Precision medicines have revolutionized the treatment of cancer. But too often, the goal of prolonged, durable responses has been difficult to achieve. Why? Three common reasons:
- Drugs do not hit the primary driver hard enough, because side effects limit dose.
- Cancer cells mutate, evolving escape pathways that evade targeted therapies.
- In late lines of treatment, the cancer has too many mutations for precision medicines to control.
At IDRx, we are intentionally designing precision combination therapies to answer these challenges.
Rather than trying to create a single drug molecule that attempts to address all mutations, we are inspired by the successful drug cocktails in other disease areas such as cystic fibrosis and HIV – approaches that have transformed life for those patients.
We start with a drug engineered to hit the primary driver mutations very hard, but with a wide therapeutic window to enable its use in early line settings, where it may be a potential best in class single agent.
Then, we add additional precision-designed molecules to stop key resistance mutations that the first drug does not address – simultaneously targeting primary genetic drivers and resistance mutations – thereby shutting down the cancer cell’s escape pathway to enable a sustained, durable response to therapy.
Because each of these drugs are engineered to be selective and potentially avoid the severe toxicities that patients cannot tolerate, combination treatment can be explored for use earlier in the course of cancer, which we hope can enable deep, durable responses. Future drug cocktails can also evolve to include more than two drugs when it is necessary to address multiple genetic pathways.
IDRX-42 and IDRX-73 are both small molecule tyrosine kinase inhibitors (TKIs) designed to inhibit the key genetic drivers and drug-resistant mutations of gastrointestinal stromal tumor (GIST). Our goal is for IDRX-42 to serve as a great base of therapy for GIST patients, and that when IDRX-73 is added, the combination may provide a transformative benefit.
A phase 1 study of IDRX-42 has been initiated, and is currently enrolling patients in the US and Europe. More information is available here.
Our team and founders have extensive experience in drug development, and collectively have been involved in the discovery, development and commercialization of more than 10 approved drugs.