This section highlights FDA-related milestones and regulatory updates for drugs developed by Cocrystal Pharma (COCP).
Over the past two years, Cocrystal Pharma has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
CDI-988 and CC-42344. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
CDI-988 FDA Regulatory Timeline and Events
CDI-988 is a drug developed by Cocrystal Pharma for the following indication: For Pandemic Norovirus and Coronavirus.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- CDI-988
- Announced Date:
- April 30, 2026
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announces that the mechanism of action and clinical advancement of its first oral protease inhibitor CDI-988 were featured today in an oral presentation at the 39th International Conference on Antiviral Research (ICAR 2026) in Prague, Czech Republic.
AI Summary
Cocrystal Pharma, Inc. announced that the mechanism of action and clinical advancement of its first oral protease inhibitor, CDI-988, were featured in an oral presentation today at the 39th International Conference on Antiviral Research (ICAR 2026) in Prague, Czech Republic. Presented by Dr. Lee, CDI-988 is a first-in-class, oral direct-acting antiviral developed using Cocrystal’s proprietary structure‑based drug discovery platform. The presentation described how the compound targets the viral protease to block replication and summarized progress through preclinical and early clinical development.
In preclinical studies, CDI-988 showed favorable gastrointestinal‑targeted pharmacokinetics at the site of norovirus infection and demonstrated potent antiviral activity in GII.4‑infected human enteronoid model systems. Those findings support the drug’s design to act where norovirus replicates and helped explain its mechanism of action. Cocrystal described the data as encouraging for further clinical advancement against norovirus infections.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- April 2, 2026
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc announces that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its oral, direct-acting protease inhibitor, CDI-988, the first oral antiviral candidate being developed for treatment and prophylaxis of norovirus infection.
AI Summary
Cocrystal Pharma announced that the U.S. Food and Drug Administration has granted Fast Track designation to CDI-988, an oral, direct-acting protease inhibitor and the first oral antiviral candidate being developed to both treat and prevent norovirus infection. Fast Track status is meant to speed development and regulatory review for drugs that address serious unmet needs, enabling early and frequent communication with the FDA, rolling review of a New Drug Application, and potential Priority Review at submission.
CDI-988 was designed to block a highly conserved region of norovirus and other 3CL viral proteases. A Phase 1b norovirus challenge study is underway at Emory University to evaluate CDI-988 for prevention and treatment. Cocrystal says the designation supports its structure-based drug discovery approach and moves the company closer to delivering the first therapeutic and preventive medicine for norovirus, which causes hundreds of millions of cases and about $60 billion in global economic impact.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- March 9, 2026
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announces the first subjects have been dosed in a Phase 1b norovirus challenge study (NCT07198139) to evaluate CDI-988 as both a preventive and treatment for norovirus infections
AI Summary
Cocrystal Pharma announced the first subjects have been dosed in a Phase 1b norovirus human challenge study (NCT07198139) to test CDI-988 as both a preventive and a treatment. The randomized, double-blind, placebo-controlled trial at Emory University School of Medicine will enroll up to 40 healthy adults ages 18–49. All participants will be deliberately infected with norovirus GII.2 (Snow Mountain Virus), and this initial cohort is designed to assess the infectivity rate of the challenge inoculum.
CDI-988 is a direct-acting oral antiviral that targets a conserved region of the viral 3CL protease found across known norovirus strains, including GII.2, GII.4 and re-emerging GII.17. It is the first oral antiviral candidate developed specifically for norovirus acute gastroenteritis. There are no approved treatments or vaccines for norovirus, creating a significant unmet need and contributing to an estimated $60 billion annual global economic burden. CDI-988 previously showed favorable safety and tolerability in an earlier Phase 1 study at the doses being tested.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- December 18, 2025
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announces the approval from the Institutional Review Board (IRB) at Emory University School of Medicine to initiate a Phase 1b human challenge study with CDI-988.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- November 14, 2025
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. provides updates on its antiviral product pipeline, upcoming milestones and business activities.
AI Summary
Cocrystal Pharma updated progress on its antiviral pipeline and near-term milestones. The company plans to begin enrolling participants in a Phase 1b norovirus challenge study in Q1 2026 to assess CDI-988, an oral broad‑spectrum protease inhibitor, for both prevention and treatment of norovirus. CDI-988 has shown in vitro activity against multiple norovirus strains and favorable Phase 1 safety and tolerability data to date.
