- Medical Updates

The FDA ( U.S. Food and Drug Administration ) has accepted and granted priority review for a new supplemental Biologics License Application ( sBLA ) for Keytruda ( Pembrolizumab ), an anti-PD-1 therapy.
The application seeks approval of Keytruda monotherapy 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.

This application for Keytruda is based on results from the phase 2 KEYNOTE-057 trial.
Data from this trial were first presented at the European Society for Medical Oncology 2018 Congress.

KEYNOTE-057 is a phase 2, multicenter, open-label, single-arm trial in 102 patients with BCG-unresponsive, high-risk, non-muscle invasive bladder cancer with carcinoma in-situ with or without papillary tumors who were ineligible for or had elected not to undergo cystectomy ( Cohort A ).
In this study, BCG-unresponsive high risk NMIBC is 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.
Patients received Pembrolizumab 200 mg every three weeks until unacceptable toxicity, persistent or recurrent high-risk NMIBC or progressive disease.
Assessment of tumor status was performed every 12 weeks, and patients without disease progression could be treated for up to 24 months.
The major efficacy outcome measures were complete response ( as defined by negative results for cystoscopy [ with transurethral resection of bladder tumor ( TURBT ) / biopsies as applicable ], urine cytology, and computed tomography urography [ CTU ] imaging ) and duration of response.

Pembrolizumab is an anti-PD-1 therapy that works by increasing the ability of the body’s immune system to help detect and fight tumor cells.
Pembrolizumab is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Bladder cancer begins when cells in the urinary bladder start to grow uncontrollably. As more cancer cells develop, they can form a tumor and spread to other areas of the body.
Bladder cancers are described based on how far they have invaded into the wall of the bladder. NMIBC occurs when the cancer has not grown into the main muscle layer of the bladder.
It is estimated that more than 80,000 new cases of bladder cancer will be diagnosed in 2019 in the United States.
Approximately 75% of patients with bladder cancer are diagnosed with non-muscle invasive bladder cancer ( NMIBC ).
For high-risk NMIBC patients who are BCG-unresponsive with persistent or recurrent disease, treatment guidelines recommend radical cystectomy, a surgery to remove the entire bladder that often requires removal of other surrounding organs and tissues. In men, removal of the prostate is common, and in women, surgeons may also remove the uterus, fallopian tubes, ovaries and cervix, and occasionally a portion of the vagina. ( Xagena )

Source: Merck, 2019