The Company is subject to various legal proceedings and claims, including patent infringement claims, product liability matters, personal injury, environmental matters, employment disputes, contractual disputes and other commercial disputes, including those described below. The Company believes that these legal proceedings and claims likely will be resolved over an extended period of time. Although it is not feasible to predict the outcome of these matters, the Company believes, unless indicated below, given the information currently available, that their ultimate resolution will not have a material adverse effect on its financial condition, results of operations and cash flows.

Since 2017, multiple U.S. states, counties, other governmental persons or entities and private plaintiffs have filed lawsuits against certain entities of the Company, as well as various other manufacturers, distributors, pharmacies, pharmacy benefit managers, individual doctors and/or others, asserting claims relating to defendants’ alleged sales, marketing, distribution, reimbursement, prescribing, dispensing and/or other practices with respect to prescription opioid medications, including certain of the Company's products. As of November 5, 2019, the cases the Company is aware of include, but are not limited to, approximately 2,315 cases filed by counties, cities, Native American tribes and/or other government-related persons or entities; approximately 207 cases filed by hospitals, health systems, unions, health and welfare funds or other third-party payers; approximately 104 cases filed by individuals and 14 cases filed by the Attorneys General for New Mexico, Kentucky, Rhode Island, Georgia, Florida, Alaska, New York, Hawaii, Nevada, South Dakota, New Hampshire, Illinois, and Idaho, with Idaho being the only state Attorney General to file in federal as opposed to state court. As of November 5, 2019, the Mallinckrodt defendants in these cases consist of Mallinckrodt plc and the following subsidiaries of Mallinckrodt plc: Mallinckrodt Enterprises LLC, Mallinckrodt LLC, SpecGx LLC, Mallinckrodt Brand Pharmaceuticals Inc., Mallinckrodt Inc., MNK 2011 Inc., and Mallinckrodt Enterprises Holdings, Inc. On September 12, 2019, the Attorney General for Ohio filed a motion in the Common Pleas Court of Ross County, Ohio to amend its complaint to add certain entities of the Company, but the court has not yet ruled on that motion. Certain of the lawsuits have been filed as putative class actions.

Most pending federal lawsuits have been coordinated in a federal multi-district litigation (“MDL”) pending in the U.S. District Court for the Northern District of Ohio. The MDL court has issued a series of case management orders permitting motion practice addressing threshold legal issues in certain cases, allowing discovery, setting pre-trial deadlines and setting a trial date on October 21, 2019 for two cases originally filed in the Northern District of Ohio by Summit County and Cuyahoga County against opioid manufacturers, distributors, and pharmacies ("Track 1 Cases"). The counties claim that opioid manufacturers' marketing activities changed the medical standard of care for treating both chronic and acute pain, which led to increases in the sales of their prescription opioid products. They also allege that opioid manufacturers’ and distributors’ failure to maintain effective controls against diversion was a substantial cause of the opioid crisis. On September 30, 2019, the Company announced that Mallinckrodt plc, along with its

wholly owned subsidiaries Mallinckrodt LLC and SpecGx LLC, had executed a definitive settlement agreement and release with Cuyahoga and Summit Counties in Ohio. The settlement fully resolves the Track 1 cases against all named Mallinckrodt entities that were scheduled to go to trial in October 2019 in the MDL. Under the agreement, the Company paid $24.0 million in cash on October 1, 2019. In addition, the Company will provide $6.0 million in generic products, including addiction treatment products, and will also provide a $0.5 million payment in two years in recognition of the counties' time and expenses. Further in the event of a comprehensive resolution of government-related opioid claims, the Company has agreed that the two plaintiff counties will receive the value they would have received under such a resolution, less the payments described above. All named Mallinckrodt entities were dismissed with prejudice from the lawsuit. The value of the settlement should not be extrapolated to any other opioid-related cases or claims. On October 21, 2019, the MDL court issued a Stipulated Dismissal Order dismissing the claims against the remaining manufacturers and distributors pursuant to a settlement agreement, and severing the claims against the remaining pharmacy defendant to be heard in a subsequent trial. A hearing is scheduled for November 6, 2019 to discuss the next steps in the MDL, including potential remand of certain cases and which defendants will be included in subsequent trials.

The lawsuits assert a variety of claims, including, but not limited to, public nuisance, negligence, civil conspiracy, fraud, violations of the Racketeer Influenced and Corrupt Organizations Act (“RICO”) or similar state laws, violations of state Controlled Substances Acts or state False Claims Acts, product liability, consumer fraud, unfair or deceptive trade practices, false advertising, insurance fraud, unjust enrichment and other common law and statutory claims arising from defendants’ manufacturing, distribution, marketing and promotion of opioids and seek restitution, damages, injunctive and other relief and attorneys’ fees and costs. The claims generally are based on alleged misrepresentations and/or omissions in connection with the sale and marketing of prescription opioid medications and/or an alleged failure to take adequate steps to prevent diversion.