For influenza, oral CC-42344 (a PB2 inhibitor) completed a Phase 2a human challenge study in November 2025 with a favorable safety profile, though efficacy analyses were not reported due to trial conduct issues. An inhaled dry‑powder formulation of CC-42344 showed strong preclinical lung exposure and completed toxicology studies. In October 2025 Cocrystal received a $500,000 NIH SBIR award to advance a novel influenza A/B polymerase program.
On the business side, Cocrystal strengthened its cash position through financings, including $4.7 million gross from a registered direct offering plus potential warrant proceeds and a $1.03 million private placement. The company reported $7.7 million in cash as of September 30, 2025 and will use these resources to continue clinical and preclinical development.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- September 8, 2025
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announces that the Company received a Study May Proceed Letter from the U.S. Food and Drug Administration (FDA) to conduct a Phase 1b challenge study evaluating CDI-988 for the prevention and treatment of norovirus infections.
AI Summary
Cocrystal Pharma, Inc. announced that it has received a Study May Proceed Letter from the U.S. Food and Drug Administration to launch a Phase 1b challenge study of its oral antiviral candidate CDI-988 for the prevention and treatment of norovirus infections. The study is expected to begin by year-end 2025.
Norovirus is the leading cause of acute viral gastroenteritis worldwide, and there are currently no approved vaccines or treatments. CDI-988 is the first novel, oral pan-viral 3CL protease inhibitor designed to block a highly conserved site on viral proteases. This broad-spectrum approach targets major norovirus strains, including GII.4 and GII.17.
Preclinical results demonstrate strong antiviral activity, and an earlier Phase 1 trial showed that CDI-988 is well tolerated with a favorable safety profile. Starting the Phase 1b challenge study marks a key step toward proving its potential efficacy in norovirus-infected patients.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- August 5, 2025
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, announces the presentation of favorable safety and tolerability data from a randomized, double-blinded, placebo-controlled Phase 1 study with its oral, direct-acting pan-viral inhibitor CDI-988 at the 2025 Military Health System Research Symposium (MHSRS), being held August 4-7 in Kissimmee, Florida. Inc
AI Summary
Cocrystal Pharma presented new safety and tolerability data for CDI-988, an oral, direct-acting pan-viral inhibitor, at the 2025 Military Health System Research Symposium in Kissimmee, Florida. In a randomized, double-blinded, placebo-controlled Phase 1 trial, single-ascending and multiple-ascending dose cohorts received CDI-988 at 100 mg to 1,200 mg. All doses were well tolerated, with treatment-emergent adverse events in 28% of CDI-988 subjects versus 40% of placebo in the single-ascending cohorts, and 53% versus 92% in the multiple-ascending cohorts. Headache was the most common side effect. No severe adverse events, clinically relevant ECG changes, or significant laboratory abnormalities were reported.
All participants in the single-ascending cohorts and all but one in the multiple-ascending cohorts completed the study. Based on these favorable results, Cocrystal expects to start a Phase 1b challenge study with CDI-988 in norovirus-infected healthy volunteers later this year.
With no approved treatments or vaccines for norovirus, CDI-988’s broad-spectrum mechanism targeting viral proteases could address a critical unmet need for prevention and therapy.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- July 10, 2025
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc announces that its first-in-class pan-viral protease inhibitor CDI-988 has been selected for an oral presentation at the 9th International Calicivirus Conference being held September 7-11, 2025 in Banff, Alberta, Canada. Sam Lee, PhD, the Company's President and co-CEO, will present "Oral Direct-Acting Antiviral CDI-988 for Norovirus Infection Prevention and Treatment: Mechanism of Action and Phase 1 Study Results" on September 11.
AI Summary
Cocrystal Pharma, Inc. announced that its first-in-class pan-viral protease inhibitor, CDI-988, has been selected for an oral presentation at the 9th International Calicivirus Conference, scheduled for September 7-11, 2025, in Banff, Alberta, Canada. This prestigious event will provide an international platform for discussing advanced treatments for viral infections.
During the conference, Sam Lee, PhD (President and Co-CEO), will present his work titled "Oral Direct-Acting Antiviral CDI-988 for Norovirus Infection Prevention and Treatment: Mechanism of Action and Phase 1 Study Results" on September 11. His presentation will cover critical Phase 1 study results and offer insights into the unique mechanism of action of CDI-988, which targets viral replication at an early stage. This development highlights the company’s innovative approach to norovirus prophylaxis and treatment, addressing a significant unmet medical need worldwide.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- September 26, 2024
- Target Action Date:
- LATE 2024
- Estimated Target Date Range:
- October 1, 2024 - December 31, 2024
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announced that Topline study results are expected in late 2024 or early 2025.
