Keros Therapeutics Presents Additional Clinical Data from Its Rinvatercept Program at the 2026 MDA Clinical & Scientific Conference
Rhea-AI Summary
Keros Therapeutics (Nasdaq: KROS) presented additional Phase 1 clinical data for rinvatercept (KER-065) at the 2026 MDA Clinical & Scientific Conference on March 9, 2026. Findings in healthy volunteers showed tolerability, body composition changes, and proteomic evidence of target engagement guiding development for DMD and ALS.
Key takeaways: generally well-tolerated with no dose-limiting toxicities or serious adverse events; increases in muscle mass and bone mineral density; decreases in fat mass; proteomic signals consistent with activin/myostatin inhibition, anti-fibrotic and anti-inflammatory effects.
Positive
- No dose-limiting toxicities or serious adverse events reported
- Observed increase in muscle mass in Phase 1 healthy volunteers
- Observed decrease in fat mass in Phase 1 healthy volunteers
- Observed increase in bone mineral density in Phase 1
- Proteomic evidence of target engagement and anti-fibrotic signals
Negative
- None.
News Market Reaction – KROS
On the day this news was published, KROS gained 0.44%, reflecting a mild positive market reaction.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
KROS fell 3.5% while peers were mixed to positive: ANAB down 0.17%, but PVLA, BCAX, RIGL and TYRA gained between 0.21% and 2.19%, pointing to a stock-specific move rather than a biotech-wide shift.
Previous Clinical trial Reports
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Sep 08 | Phase 1 data update | Positive | -0.8% | Additional KER-065 Phase 1 data showed sustained bone mineral density improvements. |
| Aug 20 | Orphan Drug status | Positive | -1.8% | FDA granted Orphan Drug designation to KER-065 for Duchenne muscular dystrophy. |
| Jul 17 | Phase 3 trial start | Positive | -0.9% | First patient dosed in Phase 3 RENEW trial of elritercept, triggering a $10M payment. |
| Mar 31 | Phase 1 topline data | Positive | -5.6% | Initial KER-065 Phase 1 topline results met safety and pharmacologic objectives. |
| Jan 15 | Trial halt | Negative | -16.5% | Complete halt of dosing in Phase 2 TROPOS PAH trial due to adverse events. |
Clinical and regulatory milestones have often coincided with negative next-day moves, even on seemingly positive updates, with one major trial halt seeing a sharper selloff.
Recent clinical and regulatory news for Keros has centered on KER-065 and the broader TGF-β platform. On Jan 15, 2025, dosing in the Phase 2 TROPOS trial of cibotercept was fully halted due to safety concerns, leading to a -16.51% move. Subsequent KER-065 Phase 1 data and bone density improvements, plus an FDA Orphan Drug designation for DMD and a Phase 3 elritercept milestone, all produced modest single-day declines. Overall, clinical updates have not translated into sustained upside in prior events.
Historical Comparison
Clinical-trial headlines have averaged a -5.11% one-day move. Today’s -3.5% reaction to new KER-065 data fits this pattern of generally negative, but moderate, responses.
Across past clinical updates, KER-065 advanced from initial Phase 1 topline data to sustained bone mineral density benefits and Orphan Drug designation for DMD, while elritercept moved into Phase 3 and TROPOS was halted for safety, underscoring both pipeline progress and risk.
Market Pulse Summary
This announcement adds mechanistic depth to Phase 1 data for rinvatercept, showing body composition changes and proteomic signals consistent with activin and myostatin inhibition over 71 days. It supports plans for Phase 2 trials in DMD and ALS. Investors may contextualize this with prior KER-065 updates, including sustained bone mineral density gains and Orphan Drug status, while balancing enthusiasm against the broader history of mixed trial outcomes in the pipeline.
Key Terms
transforming growth factor-beta medical
phase 1 clinical trial medical
double-blind medical
placebo-controlled medical
pharmacokinetics medical
proteomic analysis medical
duchenne muscular dystrophy medical
amyotrophic lateral sclerosis medical
AI-generated analysis. Not financial advice.
LEXINGTON, Mass., March 09, 2026 (GLOBE NEWSWIRE) -- Keros Therapeutics, Inc. (“Keros” or the “Company”) (Nasdaq: KROS), a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the transforming growth factor-beta (“TGF-ß”) family of proteins, today announced that it presented additional data from its Phase 1 clinical trial of rinvatercept (KER-065) in healthy volunteers at the 2026 Muscular Dystrophy Association Clinical & Scientific Conference.
“We are pleased to present additional data that further underscore the wide-ranging therapeutic potential of rinvatercept,” said Jasbir S. Seehra, President and Chief Executive Officer of Keros. “These data continue to reinforce the potential of rinvatercept to treat neuromuscular diseases, and our focus remains on advancing the rinvatercept program into two Phase 2 clinical trials, one in Duchenne muscular dystrophy (“DMD”) and one in amyotrophic lateral sclerosis (“ALS”).”