The Company will continue to vigorously defend itself against all of these lawsuits as detailed above and similar lawsuits that may be brought by others. As of the date of this report, the Company has been in discussions with certain plaintiffs in other pending opioid lawsuits and is likely to have further discussions and/or enter into additional discussions with other parties in connection with opioid lawsuits. Mallinckrodt may be required to pay material amounts and/or incur other material obligations as a result of any settlements that are entered into as a result of such discussions, but the Company is unable to predict outcomes or estimate a range of reasonably possible losses at this stage. Further, such matters or the resolution thereof, whether through judicial process or settlement or otherwise, may make it necessary or advisable for the Company and/or one or more of its subsidiaries to seek to restructure its or their obligations in a bankruptcy proceeding. The Company is exploring a wide array of such potential outcomes as part of its contingency planning, including the impact such actions could have on its business and operations. Should a bankruptcy occur, the Company would be subject to additional risks and uncertainties that could adversely affect the Company’s business prospects and ability to continue as a going concern.

In addition to the lawsuits described above, certain entities of the Company have received subpoenas and civil investigative demands ("CID(s)") for information concerning the sale, marketing and/or distribution of prescription opioid medications and the Company's suspicious order monitoring programs, including from the U.S. Department of Justice ("DOJ") and the Attorneys General for Missouri, New Hampshire, Kentucky, Washington, Alaska, South Carolina, Puerto Rico, New York, West Virginia, Indiana, the Divisions of Consumer Protection and Occupational and Professional Licensing of the Utah Department of Commerce, and the New York State Department of Financial Services. The Company has been contacted by the coalition of State Attorneys General investigating the role manufacturers and distributors may have had in contributing to the increased use of opioids in the U.S. On January 27, 2018, the Company received a grand jury subpoena from the U.S. Attorneys’ Office (“USAO”) for the Southern District of Florida for documents related to the distribution, marketing and sale of generic oxymorphone products. On April 17, 2019, the Company received a grand jury subpoena from the USAO for the Eastern District of New York ("EDNY") for documents related to the sales and marketing of controlled substances, the policies and procedures regarding controlled substances, and other related documents. On June 4, 2019, the Company received a rider from the USAO for EDNY requesting additional documents regarding the Company's anti-diversion program. The Company is responding or has responded to these subpoenas, CIDs and any informal requests for documents.

New York State Opioid Stewardship Act. On October 24, 2018, the Company filed suit in the U.S. District Court for the Southern District of New York against the State of New York, asking the court to declare New York State’s Opioid Stewardship Act (“OSA”) unconstitutional and to enjoin its enforcement. On December 19, 2018, the court declared the OSA unconstitutional and granted the Company’s motion for preliminary injunctive relief. On January 17, 2019, the State of New York appealed the court’s decision. The Company intends to vigorously assert its position in this matter. In April 2019, the State of New York passed its 2020 budget, which amended the OSA so that if the OSA decision is reversed on appeal, the OSA would apply only to the sale or distribution of certain opioids in New York for 2017 and 2018 and, effective July 1, 2019, imposed an excise tax on certain opioids.

SEC Subpoena. In August 2019, the Company received a subpoena from the U.S. Securities and Exchange Commission (“SEC”) for documents related to the Company’s disclosure of its dispute with the U.S. Department of Health and Human Services ("HHS") and Centers for Medicare & Medicaid Services ("CMS" and together with HHS, the "Agency") concerning the base date average manufacturer price ("AMP") under the Medicaid Drug Rebate Program for Mallinckrodt’s Acthar^® Gel (repository corticotropin injection) ("Acthar Gel"), which is now the subject of litigation between the Company and the Agency (see Medicaid Lawsuit below). The Company is cooperating with the SEC’s investigation.

Medicaid Lawsuit. In May 2019, the Company filed a lawsuit under the Administrative Procedure Act ("APA") in federal district court for the District of Columbia against the Agency. The dispute involves the base date AMP under the Medicaid Drug Rebate Program for Acthar Gel. A drug’s “base date AMP” is used to calculate the Medicaid rebate amount payable by the drug’s manufacturer to state Medicaid agencies when the drug is prescribed to Medicaid beneficiaries. At issue in the lawsuit is whether FDA’s 2010 approval of a new drug application for use of Acthar Gel in treating infantile spasms rendered Acthar Gel eligible for a new base date AMP, as indicated by CMS's written communications in 2012. In May 2019, CMS indicated that if the Company failed to revert to use of the original base date AMP in its calculation of Acthar Medicaid rebates, CMS would identify the Company as being out of compliance with its Medicaid Drug Rebate Program reporting requirements, among other potential actions, triggering certain negative consequences. As such, the Company filed a lawsuit alleging (i) that CMS has violated the Medicaid drug rebate statute, (ii) that CMS has violated its own regulations defining “single source drug,” (iii) that CMS has failed to adequately explain its change in position based on two letters that CMS sent Questcor Pharmaceuticals Inc. ("Questcor") in 2012 regarding the base date AMP for Acthar Gel, (iv) that CMS failed to give the Company fair notice of its latest position, and (v) that CMS should be prohibited from applying its new position retroactively. The court held a hearing regarding this matter on August 2, 2019 and the court took the matter under advisement. While the Company believes that its lawsuit has strong factual and legal bases, as of September 27, 2019, the potential for retroactive non-recurring charges could range from zero to approximately $600.0 million.

