Pharmacology: Mechanism of Action: Expression of programmed cell death ligand-1 (PD-L1) can be induced by inflammatory signals (e.g., IFN-gamma) and can be expressed on both tumor cells and tumor-associated immune cells in the tumor microenvironment. PD-L1 blocks T-cell function and activation through interaction with PD-1 and CD80 (B7.1). By binding to its receptors, PD-L1 reduces cytotoxic T-cell activity, proliferation, and cytokine production.
Durvalumab is a human immunoglobulin G1 kappa (IgG1κ) monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80 (B7.1). Blockade of PD-L1/PD-1 and PD-L1/CD80 interactions releases the inhibition of immune responses, without inducing antibody dependent cell-mediated cytotoxicity (ADCC).
PD-L1 blockade with durvalumab led to increased T-cell activation
in vitro and decreased tumor size in co-engrafted human tumor and immune cell xenograft mouse models.
Pharmacodynamics: The steady state AUC, Ctrough, and Cmax in patients administered with 1,500 mg every 4 weeks are 6% higher, 19% lower, and 55% higher than those administered with 10 mg/kg every 2 weeks, respectively. Based on the modeling of pharmacokinetic data and exposure relationships for safety, there are no anticipated clinically meaningful differences in efficacy and safety for the doses of 1,500 mg every 4 weeks compared to 10 mg/kg every 2 weeks in patients weighing > 30 kg with NSCLC.
Clinical Studies: Non-Small Cell Lung Cancer (NSCLC):
Neoadjuvant and Adjuvant Treatment of Resectable NSCLC - AEGEAN Study: The efficacy of IMFINZI in combination with neoadjuvant chemotherapy, followed by surgery and continued adjuvant treatment with IMFINZI as a single agent was investigated in AEGEAN (NCT03800134), a randomized, double-blind, placebo-controlled, multicenter trial conducted in 802 patients with previously untreated and resectable squamous or non-squamous NSCLC (Stage IIA to select Stage IIIB [AJCC, 8th edition]). Patients were enrolled regardless of tumor PD-L1 expression. Eligible patients had no prior exposure to immune-mediated therapy, a WHO/ECOG Performance status of 0 or 1, and at least one RECIST 1.1 target lesion.
Patients with active or prior documented autoimmune disease, or use of any immunosuppressive medication within 14 days of the first dose of IMFINZI were ineligible. The population for efficacy analyses was a modified intent-to-treat [mITT] which excluded patients with known EGFR mutations or ALK rearrangements.
Crossover between the study arms was not permitted. Randomization was stratified by disease stage (Stage II vs. Stage III) and by PD-L1 expression (TC < 1% vs. TC ≥ 1%) status. Patients were randomized 1:1 to one of the following treatment arms: Arm 1: Neoadjuvant IMFINZI 1500 mg once every 3 weeks for up to 4 cycles in combination with: Squamous tumor histology: carboplatin AUC 6 and paclitaxel 200 mg/m2 on Day1 of each 3 week cycle, OR cisplatin 75 mg/m2 on Day 1 and gemcitabine 1250 mg/m2 on Day 1 and Day 8 of each 3-week cycle, for 4 cycles; Non-squamous tumor histology: pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 on Day 1 of each 3-week cycle, for 4 cycles OR pemetrexed 500 mg/m2 and carboplatin AUC 5 on Day 1 of each 3-week cycle, for 4 cycles. Followed by adjuvant IMFINZI 1500 mg as a single agent for up to 12 cycles post-surgery.
Arm 2: Neoadjuvant placebo in combination with 4 cycles of chemotherapy (see previously mentioned) prior to surgery. Followed by placebo for up to 12 cycles post-surgery.
All study medications were administered via intravenous infusion. In the event of unfavorable tolerability, patients who met the eligibility criteria were switched from cisplatin to carboplatin therapy at any point during the study. In patients with comorbidities or unable to tolerate cisplatin as per Investigators judgment, carboplatin AUC 5 could be administered from cycle 1. Treatment with IMFINZI or placebo continued until completion of the treatment, disease progression that precluded definitive surgery, inability to complete definitive surgery, disease recurrence in the adjuvant phase, or unacceptable toxicity.
