FDA Approves TRODELVY® for Advanced Urothelial Cancer

SUMMARY: The FDA on April 13, 2021, granted accelerated approval to TRODELVY® (Sacituzumab Govitecan) for patients with locally advanced or metastatic Urothelial Cancer who previously received a Platinum-containing chemotherapy, and either a Programmed Death receptor-1 (PD-1) or a Programmed Death-Ligand 1 (PD-L1) inhibitor. The American Cancer Society estimates that in the United States for 2021, about 83,730 new cases of bladder cancer will be diagnosed and approximately 17,200 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but it is less common in women. A third of the patients initially present with locally invasive or metastatic disease. Patients with Urothelial Carcinoma are currently treated in the first line setting with a Platinum based chemotherapy regimen, and a checkpoint Inhibitor (PD-1 or PD-L1 inhibitor) in the second line setting. Treatment options for patients who progress after first and second line therapies are limited, with poor outcomes. The response rates with standard chemotherapy in this patient population, is about 10%, with a median Overall Survival (OS) of 7-8 months.

Two new agents approved by the FDA include BALVERSA® (Erdafitinib), a pan-Fibroblast Growth Factor Receptor (FGFR) inhibitor, for patients with locally advanced or metastatic Urothelial Carcinoma with susceptible FGFR3 or FGFR2 genetic alterations, that has progressed during or following Platinum-containing chemotherapy, as well as PADCEV® (Enfortumab Vedotin), an Antibody-Drug Conjugate (ADC) that targets Nectin-4, a cell adhesion molecule, highly expressed in Urothelial Cancers and other solid tumors. These two agents have Objective Response Rates (ORRs) of approximately 40%, and most patients will progress on these therapies. Further, FGFR alterations occur in only 20% of patients with metastatic Urothelial Carcinoma, limiting the use of BALVERSA®. Hence, there is an unmet need for novel therapies.

Trop-2 is a transmembrane glycoprotein and calcium signal transducer. It stimulates cancer-cell growth, and this cell surface receptor is overexpressed in several epithelial cancers including cancers of the Breast, Colon, Lung and Urothelial Cancer, and has limited expression in normal human tissues. TRODELVY® is an Antibody-Drug Conjugate (ADC) in which SN-38, an active metabolite of Irinotecan, a Topoisomerase I inhibitor, is coupled to the humanized Anti-Trophoblast cell-surface antigen 2 (Trop-2) monoclonal antibody (hRS7 IgG1κ), through the cleavable CL2A linker. SN-38 cannot be given directly to patients because of its toxicity and poor solubility. Upon binding to Trop-2, the anti-TROP-2 monoclonal antibody is internalized and delivers SN-38 directly into the tumor cell, making it a suitable transporter for the delivery of cytotoxic drugs. Further, the cleavable linker enables SN-38 to be released both intracellularly into the tumor cells, as well as the tumor microenvironment, thereby allowing for the delivery of therapeutic concentrations of the active drug in bystander cells to which the conjugate has not bound. Thus, TRODELVY®-bound tumor cells are killed by intracellular uptake of SN-38, whereas the adjacent tumor cells are killed by the extracellular release of SN-38.

TRODELVY® in a Phase I/II trial involving patients with advanced epithelial cancers, showed encouraging clinical activity across various solid tumors and was associated with a Objective Response Rate (ORR) of 31% in patients with relapsed or refractory metastatic Urothelial Carcinoma, including a 27% ORR among patients who had received prior checkpoint inhibitor and Platinum based therapy. The TROPHY-U-01 Phase II trial was designed to assess the activity of TRODELVY® and confirm these findings in patients with locally advanced unresectable or metastatic Urothelial Carcinoma. This trial includes 5 patient cohorts, evaluating the role of TRODELVY® in various groups of patients and in combination with various agents including checkpoint inhibitors. The authors in this publication reported the primary results from the full Cohort 1 of the TROPHY-U-01 study in patients with metastatic Urothelial Cancer who progressed after prior Platinum based and checkpoint inhibitor based therapies.

