Regeneron's Fianlimab Trial Fails to Meet Key Goals
Written by Emily J. Thompson, Senior Investment Analyst
Updated: May 16 2026
0mins
Source: stocktwits
- Trial Results: Regeneron's pivotal late-stage melanoma trial for its experimental drug fianlimab, combined with Libtayo, failed to meet its primary endpoint, as the fianlimab arm showed numerical improvement in progression-free survival but lacked statistical significance, leading to a slight decline in stock price during after-hours trading.
- Survival Data: In the high-dose arm, patients had a median progression-free survival of 11.5 months compared to 6.4 months for those on Keytruda alone, indicating a potential benefit but failing to meet clinical trial statistical requirements, highlighting challenges in market competition.
- Market Reaction: Despite 22 out of 29 analysts rating Regeneron stock as 'Buy' or higher, retail sentiment on Stocktwits remained bearish, reflecting concerns about the company's future performance, especially with the investigational status of the drug.
- Future Outlook: Regeneron is continuing a separate late-stage trial comparing the same combination against Bristol Myers Squibb’s Opdualag; although this trial's results are disappointing, the company is striving to establish a foothold in the rapidly growing melanoma immunotherapy market, with full results to be presented at an upcoming medical meeting.
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Analyst Views on REGN
Wall Street analysts forecast REGN stock price to rise
22 Analyst Rating
16 Buy
6 Hold
0 Sell
Moderate Buy
Current: 621.520
Low
637.00
Averages
808.50
High
1057
Current: 621.520
Low
637.00
Averages
808.50
High
1057
About REGN
Regeneron Pharmaceuticals, Inc. is a fully integrated biotechnology company. The Company invents, develops, manufactures, and commercializes medicines for people with serious diseases. Its products and product candidates in development are designed to help patients with eye diseases, allergic and inflammatory diseases, cancer, cardiovascular and metabolic diseases, neurological diseases, hematologic conditions, infectious diseases, and rare diseases. The Company is accelerating drug development using its proprietary technologies, such as VelociSuite, which produces optimized fully human antibodies and new classes of bispecific antibodies. VelociSuite consists of VelocImmune, VelociGene, VelociMouse, VelociMab, Veloci-Bi, VelociT, VelociHum, and other related technologies. Its marketed products include EYLEA (aflibercept); Dupixent (dupilumab); Libtayo (cemiplimab); Ordspono (odronextamab); Kevzara (sarilumab); Itepekimab; Lynozyfic, and others.
About the author
Emily J. Thompson
Emily J. Thompson, a Chartered Financial Analyst (CFA) with 12 years in investment research, graduated with honors from the Wharton School. Specializing in industrial and technology stocks, she provides in-depth analysis for Intellectia’s earnings and market brief reports.
Regeneron Recommends Maftivimab for Ebola Treatment Trials
- WHO Recommendation: The World Health Organization has recommended prioritizing maftivimab for evaluation as a monotherapy against Bundibugyo ebolavirus, demonstrating broad in vitro activity against multiple Ebola species, potentially offering new treatment options for the current outbreak.
- Emergency Response Coordination: Regeneron is closely coordinating with the U.S. Department of Health and Human Services to prepare for clinical trials in the Democratic Republic of the Congo and Uganda, aiming to respond swiftly to WHO's declaration of the current Ebola outbreak as a public health emergency.
- Historical Contributions: Since 2018, Regeneron has provided Inmazeb to infected individuals under a compassionate use protocol, showcasing its rapid response capabilities during global health crises and solidifying its leadership in infectious disease treatment.
- Donations and Stockpiles: In September 2025, Regeneron donated 500 doses of Inmazeb to the WHO for exclusive use in low-income countries, enhancing global preparedness for Ebola outbreaks while also supplying stockpiles to the U.S. government to bolster national public health emergency readiness.
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- Clinical Trial Recommendation: The WHO's Therapeutics Advisory Group has recommended Regeneron's Maftivimab for prioritized evaluation to address the Bundibugyo ebolavirus outbreak in the DRC and Uganda, highlighting the urgency of the public health crisis.
- Drug Background: Maftivimab is one of three antibodies in Inmazeb, the first FDA-approved treatment for infections caused by the Zaire ebolavirus, showing broad in-vitro activity against multiple Ebola species, although it has not yet been tested in vivo as a monotherapy.
- Patient Usage: Hundreds of patients have already received Maftivimab as part of Inmazeb, which has demonstrated an acceptable safety profile, indicating its potential in combating Ebola outbreaks.
- Company Coordination Efforts: Regeneron is closely coordinating with the U.S. Department of Health and Human Services and WHO as clinical evaluations progress, emphasizing its history of rapidly delivering medical solutions during global health crises, thereby enhancing its reputation in public health.
