A One-Minute Subcutaneous Keytruda Wins Japan's Approval

MHLW Approval for All Indications

Japan's Ministry of Health, Labor and Welfare has approved pembrolizumab and berahyaluronidase alfa-pmph (Keytruda Qlex) for subcutaneous administration across all indications approved in Japan for intravenous pembrolizumab, according to Merck. The subcutaneous formulation, which will be marketed in Japan under the planned trademark Keyject, can be administered by a health care provider in as little as 1 minute every 3 weeks.

Marketed in Japan under the planned trademark Keyject and known globally as Keytruda Qlex, the product combines pembrolizumab with berahyaluronidase alfa, an enzyme that enables rapid dispersion under the skin. The approval covers every indication already held by intravenous Keytruda in Japan, making it the first and only subcutaneous immune checkpoint inhibitor available in the country.

One Minute vs 30 Minutes

The treatment cuts the 30-minute infusion time of traditional Keytruda down to one minute every three weeks or two minutes every six weeks, depending on the regimen. Keytruda Qlex is the first and only subcutaneous immune checkpoint inhibitor in Japan that can be administered by a healthcare provider in as little as one minute.

Japan's health ministry cleared subcutaneous Keytruda, the drug injected under the skin rather than dripped through an IV, sold there under the name Keyject, for every indication the intravenous version is already approved for in that market.

Based on Single Lung Cancer Trial

Merck said on 21 September 2026 that Japan's Ministry of Health, Labour and Welfare approved Keytruda Qlex for subcutaneous use across every indication Keytruda holds in Japan. It will be sold as Keyject, given in one minute every three weeks or two minutes every six weeks.

Merck's Keytruda Qlex approved in Japan for subcutaneous use across all Keytruda indications, first subcutaneous immune-checkpoint inhibitor in Japan, can be given in as little as one minute and showed comparable exposure and response to IV pembrolizumab in a phase-3 trial. Merck moved every Japanese Keytruda indication to a one-minute injection on a single lung cancer trial, using pharmacokinetic bridging.

Global Rollout Context

The approval expands the global availability of subcutaneous pembrolizumab. The US Food and Drug Administration approved Keytruda Qlex in September 2025 for adults across most solid tumor indications, and the European Commission approved the subcutaneous formulation, known as Keytruda SC in Europe, in November 2025.

Beyond Europe, Japan's MHLW signed off on Keytruda Qlex for all indications where Keytruda is approved. This approval expands the market for Keytruda's more convenient dosing in a major oncology market and follows prior approvals in the US and EU.

What Berahyaluronidase Does

The product combines pembrolizumab with berahyaluronidase alfa, an enzyme that enables rapid dispersion under the skin. Hyaluronidase temporarily degrades hyaluronan in subcutaneous tissue, allowing large-volume antibody delivery that would otherwise require IV.

Why Subcutaneous Matters for Health Systems

Japan's oncology infusion capacity is constrained, with aging population and nursing shortages. One-minute administration frees chair time, reduces pharmacy compounding and allows administration in community clinics rather than hospital infusion centers. For patients, it reduces half-day hospital visits to minutes.

Merck's One-Minute Keytruda Is a Defense of the Stock's Dividend Engine, as Keytruda faces biosimilar pressure after 2028 patent expiry. Subcutaneous formulation extends lifecycle, improves adherence and maintains market share versus IV biosimilars.

Safety and Exposure Equivalence

The phase 3 trial showed comparable exposure and response to IV pembrolizumab, supporting extrapolation to all indications. Local injection site reactions replace infusion reactions, with similar immune-related adverse event profile. No new safety signals reported in Japan filing.

Working Source Links:

Japan Approves a One-Minute Version of the World's Top Cancer Drug - https://www.chemicalsblog.com/en/blog/japan-approves-a-one-minute-version-of-the-worlds-top-cancer-drug

Merck's KEYTRUDA QLEX Approved in Japan for Subcutaneous Administration for All KEYTRUDA Indications - BusinessWire - https://www.businesswire.com/news/home/20260921161118/en/Mercks-KEYTRUDA-QLEX-pembrolizumab-and-berahyaluronidase-alfa-pmph-Approved-in-Japan-for-Subcutaneous-Administration-for-All-KEYTRUDA-pembrolizumab-Indications-Approved-in-Japan

Japan Approves Merck's Subcutaneous Keytruda for All Indications - https://wiseek.ai/ticker/mrk/news/japan-approves- [STRIPPED 115 bytes]

Regulatory tracker: J&J, Ono, LIB Therapeutics gain approvals - Japan MHLW approves Keytruda QLEX - https://www.fiercepharma.com/pharma/fierce-pharma-regulatory-tracker-2026-h2

Merck's KEYTRUDA QLEX Approved in Japan for Subcutaneous Use - https://www.pharmajournalist.com/mercks-keytruda-qlex-approved-in-japan-for-subcutaneous-use/