Cohort 1 included 113 patients who had received a median of three prior therapies. Patients received TRODELVY® 10 mg/kg IV, on days 1 and 8 of a 21-day treatment cycle, until disease progression or unacceptable toxicities. The median patient age was 66 years and 66% of patients had visceral metastases. The main efficacy endpoints were Objective Response Rate (ORR) and Duration of Response (DOR), evaluated by Independent Review, using RECIST 1.1 criteria.

At a median follow up of 9.1 months, the ORR was 27.7%, and 77% of patients had decrease in measurable disease. The Complete Response rate was 5.4% and 22.3% had Partial Responses. The median DOR was 7.2 months. The median Progression Free Survival was 5.4 months and Overall Survival was 10.9 months. Important Grade 3 or more treatment related adverse events included, neutropenia, anemia, diarrhea, and febrile neutropenia, with 6% of patients discontinuing treatment due to adverse events because of treatment-related adverse events.

It was concluded that TRODELVY® is an active agent and has notable efficacy, compared with historical controls, in pretreated metastatic Urothelial Cancer, that has progressed on both prior Platinum regimens and checkpoint inhibitors, and has manageable safety profile.

TROPHY-U-01: A Phase II Open-Label Study of Sacituzumab Govitecan in Patients With Metastatic Urothelial Carcinoma Progressing After Platinum-Based Chemotherapy and Checkpoint Inhibitors. Tagawa, ST, Balar AV, Petrylak DP, et al. J Clin Oncol. 2021;39:2474-2485.

PADCEV® (Enfortumab Vedotin-ejfv)

The FDA on July 9, 2021 approved PADCEV®, a Nectin-4-directed antibody and microtubule inhibitor conjugate, for adult patients with locally advanced or metastatic urothelial cancer who

  • have previously received a Programmed Death receptor-1 (PD-1) or Programmed Death-Ligand (PD-L1) inhibitor and Platinum-containing chemotherapy, or
  • are ineligible for Cisplatin-containing chemotherapy and have previously received one or more prior lines of therapy.

PADCEV® is a product of Astellas Pharma US, Inc.

Adjuvant Treatment with OPDIVO® in Muscle-Invasive Urothelial Carcinoma

SUMMARY: The American Cancer Society estimates that in the United States for 2021, about 83,730 new cases of bladder cancer will be diagnosed and approximately 17,200 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but it is less common in women. A third of the patients initially present with locally invasive or metastatic disease. Even though radical cystectomy is considered the standard of care for patients with localized Muscle Invasive Bladder Cancer (MIBC), two large randomized trials and two meta-analysis have shown greater survival benefit with neoadjuvant Cisplatin-based combination chemotherapy for patients with MIBC, compared to surgery alone. However, not all patients with MIBC benefit from neoadjuvant Cisplatin based therapy, with only 25-50% attaining a pathologic response. More than 50% of patients with MIBC or regional lymph node involvement will develop metastatic disease following radical cystectomy. There is presently no clear consensus with regards to the routine use of adjuvant Cisplatin-based chemotherapy. Further, not all patients are eligible for adjuvant or neoadjuvant Cisplatin-based chemotherapy.

OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2. Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response. OPDIVO® has been shown to have antitumor activity in patients with metastatic urothelial carcinoma who had previously received platinum treatment, and is presently approved by the FDA for this patient group.

