After considering if early-stage trials were enough to recommend accelerated approval, the FDA’s Oncologic Drugs Advisory Committee (ODAC) ultimately voted against the accelerated approval of rociletinib for patients with metastatic EGFR T790M–mutated non–small cell lung cancer (NSCLC) who have previously received an EGFR-targeted therapy.
The panel, which produced a 12-1 vote against the accelerated approval, was considering whether a pooled efficacy and safety analysis from the early-stage CO-1686-008 (TIGER-X) and CO-1686-019 (TIGER-2) trials was sufficient to recommend accelerated approval of the third-generation EGFR inhibitor. With its negative vote, the panel recommended that the results of the randomized phase 3 CO-1686-020 trial (TIGER-3) should be submitted before the FDA makes a decision on the application.
The open-label, multinational TIGER-3 trial is comparing rociletinib with single-agent chemotherapy such as Alimta (pemetrexed), Taxotere (docetaxel) or Gemzar (gemcitabine) in patients with EGFR-mutation positive NSCLC with disease progression following both an EGFR-TKI and platinum doublet chemotherapy.
The current action date for a final FDA approval decision on rociletinib is June 28, 2016.
In the pooled TIGER-X or TIGER-2 analysis, the overall response rate (ORR) with rociletinib (dose range, 500 mg to 750 mg twice daily) among 325 patients with EGFR T790M–positive metastatic NSCLC who progressed on at least one EGFR inhibitor was 30.2 percent. The ORR was 32 percent and 23 percent in the 170 patients receiving the 625 mg and the 79 patients receiving 500 mg doses, respectively.
For its safety analysis, ODAC considered pooled data from 400 patients enrolled in either TIGER-X or TIGER-2 who were treated at either 500 mg, 625 mg, 750 mg or 1000 mg twice daily.
The most common all-grade adverse events (AEs), occurring in more than 30 percent of patients, were diarrhea, hyperglycemia, fatigue, nausea, decreased appetite, QT prolongation and vomiting. The most frequent grade 3/4 AEs, which occurred in more than 10 percent, were hyperglycemia and QTc prolongation.
Dose reductions occurred in 51 percent of patients, most commonly due to hyperglycemia (22 percent) and QTc prolongation (11 percent). Fifty-seven percent of patients had dose interruptions, which were most often due to hyperglycemia (22 percent), QTc prolongation (10 percent) and nausea (10 percent). AEs led to discontinuation for 11 percent of patients, most frequently due to QTc prolongation (2 percent), and pneumonia/pneumonitis (2 percent).
Serious AEs were experienced by 47 percent of patients, with the most common being malignant neoplasm progression (16 percent), hyperglycemia (8 percent) and pneumonia (4 percent). Post-baseline QTc intervals of greater than 500 msec on at least one occasion occurred in 17 percent of patients. One patient experienced Torsades de Pointes, and there were two sudden deaths (on day four and the other day 13), according to the ODAC briefing documents.
A rolling submission was originally completed for rociletinib in July 2015, which was subsequently granted a priority review by the FDA. However, at a preplanned 90-day review meeting, changes in response rates from TIGER-X and TIGER-2 prompted the FDA to request additional data, which set off a chain of events leading to the scheduling of the ODAC hearing.
In the earlier TIGER-X/TIGER-2 data submitted to the FDA, 243 patients with T790M mutations experienced an ORR across all dose levels of 53 percent and a disease control rate of 85 percent.
TIGER-X included 456 patients with EGFR-positive NSCLC received rociletinib across four doses (range, 500-1000 mg). The median age of patients was 63 years, 10 percent had a prior history of diabetes, and 41 percent had central nervous system (CNS) metastases. The median number of prior therapies was two and nearly half of patients had received more than one TKI (44 percent).
At a data cutoff of April 27, 2015, the median progression-free survival (PFS) in 270 evaluable patients with T790M mutations across the 500- and 625-mg doses was eight months. In those without baseline CNS metastases, the median PFS was 10.3 months. The company did not release new data for PFS.
In the safety analysis, the most frequently occurring all-grade adverse events (AEs) in the 500-mg arm were hyperglycemia (35 percent), diarrhea (33 percent), fatigue (29 percent), decreased appetite (15 percent), muscle spasms (14 percent), weight loss (10 percent) and vomiting (8 percent).
Grade 3 QTc prolongation was seen in 2.5 percent of patients. No cases of interstitial lung disease were seen at the 500-mg dose level. AEs leading to treatment discontinuation were seen in 2.5 percent of patients with the 500 mg dose.
Grade 3/4 hyperglycemia occurred in 17 percent of patients treated with the 500-mg dose. To adjust for this, a monitoring and treatment algorithm was put in place to detect glucose levels and initiate treatment with oral insulin sensitizing agents, when needed. Prior to initiating these measures in September 2014, the rate of grade 3/4 hyperglycemia was 22 percent. With proper monitoring and treatment, this rate dropped to 8 percent.
In the single-arm phase II TIGER-2 trial, rociletinib is being explored as a second-line therapy in patients with EGFR T790M-mutated NSCLC.