Therakos^® Subpoena. In March 2014, the USAO for the Eastern District of Pennsylvania requested the production of documents related to an investigation of the U.S. promotion of Therakos’ drug/device system UVADEX/UVAR XTS and UVADEX/CELLEX (collectively, the "Therakos System"), for indications not approved by the FDA, including treatment of patients with graft versus host disease ("GvHD") and solid organ transplant patients, including pediatric patients. The investigation also includes Therakos’ efforts to secure FDA approval for additional uses of, and alleged quality issues relating to, UVADEX/UVAR. In August 2015, the USAO for the Eastern District of Pennsylvania sent Therakos a subsequent request for documents related to the investigation and has since made certain related requests. The Company responded to these requests and continues to cooperate fully in the investigation.

MNK 2011 Inc. (formerly known as Mallinckrodt Inc.) v. U.S. Food and Drug Administration and United States of America. In November 2014, the FDA reclassified the Company's Methylphenidate ER in the Orange Book: Approved Drug Products with Therapeutic Equivalence ("the Orange Book"). In November 2014, the Company filed a Complaint in the U.S. District Court for the District of Maryland Greenbelt Division against the FDA and the United States (the "MD Complaint") for judicial review of the FDA’s reclassification. In July 2015, the court granted the FDA's motion to dismiss with respect to three of the five counts in the MD Complaint and granted summary judgment in favor of the FDA with respect to the two remaining counts (the “MD Order”). On October 18, 2016, the FDA initiated proceedings, proposing to withdraw approval of the Company's Abbreviated New Drug Application ("ANDA") for Methylphenidate ER. On October 21, 2016, the U.S. Court of Appeals for the Fourth Circuit issued an order placing the Company’s appeal of the MD Order in abeyance pending the outcome of the withdrawal proceedings. The parties exchanged documents and in April 2018, the Company filed its submission in support of its position in the withdrawal proceedings. A potential outcome of the withdrawal proceedings is that the Company's Methylphenidate ER products may lose their FDA approval and have to be withdrawn from the market.

Questcor Subpoena. In September 2012, Questcor received a subpoena from the USAO for the Eastern District of Pennsylvania for information relating to its promotional practices related to Acthar Gel. Questcor subsequently was informed by the USAO for the Eastern District of Pennsylvania that the USAO for the Southern District of New York and the SEC were participating in the investigation to review Questcor's promotional practices and related matters pertaining to Acthar Gel. The current investigation also relates to Questcor's provision of financial and other support to patients, including through charitable foundations and related matters. On March 9, 2015, the Company received a "No Action" letter from the SEC regarding its review of the Company's promotional practices related to Acthar Gel. On or about March 8, 2019, the U.S. District Court for the Eastern District of Pennsylvania unsealed two qui tam actions involving the allegations under investigation by the USAO for the Eastern District of Pennsylvania. The DOJ intervened in both actions, which were later consolidated. In September 2019, the Company executed a settlement agreement with the DOJ for $15.4 million and finalized settlements with the three qui tam plaintiffs. These settlements were paid during the three months ended September 27, 2019 and resolve the portion of the investigation and litigation involving Questcor's promotional practices related to Acthar Gel.

On or about June 4, 2019, the DOJ filed its Complaint in Intervention in the litigation, alleging claims under the federal False Claim Act based on Questcor's relationship with and donations to an independent charitable patient co-pay foundation. The Company disagrees with the DOJ's characterization of the facts and applicable law. The Company intends to vigorously defend itself in this matter and on August 19, 2019, moved to dismiss the complaint. The Company's motion to dismiss remains pending. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit.

Ofirmev Patent Litigation: Altan Pharma Ltd. In March 2019, Mallinckrodt Hospital Products Inc. and Mallinckrodt Hospital Products IP Limited, both subsidiaries of the Company, and New Pharmatop LP, the current owner of the U.S. patents licensed exclusively by the Company, filed suit in the U.S. District Court for the District of Delaware against Altan Pharma Ltd. (“Altan”) alleging that Altan infringed U.S. Patent No. 6,992,218, U.S. Patent No. 9,399,012, U.S. Patent No. 9,610,265 and U.S. Patent No. 9,987,238 following receipt of a February 2019 notice from Altan concerning its submission of a new drug application, containing a Paragraph IV patent certification with the FDA for a competing version of Ofirmev. On August 29, 2019, the parties entered into a settlement agreement under which Altan was granted the non-exclusive right to market a competing intravenous acetaminophen product in the U.S. under its New Drug Application (NDA) on or after December 6, 2020, or earlier under certain circumstances.

