After raising $175.2 million in an initial public offering this spring, Turning Point Therapeutics has returned to the public market.

The cancer drug developer on Sept. 10 raised $202.5 million in a follow-on offering. Turning Point sold 4.5 million shares of common stock at a price of $45 a share.

CEO Athena Countouriotis told the San Diego Business Journal that the company wanted to capitalize on strong clinical data that was released after the IPO. In addition, some investors who missed the offering wanted in on the action.

“We had a lot of demand that we didn't meet on the IPO,” Countouriotis said.

As evidence of this demand, Turning Point’s stock has shot up 139% since the company’s public debut, the best-performing biotech IPO this year.

While a follow-on offering can provide liquidity, Countouriotis said this wasn’t Turning Point’s aim. She noted that Turning Point reported $250.5 million in cash as of June 30.

Rather, Countouriotis said the cash injection will build out the company’s pipeline.

The San Diego biotech is working on drugs for cancerous tumors that develop treatment resistance. The company’s lead drug candidate, repotrectinib, is undergoing a mid-stage clinical trial, or phase 2.

Earlier this month, analyst Andrew Berens with SVB Leerink said updated repotrectinib data showed even better patient response rates, boding well for Turning Point.

Investors and analysts have said Turning Point’s promise makes the company an acquisition target along the lines of Ignyta, a San Diego cancer drugmaker that Roche bought for $1.7 billion in 2017. But in July Countouriotis told the Business Journal that Turning Point strives to be around long term, not a build-to-buy operation.

The $202.5 million raised — which could rise to $233 million when factoring in a clause that allows underwriters to buy additional shares — is the largest fast follow-on offering in biotech since 2015, according to Turning Point.

The term follow-on offering is reserved for newly public companies that soon return to the public market.

Turning Point was founded in 2013 by Jean Cui, also Turning Point’s chief scientific officer, and her husband, Y. Peter Li.

Cui was the lead inventor of a Pfizer cancer drug called xalkori that falls under the umbrella of kinase inhibitors. She left the pharmaceutical for Turning Point to unleash more advanced kinase inhibitors that overcome cancer resistance.

This article was updated to note that Turning Point's follow-on offering could ultimately raise $233 million.