See More
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- Targeting Specific Virus: Maftivimab is one of the antibodies in the FDA-approved Inmazeb, primarily used for Orthoebolavirus zairen, with WHO recommending its prioritization for Bundibugyo ebolavirus to address the outbreaks in the Democratic Republic of the Congo and Uganda.
- Alternative Treatment Options: WHO also suggests evaluating Gilead Sciences' antiviral remdesivir and its experimental drug obeldesivir for post-exposure prophylaxis, aiming to enhance treatment options and response capabilities against the outbreak.
- Vaccine Usage Restrictions: Merck's Ervebo is the only licensed Ebola vaccine; however, WHO emphasizes that it should only be used in carefully designed research settings to assess its effectiveness against Bundibugyo ebolavirus, ensuring safety and efficacy.
See More
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- False Statement Allegations: A recently filed securities fraud class action claims that Commvault's executives made materially false and misleading statements, failing to disclose critical variables affecting the projected ARR growth for fiscal year 2026, misleading investors significantly.
- Legal Action Possibility: Investors who purchased Commvault shares between April 29, 2025, and January 26, 2026, may participate in the class action lawsuit, seeking legal remedies and corporate governance reforms.
- Significant Stock Impact: Following Regeneron's Phase 3 trial results failing to achieve statistical significance, its stock dropped 9.82% on May 16, 2026, indicating market concerns over the company's future prospects, which could affect its financing capabilities and investor confidence.
See More
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- Shareholder Investigation Initiated: Grabar Law Office is investigating Molina Healthcare, Inc. (NYSE: MOH) for potential breaches of fiduciary duties by executives, allowing shareholders who purchased before February 5, 2025, to seek corporate reforms and fund recovery.
- Securities Fraud Allegations: A federal securities fraud class action against MongoDB, Inc. (NASDAQ: MDB) has survived a motion to dismiss, with the court finding that executives failed to disclose that FY2024 workloads were not materializing as expected, misleading investors and potentially impacting stock prices.
- Environmental Liability Issues: New Era Energy & Digital, Inc. (NASDAQ: NUAI) faces shareholder scrutiny over alleged misrepresentations regarding its Texas Critical Data Centers project and dealings with bankrupt entities, resulting in a 6.9% stock drop on December 12, 2025.
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See More
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- Collaboration Value: Regeneron's $2.32 billion research collaboration with Parabilis includes a $125 million upfront payment and a $75 million future equity investment, demonstrating Regeneron's strong commitment to developing new therapies.
- Innovative Focus: The partnership will concentrate on developing the Helicon peptide platform, aiming to create therapies that can act as standalone treatments or components of antibody-Helicon conjugates targeting previously 'undruggable' intracellular proteins, which holds significant market potential.
- Milestone Payment Structure: Under the agreement, Parabilis is eligible for up to $2.2 billion in milestone payments and tiered royalties, which not only incentivizes collaborative R&D but also provides substantial future revenue potential for Parabilis.
- Market Strategy Integration: Regeneron will manage subsequent development, manufacturing, and global commercialization, combining its antibody expertise with Parabilis' peptide technology to create a new class of therapeutics, further solidifying its leadership position in the biopharmaceutical market.
See More
Regeneron Recommends Maftivimab for Ebola Treatment Trials
- WHO Recommendation: The World Health Organization has recommended prioritizing maftivimab for evaluation as a monotherapy against Bundibugyo ebolavirus, demonstrating broad in vitro activity against multiple Ebola species, potentially offering new treatment options for the current outbreak.
- Emergency Response Coordination: Regeneron is closely coordinating with the U.S. Department of Health and Human Services to prepare for clinical trials in the Democratic Republic of the Congo and Uganda, aiming to respond swiftly to WHO's declaration of the current Ebola outbreak as a public health emergency.
- Historical Contributions: Since 2018, Regeneron has provided Inmazeb to infected individuals under a compassionate use protocol, showcasing its rapid response capabilities during global health crises and solidifying its leadership in infectious disease treatment.
- Donations and Stockpiles: In September 2025, Regeneron donated 500 doses of Inmazeb to the WHO for exclusive use in low-income countries, enhancing global preparedness for Ebola outbreaks while also supplying stockpiles to the U.S. government to bolster national public health emergency readiness.
See More
WHO Recommends Maftivimab for Ebola Treatment Evaluation
- Clinical Trial Recommendation: The WHO's Therapeutics Advisory Group has recommended Regeneron's Maftivimab for prioritized evaluation to address the Bundibugyo ebolavirus outbreak in the DRC and Uganda, highlighting the urgency of the public health crisis.
- Drug Background: Maftivimab is one of three antibodies in Inmazeb, the first FDA-approved treatment for infections caused by the Zaire ebolavirus, showing broad in-vitro activity against multiple Ebola species, although it has not yet been tested in vivo as a monotherapy.
