FDA Grants Durvalumab Orphan Drug Designation in SCLC

Jose Baselga, MD, PhD

Jose Baselga, MD, PhD

The FDA has granted an orphan drug designation to durvalumab (Imfinzi) for the treatment of patients with small cell lung cancer (SCLC).¹

Data supporting the orphan drug designation come from thephase III CASPIAN trial, which was announced as having met its primary endpoint in June.²In patients with extensive-stage SCLC, the addition of durvalumab to etoposide and platinum-based chemotherapy demonstrated a statistically significant and clinically meaningful improvement in overall survival.

“This orphan drug designation comes on the heels of positive results from the phase III CASPIAN trial, which is the first trial to offer the flexibility of combining immunotherapy with different platinum-based regimens in small cell lung cancer. We are eager to expand treatment options for patients facing such a devastating diagnosis and look forward to working with regulatory authorities to bring forward new options as soon as possible,” said José Baselga, MD, PhD, executive vice president of oncology research and development, AstraZeneca, in a statement.

An orphan drug designation is granted to new therapies intended to treat rare diseases that affect less than 200,000 in the United States and allows for increased assistance from the FDA regarding the clinical trial design and development of the agent. SCLC accounts for about 15% of all lung cancer diagnoses and has a 5-year survival rate of approximately 6%.  

The CASPIAN trial is randomized, open-label, multicenter, global phase III study with 3-arms looking at durvalumab in patients with previously untreated extensive-stage SCLC. Patients in the trial were randomized 1:1:1 to receive either durvalumab and the investigational CTLA-4 inhibitor tremelimumab with carboplatin or cisplatin plus etoposide, durvalumab and platinum-based chemotherapy plus etoposide, or etoposide and platinum-based chemotherapy alone.

Adult patients with extensive disease who were candidates to receive a platinum-based chemotherapy and had an ECOG performance status of 0 or 1 were eligible for enrollment. Patients with active or prior autoimmune or inflammatory disorders, active infections, or paraneoplastic syndrome were excluded from the trial, as well as those who had received prior radiotherapy to the chest prior to systemic therapy.

The primary endpoint of the CASPIAN trial is OS and secondary endpoints include progression-free survival (PFS), objective response rate, the PFS rate at 6 months and 12 months, and the OS rate at 18 months. The investigators are also looking atquality-of-life measurements, safety, and pharmacokinetics. Exploratory endpoints include PFS after subsequent anticancer therapy and biomarker correlation with response to treatment.

Findings from the CASPIAN trial are expected to be submitted for presentation at an upcoming medical meeting.

Durvalumab has received FDA approval for the treatment of patients with unresectable, stage III non—small cell lung cancer after chemoradiotherapy and for the treatment of previously treated patients with advanced bladder cancer.

The PD-L1 inhibitor is currently being investigated following concurrent chemoradiotherapy in patients with limited-stage SCLC in the phase III ADRIATIC trial (NCT03703297), and is also being explored in a number of other solid tumors as both monotherapy and in combination regimens.

References

1. Imfinzi granted US Orphan Drug Designation for small cell lung cancer [press release]. Wilmington, DE: AstraZeneca; July 12, 2019. https://bit.ly/32lVIIE. Accessed July 12, 2019.
2. Imfinzi improves overall survival at interim analysis in the Phase III CASPIAN trial in 1st-line extensive-stage small cell lung cancer [press release]. Wilmington, DE: AstraZeneca; June 27, 2019. https://bit.ly/2RFpKlz. Accessed July 12, 2019.