A RECIST 1.1 tumor assessment was performed at baseline, and upon completion of the neoadjuvant period (prior to surgery). Tumor assessments were conducted at 5 weeks postoperatively, prior to the start of adjuvant therapy and every 12 weeks until week 48, every 24 weeks for approximately 4 years, and then every 48 weeks thereafter until disease progression, consent withdrawal, or death.
The trial was not designed to isolate the effect of IMFINZI in each phase (neoadjuvant or adjuvant) of treatment.
The major efficacy outcome measures of the study were pathological complete response (pCR) by blinded central pathology review and event-free survival (EFS) by blinded independent central review (BICR) assessment. Additional efficacy outcome measures were major pathological response (MPR) by blinded central pathology review, DFS by BICR, and OS.
The demographics and baseline disease characteristics were as follows: male (72%); median age 65 years (range: 30 to 88); age ≥ 65 years (52%); WHO/ECOG PS 0 (68%), WHO/ECOG PS 1 (32); White (54%), Asian (41%), Black or African American (0.9%), American Indian or Alaska Native (1.4%), Other Race (2.6%); Not Hispanic or Latino (84%); current or past smokers (86%); squamous histology (49%) and non-squamous histology (51%); Stage II (28%), Stage III (71%); PD-L1 expression status TC ≥ 1% (67%), PD-L1 expression status TC < 1% (33%).
In the mITT population, 78% of patients in Arm 1 completed definitive surgery compared to 77% of patients in Arm 2.
The trial demonstrated statistically significant improvements in EFS and pCR rate (see Table 1 and Figure 1) in the IMFINZI in combination with chemotherapy arm compared to the placebo in combination with chemotherapy arm.
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
At the interim analysis, the trial demonstrated a statistically significant difference in MPR rate (34% vs. 14%; p < 0.0001). At the time of the prespecified interim analyses, overall survival (OS) was not formally tested for statistical significance.
Unresectable Stage III NSCLC - PACIFIC: The efficacy of IMFINZI was evaluated in the PACIFIC study (NCT02125461), a multicenter, randomized, double-blind, placebo-controlled study in patients with unresectable Stage III NSCLC who completed at least 2 cycles of concurrent platinum-based chemotherapy and definitive radiation within 42 days prior to initiation of the study drug and had a WHO performance status of 0 or 1. The study excluded patients who had progressed following concurrent chemoradiation, patients with active or prior documented autoimmune disease within 2 years of initiation of the study or patients with medical conditions that required systemic immunosuppression. Randomization was stratified by sex, age (<65 years vs. ≥ 65 years), and smoking history (smoker vs. non-smoker). Patients were randomized 2:1 to receive IMFINZI 10 mg/kg or placebo intravenously every 2 weeks for up to 12 months or until unacceptable toxicity or confirmed RECIST v1.1-defined progression. Assessment of tumor status was performed every 8 weeks. The major efficacy outcome measures were progression-free survival (PFS) as assessed by a BICR RECIST v1.1, and overall survival (OS). Additional efficacy outcome measures included ORR and DoR assessed by BICR.
A total of 713 patients were randomized: 476 patients to the IMFINZI arm and 237 to the placebo arm. The study population characteristics were: median age of 64 years (range: 23 to 90); 70% male; 69% White and 27% Asian; 16% current smokers, 75% former smokers, and 9% never smokers; 51% WHO performance status of 1; 53% with Stage IIIA and 45% were Stage IIIB; 46% with squamous and 54% with non-squamous histology. All patients received definitive radiotherapy as per protocol, of which 92% received a total radiation dose of 54 Gy to 66 Gy; 99% of patients received concomitant platinum-based chemotherapy (55% cisplatin-based, 42% carboplatin-based chemotherapy, and 2% switched between cisplatin and carboplatin).
At a pre-specified interim analysis for OS based on 299 events (61% of total planned events), the study demonstrated a statistically significant improvement in OS in patients randomized to IMFINZI compared to placebo. The pre-specified interim analysis of PFS based on 371 events (81% of total planned events) demonstrated a statistically significant improvement in PFS in patients randomized to IMFINZI compared to placebo. Table 2 and Figure 2 summarizes the efficacy results for PACIFIC. (See Table 2 and Figure 2.)