CheckMate 274 is a multicenter, double-blind, randomized, Phase III trial conducted to evaluate the efficacy and safety of adjuvant OPDIVO®, as compared with placebo, in patients with muscle-invasive urothelial carcinoma following radical surgery (with or without previous neoadjuvant Cisplatin-based combination chemotherapy). A total of 709 patients with muscle-invasive urothelial carcinoma who had undergone radical surgery were randomly assigned in a 1:1 ratio to receive either OPDIVO® 240 mg as a 30-minute IV infusion (N=353) or placebo (N=356), every 2 weeks for up to 1 year. To be eligible, patients must have had radical surgery (R0, with negative surgical margins), with or without neoadjuvant Cisplatin-based chemotherapy. Patients must have had pathological evidence of urothelial carcinoma (originating in the bladder, ureter or renal pelvis) with a high risk of recurrence defined as follows: pathological stage of pT3, pT4a, or pN+ and patients not eligible for or declined adjuvant Cisplatin-based combination chemotherapy, patients who had not received neoadjuvant Cisplatin-based chemotherapy, and pathological stage of ypT2 to ypT4a or ypN+ for patients who received neoadjuvant Cisplatin. Both treatment groups were well balanced and approximately 40% of patients in both treatment groups had PD-L1 expression of 1% or more and 43% of patients had received previous neoadjuvant cisplatin therapy. The two Primary endpoints were Disease Free Survival (DFS) among all the patients, and among patients with a tumor Programmed Death-Ligand 1 (PD-L1) expression level of 1% or more. Secondary endpoints included Survival free from recurrence outside the urothelial tract, Overall Survival and Safety. The median follow up was 20.9 months among patients who received OPDIVO® and 19.5 months among those who received placebo.

The median DFS was 20.8 months in the OPDIVO® group and 10.8 months in the placebo group in the intention-to-treat population, which was nearly double that with placebo. The percentage of patients who were alive and disease-free at 6 months was 74.9% with OPDIVO® and 60.3% with placebo, in the intention-to-treat population (HR for disease recurrence or death=0.70; P<0.001). Among patients with a PD-L1 expression level of 1% or more, the percentage who were alive and disease-free at 6 months was 74.5% with OPDIVO® and 55.7% with placebo, in the Intention-to-Treat Population (HR=0.55; P<0.001). The subgroup analysis showed that there was a higher probability of DFS with OPDIVO® than with placebo, and this benefit was observed regardless of nodal status, PD-L1 status, or use or nonuse of previous neoadjuvant Cisplatin-based chemotherapy.

The median survival free from recurrence outside the urothelial tract, in the intention-to-treat population, was 22.9 months among patients who received OPDIVO® and 13.7 months with placebo. The percentage of patients who were alive and free from recurrence outside the urothelial tract at 6 months was 77% with OPDIVO® and 62.7% with placebo (HR for recurrence outside the urothelial tract or death=0.72). Among those with a PD-L1 expression level of 1% or more, the percentage who were alive and free from recurrence outside the urothelial tract at 6 months was 75.3% and 56.7%, respectively (HR=0.55). Grade 3 or higher toxicities were noted in 17.9% of patients in the OPDIVO® group and 7.2% of patients in the placebo group.

It was concluded that among patients with high risk muscle-invasive urothelial carcinoma who had undergone radical surgery with curative intent, adjuvant treatment with OPDIVO® significantly improved Disease Free Survival, compared to placebo, in both intention-to-treat population and among patients with a PD-L1 expression level of 1% or more.

Adjuvant Nivolumab versus Placebo in Muscle-Invasive Urothelial Carcinoma. Bajorin DF, Witjes JA, Gschwend JE, et al. N Engl J Med 2021;384:2102-2114.

PADCEV® Prolongs Overall Survival in Metastatic Urothelial Carcinoma

SUMMARY: The American Cancer Society estimates that in 2021, approximately 83,730 new cases of Bladder Cancer will be diagnosed and 17,200 patients will die of the disease. Patients with urothelial carcinoma are currently treated in the first line setting with a Platinum based chemotherapy regimen and a checkpoint Inhibitor (PD-1 or PD-L1 inhibitor) in the second line setting. Treatment options for patients who progress after first and second line therapies are limited, with poor outcomes. The response rates with standard chemotherapy in this patient population, is about 10%.

