Overview
Keytruda Qlex is approved by the U.S. Food and Drug Administration (FDA) to treat several forms of bladder cancer, which is the most common type of urothelial cancer. It is approved in combination with enfortumab vedotin (Padcev) for adults with locally advanced or metastatic urothelial carcinoma. It is also approved as a perioperative treatment — both before and after surgery — for adults with muscle-invasive bladder cancer (MIBC) who are not eligible for cisplatin-based chemotherapy. 

Additionally, it may be used alone in adults with locally advanced or metastatic urothelial carcinoma who are ineligible for platinum chemotherapy or whose disease progressed during or after platinum-containing chemotherapy. 

Keytruda Qlex is also approved for treating high-risk, non-muscle invasive bladder cancer (NMIBC) that is Bacillus Calmette-Guérin (BCG)-unresponsive in people who cannot or choose not to undergo cystectomy (bladder removal surgery).

Keytruda Qlex is also known by its drug name, pembrolizumab and berahyaluronidase alfa-pmph.

Keytruda Qlex is a type of immunotherapy. It works by blocking PD-1, a protein on immune cells that helps cancer avoid detection. Blocking PD-1 allows the immune system to attack cancer cells. Berahyaluronidase alfa helps the drug absorb more efficiently under the skin. When combined with enfortumab vedotin, which delivers chemotherapy directly to tumor cells, the two treatments work together to shrink or eliminate cancer before and after surgery.

How do I take it?
Prescribing information states that Keytruda Qlex is given as a subcutaneous (under the skin) injection into the abdomen or thigh by a healthcare provider. It is typically administered once every three or six weeks, depending on the dosing schedule. Depending on the setting, it may be used alone or in combination with enfortumab vedotin. It should be administered exactly as prescribed by a healthcare provider.

Side effects
Common side effects of Keytruda Qlex include fatigue, nausea, musculoskeletal pain (pain in muscles, bones, or joints), rash, diarrhea, decreased appetite, cough, shortness of breath, constipation, abdominal pain, fever, itching, and hypothyroidism (low thyroid hormone levels).

When used in combination with enfortumab vedotin, side effects may also include rash, peripheral neuropathy (nerve damage causing pain or numbness), fatigue, itching, diarrhea, hair loss, weight loss, decreased appetite, dry eyes, nausea, constipation, altered taste, and urinary tract infections.

Rare but serious side effects may include immune-mediated reactions such as pneumonitis (lung inflammation), colitis (intestinal inflammation), hepatitis (liver inflammation), endocrinopathies (hormone gland problems), nephritis (kidney inflammation), severe skin reactions, and rejection of transplanted organs. Severe allergic reactions and complications following stem cell transplant may also occur. The drug may cause harm to an unborn baby and is not recommended during pregnancy.

For more information about this treatment, visit:
Keytruda Qlex (Pembrolizumab and Berahyaluronidase Alfa-Pmph) Injection, for Subcutaneous Use — Merck Sharp & Dohme