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
Metastatic NSCLC - POSEIDON: The efficacy of IMFINZI in combination with tremelimumab and platinum-based chemotherapy in previously untreated metastatic NSCLC patients with no sensitizing epidermal growth factor receptor (EGFR) mutation or anaplastic lymphoma kinase (ALK) genomic tumor aberrations was investigated in POSEIDON, a randomized, multicenter, active-controlled, open-label trial (NCT03164616). Eligible patients had Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1 and must have had no prior chemotherapy or any other systemic therapy for metastatic NSCLC. Choice of platinum-based chemotherapy was at the investigator's discretion, taking into consideration the calculated creatinine clearance. Patients with active and/or untreated brain metastases; a history of active primary immunodeficiency; autoimmune disorders including active or prior documented autoimmune or inflammatory disorders; use of systemic immunosuppressants within 14 days before the first dose of the treatment except physiological dose of systemic corticosteroids were ineligible.
Randomization was stratified by tumor cells (TC) PD-L1 expression (TC ≥ 50% vs. TC < 50%), disease stage (Stage IVA vs. Stage IVB), and histology (non-squamous vs. squamous).
Patients were randomized 1:1:1 to receive IMFINZI in combination with tremelimumab and platinum-based chemotherapy according to the regimens listed as follows, IMFINZI and platinum-based chemotherapy (an unapproved regimen for metastatic NSCLC), or platinum-based chemotherapy. The evaluation of efficacy for metastatic NSCLC relied on comparison between: IMFINZI 1,500 mg with tremelimumab 75 mg (or 1 mg/kg for patients < 30 kg) and platinum-based chemotherapy every 3 weeks for 4 cycles, followed by IMFINZI 1,500 mg every 4 weeks as a single agent. A fifth dose of tremelimumab 75 mg (or 1 mg/kg for patients < 30 kg) was given at Week 16 in combination with IMFINZI dose 6.
Platinum-based chemotherapy every 3 weeks as monotherapy for 4 cycles. Patients could receive an additional 2 cycles (a total of 6 cycles post-randomization), as clinically indicated, at investigator's discretion.
Patients received IMFINZI in combination with tremelimumab with one of the following platinum-based chemotherapy regimens: Non-squamous NSCLC: Pemetrexed 500 mg/m
2 with carboplatin AUC 5-6 or cisplatin 75 mg/m
2 every 3 weeks for 4 cycles.
Squamous NSCLC: Gemcitabine 1,000 or 1,250 mg/m
2 on Days 1 and 8 with cisplatin 75 mg/m
2 or carboplatin AUC 5-6 on Day 1 every 3 weeks for 4 cycles.
Non-squamous and Squamous NSCLC: Nab-paclitaxel 100 mg/m
2 on Days 1, 8, and 15 with carboplatin AUC 5-6 on Day 1 every 3 weeks for 4 cycles.
Tremelimumab was given up to a maximum of 5 doses. IMFINZI and histology-based pemetrexed continued every 4 weeks until disease progression or unacceptable toxicity. Administration of IMFINZI monotherapy was permitted beyond disease progression if the patient was clinically stable and deriving clinical benefit as determined by the investigator. Patients with disease progression during IMFINZI monotherapy were given the option to be retreated with 4 additional cycles of tremelimumab in combination with IMFINZI. Tumor assessments were performed at Week 6, Week 12, and then every 8 weeks thereafter.
The major efficacy outcome measures were progression free survival (PFS) and overall survival (OS) of IMFINZI and tremelimumab in combination with platinum-based chemotherapy compared to platinum-based chemotherapy alone. Additional efficacy outcome measures were overall response rate (ORR) and duration of response (DoR). PFS, ORR, and DoR were assessed using Blinded Independent Central Review (BICR) according to RECIST v1.1.
A total of 675 patients were randomized to receive either IMFINZI with tremelimumab and platinum-based-chemotherapy (n=338) or platinum-based chemotherapy (n=337). The median age was 63 years (range: 27 to 87), 46% of patients age ≥ 65 years, 77% male, 57% White, 34% Asian, 0.3% Native Hawaiian or Other Pacific Islander, 3% American Indian or Alaska Native, 2% Black or African American, 4% Other Race, 79% former or current smoker, 34% ECOG PS 0, and 66% ECOG PS 1. Thirty-six percent had squamous histology, 63% non-squamous histology, 29% PD-L1 expression TC ≥ 50%, 71% PD-L1 expression TC < 50%.
Efficacy results are summarized in Table 3 and Figure 3. (See Table 3 and Figure 3.)
