- Ignyta Inc.'s oncology drug may be a best-in-class initial treatment for a small group of lung cancer patients, early data presented Tuesday suggest.
- The interim data come from an open-label study that is testing Igynta's entrectinib as a treatment for a variety of cancer patients who have protein mutations. Those with non-small cell lung cancer (NSCLC) and gene rearrangements in their ROS1 enzymes demonstrated objective response rates (ORRs) between 69% and 78%, depending on the clinical evaluator.
- Additionally, and perhaps most importantly, those NSCLC patients also went a median 29.6 months before their disease progressed. Median duration of response (mDOR) clocked in at 28.6 months.
ROS1 enzymes are similar to the more widely recognized anaplastic lymphoma kinases (ALKs). In recent years, the Food and Drug Administration has approved a few treatments for ALK-positive cancer patients, including Roche AG's Alecensa (alectinib) and Novartis AG's Zykadia (ceritinib).
Last year, Pfizer Inc.'s Xalkori (crizotinib) became the first drug targeting both ALK and ROS1 to be green lit by U.S. regulators. The approval hinged on clinical results showing patients with ROS1-positive metastatic NSCLC who took the big pharma's drug had a 66% ORR, according to an independent radiology review. Meanwhile, Xalkori had an mDOR of 18.3 months.
While it's quite difficult to compare medications unless they go head-to-head in an investigation, Ignyta believes its latest data gives it a strong standing against competitors.
"The extended duration of response and progression free survival times observed in these interim data are particularly compelling, and we believe may be driven by entrectinib's CNS activity," Ignyta CEO Jonathan Lim, said in an Oct. 17 statement. "Entrectinib was designed to cross the blood-brain barrier, allowing it to both address preexisting CNS lesions and have the potential to prevent or delay the onset of metastases to the brain, a common site of progression, particularly in NSCLC."
Ignyta also reported safety results that were in line with earlier trials — with 3% of patients discontinuing the STARTRK-2 study because of adverse events (AEs) related to entrectinib. Grade 3 treatment-related AEs included increased weight and anemia, and there were almost no Grade 4 events.
Entrectinib's benefits appear to have extended beyond the NSCLC population as well. The drug showed preliminary antitumor activity for patients with mutations in their neurotropic tropomyosin receptor kinases.
"Based on recent guidance from the FDA, the company is on track for dual NDA submissions in both the NTRK tissue-agnostic and the ROS1-positive NSCLC indications in 2018," Ignyta said in the statement.
Should entrectinib gain approval, it would add yet another drug to the increasingly crowded yet highly lucrative NSCLC market.
Targeting the very small — estimates hold between 1% and 2% — portion of the NSCLC population with ROS-1 gene rearrangements may help Ignyta carve out a niche for itself. Even so, more competition is on the horizon. Just this week, Pfizer reported positive Phase 2 results for its investigational drug lorlatinib, which combated lung tumors and brain metastases in patients with ALK-positive and ROS1-positive advanced NSCLC.
Ignyta shares opened at $17.50 apiece Wednesday morning, a 22% leap from Tuesday's close. The companies stock has roughly tripled since the beginning of the year.