PADCEV® (Enfortumab vedotin-ejfv) is an Antibody-Drug Conjugate (ADC) that targets Nectin-4, a cell adhesion molecule highly expressed in urothelial cancers and other solid tumors. Nectin-4 has been implicated in tumor cell growth and proliferation. Following binding to Nectin-4 on the cell surface, PADCEV® becomes internalized and is processed by lysosomes, with the liberation of its cytotoxic payload, Monomethyl auristatin E, which in turn disrupts microtubule assembly, leading to cell cycle arrest and apoptosis. The FDA in 2019 granted accelerated approval to PADCEV® for adult patients with locally advanced or metastatic urothelial cancer, who have previously received a Programmed Death receptor-1 (PD-1) or Programmed Death-Ligand1 (PD-L1) inhibitor, and a Platinum-containing chemotherapy in the neoadjuvant/adjuvant, locally advanced or metastatic setting. This approval was based on the results from the pivotal Phase II EV-201 study which concluded that treatment with PADCEV® demonstrated a clinically meaningful 44% Objective Response Rate (ORR) in this patient group. EV-301 study was designed to confirm the clinical benefit of PADCEV® as compared with standard chemotherapy, by assessing Overall Survival in patients with advanced urothelial carcinoma, who had previously received treatment.

EV-301 is a global, open-label, randomized, Phase III trial, that evaluated the efficacy of PADCEV®, as compared with chemotherapy, in patients with locally advanced or metastatic urothelial carcinoma, who had previously received treatment with a platinum-based chemotherapy and a PD-1 or PD-L1 inhibitor. A total of 608 patients were randomly assigned 1:1 to receive either PADCEV® 1.25 mg/kg IV on days 1, 8, and 15 of a 28-day cycle (N=301), or investigator choice of chemotherapy (Docetaxel 75 mg/m2 IV, Paclitaxel 175 mg/m2 IV, or Vinflunine 320 mg/m2 IV, administered on day 1 of a 21-day cycle (N=307). Both treatment groups were well balanced. The median patient age was 68 years, about 79% of patients had visceral metastases, and 69% of patients had no response to previous treatment with checkpoint inhibitor. The Primary end point was Overall Survival (OS). Secondary end points included Progression Free Survival (PFS) and Overall Response Rate (ORR) and Safety. At the prespecified interim analysis, the median follow up was 11.1 months.

The median OS was 12.88 months in the PADCEV® group versus 8.97 months in patients treated with chemotherapy (H= 0.70; P=0.001), suggesting a 30% reduction in the risk of death with PADCEV®. The PFS was also longer in the PADCEV® group, and was 5.6 months versus 3.7 months with chemotherapy (HR=0.62; P<0.001). The confirmed ORR was higher in the PADCEV® group than in the chemotherapy group (40.6% versus 17.9%; P<0.001), and a Complete Response was observed in 4.9% of the patients in the PADCEV® group and in 2.7% of the patients in the chemotherapy group. Disease Control Rate was 71.9% and 53.4%, respectively (P<0.001). Treatment-related Adverse Events were similar in the two treatment groups.

The authors concluded that treatment with PADCEV® resulted in significantly longer Overall Survival, Progression Free Survival and a higher Overall Response Rate, than standard chemotherapy, in patients with locally advanced or metastatic urothelial carcinoma, who had previously received Platinum-based treatment and a PD-1 or PD-L1 inhibitor.

Enfortumab Vedotin in Previously Treated Advanced Urothelial Carcinoma. Powles T, Rosenberg JE, Sonpavde GP, et al. N Engl J Med 2021; DOI: 10.1056/NEJMoa2035807

Late Breaking Abstract – ASCO 2020: FDA Approves BAVENCIO® for Maintenance Treatment in Advanced Urothelial Carcinoma

SUMMARY: The FDA on June 30, 2020 approved BAVENCIO® for maintenance treatment of patients with locally advanced or metastatic Urothelial Carcinoma (UC) that has not progressed with first-line platinum-containing chemotherapy. The American Cancer Society estimates that for 2020, about 81,400 new cases of bladder cancer will be diagnosed in the US and about 17,980 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but is less common in women, and the average age at the time of diagnosis is 73. Patients with advanced Urothelial Carcinoma are currently treated in the first line setting with a Platinum based chemotherapy regimen. Progression Free Survival (PFS) and Overall Survival (OS) however are generally short because of resistance to chemotherapy. Treatment options for patients who progress after Platinum based chemotherapy are limited, with poor outcomes. The response rates with standard chemotherapy in this patient population, is about 10%.

