US equity futures were mixed before the opening bell on Monday as traders awaited the Federal Reserve's regular meeting to discuss monetary policy.

Dow Jones Industrial Average futures gained 0.2%, S&P 500 futures slipped 0.1%, and Nasdaq futures declined 0.5%.

The policy-setting Federal Open Market Committee is scheduled to start its two-day meeting on Tuesday.

Oil prices were higher, with front-month global benchmark North Sea Brent crude up 1.3% at $72.52 per barrel and US West Texas Intermediate crude 1.4% higher at $68.71 per barrel.

The Empire State Manufacturing Index, released at 8:30 am ET, came in at 11.5 in September after August's negative 4.7 reading, compared with estimates compiled by Bloomberg for negative 4.0.

In other world markets, Japan's Nikkei closed 0.7% lower, Hong Kong's Hang Seng ended 0.3% higher, while the Chinese market was closed for a holiday. Meanwhile, the UK's FTSE 100 was down 0.02% and Germany's DAX index was 0.3% lower in Europe's early afternoon session.

In equities, shares of NuCana (NCNA) were up more than 200% pre-bell after the company said that a combination of NUC-7738 and pembrolizumab led to prolonged progression-free survival in a phase 2 trial for patients with metastatic melanoma.