Insmed Reports Third Quarter 2020 Financial Results and Provides Business Update -ARIKAYCE (amikacin liposome inhalation suspension) Total Revenue of $43.6 Million for Third Quarter 2020- -Marketing Authorization for ARI

Reports Third Quarter 2020 Financial Results and Provides Business Update

(amikacin liposome inhalation suspension) Total Revenue of $43.6 Million for Third Quarter 2020-

Authorization for ARIKAYCE Liposomal 590 mg Nebuliser Dispersion Granted in European Union-

New Drug Application (sNDA) Approved by U.S. FDA for ARIKAYCE, Adding Culture Conversion Data Beyond 12 Months to Label-

Three Key Clinical Trials Expected to Begin by End of 2020: Phase 3 ASPEN Study of Brensocatib in Non-Cystic Fibrosis Bronchiectasis

(NCFBE), Pivotal ENCORE Study of ARIKAYCE in Front-Line NTM, and ARISE Study to Validate PRO Tool in NTM -

1 Study of Treprostinil Palmitil Inhalation Powder (TPIP) Under Way with Four Dosing Strengths Completed-

BRIDGEWATER, N.J., October 29,

2020 /PRNewswire/ - Insmed Incorporated (Nasdaq:INSM), a global biopharmaceutical company on a mission to transform the

lives of patients with serious and rare diseases, today reported financial results for the third quarter ended September 30, 2020,

and provided a business update.

"I am pleased to report

on a very productive third quarter for Insmed as we made significant progress across our programs while maintaining ARIKAYCE performance

in the U.S. amidst the ongoing pandemic," commented Will Lewis, Chair and Chief Executive Officer of Insmed. "Driven

by the efforts of a world-class team, we reached several critical milestones for ARIKAYCE, including marketing authorization in

the European Union, approval of an sNDA that adds meaningful efficacy data to our U.S. label, and continued advancement of our

frontline clinical program. Importantly, we also advanced plans to initiate a global, registrational Phase 3 study of brensocatib

in NCFBE and initiated a Phase 1 study of TPIP. As we look ahead to 2021, we believe we are well-positioned to carry this momentum

forward and execute on our goals."

Third Quarter 2020 Financial

Recent Corporate Developments

& Program Highlights

ARIKAYCE Global Advancement

On October 28, 2020, Insmed announced

that the European Commission (EC) had granted marketing authorization for ARIKAYCE Liposomal 590 mg Nebuliser Dispersion for the

treatment of nontuberculous mycobacterial (NTM) lung infections caused by Mycobacterium avium complex (MAC) in adults with

limited treatment options who do not have cystic fibrosis (CF). Consideration should be given to official guidance on the appropriate

use of antibacterial agents. The Company plans to launch ARIKAYCE first in Germany, with the United Kingdom and other European

markets to follow, subject to local reimbursement processes.

In Japan, Insmed continues to

anticipate launching ARIKAYCE in the middle of 2021, pending approval of its new drug application for the treatment of patients

with NTM lung disease caused by MAC who did not sufficiently respond to prior treatment.

ARIKAYCE Label Expansion

On October 19, 2020, the U.S.

Food and Drug Administration (FDA) approved an sNDA for ARIKAYCE, adding important efficacy data regarding the durability and

sustainability of culture conversion to the ARIKAYCE label. The data, which are from the Phase 3 CONVERT study of ARIKAYCE, demonstrate

that the addition of ARIKAYCE to guideline-based therapy (GBT) was associated with sustained culture conversion through the end

of treatment as well as durable culture conversion three months post-treatment compared with GBT alone.

Insmed also continues to advance

plans to pursue regulatory approval of ARIKAYCE as a front-line therapy for patients with MAC lung disease. The Company plans

to initiate two clinical trials in the fourth quarter of 2020 that will be conducted in parallel: ENCORE, a pivotal study intended

to fulfill the post-marketing requirement to allow full approval of ARIKAYCE in the U.S., and ARISE, an interventional study designed

to validate the patient-reported outcome (PRO) tool that will be used to measure efficacy in ENCORE.

Brensocatib Advancement

In September 2020, data from

the Phase 2 WILLOW study of brensocatib in patients with NCFBE were published online in the New England Journal of Medicine

and presented during a late-breaking session at the European Respiratory Society International Congress 2020.

Insmed remains on track to initiate

its planned registrational Phase 3 ASPEN trial of brensocatib in patients with NCFBE by the end of 2020. The Company has also

announced plans to advance a clinical development program for brensocatib in patients with CF.

