Replimune (NASDAQ: REPL) more than doubled on Friday, closing up roughly 128% into the low $12s from about $5.41 — one of the biggest single-day pops on the US market this week, as reported by StocksToTrade, Quartz and GuruFocus.

The trigger: an FDA advisory committee voted 10–3 that Replimune's lead therapy — RP1 (vusolimogene oderparepvec) paired with Bristol Myers Squibb's Opdivo (nivolumab) — shows a clinically meaningful benefit in advanced melanoma, backing data from the single-arm IGNYTE study.

Here's the whiplash. Just days earlier, the FDA's own reviewers put out briefing documents questioning whether a single-arm trial (no control group) could actually prove RP1 works. That warning had cratered REPL about 32% going into the meeting, down to ~$5.41. Friday's 10–3 vote flipped that fear on its head — which is why it's a double, not a bounce. RP1 has been turned down twice before, so the panel siding with the company was a real surprise, not a rubber stamp.

The market read-through

The cleanest exposure outside REPL itself is Bristol Myers Squibb (NYSE: BMY). RP1 is being reviewed as a combination with BMY's Opdivo, so a green light pulls more nivolumab into first-line melanoma treatment — incremental scripts for a drug BMY already sells. It's also a sentiment lift for the beaten-down oncolytic-virus and small-cap immuno-oncology names that trade almost entirely on binary FDA events.

The one thing that flips it back: the panel vote is non-binding, and the FDA's final decision (the PDUFA date) is due August 2. The agency has rejected RP1 before and its own staff just flagged the same efficacy doubts — so a rejection or a delay would unwind most of Friday's move fast. Watch August 2.

As of Sat 1 Aug 2026, ~2:35 PM IST. Sources: StocksToTrade, Quartz, GuruFocus. For discussion and education only — not investment advice. Verify before acting.