Treatment for cancer

Patent metadata

Field	Value
Publication number	US-2016287675-A1
Application number	US-201415038345-A
Country	US
Kind code	A1
Filing date	Nov 24, 2014
Priority date	Nov 22, 2013
Publication date	Oct 6, 2016
Grant date	—

Abstract

The present invention provides a method of treatment for cancer in a subject comprising the administration of a prodrug, wherein the subject is colonised with an obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar. The present invention further provides an isolated polypeptide, nucleic acids encoding said polypeptide, vectors and host cells comprising said nucleic acids and vectors and uses of the above in treating solid tumours.

First claim

1 . A method of treatment for cancer in a subject comprising the administration to the subject of spores of an obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar.

2 . A method of preparing a subject for treatment with a prodrug for cancer comprising the administration to the subject of spores of an obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar.

3 . The method of claim 1 or claim 2 , further comprising the administration of a prodrug to the subject.

4 . A method of treatment for cancer in a subject comprising the administration of a prodrug, wherein the subject is colonised with an obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar.

5 . An obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar,
for use as a medicament for treatment of a subject.

6 . An obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar,
for use in the preparation of a medicament for the treatment of cancer in a subject.

7 . The use of claim 4 or claim 5 , wherein the use is in combination with a prodrug, or in preparation of a subject for administration of a prodrug.

8 . A prodrug for use as a medicament in a subject colonised with an obligate anaerobic microorganism capable of expressing a polypeptide having nitroreductase activity, wherein the polypeptide:
exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar.

9 . The method according to claim 3 or claim 4 , the use of claim 7 or claim 8 , wherein the prodrug comprises or consists of CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide) or its analogue SN 23862 5-(N,N-bis(2-chloroethyl)amino)-2,4-dinitrobenzamide).

10 . The method or use according to any preceding claim, wherein a tumour of the subject is colonised with the obligate anaerobic microorganism.

11 . The method or use according to any preceding claim, wherein the subject is colonised with the obligate anaerobic microorganism by administration of the obligate anaerobic microorganism, and/or spores thereof.

12 . The method or use according to any preceding claim, wherein the subject is colonised with the obligate anaerobic microorganism by intravenous administration.

13 . The method according to any of claims 3 , 4 , or 9 to 12 or the use according to any of claims 7 , 8 or 9 to 12 , wherein the subject is colonised with the obligate anaerobic microorganism prior to administration of the prodrug.

14 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is capable of sporulation.

15 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is administered in spore form.

16 . The method or use according to any preceding claim, wherein at least about 5×10 7 spores of the obligate anaerobic microorganism are administered to the subject.

17 . The method according to any of claims 3 , 4 , or 9 to 16 or the use according to any of claims 7 , 8 or 9 to 16 , wherein the prodrug is administered at a dose of at least 15 mg/kg.

18 . The method or use according to any preceding claim, wherein the cancer is a solid tumour cancer.

19 . The method or use according to any preceding claim, wherein the polypeptide is capable of reducing CB1954 to the 4HX derivative with a K m of 25 micromolar or less.

20 . The method or use according to any preceding claim, wherein the polypeptide is capable of reducing CB1954 to the 4HX derivative with a K m of 6.3 micromolar or less.

21 . The method or use according to any preceding claim, wherein the polypeptide is capable of reducing CB1954 to a 4-hydroxylamine (4HX) derivative substantially without producing the 2-hydroxylamine derivative.

22 . The method or use according to any preceding claim, wherein the polypeptide comprises or consists of the amino acid sequence of:
a. SEQ ID NO: 1 (NmeNTR); or b. SEQ ID NO: 2 (HsoNTR); or a fragment, variant or derivative thereof.

23 . The method or use according to any preceding claim, wherein the variant shares at least 20% sequence identify with the native polypeptide sequence.

24 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is a bacterium.

25 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is a bacterium of the class Clostridia.

26 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is a Clostridial species selected from the group consisting of:
c. Clostridium sporogenes ; and d. Clostridium novyi.

27 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism is auxotrophic for one or more essential nutrient.

28 . The method or use according to any preceding claim, wherein the obligate anaerobic microorganism does not comprise an exogenous antibiotic resistance gene.

29 . The method or use according to any preceding claim, wherein the polypeptide is encoded on the chromosome of the obligate anaerobic microorganism.

30 . An isolated polypeptide having nitroreductase activity wherein the isolated polypeptide:
e. exhibits preferential reduction of CB1954 to a 4-hydroxylamine (4HX) derivative instead of a 2-hydroxylamine derivative; and f. is capable of reducing CB1954 to the 4HX derivative with a K m of less than 30 micromolar.

31 . The isolated polypeptide according to claim 30 , wherein the polypeptide is capable of reducing CB1954 to the 4HX derivative with a K m of 25 micromolar or less.

32 . The isolated polypeptide according to claim 30 or claim 31 , wherein the polypeptide is capable of reducing CB1954 to the 4HX derivative with a K m of 6.3 micromolar or less.

Assignees

• Univ Nottingham

Inventors

• Minton Nigel Peter
• Heap John Timothy

Classifications

• A61P35/00

  Antineoplastic agents · CPC title

• C12N15/74

  Vectors or expression systems specially adapted for prokaryotic hosts other than E. coli, e.g. Lactobacillus, Micromonospora · CPC title

• A61K35/742

  Spore-forming bacteria, e.g. Bacillus coagulans, Bacillus subtilis, clostridium or Lactobacillus sporogenes · CPC title

• A61K35/745

  Bifidobacteria · CPC title

• C12Y105/01034

  6,7-Dihydropteridine reductase (1.5.1.34) · CPC title