The market may be heading lower today but that hasn't stopped two ASX 200 pharmaceutical shares from charging higher.

Let's find out what big news out of the United States is giving them a big boost today. Here's what you need to know:

Neuren Pharmaceuticals Ltd (ASX: NEU)

The Neuren Pharmaceuticals share price is up 4% to $13.62.

This morning, the pharmaceuticals company revealed that the US Food and Drug Administration (FDA) has granted Fast Track designation for NNZ-2591 for the treatment of Pitt Hopkins syndrome (PTHS).

PTHS is a neurodevelopmental condition caused by the loss of one copy or a mutation of the TCF4 gene on chromosome 18. The incidence of PTHS has been estimated at between 1 in 34,000 and 1 in 41,000 people.

The ASX 200 pharmaceutical share notes that US FDA Fast Track designation is designed to facilitate the development and expedite the review of drugs to treat serious conditions. The company points out that there are currently no treatments approved to treat PTHS.

The good news for sufferers of PTHS is that in Neuren's Phase 2 clinical trial of NNZ-2591 in children with PTHS, 82% of participants showed improvement. This includes communication, social interaction, cognition and motor abilities.

Clarity Pharmaceuticals Ltd (ASX: CU6)

The Clarity Pharmaceuticals share price is up 2.5% to $3.47.

Investors have been buying the ASX 200 pharmaceutical company's shares this morning after it was given a boost from the US FDA as well.

The regulator has granted Fast Track Designation for 67Cu-SAR-bisPSMA. This is for the treatment of adult patients with prostate-specific membrane antigen (PSMA)-positive metastatic castration-resistant prostate cancer (mCRPC) who have been previously treated with androgen receptor pathway inhibition (ARPI).

Management notes that this milestone builds on Clarity's earlier receipt of two Fast Track Designations for the diagnostic 64Cu-SAR-bisPSMA in patients with suspected metastasis of prostate cancer who are candidates for initial definitive therapy, as well as patients with biochemical recurrence (BCR) of prostate cancer following definitive therapy, with two Phase III registration trials underway.

The company's executive chair, Dr Alan Taylor, was pleased with the news. He commented:

Receiving 3 FTDs for the one molecule, SAR-bisPSMA, within the last 6 months is an incredible achievement for Clarity, highlighting how impressive our science and development are, the significance of the diagnostic and therapeutic data so far, and the high unmet need for better therapies and diagnostics in prostate cancer.