- Patient Usage: Hundreds of patients have already received Maftivimab as part of Inmazeb, which has demonstrated an acceptable safety profile, indicating its potential in combating Ebola outbreaks.
- Company Coordination Efforts: Regeneron is closely coordinating with the U.S. Department of Health and Human Services and WHO as clinical evaluations progress, emphasizing its history of rapidly delivering medical solutions during global health crises, thereby enhancing its reputation in public health.
See More
WHO Approves Evaluation of Regeneron's Antibody for Ebola Treatment
- Antibody Evaluation Approval: The World Health Organization has approved the evaluation of Regeneron Pharmaceuticals' antibody maftivimab as a potential treatment for the current Ebola outbreak, reflecting a proactive stance in combating the epidemic.
- Targeting Specific Virus: Maftivimab is one of the antibodies in the FDA-approved Inmazeb, primarily used for Orthoebolavirus zairen, with WHO recommending its prioritization for Bundibugyo ebolavirus to address the outbreaks in the Democratic Republic of the Congo and Uganda.
- Alternative Treatment Options: WHO also suggests evaluating Gilead Sciences' antiviral remdesivir and its experimental drug obeldesivir for post-exposure prophylaxis, aiming to enhance treatment options and response capabilities against the outbreak.
- Vaccine Usage Restrictions: Merck's Ervebo is the only licensed Ebola vaccine; however, WHO emphasizes that it should only be used in carefully designed research settings to assess its effectiveness against Bundibugyo ebolavirus, ensuring safety and efficacy.
See More
Commvault and Others Under Shareholder Investigation
- Shareholder Investigation Launched: Grabar Law Office is investigating Commvault Systems, Inc. for potential breaches of fiduciary duties by its executives, allowing shareholders who held shares prior to April 29, 2025, to seek corporate reforms and fund recovery.
- False Statement Allegations: A recently filed securities fraud class action claims that Commvault's executives made materially false and misleading statements, failing to disclose critical variables affecting the projected ARR growth for fiscal year 2026, misleading investors significantly.
- Legal Action Possibility: Investors who purchased Commvault shares between April 29, 2025, and January 26, 2026, may participate in the class action lawsuit, seeking legal remedies and corporate governance reforms.
- Significant Stock Impact: Following Regeneron's Phase 3 trial results failing to achieve statistical significance, its stock dropped 9.82% on May 16, 2026, indicating market concerns over the company's future prospects, which could affect its financing capabilities and investor confidence.
See More
Multiple Companies Under Shareholder Investigation
- Shareholder Investigation Initiated: Grabar Law Office is investigating Molina Healthcare, Inc. (NYSE: MOH) for potential breaches of fiduciary duties by executives, allowing shareholders who purchased before February 5, 2025, to seek corporate reforms and fund recovery.
- Securities Fraud Allegations: A federal securities fraud class action against MongoDB, Inc. (NASDAQ: MDB) has survived a motion to dismiss, with the court finding that executives failed to disclose that FY2024 workloads were not materializing as expected, misleading investors and potentially impacting stock prices.
- Environmental Liability Issues: New Era Energy & Digital, Inc. (NASDAQ: NUAI) faces shareholder scrutiny over alleged misrepresentations regarding its Texas Critical Data Centers project and dealings with bankrupt entities, resulting in a 6.9% stock drop on December 12, 2025.
- Clinical Trial Failure: Regeneron Pharmaceuticals, Inc. (NASDAQ: REGN) reported that its Phase 3 trial results did not achieve statistical significance, leading to a 9.82% drop in stock price on May 16, 2026, highlighting challenges in its drug development efforts.
See More
Regeneron Enters $2.32 Billion Collaboration with Parabilis for Undruggable Proteins
- Collaboration Value: Regeneron's $2.32 billion research collaboration with Parabilis includes a $125 million upfront payment and a $75 million future equity investment, demonstrating Regeneron's strong commitment to developing new therapies.
- Innovative Focus: The partnership will concentrate on developing the Helicon peptide platform, aiming to create therapies that can act as standalone treatments or components of antibody-Helicon conjugates targeting previously 'undruggable' intracellular proteins, which holds significant market potential.
- Milestone Payment Structure: Under the agreement, Parabilis is eligible for up to $2.2 billion in milestone payments and tiered royalties, which not only incentivizes collaborative R&D but also provides substantial future revenue potential for Parabilis.
- Market Strategy Integration: Regeneron will manage subsequent development, manufacturing, and global commercialization, combining its antibody expertise with Parabilis' peptide technology to create a new class of therapeutics, further solidifying its leadership position in the biopharmaceutical market.
See More