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
Small Cell Lung Cancer (SCLC): Extensive-stage SCLC - CASPIAN: The efficacy of IMFINZI in combination with etoposide and either carboplatin or cisplatin in previously untreated ES-SCLC was investigated in CASPIAN, a randomized, multicenter, active-controlled, open-label trial (NCT03043872). Eligible patients had WHO Performance Status of 0 or 1 and were suitable to receive a platinum-based chemotherapy regimen as first-line treatment for SCLC. Patients with asymptomatic or treated brain metastases were eligible. Choice of platinum agent was at the investigator's discretion, taking into consideration the calculated creatinine clearance. Patients with history of chest radiation therapy; a history of active primary immunodeficiency; autoimmune disorders including paraneoplastic syndrome; active or prior documented autoimmune or inflammatory disorders; use of systemic immunosuppressants within 14 days before the first dose of the treatment except physiological dose of systemic corticosteroids were ineligible.
Randomization was stratified by the planned platinum-based therapy in cycle 1 (carboplatin or cisplatin).
The evaluation of efficacy for ES-SCLC relied on comparison between: IMFINZI 1,500 mg, and investigator's choice of carboplatin (AUC 5 or 6 mg/mL/min) or cisplatin (75-80 mg/m
2) on Day 1 and etoposide (80-100 mg/m
2) intravenously on Days 1, 2, and 3 of each 21-day cycle for 4 cycles, followed by IMFINZI 1,500 mg every 4 weeks until disease progression or unacceptable toxicity; or Investigator's choice of carboplatin (AUC 5 or 6 mg/mL/min) or cisplatin (75-80 mg/m
2) on Day 1 and etoposide (80-100 mg/m
2) intravenously on Days 1, 2, and 3 of each 21-day cycle, up to 6 cycles. After completion of chemotherapy, PCI as administered per investigator discretion.
Administration of IMFINZI as a single agent was permitted beyond disease progression if the patient was clinically stable and deriving clinical benefit as determined by the investigator.
The major efficacy outcome measure was overall survival (OS) of IMFINZI plus chemotherapy vs. chemotherapy alone. Additional efficacy outcome measures were investigator-assessed progression-free survival (PFS) and objective response rate (ORR), per RECIST v1.1.
The study population characteristics were: median age of 63 years (range: 28 to 82); 40% age 65 or older; 70% male; 84% White, 15% Asian, and 0.9% Black; 65% WHO/ECOG PS of 1; and 93% were former/current smokers. Ninety percent of patients had Stage IV disease and 10% had brain metastasis at baseline. A total of 25% of the patients received cisplatin and 74% of the patients received carboplatin. In the chemotherapy alone arm, 57% of the patients received 6 cycles of chemotherapy, and 8% of the patients received PCI.
The OS results are summarized in Table 4 and Figure 4. (See Table 4 and Figure 4.)
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
Investigator-assessed PFS (96% of total planned events) showed a HR of 0.78 (95% CI: 0.65, 0.94), with median PFS of 5.1 months (95% CI: 4.7, 6.2) in the IMFINZI plus chemotherapy arm and 5.4 months (95% CI: 4.8, 6.2) in the chemotherapy alone arm. The investigator-assessed confirmed ORR was 68% (95% CI: 62%, 73%) in the IMFINZI plus chemotherapy arm and 58% (95% CI: 52%, 63%) in the chemotherapy alone arm.
In the exploratory subgroup analyses of OS based on the planned platinum chemotherapy received at cycle 1, the HR was 0.70 (95% CI 0.55, 0.89) in patients who received carboplatin, and the HR was 0.88 (95% CI 0.55, 1.41) in patients who received cisplatin.
Biliary Tract Cancer (BTC): Locally Advanced or Metastatic BTC - TOPAZ-1: The efficacy of IMFINZI in combination with gemcitabine and cisplatin in patients with locally advanced or metastatic BTC was investigated in TOPAZ-1 (NCT03875235), a randomized, double-blind, placebo-controlled, multicenter trial that enrolled 685 patients with histologically confirmed locally advanced unresectable or metastatic BTC who have not previously received systemic therapy. Patients with recurrent disease > 6 months after surgery and/or completion of adjuvant therapy were eligible. Patients had an ECOG Performance status of 0 and 1 and at least one target lesion by RECIST 1.1. Patients with ampullary carcinoma; active or prior documented autoimmune or inflammatory disorders; HIV infection or active infections, including tuberculosis or hepatitis C; current or prior use of immunosuppressive medication within 14 days before the first dose of IMFINZI were ineligible.
