US4340535A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cytotoxic products formed by covalent bonding of the A chain of ricin with an antibody and the process for their preparation and use
Assignee: Sanofi SA
•
Filing: 1979-09-27
•
Granted: 1982-07-20
•
Expires: 1999-09-27
Abstract
Abstract Carcinostatic products are formed by coupling, by covalent bonding, the A chain of ricin with an antibody which is capable of selectively recognizing a given antigen at the surface of cancerous cells. Such products can be made by the formation of a disulphide bridge between the free thiol group in the A chain of ricin and an immunoglobulin or immunoglobulin fragment into which a thiol group or an activated disulphide group has been introduced. The A chain of ricin and the immunoglobulin are carefully purified before use.
Inventors
- 👤 Guy Voisin
- 👤 Franz Jansen
- 👤 Pierre Gros
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:48
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/415; C07K14/42; A; A61; A61K; A61K36/00; A61K36/18; A61K36/185; A61K36/47; A61K47/00; A61K47/50; A61K47/51; A61K47/68; A61K47/6801; A61K47/6803; A61K47/6811; A61K47/6817; A61K47/6819; A61K47/6825; A61K47/6827; A61P; A61P35/00; Y; Y10; Y10S; Y10S424/00; Y10S424/806; Y10S424/807; Y10S530/00; Y10S530/806; Y10S530/863; Y10S530/864; Y10S530/866
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
61 words
Process for the preparation of a cytotoxic product having a covalent disulphide bond between a cytotoxic compound and an antibody, the process comprising forming a disulphide bridge between the A chain of ricin and the antibody, the antibody being an immunoglobulin or an immunoglobulin fragment and being specific for a given antigen carried by the cells which are to be destroyed.
Claim 2
Dependent Claim
61 words
Process for the preparation of a cytotoxic product having a covalent disulphide bond between a cytotoxic compound and an antibody, the process comprising forming a disulphide bridge between the A chain of ricin and the antibody, the antibody being an immunoglobulin or an immunoglobulin fragment and being specific for a given antigen carried by the cells which are to be destroyed.
Claim 3
Dependent Claim
104 words
Process as claimed in claim 1, wherein a compound of the formula P 1 -SH is reacted with a compound of the formula P 2 -S-S-X in accordance with the equation: P 1 SH+P 2 -S-S-X→P 1 -S-S-P 2 +XSH, in which when P 1 is the radical of the A chain of ricin to which the free thiol group of this molecule is fixed, P 2 is an immunoglobulin or an immunoglobulin fragment, or conversely when P 1 is an immonoglobulin or an immunoglobulin fragment, P 2 is the radical of the A chain of ricin, and X is an organic activator radical.
Claim 4
Dependent Claim
94 words
Process as claimed in claim 2, wherein P 1 is an immunoglobulin or an immunoglobulin fragment into which a free thiol group is to be introduced, the recognition site of the said immunoglobulin or immunoglobulin fragment is first blocked by prior treatment with the antigen, or with another antigen exhibiting a cross-reaction, or with a hapten, the immunoglobulin or immunoglobulin fragment, protected in this way, then being reacted with δ-acetylmercaptosuccinic anhydride, the thiol groups are liberated by the action of hydroxylamine, and the recognition site is finally unblocked by removing the antigen or hapten.
Claim 5
Dependent Claim
109 words
Process as claimed in claim 2, wherein P 2 SH represents the A chain of ricin, and the latter is converted into the disulphide by the exchange reaction: P.sub.2 SH+X-S-S-X⃡P.sub.2 -S-S-X+XSH in which X represents an activator radical selected from the pyrid-2-yl or pyrid-4-yl group which is optionally substituted by one or more alkyl, halogen or carboxylic acid groups phenyl, or phenyl which is substituted by one or more nitro or carboxylic acid groups, and the reaction is carried out with a large molar excess of the reagent XSSX, which is removed at the end of the reaction by dialysis or filtration on a molecular sieve in gel form.
Claim 6
Dependent Claim
24 words
Process as claimed in claim 3, wherein all the reactions are carried out at pH 7.0 in a phosphate buffer and at ambient temperature.
Claim 7
Dependent Claim
140 words
Process as claimed in claim 2, wherein P 1 SH represents the A chain of ricin and P 2 represents the immunoglobulin or a fragment thereof, and P 2 is converted into the activated disulphide in accordance with the equation: P.sub.2 +Y-R-S-S-X→P.sub.2 -R-S-S-X in which Y represents a functional group which is capable of covalently bonding to any one of the functional groups carried by the side chains of the constituent aminoacids of the immunoglobulin, R represents a group --(CH 2 ) n --, n being an integer from 2 to 10, or a group ##STR11## R 4 denoting a hydrogen atom or an alkyl group of 1 to 8 C atoms, and R 3 denoting a substituent which is inert towards the reactants subsequently used, the reaction being carried out in the homogeneous liquid phase and at ambient temperature.
Claim 8
Dependent Claim
29 words
Process as claimed in claim 2, wherein after all the reactions are complete, the conjugate obtained is purified, in order to remove the unreacted compound P 2 -S-S-X therefrom.
Claim 9
Dependent Claim
56 words
A cytotoxic product, consisting in compounds called "conjugates", wherein the A chain of ricin is coupled by a disulphide bridge to a protein structure which is an antibody, the protein structure being capable of selectively recognising an antigen presented at the surface of the carrier cells and the antibody being an immunoglobulin or an immunoglobulin fragment.
Claim 10
Dependent Claim
56 words
A cytotoxic product, consisting in compounds called "conjugates", wherein the A chain of ricin is coupled by a disulphide bridge to a protein structure which is an antibody, the protein structure being capable of selectively recognising an antigen presented at the surface of the carrier cells and the antibody being an immunoglobulin or an immunoglobulin fragment.
Claim 11
Dependent Claim
14 words
A product as claimed in claim 8, wherein the antibody is an anti-DNP antibody.
Claim 12
Dependent Claim
19 words
A product as claimed in claim 8, wherein the antibody is the F(ab)' 2 fragment of the anti-DNP antibody.
Claim 13
Dependent Claim
15 words
A product as claimed in claim 8, wherein the antibody is the anti-Thy 1.2 IgM.
Claim 14
Dependent Claim
20 words
Process according to claim 7 in which the unreacted compound is removed by fractional precipitation with a water-miscible organic solvent.
Claim 15
Dependent Claim
15 words
Process according to claim 7 wherein the unreacted compound is removed by gel permeation chromatography.
Claim 16
Dependent Claim
14 words
Process according to claim 7 wherein the unreacted compound is removed by affinity chromatography.
References Cited (Backward Citations)
US4046722A
Cited
US4093607A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-07-19 | 1986-01-18 | 1986-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-07-19 | 1990-01-18 | 1990-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-07-19 | 1994-01-18 | 1994-07-20 | $7700.00 | Window Closed / Lapsed |