BTK Inhibitor Salt Forms for Scalable Purification and Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing synthesis methods for the BTK inhibitor compound (I) are not suitable for large-scale manufacturing and result in high residual solvent content and thermal instability, posing challenges for effective formulation and increased costs.

Innovation Solution

Development of specific salts and solid forms of compound (I), particularly sulfonic acid and carboxylic acid salts, in amorphous form, with high purity (E) or (Z) isomers, to enhance stability and reduce residual solvent levels, enabling efficient large-scale synthesis and formulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If column chromatography purification is used to obtain compound (I), then purity is improved, but manufacturing complexity and cost increase significantly

Engineering Contradiction:
Improvecompound purityVSAvoidpurification process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the problematic foam formation and column chromatography step by developing alternative purification methods using salt formation and crystallization techniques, thereby simplifying the manufacturing process while maintaining purity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the physical and chemical parameters of compound (I) by forming salts with different counterions (e.g., hydrochloride, sulfate, methanesulfonate) to alter solubility and crystallization behavior, enabling simplified purification without column chromatography

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If the compound is isolated as foam and dried under vacuum at ambient temperature, then processing simplicity is improved, but residual solvent content increases beyond ICH limits

Engineering Contradiction:
Improveisolation simplicityVSAvoidresidual solvent content
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs phase transition from foam to crystalline solid form through controlled crystallization and drying processes, transforming the physical state to eliminate residual solvents while maintaining processing efficiency

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The patent creates composite salt forms of compound (I) with pharmaceutically acceptable counterions, which exhibit improved physical properties including reduced solvent retention and enhanced stability during processing

Inventive Principle:
Principle #40Composite materials

3Adaptability or versatility

If the compound is stored and handled as the free base form, then formulation flexibility is improved, but thermal stability deteriorates

Engineering Contradiction:
Improveformulation flexibilityVSAvoidthermal stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent changes the chemical form of compound (I) from free base to salt forms, fundamentally altering thermal stability parameters while maintaining or enhancing formulation flexibility through diverse salt options

Inventive Principle:
Principle #35Parameter changes

4Productivity

If large-scale synthesis is attempted using existing methods, then production volume is improved, but product quality and stability deteriorate

Engineering Contradiction:
Improveproduction volumeVSAvoidproduct quality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent extracts and removes the problematic steps (column chromatography, foam isolation) from the synthesis protocol, replacing them with scalable crystallization and filtration operations that maintain quality at large scale

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements parameter changes in the synthesis and isolation process, including controlled crystallization conditions and salt formation, to enable large-scale production while maintaining high product quality and stability

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3795158B1Salts and solid form of a BTK inhibitor
Publication Date: 2025.11.05 PRINCIPIA BIOPHARMA INC
  • EP3795158B1 patent drawingFigure 1A
  • EP3795158B1 patent drawingFigure 1B
  • EP3795158B1 patent drawingFigure 2A

AI summary

Disclosed herein are processes for preparing 2-[(3R)-3-[4-amino-3-(2-fluoro-4-phenoxy-phenyl)pyrazolo[3,4-d]pyrimidin-1-yl]piperidine-1-carbonyl]-4-methyl-4-[4-(oxetan-3-yl)piperazin-1-yl]pent-2-enenitrile free base (compound (I)), salts of compound (I) and solid state form of said salts. Also disclosed herein are pharmaceutical compositions comprising such salts and solid state form thereof and methods of treating cancer, autoimmune, and inflammatory diseases using compound (I) or a pharmaceutically acceptable salt thereof.