Cabaletta Bio reports year-long rese‑cel responses in six myositis patients

Year-long responses persisted without immunomodulators in all six dermatomyositis patients as Cabaletta Bio, Inc. NASDAQCABA reported new Phase 1/2 rese-cel data on Sunday.

The Nov. 8 release covers open-label, single-arm studies with a Sept. 4 data cutoff. A separate, 17-patient registrational adult myositis cohort is expected to deliver topline results in the second half of 2027.

Cabaletta is a small Philadelphia-based clinical biotechnology company developing targeted cell therapies for autoimmune diseases. Rese-cel is an investigational CD19-targeted CAR T-cell therapy.

Shares closed at US$1.30 on Nasdaq at 4:00 p.m. EST on Nov. 6, before Sunday's announcement NASDAQCABA.

All six dermatomyositis patients maintained moderate-to-major responses on the Total Improvement Score through one year without immunomodulators. Five reached that response level by Week 16, the timepoint corresponding to the ongoing registrational cohort's primary endpoint. Most were also off steroids at Week 52.

The studies evaluated a single, weight-based infusion following preconditioning. Without a control arm, the response rates cannot establish benefit against placebo or standard treatment.

"We believe these emerging data reinforce the potential of rese-cel to deliver an immune reset that leads to durable efficacy with a favorable benefit-risk profile for autoimmune disease patients," Cabaletta chief medical officer David J. Chang said.

Durability Extends Across Small Disease Cohorts

Among five lupus nephritis patients who underwent an optional repeat kidney biopsy, all achieved the DORIS definition of remission without immunomodulators and with no or low-dose steroids. All five also showed a histologic response or remission, with follow-up ranging from six months to two years.

Those results describe the biopsied subgroup. They should not be read as a response rate for every lupus nephritis patient treated in the programme.

In systemic sclerosis, five of seven patients achieved the rCRISS-50 response measure at one year. Mean percent-predicted forced vital capacity improved 9 per cent among the five patients with interstitial lung disease.

The safety analysis covered 71 patients treated after preconditioning across four autoimmune diseases. Cytokine release syndrome was absent or Grade 1 in 67 patients; the other four had Grade 2 events.

The company reported no immune effector cell-associated neurotoxicity syndrome in 68 patients. No immune effector cell-associated haemophagocytic lymphohistiocytosis-like syndrome was reported.

Registrational Results Are Expected In 2027

The listed peer group at ACR includes CRISPR Therapeutics AG NASDAQCRSP. Its Oct. 2 announcement scheduled clinical data on zugocabtagene geleucel, or zugo-cel, in autoimmune disease for the same meeting.

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For broader sector context, the iShares Biotechnology ETF NASDAQIBB closed at US$213.63 on Nasdaq at 4:00 p.m. EST on Nov. 6. That benchmark also predates the Sunday clinical disclosures.

Cabaletta's Nov. 5 business update reported approximately US$299.4 million in cash and cash equivalents at Sept. 30. Management expects its operational runway to extend into the first quarter of 2028.

The same update said a recent Type B FDA interaction allows multi-year Phase 1/2 myositis durability data to support the planned biologics application. Cabaletta plans to submit in the first quarter of 2028, including available juvenile dermatomyositis data.

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The adult myositis registrational cohort is expected to deliver topline results in the second half of 2027 to support the planned application. The dermatomyositis oral presentation is scheduled for 1 p.m. EST on Nov. 8 at ACR, followed by the lupus nephritis and pooled safety posters on Nov. 9.