The information in this prospectus supplement and the accompanying base prospectus is
not complete and may be changed. We may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus supplement is not an offer to sell these securities and we are not
soliciting offers to buy these securities in any state where the offer or sale is not permitted.
Subject to Completion, Dated July 2, 2018
PROSPECTUS SUPPLEMENT
(To Prospectus Dated , 2018)
$15,000,000
Common Stock
We have entered
into an At the Market Issuance Sales Agreement, or the Sales Agreement, with B. Riley FBR, Inc., or B. Riley FBR, dated July 2, 2018, relating to the sale of our common stock offered by this prospectus supplement. In accordance with the
terms of the Sales Agreement, under this prospectus supplement we may offer and sell shares of our common stock, $0.0001 par value per share, having an aggregate offering price of up to $15,000,000 from time to time through B. Riley FBR, acting as
our agent. Sales of our common stock, if any, under this prospectus supplement will be made by any method permitted that is deemed an at the market offering as defined in Rule 415 under the Securities Act of 1933, as amended, or the
Securities Act. B. Riley FBR is not required to sell any specific amount, but will act as our distribution agent using commercially reasonable efforts consistent with its normal trading and sales practices. There is no arrangement for funds to
be received in escrow, trust or similar arrangement.
B. Riley FBR will be entitled to compensation at a commission rate equal to 3% of the
gross sales price per share sold under the Sales Agreement. The net proceeds, if any, that we receive from the sales of our common stock will depend on the number of shares actually sold and the offering price for such shares. See Plan of
Distribution beginning on page S-14 for additional information regarding the compensation to be paid to B. Riley FBR. In connection with the sale of the common stock on our behalf, B. Riley FBR will be deemed to be an underwriter within
the meaning of the Securities Act and the compensation of B. Riley FBR will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to B. Riley FBR with respect to certain liabilities,
including liabilities under the Securities Act.
You should read this prospectus supplement in conjunction with the accompanying base
prospectus, including any supplements and amendments thereto. This prospectus supplement is qualified by reference to the accompanying base prospectus except to the extent that the information in this prospectus supplement supersedes the information
contained in the accompanying base prospectus. This prospectus supplement is not complete without, and may not be delivered or utilized except in connection with, the accompanying base prospectus, including any supplements and amendments thereto.
Our common stock is listed on The NYSE American under the symbol MYO. On June 28, 2018, the closing price for our common
stock, as reported on The NYSE American, was $2.83 per share. Our principal executive offices are located at One Broadway, 14
th
Floor Cambridge, MA 02142.
The aggregate market value of our outstanding common stock held by non-affiliates was $45,100,460 based on 12,411,123 shares of outstanding
common stock as of June 28, 2018, of which approximately 11,135,916 shares were held by non-affiliates, and based on the highest reported closing sale price of our common stock of $4.05 on May 3, 2018. Pursuant to General Instruction I.B.6 of
Form S-3, in no event will we sell securities pursuant to this prospectus supplement with a value of more than one-third of the aggregate market value of our common stock held by nonaffiliates in any 12-month period, so long as the aggregate market
value of our common stock held by non-affiliates is less than $75,000,000. In the event that subsequent to the date of this prospectus supplement, the aggregate market value of our outstanding common stock held by nonaffiliates equals or exceeds
$75,000,000, then the one-third limitation on sales shall not apply to additional sales made pursuant to this prospectus supplement. During the prior 12 calendar months prior to, and including, the date of this prospectus supplement, we have not
sold any securities pursuant to General Instruction I.B.6 of Form S-3.
Investing in
our securities involves a high degree of risk. You should review carefully the risks and uncertainties referenced under the heading
Risk Factors
contained in this prospectus supplement
beginning on page S-3 and the corresponding sections in the accompanying base prospectus, and under similar headings in the other documents that are incorporated by reference into this prospectus.
Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or
determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
B. Riley FBR
The date of this Prospectus Supplement is July 2, 2018.