Randomization was stratified by disease status (recurrent vs. initially unresectable) and primary tumor location (intrahepatic cholangiocarcinoma [ICCA] vs. extrahepatic cholangiocarcinoma [ECCA] vs. gallbladder cancer [GBC]). Patients were randomized 1:1 to receive: IMFINZI 1,500 mg on Day 1+ gemcitabine 1,000 mg/m
2 and cisplatin 25 mg/m
2 on Days 1 and 8 of each 21-day cycle up to 8 cycles, followed by IMFINZI 1,500 mg every 4 weeks; or Placebo on Day 1+ gemcitabine 1,000 mg/m
2 and cisplatin 25 mg/m
2 on Days 1 and 8 of each 21-day cycle up to 8 cycles, followed by placebo every 4 weeks.
Treatment with IMFINZI or placebo continued until disease progression, or unacceptable toxicity. Treatment beyond disease progression was permitted if the patient was clinically stable and deriving clinical benefit as determined by the investigator.
The major efficacy outcome measure was overall survival (OS). Additional efficacy outcome measures were investigator-assessed progression-free survival (PFS), objective response rate (ORR) and duration of response (DoR). Tumor assessments were conducted every 6 weeks for the first 24 weeks after the date of randomization, and then every 8 weeks until confirmed objective disease progression.
The study population characteristics were: 50% male, median age of 64 years (range 20-85), 47% age 65 or older; 56% Asian, 37% White, 2% Black or African American, 0.1% American Indian or Alaskan Native, and 4% other; 51% had an ECOG PS of 1; primary tumor location was ICCA 56%, ECCA 18% and GBC 25%; 20% of patients had recurrent disease; 86% of patients had metastatic and 14% had locally advanced disease.
At a pre-specified interim analysis, the trial demonstrated a statistically significant improvement in OS and PFS in patients randomized to IMFINZI in combination with chemotherapy compared to placebo in combination with chemotherapy. Table 5 summarizes the efficacy results for TOPAZ-1. (See Table 5.)
Click on icon to see table/diagram/image
The investigator-assessed ORR was 27% (95% CI: 22% - 32%) in the IMFINZI plus chemotherapy arm and 19% (95% CI: 15%-23%) in the chemotherapy alone arm. (See Figure 5.)
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Hepatocellular Carcinoma (HCC):
Unresectable HCC - HIMALAYA: The efficacy of IMFINZI in combination with tremelimumab was evaluated in the HIMALAYA study (NCT03298451), a randomized (1:1:1), open-label, multicenter study in patients with confirmed uHCC who had not received prior systemic treatment for HCC. Patients were randomized to one of two investigational arms (IMFINZI plus trememlimumab or IMFINZI) or sorafenib. Study treatment consisted of IMFINZI 1,500 mg in combination with tremelimumab as a one-time single intravenous infusion of 300 mg on the same day, followed by IMFINZI every 4 weeks; IMFINZI 1,500 mg every 4 weeks; or sorafenib 400 mg given orally twice daily, until disease progression or unacceptable toxicity. The efficacy assessment of IMFINZI is based on patients randomized to the IMFINZI plus tremelimumab arm versus the sorafenib arm. Randomization was stratified by macrovascular invasion (MVI) (yes or no), etiology of liver disease (hepatitis B virus vs. hepatitis C virus vs. others) and ECOG performance status (0 vs. 1).
The study enrolled patients with BCLC Stage C or B (not eligible for locoregional therapy). The study excluded patients with co-infection of viral hepatitis B and hepatitis C; active or prior documented gastrointestinal (GI) bleeding within 12 months; ascites requiring non-pharmacologic intervention within 6 months; hepatic encephalopathy within 12 months before the start of treatment; active or prior documented autoimmune or inflammatory disorders. Esophagogastroduodenoscopy was not mandated prior to enrollment but adequate endoscopic therapy, according to institutional standards, was required for patients with history of esophageal variceal bleeding or those assessed as high risk for esophageal variceal bleeding by the treating physician.
Study treatment was permitted beyond disease progression if the patient was clinically stable and deriving clinical benefit as determined by the investigator.
