Krystal Biotech, Inc. KRYS announced initial clinical data updates on its two inhaled genetic medicine pipeline candidates, KB407 and KB408, which are being developed in early-stage studies for treating rare respiratory diseases.

Shares of the company were down 7.3% on Dec. 12 following the announcement of the news.

KB407 is being developed in a phase I study for the treatment of cystic fibrosis (CF), while KB408 is being developed in a phase I study for treating alpha-1 antitrypsin deficiency (AATD).

The latest clinical updates include molecular data as well as safety and tolerability data for both KB407 and KB408.

Year to date, shares of Krystal Biotech have rallied 39.8% against the industry’s decline of 8.7%.

Image Source: Zacks Investment Research

More on KRYS' Development of KB407

The open-label, phase I CORAL-1 study is evaluating KB407 for treating adult patients with CF. The company recently activated two additional clinical sites for its KB407 phase I CORAL-1 study.

Per the company, the CORAL-1 study is designed to include up to three dose escalation cohorts evaluating either one, two, or four daily administrations of 10⁹ PFU of KB407 via inhalation.

Based on the preclinical data submitted to date by Krystal Biotech, the Cystic Fibrosis Foundation (CFF) Therapeutic Development Network (TDN) Clinical Research Executive Committee has granted conditional sanctioning of the KB407 phase I CORAL-1 study protocol. It is subject to review by the data monitoring committee charter, if required, to match CFF TDN standards.

As of the data cut-off date of Dec 6, 2024, a total of five patients from Cohort 1 and Cohort 2 have been enrolled in the CORAL-1 study. Treatment with KB407 was well tolerated in all patients and no serious adverse events were observed.

KRYS plans to report data from Cohort 3 of the CORAL-1 study in the first half of 2025.

More on KRYS' Development of KB408

The open-label, phase I SERPENTINE-1 study is investigating KB408 for treating adult patients with AATD. In September, Krystal Biotech amended the protocol for its phase I SERPENTINE-1 study on KB408 to include mandatory bronchoscopies in this cohort to measure alpha-1 antitrypsin expression.

Per the company, the SERPENTINE-1 study is designed to include up to three dose escalation cohorts evaluating single administrations of 10⁹, 10¹⁰ and 10¹¹ PFU of KB408 via inhalation.

As of the data cut-off date of Dec 6, 2024, a total of seven patients from Cohort 1 and Cohort 2 have been enrolled in the SERPENTINE-1 study.

Clear evidence of SERPINA1 gene delivery and AAT expression following treatment with KB408 was observed in AATD patients and no serious adverse events were reported.

Additional updates on the SERPENTINE-1 study are expected in 2025.

KRYS' Zacks Rank & Key Picks

Krystal Biotech currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks from the biotech sector are CytomX Therapeutics, Inc. CTMX, Spero Therapeutics, Inc. SPRO and Castle Biosciences, Inc. CSTL, each sporting a Zacks Rank #1 (Strong Buy) at present. You can see the complete list of today’s Zacks #1 Rank stocks here.

In the past 60 days, estimates for CytomX Therapeutics’ 2024 loss per share have narrowed from 29 cents to 5 cents. Loss per share estimates for 2025 have narrowed from 56 cents to 35 cents during the same time. Year to date, shares of CTMX have declined 27.7%.

CTMX’s earnings beat estimates in two of the trailing four quarters while missing the same on the remaining two occasions, the average surprise being 115.70%.

In the past 60 days, estimates for Spero Therapeutics’ 2024 loss per share have narrowed from $1.59 to $1.29. Loss per share estimates for 2025 have narrowed from $1.54 to 79 cents during the same time. Year to date, shares of SPRO have declined 25.2%.

SPRO’s earnings beat estimates in two of the trailing four quarters while missing the same on the remaining two occasions, the average surprise being 94.42%.

In the past 60 days, estimates for Castle Biosciences’ 2024 bottom line have moved from a loss of 58 cents per share to earnings of 34 cents per share. Loss per share estimates for 2025 have narrowed from $2.13 to $1.84 during the same time. Year to date, shares of CSTL have surged 34.9%.

CSTL’s earnings beat estimates in each of the trailing four quarters, the average surprise being 172.72%.

Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report

CytomX Therapeutics, Inc. (CTMX) : Free Stock Analysis Report

Spero Therapeutics, Inc. (SPRO) : Free Stock Analysis Report

Krystal Biotech, Inc. (KRYS) : Free Stock Analysis Report

Castle Biosciences, Inc. (CSTL) : Free Stock Analysis Report

To read this article on Zacks.com click here.

Zacks Investment Research