In September 2020, Insmed announced

that it had initiated a Phase 1 healthy volunteer trial of TPIP in the United States. The objective of this first-in-human single

ascending dose and multiple ascending dose study is to assess the pharmacokinetics and tolerability profile of TPIP. Four dosing

strengths have now been completed. Top-line data from the full Phase 1 study are expected in the first quarter of 2021 and the

Company has announced plans to initiate a Phase 2a study in patients with pulmonary arterial hypertension (PAH) in early 2021.

As of September 30, 2020, Insmed had

cash and cash equivalents of $588.8 million. The Company's total operating expenses for the third quarter of 2020 were $89.2

million. Adjusted operating expenses, a non-GAAP measure defined below, for the third quarter of 2020 were $76.8 million.

The Company plans to continue

investing in the following key activities in 2020:

host a conference call beginning today at 8:30 AM Eastern Time. Shareholders and other interested parties may

participate in the conference call by dialing (833) 340-0284 (domestic) or (236) 712-2425 (international) and referencing

conference ID number 8292364. The call will also be webcast live on the Company's website at www.insmed.com.

replay of the conference call will be accessible approximately two hours after its completion through November 12, 2020 by

dialing (800) 585-8367 (domestic) or (416) 621-4642 (international) and referencing conference ID number 8292364. A webcast

of the call will also be archived for 90 days under the Investor Relations section of the Company's website at

addition to the U.S. generally accepted accounting principles (GAAP) results, this earnings release includes adjusted

operating expenses, a non-GAAP financial measure, which Insmed defines as total operating expenses less stock-based

compensation expense, depreciation, amortization of intangibles and certain milestones related

to ARIKAYCE, which are payable under our amended agreements with Cystic Fibrosis Foundation Therapeutics,

Inc. (CFFT). A reconciliation of this non-GAAP financial measure to its most directly comparable GAAP financial measure is presented

in the table attached to this press release.

believes that this non-GAAP financial measure is useful to both management and investors in analyzing our ongoing business and

operating performance. Management believes that providing this non-GAAP information to investors, in addition to the GAAP results,

allows investors to view our financial results in the way that management views financial results. Management does not intend

the presentation of this non-GAAP financial measure to be considered in isolation or as a substitute for results prepared in accordance

with GAAP. In addition, this non-GAAP financial measure may differ from similarly named measures used by other companies.

is approved in the United States as ARIKAYCE (amikacin liposome inhalation suspension) and in the EU as ARIKAYCE

Liposomal 590 mg Nebuliser Dispersion. Current international treatment guidelines recommend the use of ARIKAYCE for appropriate

patients. ARIKAYCE is a novel, inhaled, once-daily formulation of amikacin, an established antibiotic that was historically administered

intravenously and associated with severe toxicity to hearing, balance, and kidney function. Insmed's proprietary PULMOVANCE

liposomal technology enables the delivery of amikacin directly to the lungs, where liposomal amikacin is taken up by lung macrophages

where the infection resides, while limiting systemic exposure. ARIKAYCE is administered once daily using the Lamira Nebulizer

System manufactured by PARI Pharma GmbH (PARI).

About PARI Pharma and the

Lamira Nebulizer System

is delivered by a novel inhalation device, the Lamira Nebulizer System, developed by PARI. Lamira is

a quiet, portable nebulizer that enables efficient aerosolization of ARIKAYCE via a vibrating, perforated membrane. Based on PARI's

100-year history working with aerosols, PARI is dedicated to advancing inhalation therapies by developing innovative delivery

platforms and new pharmaceutical formulations that work together to improve patient care.

Brensocatib is a small molecule,

oral, reversible inhibitor of dipeptidyl peptidase 1 (DPP1) being developed by Insmed for the treatment of patients with non-cystic

fibrosis bronchiectasis (NCFBE) and other neutrophil-mediated diseases. DPP1 is an enzyme responsible for activating neutrophil

serine proteases (NSPs), such as neutrophil elastase, in neutrophils when they are formed in the bone marrow. Neutrophils are

the most common type of white blood cell and play an essential role in pathogen destruction and inflammatory mediation. In chronic

inflammatory lung diseases, neutrophils accumulate in the airways and result in excessive active NSPs that cause lung destruction

and inflammation. Brensocatib may decrease the damaging effects of inflammatory diseases such as bronchiectasis by inhibiting

DPP1 and its activation of NSPs.