AI Summary
Cocrystal Pharma, Inc. recently announced that dosing has begun in the multiple-ascending dose (MAD) portion of its Phase 1 study with CDI-988, an innovative oral pan-viral protease inhibitor. This drug is designed to combat viral gastroenteritis and COVID-19 by targeting key viral enzymes. The study will assess the safety, tolerability, and pharmacokinetics of CDI-988 in healthy adults. Notably, the company expects to announce topline study results in late 2024 or early 2025, a timeline that could mark an important milestone in the clinical development of a first-in-class antiviral treatment.
The development of CDI-988 is supported by a proprietary structure-based drug discovery platform, and this trial is a critical step forward. The outcome of this study is being closely watched, as it could pave the way for future advances in antiviral therapies against both noroviruses and coronaviruses.
Read Announcement- Drug:
- CDI-988
- Announced Date:
- September 26, 2024
- Indication:
- For Pandemic Norovirus and Coronavirus
Announcement
Cocrystal Pharma, Inc. announces dosing of the first subjects in the multiple-ascending dose (MAD) portion of the Phase 1 study with CDI-988, its potent, broad-spectrum, oral pan-viral protease inhibitor.
AI Summary
Cocrystal Pharma, Inc. announced that the first subjects have been dosed in the multiple-ascending dose (MAD) portion of its Phase 1 study with CDI-988, a potent and broad-spectrum oral pan-viral protease inhibitor. CDI-988 is designed to fight viral gastroenteritis caused by noroviruses and COVID-19 caused by coronaviruses. The study, which is being conducted at a single center in Australia, will assess the safety, tolerability, and pharmacokinetics of the drug in healthy adults. This advancement follows favorable safety outcomes from the single-ascending dose (SAD) part of the trial, where no serious or severe adverse events were observed. Topline results for the MAD study are expected later this year or in early 2025 as researchers continue to determine if CDI-988 could become a groundbreaking option for antiviral therapy.
Read Announcement
CC-42344 FDA Regulatory Events
CC-42344 is a drug developed by Cocrystal Pharma for the following indication: Seasonal and pandemic influenza A.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- CC-42344
- Announced Date:
- December 31, 2024
- Indication:
- Seasonal and pandemic influenza A
Announcement
Cocrystal Pharma, Inc. announces plans to extend enrollment in the Phase 2a human challenge study with its investigational, broad-spectrum, oral influenza PB2 inhibitor CDI-42344 due to unexpectedly low influenza infection among study participants who were challenged with a H3N2 viral strain.
AI Summary
Cocrystal Pharma, Inc. has announced plans to extend enrollment in its Phase 2a human challenge study for the investigational, broad-spectrum oral influenza PB2 inhibitor CDI-42344. This decision comes after the study team observed an unexpectedly low rate of influenza infection among participants exposed to an H3N2 viral strain. Researchers need a higher infection rate to accurately assess the drug’s antiviral effects and determine important clinical endpoints.
Even though the targeted infection levels were not achieved, the study has so far shown a favorable safety and tolerability profile, with no serious adverse events or study-related drug discontinuations noted. The company is now working with its clinical research organization and the United Kingdom’s Medicines and Healthcare Products Regulatory Agency to amend the study protocol. This extension will aim to enroll more subjects and ensure the necessary infection rates to effectively evaluate CDI-42344 as a potential treatment for both pandemic and seasonal influenza.
Read Announcement- Drug:
- CC-42344
- Announced Date:
- June 20, 2024
- Target Action Date:
- H2 2024
- Estimated Target Date Range:
- July 1, 2024 - December 31, 2024
- Indication:
- Seasonal and pandemic influenza A
Announcement
Cocrystal Pharma, Inc. announced that Cocrystal is conducting an influenza A Phase 2a clinical study with orally administered CC-42344 and expects to report topline results in the second half of 2024.
AI Summary
Cocrystal Pharma, Inc. has announced that it is now conducting a Phase 2a clinical study using its oral antiviral candidate, CC-42344, to treat individuals infected with influenza A. The trial will assess the drug's safety, tolerability, antiviral properties, and clinical benefits in those exposed to the virus. The company expects to report topline results in the second half of 2024, which could provide important insights into the potential of CC-42344 as a new treatment option.
CC-42344 is designed to interfere with key processes in the influenza A virus's replication cycle by targeting a highly conserved region in a viral protein. This Phase 2a study aims to build on promising preclinical findings, and if successful, may offer a novel approach to managing both seasonal and pandemic influenza A infections.
Read Announcement
