Cabaletta Delays Rese-Cel Myositis BLA to 1Q28

The Tip Desk · November 6, 2026 · 3 min read

The company now targets a first-quarter 2028 biologics license application after third-quarter cash of $299.4 million.

Cabaletta Bio, Inc. (CABA), a late-stage clinical biotechnology company developing CAR T cell therapies for autoimmune disease, moved its planned first biologics license application for rese-cel into the first quarter of 2028, after a slower third-quarter enrollment period in the registrational adult myositis study that it said was influenced by patient and physician caution following recently reported safety events from others in the field.

The company now expects topline results from the 17-patient dermatomyositis and antisynthetase syndrome registrational cohort in the second half of 2027 to support that 1Q28 BLA. In the second-quarter update, it had said registrational data were on track for mid-2027 to support a 2H27 submission.

Chief Executive Officer Steven Nichtberger said enrollment and screening activity had increased, with multiple patients enrolled in the past few weeks after the slower third quarter. The company said it is now seeing that recovery in the adult myositis registrational study.

Juvenile dermatomyositis remains part of the same BLA package. The Phase 1/2 juvenile myositis cohort, which incorporates an outpatient dosing option, continues to be open for enrollment. Cabaletta plans to include that data to support a potential pediatric indication and potential eligibility for a Priority Review Voucher. Based on a recent Type B interaction with the FDA, the company said it has the ability to include multi-year Phase 1/2 myositis durability data in the planned filing. It will present one-year data from the complete Phase 1/2 dermatomyositis cohort at ACR Convergence 2026 and expects three-year durability data from some Phase 1/2 patients at the time of a potential launch.

Cabaletta also initiated the registrational, approximately 25-patient RESET-SSc cohort in systemic sclerosis patients with interstitial lung disease. The second-quarter update had anticipated that enrollment would start in the fourth quarter of 2026. The primary endpoint is designed to measure the mean change from baseline in percent-predicted forced vital capacity without immunomodulators or anti-fibrotic medications and on no or a low dose of steroids.

Preconditioning-free work continued across RESET-SLE, RESET-MG and RESET-PV. The company said maturing PC-free data are expected to inform go-forward clinical development plans in the first half of 2027.

Research and development expenses were $47.1 million for the three months ended September 30, 2026, compared with $39.8 million a year earlier. General and administrative expenses were $7.6 million. Total operating expenses were $54.7 million. Net loss was $53.1 million, or $0.28 a share, versus $44.9 million, or $0.44 a share, for the same period in 2025.

Cash, cash equivalents and short-term investments were $299.4 million as of September 30, 2026, up from $133.6 million at December 31, 2025. That balance included approximately $115.0 million from exercises of common stock warrants received between July 1, 2026, and the warrants’ expiration on September 12, 2026. The company said it expects that cash position to fund its operating plan into the first quarter of 2028.

At the European Society of Gene and Cell Therapy 2026 meeting, Cabaletta presented longer-term Phase 1/2 systemic sclerosis efficacy data. At one year and off immunomodulators, five patients with interstitial lung disease achieved a mean percent-predicted FVC improvement of approximately 9%, and among systemic sclerosis patients with at least one year of follow-up, six of seven achieved rCRISS-25. At the American Association of Neuromuscular & Electrodiagnostic Medicine 2026 meeting, it presented data from the first 14 RESET-MG patients treated with rese-cel and preconditioning; at 24 weeks, patients who remained off immunomodulators had a mean change from baseline of -7.9 on the MG-ADL scale and -7.8 on the Quantitative Myasthenia Gravis score.

The company will present one-year dermatomyositis responses and updated RESET safety data at ACR Convergence 2026, including an oral presentation on November 8 and posters on November 9.