BAVENCIO® (Avelumab) is a human, immunoglobulin G1 lambda, PD-L1 targeted monoclonal antibody that binds to PD-L1 and blocks the interaction between PD-L1 and its receptor PD-1. This in turn negates the inhibitory effects of PD-L1 on the immune response by unleashing the immune system and restoring antitumor immune responses. In addition, BAVENCIO® induces Antibody Dependent Cell-mediated Cytotoxicity (ADCC). BAVENCIO® was previously granted an accelerated approval by the FDA in 2017 for the treatment of patients with locally advanced or metastatic Urothelial Carcinoma who have disease progression during or following Platinum-containing chemotherapy.

JAVELIN Bladder 100 study is an international, multicenter, open-label, parallel-arm, randomized Phase III trial, which evaluated BAVENCIO® as maintenance therapy following response or stable disease with first-line Platinum-based chemotherapy, in patients with advanced Urothelial Carcinoma. This study included 700 patients with unresectable locally advanced or metastatic Urothelial Cancer, whose disease did not progress following 4 to 6 cycles of standard Gemcitabine with either Cisplatin or Carboplatin. These patients were randomly assigned 1:1 to receive maintenance BAVENCIO® 10 mg/kg IV every 2 weeks in 4 week cycles plus Best Supportive Care (N=350) or BSC alone (N=350). Best Supportive Care included symptom control and pain management, supportive nutrition, correction of metabolic disorders and antibiotics if indicated. Patients were stratified by best response to first-line chemotherapy (Complete vs Partial Response vs stable disease), and by visceral vs non-visceral disease, when initiating first-line chemotherapy. Across the study population, 51% of patients had tumors that were PD-L1 positive. The Coprimary end points were Overall Survival (OS) in all randomized patients, and in those with PD-L1 positive tumors. Secondary end points included Progression Free Survival (PFS), Objective Response Rate (ORR), and safety. The median follow up was 19.6 months for the BAVENCIO® cohort and 19.2 months for the BSC-alone cohort.

The combination of BAVENCIO® plus BSC significantly prolonged OS, compared with BSC alone, in all randomized patients (HR=0.69; P=0.0005), suggesting a 31% reduction in the risk of death with the addition of  maintenance BAVENCIO®. The median OS was 21.4 months with BAVENCIO® plus BSC compared with 14.3 months with BSC alone. Significantly prolonged OS with BAVENCIO® plus BSC, compared with BSC alone, was also noted among patients with PD-L1 positive tumors, and the median OS was not reached in the BAVENCIO® group versus 17.1 months in the control group (HR=0.56; P=0.0003). The OS benefit with BAVENCIO® was noted across all prespecified subgroups, including those defined by Cisplatin-based or Carboplatin-based chemotherapy, and regardless of whether response or stable disease was reached after first-line induction chemotherapy. Based on blinded Independent Central Review, the median PFS favored the BAVENCIO® group both in the overall randomized population (3.7 months versus 2 months, HR=0.62; P<0.001) as well as in the PD-L1 positive subgroup (HR=0.56). All-grade Adverse Events occurred in 98% of the BAVENCIO® group versus 77.7% of the control group, and grade 3/4 AEs occurred in 47.4% versus 25.2%, respectively.

It was concluded that this study met its primary objective, demonstrating significantly prolonged Overall Survival with first-line maintenance BAVENCIO® plus BSC compared with BSC alone, in all patients with advanced Urothelial Carcinoma, and should therefore be the new first-line standard of care in this patient group.

Maintenance avelumab + best supportive care (BSC) versus BSC alone after platinum-based first-line (1L) chemotherapy in advanced urothelial carcinoma (UC): JAVELIN Bladder 100 phase III interim analysis. Powles T, Park SH, Voog E, et al. J Clin Oncol 38: 2020 (suppl; abstr LBA1)

FDA Approves KEYTRUDA® for BCG-Unresponsive, High-Risk Non-Muscle Invasive Bladder Cancer

SUMMARY: The FDA on January 8, 2020, approved KEYTRUDA® (Pembrolizumab) for the treatment of patients with Bacillus Calmette-Guerin (BCG)-unresponsive, high-risk, Non-Muscle Invasive Bladder Cancer (NMIBC) with Carcinoma In Situ (CIS) with or without papillary tumors, who are ineligible for or have elected not to undergo cystectomy.