Clinical Presentation
Proteome Analysis in a Phase 1 Trial of KER-065, a Modified Activin Receptor Ligand Trap, Confirmed Target Engagement and Guides Clinical Development in Neuromuscular Diseases
This Phase 1 clinical trial was a randomized, double-blind, placebo-controlled, two-part dose escalation (single and multiple ascending dose) trial in healthy adult male volunteers. The primary objectives of this trial were to assess safety, tolerability and pharmacokinetics of rinvatercept. Exploratory proteomic analysis was performed on serum samples. Differential expression analysis was used to compare protein levels in serum samples from volunteers who received rinvatercept or placebo over 71 days. Initial topline data from this trial was reported in March 2025.
As previously reported, treatment with rinvatercept was generally well-tolerated at all dose levels evaluated. No dose-limiting toxicities or serious adverse events were reported.
Administration of rinvatercept led to changes in body composition consistent with activin and myostatin inhibition. An increase in muscle mass, decrease in fat mass and an increase in bone mineral density were observed.
Proteomic data further demonstrated the mechanism of action of rinvatercept, including its observed effects on mitigating fibrosis and inflammation by inhibiting activins, consistent with the anti-fibrotic and anti-inflammatory effects observed preclinically. Changes in serum markers of energy metabolism indicated a shift in macronutrient requirements for muscle growth, which aligned with the observed increases in muscle mass. These data provide multiple lines of evidence that rinvatercept may potentially achieve sufficient activin inhibition across tissues of interest, at drug exposures that we anticipate targeting in DMD and ALS.
Preclinical Presentations
Additionally, the Company presented the following preclinical presentations from its rinvatercept program that continue to support the further development of rinvatercept in DMD and ALS:
- RKER-065 Improved Muscle and Bone Mass and Strength in the D2.mdx Mouse Model of Duchenne Muscular Dystrophy
- RKER-065 Exhibited Beneficial Effects in an Amyotrophic Lateral Sclerosis Mouse Model
About Rinvatercept
Rinvatercept is a novel ligand trap comprised of a modified ligand-binding domain derived from activin receptor type IIA and activin receptor type IIB that is fused to the portion of the human antibody known as the Fc domain. Rinvatercept is designed to act as a ligand trap and inhibit the biological effects of myostatin and activin A, which are negative regulators of muscle and bone mass and strength, to improve skeletal muscle regeneration, increase muscle size and strength, inhibit and reduce fibrosis, inhibit inflammation, reduce fat accumulation and improve bone health through bone anabolic mechanisms. We are developing rinvatercept for the treatment of DMD and for the treatment of ALS.
About Keros Therapeutics, Inc.
Keros is a clinical-stage biopharmaceutical company focused on developing and commercializing novel therapeutics to treat a wide range of patients with disorders that are linked to dysfunctional signaling of the TGF-ß family of proteins. Keros is a leader in understanding the role of the TGF-ß family of proteins, which are master regulators of the growth, repair and maintenance of a number of tissues, including skeletal muscle, bone, adipose, heart tissue and blood. By leveraging this understanding, Keros has discovered and is developing protein therapeutics that have the potential to provide meaningful and potentially disease-modifying benefit to patients. Keros’ lead product candidate, rinvatercept, is being developed for the treatment of DMD and for the treatment of ALS. Keros’ most advanced product candidate, elritercept, is being developed for the treatment of cytopenias, including anemia and thrombocytopenia, in patients with myelodysplastic syndrome and in patients with myelofibrosis.
Cautionary Note Regarding Forward-Looking Statements
Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Words such as “potential” or similar expressions are intended to identify forward-looking statements. Examples of these forward-looking statements include statements concerning: Keros’ expectations regarding its strategy and timing of its two Phase 2 clinical trials for rinvatercept; and the potential of rinvatercept to treat neuromuscular diseases, including DMD and ALS. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. These risks and uncertainties include, among others: Keros’ limited operating history and historical losses; Keros’ ability to raise additional funding to complete the development and any commercialization of its product candidates; Keros’ dependence on the success of its product candidates, rinvatercept and elritercept; that Keros may be delayed in initiating, enrolling or completing any clinical trials; competition from third parties that are developing products for similar uses; Keros’ ability to obtain, maintain and protect its intellectual property; and Keros’ dependence on third parties in connection with manufacturing, clinical trials and preclinical studies.
These and other risks are described more fully in Keros’ filings with the Securities and Exchange Commission (“SEC”), including the “Risk Factors” section of the Company’s Annual Report on Form 10-K, filed with the SEC on March 4, 2026, and its other documents subsequently filed with or furnished to the SEC. All forward-looking statements contained in this press release speak only as of the date on which they were made. Except to the extent required by law, Keros undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.
Contacts
Investor Contact:
Justin Frantz
jfrantz@kerostx.com
617-221-6042
Media Contact:
Mahmoud Siddig / Adam Pollack / Viveca Tress
Joele Frank, Wilkinson Brimmer Katcher
(212) 355-4449
FAQ
What did KROS announce about rinvatercept at the March 9, 2026 MDA conference?
Was rinvatercept safe in the Phase 1 trial reported by KROS (KER-065)?
What biological effects did KROS observe with rinvatercept in the Phase 1 study?
How will KROS use the Phase 1 proteomic data for rinvatercept development?
What are KROS's next clinical steps for rinvatercept (KER-065)?
