Why Is Corbus Pharmaceuticals Stock Up Today?

Corbus Pharmaceuticals stock is up today after the company reported that its daily oral obesity pill CRB-913 produced 5.0% placebo-adjusted weight loss at 12 weeks at the top dose in the CANYON-1 trial. The release crossed MoveSurge's tape at 07:00:04 ET; the stock was 2.004% higher one minute later and 3.786% lower ten minutes later, and at 12:16 ET it traded at $8.31, up 2.40% on the session and 7.41% below its last premarket print before the data.

What the CANYON-1 trial showed

CANYON-1 is a 16-week, double-blind, placebo-controlled Phase 1b study that enrolled 254 adults with obesity and without diabetes at 15 U.S. sites, randomized equally to 20 mg, 40 mg or 60 mg of CRB-913 once daily or placebo. Corbus reported the weight results at week 12 and said none of the doses had plateaued.

All three weight results were statistically significant. Corbus said gastrointestinal side effects were mild or moderate, with no serious or severe cases, and were generally not dose-dependent. Discontinuations because of adverse events ranged from 3.1% to 13.1% across the CRB-913 groups.

Why psychiatric safety comes first for a CB1 drug

CRB-913 blocks the CB1 cannabinoid receptor, the same target as the first generation of obesity drugs in this class, which were abandoned over neuropsychiatric risk. Corbus built CRB-913 to stay out of the brain: in preclinical models it was 15-fold less brain-penetrant than monlunabant and had a brain-to-plasma ratio 50 times lower than rimonabant. In CANYON-1 the company reported no serious or severe psychiatric events and one transient moderate depressive symptom among 188 participants who received the drug. In the earlier Phase 1a study, the obese multiple-dose cohort at 150 mg a day had three mild anxiety events and one mild irritability event.

How the stock traded, measured minute by minute

Corbus stock rose before the data crossed: the last premarket print ahead of the release was $8.98, 10.59% above Friday's close of $8.12. Across the 07:00 to 07:10 ET minutes the price reached $9.91, 10.36% above that print, and fell as low as $5.56, 38.08% below it, on 1,160,408 shares.

The $5.56 low came in the 07:02 minute, the busiest of the 11 with 170,841 shares, and the price closed the 07:04 minute at $8.93. The measured reaction stood at $9.16 after one minute and $8.64 after ten.

CRB-913 timeline

1. December 11, 2025 — Phase 1a results: favorable safety and early signs of weight loss.
2. August 4, 2026 — last patient last visit in CANYON-1.
3. August 6, 2026 — second-quarter results: $117.9 million in cash, cash equivalents and investments at June 30, which Corbus said funds operations into 2028.
4. September 11, 2026 — Corbus scheduled a conference call on the CANYON-1 topline data.
5. September 14, 2026 — topline CANYON-1 results.
6. November 14–17, 2026 — late-breaking presentation of the data at ObesityWeek 2026.
7. First half of 2027 — planned start of a Phase 2 monotherapy study, after talks with the FDA. Corbus is also evaluating a combination with GLP-1 therapy.

Corbus also runs CRB-701, an antibody-drug conjugate for which it expected to begin enrolling the registrational TEMPO-1 study in oropharyngeal cancer in September 2026, so the same cash funds two programs.