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Mavacamten Met Primary Endpoint and Key Secondary Endpoints of PIONEER-HCM Study in Both Study Cohorts:  In the PIONEER-HCM Phase 2 clinical trial of 21 symptomatic obstructive HCM patients, mavacamten achieved the primary endpoint of reduction in post-exercise left ventricular outflow tract (LVOT) gradient from baseline to week 12 with statistical significance across both cohorts tested.  Improvements in peak VO₂, New York Heart Association (NYHA) classification and dyspnea rating scores were also observed.  Mavacamten was generally well-tolerated.

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Mavacamten Activity was Persistent and Safety was not Discernably Impacted by Use of Background Beta Blockers: Benefits were observed across endpoints among those taking once-daily 2mg and 5mg doses of mavacamten who remained on background beta blocker therapy (“Cohort B”), and those who received daily doses ranging from 10mg, 15mg and 20mg who had discontinued background medications (as presented at the Heart Failure Society of America Annual Meeting in September 2017).

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Target Concentration Range Identified to Inform EXPLORER-HCM Trial:  The PIONEER-HCM study has informed a target concentration range at which mavacamten is expected to achieve a clinical improvement in oHCM symptoms (e.g., NYHA class) and exercise capacity (peak VO₂) while maintaining normal ejection fraction of greater than or equal to 50 percent. Data from the PIONEER-HCM study will guide the starting dose and inform dose-adjustments for MyoKardia’s planned Phase 3 pivotal EXPLORER-HCM clinical trial expected to start in the second quarter of 2018.  

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Mavacamten Registration Program Outlined with FDA in September: MyoKardia established key elements of the registration program for mavacamten in symptomatic oHCM, including the Phase 3 EXPLORER-HCM clinical trial and a planned long-term extension study in consultation with the U.S. Food and Drug Administration’s (FDA) Division of Cardiovascular and Renal Products during an end-of-Phase 2 meeting following results from the first cohort of the PIONEER-HCM clinical trial.  

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Presented New Data at AHA:  MyoKardia researchers presented new digital health and in vivo preclinical data related to its mavacamten program at the American Heart Association Scientific Sessions in November 2017.

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First-in-Human Phase 1 Clinical Trial of MYK-491 Completed:  In a single-ascending dose study of healthy volunteers, MYK-491 was generally well tolerated across the range of oral doses tested.  Adverse events (AE) observed were benign and transient.  Evidence of clinical proof-of-mechanism was observed at higher dose levels in the form of increased contractility, as measured by echocardiographic biomarkers.

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MYK-491 Phase 1b Study in DCM Patients Initiated:  A single-ascending dose study of MYK-491 in symptomatic DCM patients was initiated with first patients dosed in February 2018.  The objectives of this randomized, double-blind, placebo-controlled Phase 1b trial are to assess safety, tolerability, preliminary pharmacokinetics and pharmacodynamics of MYK-491 in DCM patients.

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Kevin Starr, Partner at Third Rock Ventures, has resigned from MyoKardia’s Board.  MyoKardia thanks Mr. Starr for his significant contributions to the company’s formation and growth.  He was not a member of any board committees.  

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Cynthia Ladd joined MyoKardia as General Counsel in January 2018.

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Present complete results from PIONEER-HCM Phase 2 clinical trial of mavacamten in symptomatic oHCM patients, including data from Cohort B assessing lower doses, during the “Highlighted Original Research: Heart Failure and Cardiomyopathies and the Year in Review” session at the American College of Cardiology (ACC) 67^th Annual Scientific Session on March 11, 2018 at 8:00 a.m. ET

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Begin Pivotal Study EXPLORER-HCM for Mavacamten in Symptomatic oHCM

o

Finalize EXPLORER-HCM Phase 3 protocol to assess mavacamten for the treatment of symptomatic oHCM and provide a regulatory update in the second quarter 2018

o

Initiate patient dosing in the Phase 3 EXPLORER-HCM clinical trial of mavacamten in second quarter 2018  

o

Initiate patient dosing in the long term EXPLORER-HCM extension study before the end of 2018

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Begin open-label extension study for patients who participated in the Phase 2 PIONEER-HCM clinical trial of mavacamten in second quarter 2018 (PIONEER-OLE clinical trial)

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Initiate Phase 2 MAVERICK-HCM clinical study of mavacamten for the treatment of non-obstructive HCM (nHCM) in first quarter 2018

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Report topline data from Phase 1b clinical trial of MYK-491 in DCM patients in the second half of 2018

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Begin Phase 2 clinical trial of MYK-491 in DCM patients in second half of 2018

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Cash Position: Cash and cash equivalents as of December 31, 2017 were $224.6 million, compared to $135.8 million as of December 31, 2016. Investments (short-term and long-term) as of December 31, 2017 were $51.8 million, compared to $16.1 million as December 31, 2016. The increase in the company’s cash position is primarily attributable to proceeds received from the follow-on offering of common stock.