Amitiza Patent Litigation: Sun Pharmaceutical Industries, Ltd. and Sun Pharmaceutical Industries, Inc. In October 2018, Sucampo AG, Sucampo Pharmaceuticals, Inc. and Sucampo Pharma LLC, all subsidiaries of the Company, and Takeda Pharmaceutical Company Limited, Takeda Pharmaceuticals USA, Inc., and Takeda Pharmaceuticals America, Inc. (collectively "Takeda," the exclusive licensee under the patents in litigation) filed suit in the U.S. District Court for the District of New Jersey against Sun Pharmaceutical Industries, Ltd. and Sun Pharmaceutical Industries, Inc. (collectively “Sun”) alleging that Sun infringed U.S. Patent Nos. 7,795,312, 8,026,393, 8,097,653, 8,338,639, 8,389,542, 8,748,481 and 8,779,187 following receipt of a September 2018 notice from Sun concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a generic version of Amitiza. The Company intends to vigorously enforce its intellectual property rights relating to Amitiza.

Inomax^® Patent Litigation: Praxair Distribution, Inc. and Praxair, Inc. (collectively “Praxair”). In February 2015, INO Therapeutics LLC and Ikaria, Inc., both subsidiaries of the Company, filed suit in the U.S. District Court for the District of Delaware against Praxair following receipt of a January 2015 notice from Praxair concerning its submission of an ANDA containing a Paragraph IV patent certification with the FDA for a nitric oxide drug product delivery system. In July 2016, the Company filed a second suit against Praxair in the U.S. District Court for the District of Delaware following receipt of a Paragraph IV notice concerning three additional patents recently added to the FDA Orange Book that was submitted by Praxair regarding its ANDA for its nitric oxide drug product delivery system. The infringement claims in the second suit were added to the original suit. In September 2016, the Company filed a third suit against Praxair in the U.S. District Court for the District of Delaware following receipt of a Paragraph IV notice

Trial for the suit filed in February 2015 was held in March 2017 and a decision was rendered September 5, 2017 that ruled five patents invalid and six patents not infringed. The Company appealed the decision to the Court of Appeals for the Federal Circuit. The oral arguments in the appeal occurred on February 6, 2019. Praxair received FDA approval of their ANDA for their Noxivent nitric oxide and clearance of their 510(k) for their NOxBOXi device on October 2, 2018. The appeal decision, issued on August 27, 2019, substantively affirmed the District Court decision with respect to the invalidity of the heart failure (HF) patents and the non-infringement of the delivery system infrared (DSIR) patents. The Company filed a petition for en banc review at the Federal Circuit on September 26, 2019. As of the date of this report there has been limited commercial launch activity by Praxair. The Company intends to continue its efforts to vigorously enforce its intellectual property rights relating to Inomax in the Praxair litigation to prevent the marketing of infringing generic products prior to the expiration of the patents covering Inomax. An adverse final outcome in the appeal of the Praxair litigation decision (or a broad at-risk launch by Praxair prior to the final appellate decision) could result in the broader-scale launch of a competitive nitric oxide product before the expiration of the last of the listed patents on May 3, 2036 (November 3, 2036 including pediatric exclusivity), which could adversely affect the Company's ability to successfully maximize the value of Inomax and have an adverse effect on its financial condition, results of operations and cash flows.

Shareholder Derivative Litigation (Brandhorst). On September 19, 2019, a purported shareholder of the Company’s stock filed a shareholder derivative complaint in the United States District Court for the District of Columbia against the Company, as nominal defendant, as well as its Chief Executive Officer ("CEO") Mark Trudeau, its former Chief Financial Officer ("CFO") Matthew K. Harbaugh, its Executive Vice President Hugh O’Neill, and the following members of the Company’s Board of Directors: Angus Russell, David Carlucci, J. Martin Carroll, David Norton, JoAnn Reed and Kneeland Youngblood (collectively with Trudeau, Harbaugh and O’Neill, the “Individual Defendants”). The lawsuit is captioned Lynn Brandhorst, derivatively on behalf of nominal defendant Mallinckrodt PLC v. Mark Trudeau et al. and relies on the allegations from the putative class action securities litigation that was filed against the Company and certain of its officers on January 23, 2017, captioned Patricia A. Shenk v. Mallinckrodt plc, et al. described further below. The complaint asserts claims for contribution, breaches of fiduciary duty, unjust enrichment, abuse of control, and gross mismanagement, and is premised on allegations that the Individual Defendants caused the Company to make the allegedly false or misleading statements at issue in the Shenk lawsuit. The complaint seeks damages in an unspecified amount and corporate governance reforms. The Company and the Individual Defendants intend to vigorously defend themselves in this matter.

