ZEPZELCA Powder for solution for injection Ref.[50657] Active ingredients:

Lurbinectedin exposure-response relationships and the pharmacodynamic time-course for efficacy have not been fully characterized.

Increased incidence of Grade 4 neutropenia and Grade ≥ 3 thrombocytopenia were observed with increased lurbinectedin exposure.

Cardiac Electrophysiology

No large mean increase in QTc (i.e. >20 ms) was detected following treatment with ZEPZELCA at the recommended dose of 3.2 mg/m².

Following the approved recommended dosage, geometric means (CV) of plasma C_max and AUC_0-inf, were 107 µg/L (79) and 551 µg•h/L (94%), respectively. No accumulation of lurbinectedin in plasma is observed upon repeated administrations every 3 weeks.

Distribution

The volume of distribution of lurbinectedin at steady state is 504 L (39%). Plasma protein binding is approximately 99%, to both albumin and α-1-acid glycoprotein.

Elimination

The terminal half-life of lurbinectedin is 51 hours. Total plasma clearance of lurbinectedin is 11 L/h (50%).

Metabolism

Lurbinectedin is metabolized by CYP3A4, in vitro.

Excretion

After a single dose of radiolabeled lurbinectedin administration, 89% of the radioactivity was recovered in feces (<0.2% unchanged) and 6% in urine (1% unchanged).

Specific Populations

No clinically significant differences in the pharmacokinetics of lurbinectedin were identified based on age (18-85 years), sex, body weight (39-154 kg), mild to moderate renal impairment (CLcr 30 to 89 mL/min) or mild hepatic impairment (total bilirubin ≤ ULN and AST > ULN, or total bilirubin between 1.0–1.5 × ULN and any AST). The effects of severe renal impairment (CLcr <30 mL/min) and moderate or severe hepatic impairment (total bilirubin >1.5 × ULN and any AST) on the pharmacokinetics of lurbinectedin have not been studied.

Drug Interactions Studies

Dedicated clinical drug-drug interaction studies with CYP3A modulators have not been conducted with lurbinectedin.

In vitro Studies

Cytochrome P450 (CYP) Enzymes: Lurbinectedin is metabolized by CYP3A4. Lurbinectedin is not an inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, or CYP3A4. Lurbinectedin is not an inducer of CYP1A2 or CYP3A4.

Transporter Systems: Lurbinectedin is a substrate of MDR1, but is not a substrate of OATB1P1, OATP1B3, OCT1, or MATE1. Lurbinectedin inhibits MDR1, OATP1B1, OATP1B3, and OCT1 but not BCRP, BSEP, MATE1, OAT1, OAT3, or OCT2.

Carcinogenicity testing of lurbinectedin has not been performed. Lurbinectedin is genotoxic to mammalian cells in the presence and absence of metabolic activation. Lurbinectedin was not mutagenic in vitro in a bacterial reverse mutation (Ames) assay.

Fertility studies with lurbinectedin were not performed. There were no findings in reproductive organs in general toxicology studies in rats, dogs, or monkeys; however, the highest doses and exposures in these studies were all at levels lower than those at the human dose of 3.2 mg/m².

PM1183-B-005-14 (Study B-005; NCT02454972) is a multicenter, open-label, multi-cohort trial evaluating ZEPZELCA as a single agent in patients with advanced or metastatic solid tumors. A cohort of patients with small cell lung cancer (SCLC) with disease progression on or after platinum-based chemotherapy received ZEPZELCA 3.2 mg/m² by intravenous infusion every 21 days (one cycle). Patients received a median of 4 cycles of ZEPZELCA (range 1 to 24 cycles). The trial excluded patients with central nervous system (CNS) involvement, grade ≥3 dyspnea, daily intermittent oxygen requirement, hepatitis or cirrhosis, and immunocompromised patients. Tumor assessments were conducted every 6 weeks for the first 18 weeks and every 9 weeks thereafter. The major efficacy outcome measure was confirmed investigator-assessed overall response rate (ORR). Additional efficacy outcome measures included duration of response (DoR), and an Independent Review Committee (IRC) assessed ORR using Response Evaluation Criteria in Solid Tumors (RECIST v1.1).

A total of 105 patients with SCLC who progressed on or after platinum-based chemotherapy were enrolled. The median age was 60 years (range: 40 to 83) with 65% of patients <65 years and 35% of patients ≥65 years, and 60% were male. The majority (75%) of the patients were White, 1% were Asian, 1% were Black and 23% were not reported. Baseline ECOG performance status was 0 or 1 in 92% of patients, and 92% were former/current smokers. All patients received at least one line of platinum-based chemotherapy (range 1-2 lines), and prior radiotherapy had been administered to 71% of patients. Eight patients (8%) had prior immunotherapy in addition to platinum-based chemotherapy. Sixty patients (57%) had platinum-sensitive SCLC, defined as recurrence or progression ≥90 days after the last dose of platinum-containing therapy (chemotherapy free interval [CTFI] ≥90 days). The remaining 45 patients had platinum-resistant SCLC, defined as recurrence or progression <90 days after the last dose of platinum-containing therapy (CTFI <90 days).

Table 5 summarizes investigator-assessed and independent review committee assessed key efficacy measures in all patients and in platinum-resistant and platinum-sensitive subgroups.

Table 5. Efficacy Results in SCLC Cohort of Study B-005:

^* CI: confidence interval, CTFI: chemotherapy free interval