The Company	12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]
The Company	1. The Company Business We were incorporated in the state of Delaware on December 19, 2000 as FaxMed, Inc., changed our name to Alexza Corporation in June 2001 and in December 2001 became Alexza Molecular Delivery Corporation. In July 2005, we changed our name to Alexza Pharmaceuticals, Inc. We are a pharmaceutical company focused on the research, development and commercialization of novel proprietary products for the acute treatment of central nervous system conditions. We operate in one business segment. Our facilities and employees are currently located in the United States. In 2012, we transitioned out of the development stage. Underwritten Public Offering On February 23, 2012, we issued an aggregate of 4,400,000 shares of our common stock and warrants to purchase up to an additional 4,400,000 shares of our common stock in an underwritten public offering. Net proceeds from the offering were $20,231,000, after deducting offering expenses. The warrants are exercisable beginning February 24, 2013, at an exercise price of $5.00 per share, and will expire on February 23, 2017. The shares of common stock and warrants were sold pursuant to a shelf registration statement declared effective by the Securities and Exchange Commission on May 20, 2010. We agreed to customary obligations, including indemnification. Private Placement On October 27, 2014 we entered into an amendment to the Collaboration, License and Supply Agreement dated October 5, 2011 Grupo Ferrer Internacional, S.A., or Ferrer, or the Ferrer Agreement, pursuant to which Ferrer and we agreed to eliminate future potential milestone payments in exchange for Ferrer’s purchase of $8,000,000 of our common stock, or the Ferrer Amendment. Ferrer purchased 2,000,000 shares of our common stock for $4.00 per share. We classified $2,400,000 of the proceeds as deferred revenue and we are recognizing the amount into revenue over the estimated performance period of the Ferrer Agreement. In September 2015, we issued a promissory note to Ferrer or the Ferrer Note. The terms of the Ferrer Note provide that (i) Ferrer will loan us up to $5,000,000 in tranches, (ii) the initial tranche of $3,000,000 was received by us on September 28, 2015, (iii) another tranche of $1,000,000 was received by us on March 21, 2016, (iv) we have the option to borrow an additional tranche of $1,000,000 at any time, (v) interest accrues on the outstanding principal at the rate of 6% per annum, compounded monthly, through May 31, 2016, (vi) all outstanding principal and accrued interest under the Ferrer Note is due and payable upon Ferrer’s demand on May 31, 2016, (vii) we may prepay the Ferrer Note at any time without premium or penalty, and (viii) we issued 125,000 shares of our common stock to Ferrer as partial consideration for the loan. The common stock was issued to Ferrer pursuant to the Stock Issuance Agreement and was not registered at the time of issuance under the Securities Act of 1933, as amended. As of March 23, 2016, an aggregate of $4,000,000 of the principal amount of the Ferrer Note was outstanding.

1. The Company

Business

We were incorporated in the state of Delaware on December 19, 2000 as FaxMed, Inc., changed our name to Alexza Corporation in June 2001 and in December 2001 became Alexza Molecular Delivery Corporation. In July 2005, we changed our name to Alexza Pharmaceuticals, Inc.

We are a pharmaceutical company focused on the research, development and commercialization of novel proprietary products for the acute treatment of central nervous system conditions. We operate in one business segment. Our facilities and employees are currently located in the United States. In 2012, we transitioned out of the development stage.

Underwritten Public Offering

On February 23, 2012, we issued an aggregate of 4,400,000 shares of our common stock and warrants to purchase up to an additional 4,400,000 shares of our common stock in an underwritten public offering. Net proceeds from the offering were $20,231,000, after deducting offering expenses. The warrants are exercisable beginning February 24, 2013, at an exercise price of $5.00 per share, and will expire on February 23, 2017. The shares of common stock and warrants were sold pursuant to a shelf registration statement declared effective by the Securities and Exchange Commission on May 20, 2010. We agreed to customary obligations, including indemnification.

Private Placement

On October 27, 2014 we entered into an amendment to the Collaboration, License and Supply Agreement dated October 5, 2011 Grupo Ferrer Internacional, S.A., or Ferrer, or the Ferrer Agreement, pursuant to which Ferrer and we agreed to eliminate future potential milestone payments in exchange for Ferrer’s purchase of $8,000,000 of our common stock, or the Ferrer Amendment. Ferrer purchased 2,000,000 shares of our common stock for $4.00 per share. We classified $2,400,000 of the proceeds as deferred revenue and we are recognizing the amount into revenue over the estimated performance period of the Ferrer Agreement.

In September 2015, we issued a promissory note to Ferrer or the Ferrer Note. The terms of the Ferrer Note provide that (i) Ferrer will loan us up to $5,000,000 in tranches, (ii) the initial tranche of $3,000,000 was received by us on September 28, 2015, (iii) another tranche of $1,000,000 was received by us on March 21, 2016, (iv) we have the option to borrow an additional tranche of $1,000,000 at any time, (v) interest accrues on the outstanding principal at the rate of 6% per annum, compounded monthly, through May 31, 2016, (vi) all outstanding principal and accrued interest under the Ferrer Note is due and payable upon Ferrer’s demand on May 31, 2016, (vii) we may prepay the Ferrer Note at any time without premium or penalty, and (viii) we issued 125,000 shares of our common stock to Ferrer as partial consideration for the loan. The common stock was issued to Ferrer pursuant to the Stock Issuance Agreement and was not registered at the time of issuance under the Securities Act of 1933, as amended. As of March 23, 2016, an aggregate of $4,000,000 of the principal amount of the Ferrer Note was outstanding.