Humana Litigation. On August 8, 2019, Humana Inc. filed a lawsuit against the Company in the U.S. District Court for the Central District of California alleging violations of federal and state antitrust laws; racketeering (“RICO”) violations under 18 U.S.C. § 1962(c); conspiracy to violate RICO under 18 U.S.C. § 1962(d); violations of state unfair competition, consumer fraud and deceptive trade practice laws; state insurance fraud; tortious interference with contract; and unjust enrichment related to the pricing of Acthar Gel. Humana alleges that it paid more than $700.0 million for Acthar Gel and seeks undisclosed damages from 2011 through present. The case alleges similar facts as those alleged in the MSP and Rockford matters below, and includes references to allegations at issue in a pending qui tam action against the Company in the U.S. District Court for the Eastern District of Pennsylvania (see Questcor Subpoena above) and is proceeding as Humana Inc. v. Mallinckrodt ARD LLC. Plaintiff filed an Amended Complaint on October 2, 2019. The Company intends to vigorously defend itself in this matter, and on October 28, 2019, moved to dismiss the complaint. The Company's motion to dismiss remains pending.

Putative Class Action Securities Litigation (Strougo). On July 26, 2019, a putative class action lawsuit was filed against the Company, its CEO Mark Trudeau, its CFO Bryan M. Reasons, its former Interim CFO George A. Kegler and its former CFO Matthew K. Harbaugh, in the U.S. District Court for the Southern District of New York, captioned Barbara Strougo v. Mallinckrodt plc, et al. The complaint purports to be brought on behalf of all persons who purchased or otherwise acquired Mallinckrodt's securities between February 28, 2018 and July 16, 2019. The lawsuit generally alleges that the defendants made false and misleading statements in violation of Sections 10(b) and 20(a) of the Exchange Act and Rule 10b-5 promulgated thereunder related to the Company’s clinical study designed to assess the efficacy and safety of its Acthar Gel in patients with amyotrophic lateral sclerosis. The lawsuit seeks monetary damages in an unspecified amount. The Company intends to vigorously defend itself in this matter.

Putative Class Action Litigation - Plumbers & Pipefitters Local 322. On July 19, 2019, Pipefitters Local 322 filed a putative state class action lawsuit against the Company in the Superior Court of New Jersey, Camden County, proceeding as United Assoc. of Plumbers & Pipefitters Local 322 of Southern New Jersey v. Mallinckrodt ARD, LLC. The complaint made similar allegations as those alleged in related state and federal actions filed by the same plaintiff law firm filed in Illinois, Pennsylvania, Tennessee and Maryland, including references to allegations at issue in pending qui tam actions against the Company with the Eastern District of Pennsylvania. In particular, the complaint alleged violations of the New Jersey Consumer Fraud Act, the New Jersey Antitrust Act, violations of state RICO statutes, negligent misrepresentation, conspiracy and unjust enrichment associated with the commercialization of Acthar Gel. Plaintiff voluntarily dismissed the lawsuit on September 6, 2019.

Putative Class Action Litigation - Steamfitters Local Union No. 420. On July 12, 2019, Steamfitters Local Union No. 420 filed a putative class action lawsuit against the Company and United BioSource Corporation in the U.S. District Court for the Eastern District of Pennsylvania, proceeding as Steamfitters Local Union No. 420 v. Mallinckrodt ARD, LLC et al. The complaint makes similar allegations as those alleged in related state and federal actions that were filed by the same plaintiff's law firm in Illinois, Pennsylvania, Tennessee and Maryland, and includes references to allegations at issue in a pending qui tam actions against the Company in the U.S. District Court for the Eastern District of Pennsylvania (see Questcor Subpoena above). In particular, the complaint alleges RICO violations under 18 U.S.C. § 1962(c); conspiracy to violate RICO under 18 U.S.C. § 1962(c); violations of the Pennsylvania (and other states) Unfair Trade Practices and Consumer Protection laws; negligent misrepresentation; aiding and abetting/conspiracy; and unjust enrichment. The complaint also seeks declaratory and injunctive relief. The Company intends to vigorously defend itself in this matter, and on August 22, 2019, moved to dismiss the complaint. The Company's motion to dismiss remains pending.

Washington County Board of Education ("WCBE"). On May 21, 2019, WCBE filed a non-class complaint against the Company and other defendants in Maryland state court alleging violations of Maryland Consumer Protection Act, negligent misrepresentation, fraud, unjust enrichment and conspiracy to defraud. The case, which was removed to the U.S. District Court for the District of Maryland on June 24, 2019, alleges similar facts as those alleged in the MSP and Rockford matters below, and is captioned Washington County Board of Education v. Mallinckrodt ARD Inc., et al. The Company moved to dismiss the original complaint on July 1, 2019. Thereafter, Plaintiff filed an amended complaint, which the Company moved to dismiss on July 29, 2019. The Company's motion to dismiss the amended complaint remains pending. Plaintiff 's July 15, 2019 motion to remand the lawsuit to Maryland state court also remains pending.