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Revenues: Collaboration and license revenue was $5.6 million during the three months ended December 31, 2017, compared with $28.6 million during the same period in 2016.  Full-year collaboration and license revenue was $22.5 million compared to $39.2 million for the full year 2016.  The decrease in collaboration revenue in 2017 was attributable to recognition of a $25.0 million one-time milestone payment in the fourth quarter of

2016 for the submission of an Investigational New Drug application for MYK-491 with the FDA in November 2016.  

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R&D Expenses: Research and development expenses, before consideration of $7.3 million in cost sharing for registration program plan (RPP) costs for the fourth quarter 2017 were $15.5 million, up from $10.0 million for the same period in 2016.  Research and development expenses were $48.1 million for the full year 2017, compared to $36.2 million for the same period in 2016. The increase in R&D expenses over the course of 2017 were primarily driven by the company’s ongoing clinical studies, including the Phase 2 PIONEER-HCM clinical study for mavacamten and the Phase 1 study for MYK-491, expansion of R&D staff and increased costs for contract research, chemistry and biology expenses on discovery and preclinical programs.

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G&A Expenses: General and administrative expenses were $5.5 million for the three months ended December 31, 2017, compared to $4.3 million for the same period in 2016.  For the twelve months ended December 31, 2017, G&A expenses were $22.0 million, compared to $16.3 million for the prior year.  The change in G&A expenses was primarily attributable to an increase in employee headcount, marketing and recruiting expenses and stock compensation expenses.

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Net Loss: Net loss was $7.4 million ($0.21 loss per share) for the fourth quarter of 2017, compared to a net income of $14.3 million ($0.46 net income per share, basic or $0.44 net income per share, fully diluted) for the fourth quarter of 2016.  For full year 2017, net loss was $46.0 million ($1.40 loss per share), compared to $13.1 million ($0.48 loss per share) for the same period in 2016. The net loss per share in the fourth quarter of 2017 versus the net income per share in 2016 was due to the $25 million received in the fourth quarter of 2016 as noted above.  

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Based on its current operating plans, MyoKardia expects that its cash, cash equivalents and investments as of December 31, 2017, together with anticipated payments from Sanofi under its collaboration agreement, will fund anticipated operating expenses and capital expenditure requirements into 2020.  

Year Ended December 31,

2017

2016

2015

Collaboration and license revenue

$

22,500

$

39,199

$

14,199

Operating expenses:

Research and development, net

48,136

36,215

28,393

General and administrative

21,973

16,289

9,019

Total operating expenses

70,109

52,504

37,412

Loss from operations

(47,609

)

(13,305

)

(23,213

)

Interest and other income, net

1,657

153

(47

)

Change in fair value of redeemable convertible

   preferred stock call option liability

—

—

314

Net loss

(45,952

)

(13,152

)

(22,946

)

Other comprehensive (loss) income

(200

)

8

—

Comprehensive loss

(46,152

)

(13,144

)

(22,946

)

Cumulative dividend relating to redeemable convertible

   preferred stock

—

—

(5,151

)

Accretion of redeemable convertible preferred stock

   to redemption value

—

—

(98

)

Net loss attributable to common stockholders

$

(45,952

)

$

(13,152

)

$

(28,195

)

Net loss per share attributable to common stockholders,

   basic and diluted

$

(1.40

)

$

(0.48

)

$

(4.48

)

Weighted average number of shares used to compute net loss

   per share attributable to common stockholders, basic and diluted

32,832,514

27,475,792

6,292,800

As of December 31,

2017

2016

Assets

Current assets

Cash and cash equivalents

$

224,571

$

135,797

Short-term investments

31,933

4,072

Receivable from collaboration partner

1,013

45,000

Prepaid expenses and other current assets

1,876

1,394

Total current assets

259,393

186,263

Property and equipment, net

3,147

2,758

Long-term investments

19,900

12,002

Other long-term assets

368

283

Total assets

$

282,808

$

201,306

Liabilities and stockholders’ equity

Current liabilities

Accounts payable

$

2,301

$

1,798

Accrued liabilities

11,639

8,690

Prepayment from collaboration partner

4,432

—

Deferred revenue - current

22,500

22,500

Total current liabilities

40,872

32,988

Other long-term liabilities

202

436

Deferred revenue - noncurrent

—

22,500

Total liabilities

41,074

55,924

Commitments and contingencies (Note 6)

Stockholders’ equity

Preferred stock, $0.0001 par value; 5,000,000 shares authorized;

   none issued and outstanding

—

—

Common stock, $0.0001 par value, 150,000,000 and 150,000,000

   shares authorized at December 31, 2017 and 2016, respectively;

   35,812,791 and 31,428,998 shares, issued and outstanding

   at December 31, 2017 and 2016, respectively

4

3

Additional paid-in capital

365,719

223,208

Accumulated other comprehensive (loss) income

(192

)

8

Accumulated deficit

(123,797

)

(77,837

)

Total stockholders’ equity

241,734

145,382

Total liabilities and stockholders’ equity

$

282,808

$

201,306