The major efficacy outcome measure was overall survival (OS) between the IMFINZI plus tremelimumab arm versus the sorafenib arm. Additional efficacy outcomes were investigator-assessed progression-free survival (PFS), objective response rate (ORR) and duration of response (DoR) according to RECIST v1.1. Tumor assessments were conducted every 8 weeks for the first 12 months and then every 12 weeks thereafter.
The baseline demographics of the IMFINZI plus tremelimumab and sorafenib arms were as follows: male (85%), age < 65 years (50%), median age of 65 years (range: 18 to 88 years), White (46%), Asian (49%), Black or African American (2%), Native Hawaiian or other Pacific Islander (0.1%), race Unknown (2%), Hispanic or Latino (5%), Not Hispanic or Latino (94%), ethnicity Unknown (1%), ECOG PS 0 (62%); Child-Pugh Class score A (99%), macrovascular invasion (26%), extrahepatic spread (53%), viral etiology; hepatitis B (31%), hepatitis C (27%), and uninfected (42%).
Efficacy results are presented in Table 6 and Figure 6. (See Table 6 and Figure 6.)
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
Endometrial cancer: Advanced or Recurrent dMMR Endometrial Cancer - DUO-E: IMFINZI was evaluated in combination with carboplatin and paclitaxel in DUO-E (NCT04269200), a randomized, multicenter, double-blind, placebo-controlled trial in patients with advanced or recurrent endometrial cancer. The trial enrolled patients with newly diagnosed Stage III disease (with measurable disease per RECIST v1.1), or newly diagnosed Stage IV disease. The trial also enrolled patients with recurrent disease with a low potential for cure by radiation therapy or surgery. For patients with recurrent disease, prior chemotherapy was allowed only if it was administered in the adjuvant setting and at least 12 months had elapsed from the date of last dose of chemotherapy to the date of relapse. The trial included patients with epithelial endometrial carcinomas of all histologies, including carcinosarcomas. Patients with endometrial sarcoma were excluded, and patients who had active autoimmune disease or a medical condition that required immunosuppression were ineligible.
Randomization was stratified by tumor mismatch repair (MMR) status (proficient or deficient), disease status (recurrent or newly diagnosed), and geographic region (Asia or rest of the world). MMR status was assessed using an immunohistochemistry tumor tissue test.
Patients were randomized (1:1:1) to one of the following treatment arms: IMFINZI 1,120 mg in combination with carboplatin and paclitaxel every 3 weeks for a maximum of 6 cycles. Following completion of chemotherapy treatment, patients received IMFINZI 1,500 mg every 4 weeks as maintenance treatment until disease progression.
Placebo in combination with carboplatin and paclitaxel every 3 weeks for a maximum of 6 cycles. Following completion of chemotherapy treatment, patients received placebo every 4 weeks as maintenance treatment until disease progression.
An additional investigational combination regimen.
Treatment was continued until Response Evaluation Criteria in Solid Tumors (RECIST) v1.1-defined progression of disease or unacceptable toxicity. Assessment of tumor status was performed every 9 weeks for the first 18 weeks and every 12 weeks thereafter.
The major efficacy outcome measure was progression-free survival (PFS), determined by investigator assessment using RECIST 1.1. Additional efficacy outcome measures included overall response rate (ORR), duration of response (DOR) and overall survival (OS).
Among 95 patients with dMMR tumor, the baseline characteristics were median age of 63 years (range: 34 to 85); 47% age 65 or older; 62% White, 31% Asian, 2% Black or African American; 7% Hispanic or Latino, 1% American Indian or Alaska Native, and 4% other or not reported; ECOG PS of 0 (55%) or 1 (45%); 48% newly diagnosed (11% Stage III and 38% Stage IV) and 52% recurrent disease. The histologic subtypes were endometrioid (78%), mixed epithelial (6%), carcinosarcoma (5%), serous (4%), undifferentiated (1%), and other (5%).
While a statistically significant improvement in PFS was observed in the overall population for IMFINZI with carboplatin and paclitaxel compared to carboplatin and paclitaxel alone, based on an exploratory analysis by MMR status, the PFS improvement in the overall population was primarily attributed to patients with dMMR tumors.
Efficacy results for DUO-E are summarized in Table 7 and Figure 7 for patients with dMMR tumors. OS data in this subpopulation at the time of PFS analysis were immature with 26% of patients who died. (See Table 7 and Figure 7.)