Local 542. On May 25, 2018, the International Union of Operating Engineers Local 542 filed a non-class complaint against the Company and other defendants in Pennsylvania state court alleging improper pricing and distribution of Acthar Gel, in violation of Pennsylvania's Unfair Trade Practices and Consumer Protection Law, aiding and abetting, unjust enrichment and negligent misrepresentation. The case alleges similar facts as the MSP and Rockford matters below, and is captioned Int'l Union of Operating Engineers Local 542 v. Mallinckrodt ARD Inc., et al. Plaintiff filed an amended complaint on August 27, 2018, the Company's objections to which were denied by the court. The Company intends to continue to vigorously defend itself in this matter. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit.

Putative Class Action Litigation (MSP). On October 30, 2017, a putative class action lawsuit was filed against the Company and United BioSource Corporation in the U.S. District Court for the Central District of California. Pursuant to a motion filed by the defendants, the case was transferred to the U.S. District Court for the Northern District of Illinois in January 2018, and is currently proceeding as MSP Recovery Claims, Series II, LLC, et al. v. Mallinckrodt ARD, Inc., et al. The Company filed a motion to dismiss on February 23, 2018, which was granted on January 25, 2019 with leave to amend. MSP filed the operative First Amended Class Action Complaint on April 10, 2019, in which it asserts claims under federal and state antitrust laws and state consumer protection laws. The complaint alleges that the Company unlawfully maintained a monopoly in a purported ACTH product market by acquiring the U.S. rights to Synacthen^® Depot ("Synacthen") and reaching anti-competitive agreements with the other defendants by selling Acthar Gel through an exclusive distribution network. The complaint purports to be brought on behalf of all third-party payers, or their assignees, in the U.S. and its territories, who have, as indirect purchasers, in whole or in part, paid for, provided reimbursement for, and/or possess the recovery rights to reimbursement for the indirect purchase of Acthar Gel from August 1, 2007 to present. The Company moved to dismiss the First Amended Class Action Complaint on May 24, 2019. The Company's motion to dismiss remains pending.

Employee Stock Purchase Plan ("ESPP") Securities Litigation. On July 20, 2017, a purported purchaser of Mallinckrodt stock through Mallinckrodt's ESPPs, filed a derivative lawsuit in the Federal District Court in the Eastern District of Missouri, captioned Solomon v. Mallinckrodt plc, et al., against the Company, its CEO Mark C. Trudeau, its former CFO Matthew K. Harbaugh, its Controller Kathleen A. Schaefer, and current and former directors of the Company. On September 6, 2017, plaintiff voluntarily dismissed its complaint in the Federal District Court for the Eastern District of Missouri and refiled virtually the same complaint in the U.S. District Court for the District of Columbia. The complaint purports to be brought on behalf of all persons who purchased or otherwise acquired Mallinckrodt stock between November 25, 2014, and January 18, 2017, through the ESPPs. In the alternative, the plaintiff alleges a class action for those same purchasers/acquirers of stock in the ESPPs during the same period. The complaint asserts claims under Section 11 of the Securities Act, and for breach of fiduciary duty, misrepresentation, non-disclosure, mismanagement of the ESPPs' assets and breach of contract arising from substantially similar allegations as those contained in the putative class action securities litigation described in the Shenk lawsuit below. Stipulated co-lead plaintiffs were approved by the court on March 1, 2018.

Putative Class Action Litigation (Rockford). On April 6, 2017, a putative class action lawsuit was filed against the Company and United BioSource Corporation in the U.S. District Court for the Northern District of Illinois. The case is captioned City of Rockford v. Mallinckrodt ARD, Inc., et al. The complaint was subsequently amended to, among other things, include an additional named plaintiff and additional defendants. As amended, the complaint purports to be brought on behalf of all self-funded entities in the U.S. and its Territories, excluding any Medicare Advantage Organizations, related entities and certain others, that paid for Acthar Gel from August 2007 to the present. Plaintiff alleges violations of federal antitrust and RICO laws, as well as various state law claims in connection with the distribution and sale of Acthar Gel. On January 22, 2018, the Company filed a motion to dismiss the Second Amended Complaint, which was granted in part on January 25, 2019, dismissing one of two named plaintiffs and all claims with the exception of Plaintiff's federal and state antitrust claims. The remaining allegation in the case is that the Company engaged in anti-competitive acts to artificially raise and maintain the price of Acthar Gel. To this end, Plaintiff alleges that the Company unlawfully maintained a monopoly in a purported ACTH product market by acquiring the U.S. rights to Synacthen and conspired with the other named defendants by selling Acthar Gel through an exclusive distributor. The Company intends to continue to vigorously defend itself in this matter. At this stage, the Company is not able to reasonably estimate the expected amount or range of cost or any loss associated with this lawsuit.

