the treatment of biliary atresia, Alagille syndrome and primary biliary cholangitis.

PATENT

https://patents.google.com/patent/US9694018B1/en

Example 5

1,1-Dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N—{(R)-α-[N—((S)-1-carboxypropyl) carbamoyl]-4-hydroxybenzyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,2,5-benzothiadiazepine, Mw. 740.94.

This compound is prepared as described in Example 29 of WO3022286.

PATENT

https://patents.google.com/patent/WO2003022286A1/sv

Example 29

1,1-Dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(N-((R)-α-[N-((S)- 1-carboxypropyl) carbamoyl]-4-hydroxybenzyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-1,2,5-benzothiadiazepine

A solution of 1,1-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-[N-((R)-α-carboxy-4-hydroxybenzyl)carbamoylmethoxy]-2,3,4,5-tetrahydro-1,2,5-benzothiadiazepine (Example 18; 0.075 g, 0.114 mmol), butanoic acid, 2-amino-, 1,1-dimethylethyl ester, hydrochloride, (2S)-(0.031 g, 0.160 mmol) and Ν-methylmorpholine (0.050 ml, 0.457 mmol) in DMF (4 ml) was stirred at RT for 10 min, after which TBTU (0.048 g, 0.149 mmol) was added. After 1h, the conversion to the ester was complete. M/z: 797.4. The solution was diluted with toluene and then concentrated. The residue was dissolved in a mixture of DCM (5 ml) and TFA (2 ml) and the mixture was stirred for 7h. The solvent was removed under reduced pressure. The residue was purified by preparative HPLC using a gradient of 20-60% MeCΝ in 0.1M ammonium acetate buffer as eluent. The title compound was obtained in 0.056 g (66 %) as a white solid. ΝMR (400 MHz, DMSO-d₆): 0.70 (3H, t), 0.70-0.80 (6H, m), 0.85-1.75 (14H, m), 2.10 (3H, s), 3.80 (2H, brs), 4.00-4.15 (1H, m), 4.65 (1H, d(AB)), 4.70 (1H, d(AB)), 5.50 (1H, d), 6.60 (1H, s), 6.65-7.40 (11H, m), 8.35 (1H, d), 8.50 (1H, d) 9.40 (1H, brs).

PATENT

https://patents.google.com/patent/US20140323412A1/en

PATENT

https://patents.google.com/patent/WO2013063526A1/e

PATENT

https://patents.google.com/patent/WO2019245448A1/en

The compound l,l-dioxo-3,3-dibutyl-5-phenyl-7-methylthio-8-(A/-{(R)-a-[A/-((S)-l-carboxypropyl) carbamoyl]-4-hydroxybenzyl}carbamoylmethoxy)-2,3,4,5-tetrahydro-l,2,5-benzothiadiazepine (odevixibat; also known as A4250) is disclosed in WO 03/022286. The structure of odevixibat is shown below.

As an inhibitor of the ileal bile acid transporter (IBAT) mechanism, odevixibat inhibits the natural reabsorption of bile acids from the ileum into the hepatic portal circulation. Bile acids that are not reabsorbed from the ileum are instead excreted into the faeces. The overall removal of bile acids from the enterohepatic circulation leads to a decrease in the level of bile acids in serum and the liver. Odevixibat, or a pharmaceutically acceptable salt thereof, is therefore useful in the treatment or prevention of diseases such as dyslipidemia, constipation, diabetes and liver diseases, and especially liver diseases that are associated with elevated bile acid levels.

According to the experimental section of WO 03/022286, the last step in the preparation of odevixibat involves the hydrolysis of a tert-butyl ester under acidic conditions. The crude compound was obtained by evaporation of the solvent under reduced pressure followed by purification of the residue by preparative HPLC (Example 29). No crystalline material was identified.

Amorphous materials may contain high levels of residual solvents, which is highly undesirable for materials that should be used as pharmaceuticals. Also, because of their lower chemical and physical stability, as compared with crystalline material, amorphous materials may display faster

decomposition and may spontaneously form crystals with a variable degree of crystallinity. This may result in unreproducible solubility rates and difficulties in storing and handling the material. In pharmaceutical preparations, the active pharmaceutical ingredient (API) is for that reason preferably used in a highly crystalline state. Thus, there is a need for crystal modifications of odevixibat having improved properties with respect to stability, bulk handling and solubility. In particular, it is an object of the present invention to provide a stable crystal modification of odevixibat that does not contain high levels of residual solvents, that has improved chemical stability and can be obtained in high levels of crystallinity.

Example 1

Preparation of crystal modification 1

Absolute alcohol (100.42 kg) and crude odevixibat (18.16 kg) were charged to a 250-L GLR with stirring under nitrogen atmosphere. Purified water (12.71 kg) was added and the reaction mass was stirred under nitrogen atmosphere at 25 ± 5 °C for 15 minutes. Stirring was continued at 25 ± 5 °C for 3 to 60 minutes, until a clear solution had formed. The solution was filtered through a 5.0 m SS cartridge filter, followed by a 0.2 m PP cartridge filter and then transferred to a clean reactor.

Purified water (63.56 kg) was added slowly over a period of 2 to 3 hours at 25 ± 5 °C, and the solution was seeded with crystal modification 1 of odevixibat. The solution was stirred at 25 ± 5 °C for 12 hours. During this time, the solution turned turbid. The precipitated solids were filtered through centrifuge and the material was spin dried for 30 minutes. The material was thereafter vacuum dried in a Nutsche filter for 12 hours. The material was then dried in a vacuum tray drier at 25 ± 5 °C under vacuum (550 mm Hg) for 10 hours and then at 30 ± 5 °C under vacuum (550 mm Hg) for 16 hours. The material was isolated as an off-white crystalline solid. The isolated crystalline material was milled and stored in LDPE bags.

An overhydrated sample was analyzed with XRPD and the diffractogram is shown in Figure 2.

Another sample was dried at 50 °C in vacuum and thereafter analysed with XRPD. The diffractogram of the dried sample is shown in Figure 1.

The diffractograms for the drying of the sample are shown in Figures 3 and 4 for 2Q ranges 5 – 13 ° and 18 – 25 °, respectively (overhydrated sample at the bottom and dry sample at the top).

ClinicalTrials.gov