Click on icon to see table/diagram/image
Click on icon to see table/diagram/image
Pharmacokinetics: The pharmacokinetics of durvalumab as a single agent was studied in patients with doses ranging from 0.1 mg/kg (0.01 times the approved recommended dosage) to 20 mg/kg (2 times the approved recommended dosage) administered once every two, three, or four weeks.
PK exposure increased more than dose-proportionally at doses < 3 mg/kg (0.3 times the approved recommended dosage) and dose proportionally at doses ≥ 3 mg/kg every 2 weeks. Steady state was achieved at approximately 16 weeks.
The pharmacokinetics of durvalumab is similar when assessed as a single agent, when in combination with chemotherapy, when in combination with tremelimumab and when in combination with tremelimumab and platinum-based chemotherapy.
Distribution: The geometric mean (% coefficient of variation [CV%]) steady state volume of distribution (Vss) was 5.4 (13.1%) L.
Elimination: Durvalumab clearance decreases over time, with a mean maximal reduction (CV%) from baseline values of approximately 23% (57%) resulting in a geometric mean (CV%) steady state clearance (CLss) of 8mL/h (39%) at day 365; the decrease in CLss is not considered clinically relevant. The geometric mean (CV%) terminal half-life, based on baseline CL was approximately 21 (26%) days.
Specific Populations: There were no clinically significant differences in the pharmacokinetics of durvalumab based on body weight (31 to 175 kg), age (18 to 96 years), sex, race (White, Black, Asian, Native Hawaiian, Pacific Islander, or Native American), albumin levels (4 to 57 g/L), lactate dehydrogenase levels (18 to 15,800 U/L), soluble PD-L1 (67 to 3,470 pg/mL), tumor type (NSCLC, SCLC, BTC and HCC), mild or moderate renal impairment (CLcr 30 to 89 mL/min), and mild or moderate hepatic impairment (bilirubin ≤ 3xULN and any AST). The effect of severe renal impairment (CLcr 15 to 29 mL/min) or severe hepatic impairment (bilirubin > 3x ULN and any AST) on the pharmacokinetics of durvalumab is unknown.
Immunogenicity: The observed incidence of anti-drug antibodies (ADA) is highly dependent on the sensitivity and specificity of the assay. Differences in assay methods preclude meaningful comparison of the incidence of ADAs in the studies described as follows with the incidence of ADAs in other studies including those of IMFINZI.
During the 10 to 48 week treatment period across PACIFIC, CASPIAN, TOPAZ-1, HIMALAYA, POSEIDON, DUO-E, AEGEAN and other clinical trials, in patients who received IMFINZI at dosages of 1,500 mg every 4 weeks, 10 mg/kg every 2 weeks, 20 mg/kg every 4 weeks as a single agent or 1,120 mg every 3 weeks, or 1,500 mg every 3 weeks in the combination therapies, 3.2% (151/4668) of evaluable patients tested positive for anti-durvalumab antibodies, and 19.2% (29/151) of ADA positive patients had neutralizing antibodies against durvalumab. There were no identified clinically significant effects of ADAs on durvalumab pharmacokinetics or safety; however, the effect of these ADAs on the effectiveness of IMFINZI is unknown.
Toxicology: Nonclinical Toxicology: Carcinogenesis, Mutagenesis, Impairment of Fertility: The carcinogenic and genotoxic potential of durvalumab have not been evaluated.
Animal fertility studies have not been conducted with durvalumab. In repeat-dose toxicology studies with durvalumab in sexually mature cynomolgus monkeys of up to 3 months duration, there were no notable effects on the male and female reproductive organs.
Animal Toxicology and/or Pharmacology: In animal models, inhibition of PD-L1/PD-1 signaling increased the severity of some infections and enhanced inflammatory responses.
Mycobacterium tuberculosis-infected PD-1 knockout mice exhibit markedly decreased survival compared with wild-type controls, which correlated with increased bacterial proliferation and inflammatory responses in these animals. PD-1 blockade using a primate anti-PD-1 antibody was also shown to exacerbate
M. tuberculosis infection in rhesus macaques. PD-L1 and PD-1 knockout mice
and mice receiving PD-L1 blocking antibody have also shown decreased survival following infection with lymphocytic choriomeningitis virus.