Putative Class Action Securities Litigation (Shenk). On January 23, 2017, a putative class action lawsuit was filed against the Company and its CEO in the U.S. District Court for the District of Columbia, captioned Patricia A. Shenk v. Mallinckrodt plc, et al. The complaint purports to be brought on behalf of all persons who purchased Mallinckrodt's publicly traded securities on a domestic exchange between November 25, 2014 and January 18, 2017. The lawsuit generally alleges that the Company made false or misleading statements related to Acthar Gel and Synacthen to artificially inflate the price of the Company's stock. In particular, the complaint alleges a failure by the Company to provide accurate disclosures concerning the long-term sustainability of Acthar Gel revenues, and the exposure of Acthar Gel to Medicare and Medicaid reimbursement rates. On January 26, 2017, a second putative class action lawsuit, captioned Jyotindra Patel v. Mallinckrodt plc, et al. was filed against the same defendants named in the Shenk lawsuit in the U.S. District Court for the District of Columbia. The Patel complaint purports to be brought on behalf of shareholders during the same period of time as that set forth in the Shenk lawsuit and asserts claims similar to those set forth in the Shenk lawsuit. On March 13, 2017, a third putative class action lawsuit, captioned Amy T. Schwartz, et al., v. Mallinckrodt plc, et al., was filed against the same defendants named in the Shenk lawsuit in the U.S. District Court for the District of Columbia. The Schwartz complaint purports to be brought on behalf of shareholders who purchased shares of the Company between July 14, 2014 and January 18, 2017 and asserts claims similar to those set forth in the Shenk lawsuit. On March 23, 2017, a fourth putative class action lawsuit, captioned Fulton County Employees' Retirement System v. Mallinckrodt plc, et al., was filed against the Company, its CEO and former CFO in the U.S. District Court for the District of Columbia. The Fulton County complaint purports to be brought on behalf of shareholders during the same period of time as that set forth in the Schwartz lawsuit and asserts claims similar to those set forth in the Shenk lawsuit. On March 27, 2017, four separate plaintiff groups moved to consolidate the pending cases and to be appointed as lead plaintiffs in the consolidated case. Since that time, two of the plaintiff groups have withdrawn their motions. Lead plaintiff was designated by the court on March 9, 2018. Lead plaintiff filed a consolidated complaint on May 18, 2018, alleging a class period from July 14, 2014 to November 6, 2017, the Company, its CEO, its former CFO, and Executive Vice President, Hugh O'Neill, as defendants, and containing similar claims, but further alleging misstatements regarding payer reimbursement restrictions for Acthar Gel. On August 30, 2018, the lead plaintiff voluntarily dismissed the claims against Mr. O'Neill without prejudice. The Company filed a motion to dismiss the complaint which was granted in part, and denied in part by the court on July 30, 2019. The Company intends to vigorously defend itself in this matter.

The Company is involved in various stages of investigation and cleanup related to environmental remediation matters at a number of sites, including those described below. The ultimate cost of site cleanup and timing of future cash outlays is difficult to predict, given the uncertainties regarding the extent of the required cleanup, the interpretation of applicable laws and regulations and alternative cleanup methods. The Company concluded that, as of September 27, 2019, it was probable that it would incur remediation costs in the range of $36.8 million to $77.6 million. The Company also concluded that, as of September 27, 2019, the best estimate within this range was $62.0 million, of which $1.7 million was included in accrued and other current liabilities and the remainder was included in environmental liabilities on the unaudited condensed consolidated balance sheet as of September 27, 2019. While it is not possible at this time to determine with certainty the ultimate outcome of these matters, the Company believes, given the information currently available, that the final resolution of all known claims, after taking into account amounts already accrued, will not have a material adverse effect on its financial condition, results of operations and cash flows.

Occidental Chemical Corp. v. 21st Century Fox America, Inc. The Company and approximately 120 other companies were named as defendants in a lawsuit filed on June 30, 2018, by OCC, in which OCC seeks cost recovery and contribution for past and future costs in response to releases and threatened releases of hazardous substances into the lower 8 miles of the River. A former Mallinckrodt facility located in Jersey City, NJ (located in Newark Bay) and the former Belleville facility were named in the suit. Due to an indemnification agreement with AVON Inc., Mallinckrodt has tendered the liability for the Jersey City site to AVON Inc. and they have accepted. The Company retains a share of the liability for this suit related to the Belleville facility. A motion to dismiss several of the claims was denied by the court. While it is not possible at this time to determine with certainty the ultimate outcome of this matter, the Company believes, given the information currently available, that the ultimate resolution of all known claims, after taking into account amounts already accrued will not have a material adverse effect on its financial condition, results of operations and cash flows.

Crab Orchard National Wildlife Refuge Superfund Site, near Marion, Illinois. Between 1967 and 1982, International Minerals and Chemicals Corporation ("IMC"), a predecessor in interest to the Company, leased portions of the Additional and Uncharacterized Sites ("AUS") Operable Unit at the Crab Orchard Superfund Site ("the CO Site") from the government and manufactured various explosives for use in mining and other operations. In March 2002, the Department of Justice, the U.S. Department of the Interior and the EPA (together, "the Government Agencies") issued a special notice letter to General Dynamics Ordnance and Tactical Systems, Inc. ("General Dynamics"), one of the other potentially responsible parties ("PRPs") at the CO Site, to compel General Dynamics to perform the RI/FS for the AUS Operable Unit. General Dynamics negotiated an AOC with the Government Agencies to conduct an extensive RI/FS at the CO Site under the direction of the U.S. Fish and Wildlife Service. General Dynamics asserted in August 2004 that the Company is jointly and severally liable, along with approximately eight other lessees and operators at the AUS Operable Unit, for costs associated with alleged contamination of soils and groundwater resulting from historic operations, and the parties have entered into a non-binding mediation process. While it is not possible at this time to determine with certainty the ultimate outcome of this matter, the Company believes, given the information currently available, that the final resolution of all known claims, after taking into account amounts already accrued, will not have a material adverse effect on its financial condition, results of operations and cash flows.

