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Weight-loss firm Gelesis to go public in $1.3 billion SPAC merger

A photo of the packaging for Gelesis' oral treatment for weight-loss management.
A photo of the packaging for Gelesis' oral treatment for weight-loss management.Courtesy of Gelesis

Boston biotech Gelesis said Monday that it plans to go public by merging with a special purpose acquisition company, following Food and Drug Administration approval of its weight-loss capsule in 2019.

The SPAC deal with Capstar Special Purpose Acquisition Corp. values the 15-year-old biotech at $1 billion and is expected to generate $376 million for the combined company. Gelesis said it would use the money to fund the full commercial launch of its product later this year.

The FDA cleared the treatment, marketed under the name Plenity and classified as a medical device, for adults with excess weight or obesity, a body mass index of 25 to 40. The pills form small, zero-calorie water pouches in the stomach, which aim to make patients feel full so that they consume smaller portions of food. Gelesis said the treatment can be delivered to patients’ homes and costs $98 per month.


The firm is testing its weight-loss treatment in adolescents while also working on programs for patients with diabetes, a liver disease that causes excess fat build-up, and constipation.

As part of the deal, which is expected to close in the fourth quarter, Gelesis raised $100 million from investors including PIMCO private funds, the Pritzker Vlock Family Office, China Medical Systems Holdings Limited, and a cofounder of PureTech Health. Gelesis is an affiliate of PureTech Health in Boston, which also founded Boston-based Karuna Therapeutics and Cambridge’s Vor Biopharma, both publicly traded companies.

Several local life sciences companies have announced SPAC mergers this year, including Valo Health, Ginkgo Bioworks, and Tango Therapeutics.

Anissa Gardizy can be reached at anissa.gardizy@globe.com. Follow her on Twitter @anissagardizy8.