Shares of Sigilon Therapeutics, Inc. SGTX plunged 25.3% after the company announced that the FDA placed a clinical hold on its phase I/II study evaluating its pipeline candidate SIG-001 in patients with severe or moderately severe hemophilia A.The clinical hold came in place following the clinical stage biotechnology company’s announcement of a serious adverse event (SAE) and a temporary enrollment halt.We note that SIG-001 is the company’s most advanced and investigational therapy in development to prevent bleeding episodes in patients with moderate-severe to severe hemophilia A.Three patients have been dosed with SIG-001 to date. The third patient who received the highest dose of the study drug developed inhibitors to Factor VIII (FVIII), a well-known complication of FVIII therapy.Consequently, the FDA requested additional information or data on factors potentially contributing to the development of inhibitors in this patient, such as family history and immune stimulation from a recent vaccination. The three patients enrolled in this study will continue to be under observation per study protocol.The setback will delay the development of the candidate, which was granted an Orphan Drug designation to treat hemophilia A by the FDA in August 2019 and EMA in November 2020.This apart, the company is developing SIG-009 for patients with Factor VII deficiency and SIG-003 for patients with Hemophilia B.The stock has slumped 86.9% so far this year compared with the industry’s decrease of 8.3%.Image Source: Zacks Investment ResearchOther candidates in the company’s pipeline include SIG-007 (developed for patients with a confirmed diagnosis of Fabry disease), SIG-018 for patients with mucopolysaccharidosis type 2 or MPS-2 and SIG-020 for patients with mucopolysaccharidosis type 6 or MPS-6. The company is also developing SIG-002 for the treatment of type 1 Diabetes in collaboration with Eli Lilly.Treatments approved for hemophilia A include Roche’s RHHBY hemophilia A and Novo Nordisk’s NVO NovoSeven among others.Zacks Rank & Stock to ConsiderSigilon currently carries a Zacks Rank #3 (Hold). A better-ranked stock in the healthcare sector is Zoetis, Inc. ZTS, which carries a Zacks Rank #2 (Buy) at present. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.Zoetis’ earnings estimates have been revised 7 cents upward for 2021 and 9 cents for 2022 over the past 90 days. The stock has rallied 16.5% year to date. Breakout Biotech Stocks with Triple-Digit Profit Potential The biotech sector is projected to surge beyond $775 billion by 2024 as scientists develop treatments for thousands of diseases. They’re also finding ways to edit the human genome to literally erase our vulnerability to these diseases. Zacks has just released Century of Biology: 7 Biotech Stocks to Buy Right Now to help investors profit from 7 stocks poised for outperformance. Our recent biotech recommendations have produced gains of +50%, +83% and +164% in as little as 2 months. The stocks in this report could perform even better.See these 7 breakthrough stocks now>>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 Roche Holding AG (RHHBY): Free Stock Analysis Report Novo Nordisk AS (NVO): Free Stock Analysis Report Zoetis Inc. (ZTS): Free Stock Analysis Report Sigilon Therapeutics, Inc. (SGTX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research