Beginning with lawsuits brought in July 1976, the Company is named as a defendant in personal injury lawsuits based on alleged exposure to asbestos-containing materials. A majority of the cases involve product liability claims based principally on allegations of past distribution of products containing asbestos. A limited number of the cases allege premises liability based on claims that individuals were exposed to asbestos while on the Company's property. Each case typically names dozens of corporate defendants in addition to the Company. The complaints generally seek monetary damages for personal injury or bodily injury resulting from alleged exposure to products containing asbestos. The Company's involvement in asbestos cases has been limited because it did not mine or produce asbestos. Furthermore, in the Company's experience, a large percentage of these claims have never been substantiated and have been dismissed by the courts. The Company has not suffered an adverse verdict in a trial court proceeding related to asbestos claims and intends to continue to defend these lawsuits. When appropriate, the Company settles claims; however, amounts paid to settle and defend all asbestos claims have been immaterial. As of September 27, 2019, there were approximately 11,700 asbestos-related cases pending against the Company.

During the three months ended March 29, 2019, the Company completed its reorganization of its intercompany financing and associated legal entity ownership. As a result, the Company had no remaining interest-bearing U.S. deferred tax liabilities as of September 27, 2019, compared to $227.5 million as of December 28, 2018. See Note 6 for further details regarding this reorganization. The GAAP calculation of interest associated with these deferred tax liabilities is subject to variable interest rates. The Company recognized interest expense associated with these deferred tax liabilities of $18.1 million during the nine months ended September 28, 2018.

The Company has reported Section 453A interest on its tax returns on the basis of its interpretation of the U.S. Internal Revenue Code and Regulations. Alternative interpretations of these provisions could result in additional interest payable on the deferred tax liability. Due to the inherent uncertainty in these interpretations, the Company has deferred the recognition of the benefit associated with the Company's interpretation and maintains a corresponding liability of $47.4 million and $56.0 million as of September 27, 2019 and December 28, 2018, respectively. The decrease of $8.6 million was recognized as a benefit to interest expense during the nine months ended September 27, 2019, due to a lapse of certain statute of limitations. Further favorable resolution of this uncertainty would likely result in a material reversal of this liability and a benefit being recorded to interest expense within the unaudited condensed consolidated statements of income.

On August 5, 2019, the IRS proposed an adjustment to the taxable income of MHP as a result of its findings in the audit of MHP’s tax year ended September 26, 2014. MHP, formerly known as Cadence Pharmaceuticals, Inc. (“Cadence”), was acquired by the Company as a U.S. subsidiary on March 19, 2014. Following the acquisition of Cadence, the Company transferred certain rights and risks in Ofirmev intellectual property (“Transferred IP”) to a wholly owned non-U.S. subsidiary of the Company. The transfer occurred at a price (“Transfer Price”) determined in conjunction with the Company’s external advisors, in accordance with applicable Treasury Regulations and with reference to the $1,329.0 million taxable consideration paid by the Company to the shareholders of Cadence. The IRS asserts the value of the Transferred IP exceeds the value of the acquired Cadence shares and, further, partially disallows the Company’s control premium subtraction. The proposed adjustment to taxable income of $871.0 million, excluding potential associated interest and penalties, is proposed as a multi-year adjustment and may result in a non-cash reduction of the Company’s U.S. Federal net operating loss carryforward of $849.3 million. The Company strongly disagrees with the proposed increase to the Transfer Price and intends to contest it through all available administrative and judicial remedies, which may take a number of years to conclude. The final outcome cannot be reasonably quantified at this time, however, the proposed adjustment may be material. The Company believes its reserve for income tax contingencies is adequate.

During the three months ended September 27, 2019, the Company paid $20.0 million upfront with cash on hand, which was recorded within research and development ("R&D") expense, and gained an exclusive worldwide license to Silence's C3 complement asset, SLN500, with options to license up to two additional complement-targeted assets in Silence's preclinical complement-directed RNAi development program. The agreement also includes additional payments to Silence of up to $10.0 million in research milestones for SLN500, in addition to funding for Phase 1 clinical development including good manufacturing practices (GMP). Silence will be responsible for preclinical activities, and for executing the development program of SLN500 until the end of Phase 1, after which the Company will assume clinical development and responsibility for global commercialization. If approved, Silence could receive up to $563.0 million in commercial milestone payments and tiered low double-digit to high-teen royalties on net sales for SLN500.