Ignyta’s Entrectinib is a game-changer for NTRK/ROS1/ALK fusion-positive solid tumors

30th October 2017 (Last Updated October 30th, 2017 11:42)

San Diego, California-based biotech firm Ignyta is attracting attention for its orally available central nervous system (CNS) active tyrosine kinase inhibitor, entrectinib.

San Diego, California-based biotech firm Ignyta is attracting attention for its orally available central nervous system (CNS) active tyrosine kinase inhibitor, entrectinib.

The drug has already been granted an FDA breakthrough therapy designation in May 2017 and an FDA orphan drug designation in July 2017. Earlier this month, on October 17, the EMA awarded entrectinib a Priority Medicines (PRIME) designation, following Ignyta’s release of its updated clinical trial results for patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). The PRIME designation allows Ignyta to have enhanced support from the regulatory body, including optimizing the development pathway and engaging in early discussions with both the EMA and health technology assessment bodies in Europe. This initiative will place the multi-targeted kinase inhibitor on a faster path to approval and ease subsequent access barriers.

The day after the PRIME designation announcement, the company announced its intent for a public offering of its common stock. On October 19, the pricing of an underwritten public offering of 10.0 million shares was announced, at a price of $16.00 per share to the public. There is an expected $160.0m in gross proceedings from this offering, before deducting the underwriting discounts, commissions, and estimated offering expenses payable by Ignyta. The offering was expected to close on or around October 24, 2017, subject to customary closing conditions. Ignyta plans to use the net proceeds from the offering to fund its R&D activities for entrectinib and its ongoing clinical and pre-clinical development of other pipeline assets.

Entrectinib is designed to target tumors that harbor activating mutations to neurotropic tropomyosin receptor kinase (NTRK) 1/2/3, the proto-oncogene ROS1, or anaplastic lymphoma kinase (ALK). There are currently no approved treatments that target NTRK-positive tumors, and this represents a clear unmet medical need.

The ongoing, global, multicenter, open-label, Phase II STARTRK-2 trial is evaluating entrectinib in a basket trial design, in which patients with a variety of tumor types are eligible for the therapy. As part of this basket trial design, entrectinib is currently being analyzed in NSCLC, salivary gland cancer, pancreatic cancer, metastatic colorectal cancer (mCRC), neuroblastoma, and papillary thyroid cancer.

On October 17, the same day as the PRIME designation announcement, Ignyta provided an update on clinical trial results in 32 patients from the ongoing STARTRK-2 trial. In this interim analysis, entrectinib demonstrated a 78.1% objective response rate (ORR) by investigator assessment and a 68.8% ORR, when assessed by a Blinded Independent Review, in patients with locally advanced or metastatic NSCLC patients who harbored ROS1 fusions. Entrectinib demonstrated an exceptional durability in this patient cohort, with a median duration of response (DOR) of 28.6 months and median progression-free survival (PFS) of 29.6 months. Safety was consistent with previous studies of entrectinib, with over 200 patients treated at the recommended Phase II dose. Safety data from earlier trials are promising, with only 3% of patients discontinued from the study due to treatment-related adverse events (TRAEs). The most common TRAEs were dysgeusia (38%), fatigue (29%), constipation (23%), dizziness (23%), and increased weight (19%). The most common Grade 3 TRAEs were increased weight (5%), anemia (4%), and fatigue (3%). There were no Grade 4 events in more than 1% of patients and no Grade 5 TRAEs.

The multi-kinase inhibitor entrectinib has proven to have a drastic effect in the NTRK, ROS1, and ALK fusion-positive solid tumor patient cohorts. With Ignyta’s positive Phase II data in an NSCLC population, enhanced regulatory body support from both the EMA and FDA, and significant capital raised, the company should be in a robust position to drive its prized asset through to the finish line. However, Ignyta’s upcoming planned Phase III trial and data readouts will be critical for determining entrectinib’s future in the precision medicine space for patients with advanced and metastatic solid tumors.