The American Cancer Society estimates that for 2020, about 81,400 new cases of bladder cancer will be diagnosed in the US and about 17,980 patients will die of the disease. Bladder cancer is the fourth most common cancer in men, but is less common in women and the average age at the time of diagnosis is 73. Approximately 50% of all bladder cancers are non-invasive or in situ cancers. Patients with high-risk, Non-Muscle Invasive Bladder Cancer that has become unresponsive to BCG treatment, are often given the treatment option of radical cystectomy, which includes removing the entire urinary bladder and a prostatectomy for men or total hysterectomy in women. While highly curative, this surgical procedure carries substantial risk for morbidity and mortality, and can negatively impact patient’s quality of life. Further, a significant proportion of patients are medically ineligible for a radical cystectomy, and even if eligible, refuse surgery and opt for other less effective treatments, which could compromise outcomes.

KEYTRUDA® is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. By doing so, it unleashes the tumor-specific effector T cells, and is thereby able to undo PD-1 pathway-mediated inhibition of the immune response. KEYTRUDA® is presently approved by the FDA for the treatment of patients with locally advanced or metastatic Urothelial carcinoma who are not eligible for Cisplatin-containing chemotherapy or for those with disease progression during or following platinum-containing chemotherapy, based on its durable antitumor activity in this patient group. Upregulation of the PD-1 pathway has been observed in BCG-resistant NMIBC, suggesting that KEYTRUDA® may be of benefit in this group of patients.

This new FDA approval for KEYTRUDA® was based on the KEYNOTE-057 study, which is a multicenter, single-arm trial that enrolled 148 patients with high-risk NMIBC, of whom 96 patients had BCG-unresponsive CIS with or without papillary tumors. BCG-unresponsive high-risk Non-Muscle Invasive Bladder Cancer was defined as persistent disease despite adequate BCG therapy, disease recurrence after an initial tumor-free state following adequate BCG therapy, or T1 disease following a single induction course of BCG. Eligible patients had received adequate BCG therapy and were unable/unwilling to undergo radical cystectomy. All patients had undergone TransUrethral Resection of Bladder Tumor (TURBT) to remove resectable disease. Patients with residual Carcinoma In Situ, not amenable to complete resection were permitted. Patients received KEYTRUDA® 200 mg every 3 weeks until unacceptable toxicity, persistent or recurrent high-risk NMIBC or progressive disease, or up to 24 months of therapy without disease progression. The median age was 73 years and the median number of prior BCG instillations was 12. More than half of patients (56.9%) had a PD-L1 Combined Positive Score (CPS) of less than 10, and most patients in this analysis had refused prior cystectomy. The Primary end point was Complete Response Rate (CRR) as defined by negative results for cystoscopy with TURBT/biopsies as applicable, urine cytology, and CT Urography imaging. Secondary end points included Duration of Response and Safety.

At a median follow up was 28 months the Complete Response Rate was 41% and the median Duration of Response was 16.2 months. Forty-six percent (46%) of responding patients experienced a Complete Response lasting at least 12 months. The most frequent adverse reactions were fatigue, diarrhea, rash, pruritis, musculoskeletal pain, peripheral edema and hypothyroidism.

It was concluded from this study that KEYTRUDA® had encouraging activity in bladder cancer patients, with high-risk, BCG-unresponsive Carcinoma in Situ, with or without papillary tumors. The authors added that this study demonstrates that immune activation with systemically administered treatment can result in local activity in the bladder, as well as long-term durable remissions of cancer.
Keynote 057: Phase II trial of Pembrolizumab (pembro) for patients (pts) with high-risk (HR) nonmuscle invasive bladder cancer (NMIBC) unresponsive to bacillus calmette-guérin (BCG). Balar AV, Kulkarni GS, Uchio EM, et al. J Clin Oncol 37, 2019 (suppl 7S; abstr 350)