ASX healthcare stock Paradigm Biopharmaceuticals Ltd (ASX: PAR) has been on a strong run in the past month, soaring 160%.

But the drug development company has requested a pause in the trading of its shares before the open on Thursday.

Before the halt, Paradigm shares finished the session on Wednesday at 58 cents. Let's take a closer look.

ASX healthcare stock on ice

Paradigm requested its shares be put on ice starting Thursday, saying that it intends to update the market on a capital raising in the coming days.

The pause in trading is expected to remain in place until next Monday, December 9, but trading will resume earlier if the ASX healthcare stock provides an update beforehand.

While the specifics are still under wraps, the news comes at an important time in the biotech company's history.

Investors have flooded into Paradigm shares in recent weeks, with prices exploding on optimism surrounding its flagship drug candidate, Zilosul.

The injectable solution contains an ingredient known as 'pentosan polysulfate sodium (iPPS)', and is being developed as a potential treatment for knee osteoarthritis (OA).

This is also a condition with an estimated $3 billion market in the United States alone, according to Bell Potter.

What's driving Paradigm's meteoric rise?

A few catalysts have fueled the recent rally in the ASX healthcare stock. They all centre around the Zilosul label.

Last week, the company confirmed it had not received feedback from the US Food and Drug Administration (FDA) regarding its revised Phase 3 clinical trial protocol for Zilosul.

According to my colleague James, investors interpreted this silence as a positive signal that the FDA might greenlight the trial.

"The next few weeks should be very interesting for this biotech stock", he also said. Too right.

Bell Potter was also bullish on the news, describing it as "significant."

Analysts say the risk of clinical trial failure is reduced, after Paradigm opened an investigational new drug (IND) application in the US.

It has a buy rating and price target of 80 cents on the ASX healthcare stock, 38% upside from Paradigm's current share price.

Meanwhile, Paradigm is also awaiting a response from Australia's Therapeutic Goods Administration (TGA) on its 'Determination Application'.

If approved, this could pave the way for the approval of Zilosul in Australia.

Foolish takeout

This ASX healthcare stock is on ice today after the company requested a trading halt. The company intends to update the market on a capital raising in the coming days.

Zooming out, Paradigm shares are now up 47% in the past year. They closed at 52-week lows of 17.5 cents apiece on September 25.